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Epithelioid sarcoma (ES) is a rare tumor hallmarked by the loss of INI1/SMARCB1 expression. Apart from this alteration, little is known about the biology of ES. Despite recent advances in treatment, the prognosis of ES remains unsatisfactory. To elucidate the molecular underpinnings of ES, and to identify diagnostic biomarkers and potential therapeutic vulnerabilities, we performed an integrated omics profiling (RNA sequencing and methylation array) of 24 primary, untreated ESs. Transcriptome and methylome analysis identified two distinct molecular clusters that essentially corresponded to the morphologic variants of ES, classic ES (C-ES) and the more aggressive proximal ES (P-ES). The P-ES group was characterized by hyperactivation of GATA3 and MYC pathways, with extensive epigenetic rewiring associated with EZH2 overexpression. Both DNA methylation and gene expression analysis indicated a striking similarity with the "MYC subgroup" of ATRT, another SMARCB1-deficient tumor, implying a shared molecular background and potential therapeutic vulnerabilities. Conversely, the C-ES group exhibited an endothelial-like molecular profile, with expression of vascular genes and elevated pro-angiogenic SOX17 signaling. Immunohistochemistry validated the overexpression of the chromatin regulators GATA3 (9/12 vs. 0/16) and EZH2 (7/7 vs. 2/6) in P-ESs, and of the vascular factors SOX17 (8/8 vs. 1/10) and N-cadherin (5/9 vs 0/10) in C-ESs. Therefore, these molecules emerge as potential diagnostic tools to fill the gap represented by the lack of ES subtype-specific biomarkers. In summary, our study shows that P-ES and C-ES represent distinct molecular entities defined by MYC/GATA3 and SOX17/endothelial molecular traits, respectively. Besides providing insights into the biology of ES, our study pinpoints subtype-specific biomarkers and potential therapeutic vulnerabilities., (Copyright © 2024 THE AUTHORS. Published by Elsevier Inc. All rights reserved.)

The aim of the study was to report the outcome of primary localized low-grade fibromyxoid sarcoma (LGFMS), sclerosing epithelioid fibrosarcoma (SEF), and hybrid LGFMS/SEF (H-LGFMS/SEF). Patients with primary localized LGFMS, SEF, or H-LGFMS/SEF, surgically treated with curative intent from January 2000 to September 2022, were enrolled from 14 countries and 27 institutions. Pathologic inclusion criteria were predefined by expert pathologists. The primary endpoint was overall survival (OS). Secondary endpoints were crude cumulative incidence (CCI) of local recurrence (LR), CCI of distant metastases (DM), and post-metastases OS (p-OS). Two hundred ninety-four patients (239 LGFMS, 32 SEF, and 23 H-LGFMS/SEF) were identified. At a median(m-) follow-up (FU) of 57.1 months, 12/294 patients died. The 5- and 10-year OS were 99.0% and 95.9% in LGFMS, 86.2% and 67.0% in SEF, and 84.8% and 84.8% in H-LGFMS/SEF, respectively. Predictors of worse OS included pathology, age at surgery, systemic therapy, and radiotherapy. LR developed in 13/294 (4.4%) patients. The observed m-time to LR was 10.7 months. The 5- and 10-yr CCI-LR were 4.7% in LGFMS and 6.6% in SEF, respectively. There were no LR events in H-LGFMS/SEF. The sole predictor of higher risk of LR was histology. DM developed in 23/294 (7.8%) patients. The observed m-time to DM was 28.2 months. The 5- and 10-yr CCI-DM were 1.3% and 2.7% in LGMFS, 29.9% and 57.7% in SEF, 48.9% and 48.9% in H-LGFMS/SEF, respectively. Predictors of higher risk of DM were histology, systemic therapy, and radiotherapy. Primary localized LGFMS treated with complete surgical resection has an excellent prognosis, while about 50% of H-LGFMS/SEF and SEF develop DM within 5 to 10 years. Very long-term FU is needed to understand absolute cure rates., Competing Interests: Conflicts of Interest and Source of Funding: The authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Background: To present findings from a retrospective study conducted by the Ultra-Rare Sarcoma Working Group on metastatic low-grade fibromyxoid sarcoma (LGFMS), sclerosing epithelioid fibrosarcoma (SEF), and hybrid (H)-LGFMS/SEF across 28 global centres., Methods: Patients treated at participating institutions from January 2000 to September 2022 were retrospectively selected. Diagnosis was confirmed by expert pathologists. Primary endpoint was progression-free survival (PFS-1) from metastasis detection to first progression or death. PFS-2 was calculated from therapy initiation., Results: A total of 101 patients were identified (32 LGFMS, 50 SEF, 19 H-LGFMS/SEF). Median (m) follow-up was 62.1 months. mPFS-1 was 28.7, 11.8, and 20.3 months for LGFMS, SEF, and H-LGFMS/SEF, respectively. mOS was 145.8, 41.9, and 113.5 months, respectively. Treatments included anthracycline-based chemotherapy, gemcitabine-based chemotherapy (G), pazopanib, trabectedin, others. mPFS-2 was: 20.1, 5.5, and 3.5 months in H-LGFMS/SEF, SEF, and LGFMS, respectively, with anthracyclines; 19.5, 7.7, and 6.9 months in LGFMS, SEF, and H-LGFMS/SEF, respectively, with pazopanib; 12.0, 9.7, and 3.1 months in H-LGFMS/SEF, LGFMS, and SEF, respectively. Occasional responses occurred with ifosfamide/oral cyclophosphamide, and prolonged stable disease with immune checkpoint inhibitors., Conclusions: In this series, the largest available, metastatic LGFMS, SEF, and H-LGFMS/SEF showed different courses. Systemic agents have modest efficacy, informing future trials of novel agents for these tumours., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Introduction: Epithelioid hemangioendothelioma (EHE) is an ultra-rare sarcoma, marked by distinctive molecular and pathological features and with a variable clinical behavior. Its natural history is still partially understood, reliable prognostic and predictive factors are lacking and many questions are still open on the optimal management. In the context of EURACAN, a prospective registry specifically dedicated to EHE was developed and launched with the aim of providing, through high-quality prospective data collection, a better understanding of this disease., Study Design: Registry-based cohort study including only new cases of patients with a pathological and molecularly confirmed diagnosis of EHE., Objectives: To improve the understanding of EHE natural history, validate and identify new prognostic and predictive factors, clarify the activity and efficacy of currently available treatment options, describe treatment pattern., Methods: Settings and participantsIt is an hospital-based registry established in centers with expertise in EHE including adult patients with a new pathological and molecularly confirmed diagnosis of EHE starting from the 1st December 2023. The characteristics of each patient in the facility who meets the above-mentioned inclusion criteria will be collected prospectively and longitudinally with follow-up at cancer progression and / or cancer relapse or patient death. It is a secondary use of data which will be collected from the clinical records. The data collected for the registry will not entail further examinations or admissions to the facility and/or additional appointments to those normally provided for routine patient follow-up. VariablesFull details on patients and disease features, treatment and outcome will be collected, according to common clinical practice guidelines developed and shared with all the contributing centers. In addition, data on potential confounders (e.g. comorbidity; functional status etc.) will also be collected. Statistical methodsThe data analyses will include descriptive statistics and analytical analyses. Multivariable Cox's proportional hazards model and Hazard ratios (HR) for all-cause or cause-specific mortality will be used to determine independent predictors of overall survival, recurrence and progression., Results: The registry has been joined by 21 sarcoma reference centers across EU and UK, covering 10 countries. Patients' recruitment started in December 2023. The estimated completion date is December 2033 upon agreement on the achievement of all the registry objectives. The already established collaboration and participation of EHE patient's associations involved in the project will help in promoting the registry and fostering accrual., Competing Interests: Anna Maria Frezza declares institutional research funding from Advenchen Laboratories, Amgen Dompé, AROG Pharmaceuticals, Ayala Pharmaceuticals, Bayer, Blueprint Medicines, Boehriger Ingelheim, Daiichi Sankyo, Deciphera, Eisai, Eli Lilly, Epizyme Inc, Foghorn Therapeutics Inc., Glaxo, Hutchison MediPharma Limited, Inhibrx, Inc., Karyopharm Pharmaceuticals, Novartis, Pfizer, PharmaMar, PTC Therapeutics, Rain Oncology, SpringWorks Therapeutics. Alexia Bertuzzi declares support for attending meeting and/or travels from Pharmamar and Istituto Gentili; support for scientific activities from Istituto Gentili. Antonella Brunello declares consulting fees or serving on advisory boards for Eli Lilly, Roche, GSK, Eisai, Pharmamar, Boehringer Ingelheim, Deciphera; payment or honoraria for educational events by GSK and Pharmamar; travel grants by Pharmamar, Istituto Gentili. Giacomo G. Baldi declares consulting fees from Eli Lilly, Pharmamar, AboutEvents; honoraria from Pharmamar, Eli Lilly, Glaxo Smith Kline, Merck Sharp & Dome, Eisai, IstitutoGentili; support for attending meetings and/or travels from Novartis, Pharmamar, Eli Lilly; participation on the advisory board from Pharmamar, Eli Lilly, Glaxo Smith Kline, Merck Sharp & Dome, Eisai. Paolo G. Casali declares institutional research funding from Advenchen Laboratories, Amgen Dompé, AROG Pharmaceuticals, Ayala Pharmaceuticals, Bayer, Blueprint Medicines, Boehriger Ingelheim, Daiichi Sankyo, Deciphera, Eisai, Eli Lilly, Epizyme Inc, Foghorn Therapeutics Inc., Glaxo, Hutchison MediPharma Limited, Inhibrx, Inc., Karyopharm Pharmaceuticals, Novartis, Pfizer, PharmaMar, PTC Therapeutics, Rain Oncology, SpringWorks Therapeutics. Virginia Ferraresi declares consultancy fees or honoraria from PharmaMar, Boehringer Ingelheim, Gentili e Serb Pharmaceuticals. Matilde Ingrosso reports institutional research funding from Advenchen Laboratories, Amgen Dompé, AROG Pharmaceuticals, Ayala Pharmaceuticals, Bayer, Blueprint Medicines, Boehriger Ingelheim, Daiichi Sankyo, Deciphera, Eisai, Eli Lilly, Epizyme Inc, Foghorn Therapeutics Inc., Glaxo, Hutchison MediPharma Limited, Inhibrx, Inc., Karyopharm Pharmaceuticals, Novartis, Pfizer, PharmaMar, PTC Therapeutics, Rain Oncology, SpringWorks Therapeutics. Laura Monteleone reports institutional research funding from Advenchen Laboratories, Amgen Dompé, AROG Pharmaceuticals, Ayala Pharmaceuticals, Bayer, Blueprint Medicines, Boehriger Ingelheim, Daiichi Sankyo, Deciphera, Eisai, Eli Lilly, Epizyme Inc, Foghorn Therapeutics Inc., Glaxo, Hutchison MediPharma Limited, Inhibrx, Inc., Karyopharm Pharmaceuticals, Novartis, Pfizer, PharmaMar, PTC Therapeutics, Rain Oncology, SpringWorks Therapeutics. Johanna Szkandera reports participation in advisory boards or invited speaker fees for PharmaMar, Bayer, Roche, Lilly, Amgen; travel expenses coverage from PharmaMar, Roche, Lilly, Amgen, Bristol Myers Squibb; research funding from PharmaMar, Roche, Eisai. Bruno Vincenzi reports consulting fees from Eisai, Lilly, Bayer, Deciphera, PharmaMar, Blueprint, Pfizer, GSK, Accord, Abbott and research support from PharmaMar, Novartis, Lilly Silvia Stacchiotti declares advisory board roles with Bayer, Boehringer, Daiichi, Ikena, Nec Oncology, Pharma Essentia, Regeneron, Servier; invited speaker roles for Bayer, Boehringer, Gentili, Pharmamar; institutional research funding from Advenchen Laboratories, Amgen Dompé, AROG Pharmaceuticals, Ayala Pharmaceuticals, Bayer, Blueprint Medicines, Boehriger Ingelheim, Daiichi Sankyo, Deciphera, Eisai, Eli Lilly, Epizyme Inc, Foghorn Therapeutics Inc., Glaxo, Hutchison MediPharma Limited, Inhibrx, Inc., Karyopharm Pharmaceuticals, Novartis, Pfizer, PharmaMar, PTC Therapeutics, Rain Oncology, SpringWorks Therapeutics. Carlo Cicala, Lorenzo D’Ambrosio, Angelo Paolo Dei Tos, Alessandro Gronchi, Nadia Hindi, Robin Jones, Iwona Lugowska, Julia Ketzer, Anna Mariuk-Jarema, Andrea Napolitano, Andri Papakonstantinou, Sandro Pasquali, Marta Sbaraglia, Federico Scolari, Elisa Crotti, Irene Benzonelli, Jean-Yves Blay, Christophe Bouvier, Javier Martin Broto, Hugh Leonard, Ninna Aggerholm-Pedersen, Andri Papakonstantinou, Giuseppe Bianchi, Federica Zuccheri, Paolo Baili, Simone Bonfarnuzzo, Domenico Campanacci, Armelle Dufresne, Sebastian Bauer, Serena Bazzurri, Stefano Gabellini, Claudia Giani, Vincenzo Giannusa, Melissa Gil-Sanjines, Teresa Grassani, Paolo Lasalvia, Stefan Lindskog, Salvatore Vizzaccaro, Nils Dieckmann, Alessandro Mazzocca, Andrei Ivanescu, Giuseppe Badalamenti, Carlo Morosi, Stephanie Elston, Kyetil Boye, Francesca Nardozza, Elisabetta Neri, Maria Nilsson and Annalisa Trama declares no conflict of interest., (Copyright: © 2024 Frezza et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: This is a multicentre, single-arm, phase II study aimed at further exploring the activity of trabectedin as second-/further-line treatment in retroperitoneal leiomyosarcoma (LMS) and well-differentiated/dedifferentiated liposarcoma (LPS)., Materials and Methods: The primary endpoint was the growth modulation index (GMI) defined as the ratio between PFS under trabectedin (PFS) and during previous chemotherapy treatment: time to progression (TTP-1). Secondary endpoints were objective response rate (ORR) and PFS. As per protocol, patients were considered responders if the GMI was >1.33, non-responders if <0.75 and neither if 0.76-1.32., Results: Overall 91 patients were assessable for the primary endpoint (32 patients with LMS and 59 patients with LPS): the median number of cycles received was 6.0 (Q1-Q3 3.0-12.0), and the main reason for treatment discontinuation was disease progression in 72% of patients. The median PFS was 6.0 months, while the median TTP1 was 7.5 months (8.1 and 6.4 months for LMS and LPS, respectively). Thirty-three patients [52%, 95% confidence interval (CI) 36% to 58%, P = 0.674, odds of response 1.1] had a GMI >1.33 (LMS 46%, 95% CI 26% to 67%, odds of response 0.85; LPS 56%, 95% CI 40% to 72%, odds of response 1.3). Overall, in LPS we observed 15/47 patients with a GMI <0.5 and 15/47 patients with a GMI >2. Among LMS patients, 9/26 had a GMI <0.5 and 10/26 had a GMI >2. Overall, ORR (complete response + partial response) was 16% (24% for LMS and 12% for LPS)., Conclusions: While the primary endpoint of the study was not met, we noticed a subgroup of patients with a markedly discrepant TTP with trabectedin in comparison to previous therapy (GMI <0.5 or >2, the latter including some patients with a long TTP with trabectedin). A mismatch between PFS and overall survival was observed, possibly due to the natural history of the two different histologies and the availability of further lines in LMS., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: We report on a series of consecutive patients with localized radiation-associated angiosarcoma (RAAS) of the breast region (BR) treated at two Italian sarcoma reference centers., Materials and Methods: We retrospectively reviewed all cases of primary, localized, resectable RAAS of the BR, treated at one of the two participating institutions from 2000 to 2019. Relapse-free survival (RFS) and overall survival (OS) were calculated. The prognostic role of several variables was investigated. A propensity score matched (PSM) analysis was carried out., Results: Eighty-four patients were retrospectively identified. Nineteen out of 84 patients (22.6%) were pretreated with an anthracycline-based regimen for previous cancer. All patients but one underwent surgery, with 37/84 (44.1%) receiving surgery alone and 46/84 (54.8%) a multimodal approach: 18/84 (21.4%) received radiation therapy (RT) and 46/84 (54.9%) received chemotherapy. An anthracycline-based regimen was used in 10/84 patients (11.9%), while a gemcitabine-based regimen was used in 33/84 (39.3%). With a median follow-up of 51 months (interquartile range: 30-126 months), 36/84 patients (42.9%) relapsed and 35/84 patients (41.7%) died (8/84, 9.5% in the lack of metastatic disease). Five-year OS and 5-year RFS were 57% [95% confidence interval (CI) 43% to 68%] and 52% (95% CI 39% to 63%), respectively. Both (neo)adjuvant RT and chemotherapy were associated with better RFS [hazard ratio (HR) 0.25, 95% CI 0.08-0.83; HR 0.45, 95% CI 0.23-0.89] with a trend towards a better OS (HR 0.51, 95% CI 0.18-1.46; HR 0.60, 95% CI 0.29-1.24). Gemcitabine-based regimens seemed to perform better (HR 4.28, 95% CI 1.29-14.14). PSM analysis retained the above results., Conclusions: This retrospective study supports the use of (neo)adjuvant RT and chemotherapy, in primary, localized resectable RAAS of the BR. An effort to prospectively validate the role of (neo)adjuvant RT and chemotherapy is warranted., Competing Interests: Disclosure EP—outside the submitted work: institutional financial interests: Advenchen Laboratories, Amgen Dompe', Bayer, Blueprint Medicines, Daiichi Sankyo, Deciphera, Eisai, Eli Lilly, Epizyme Inc, Glaxo Smith Kline, Karyopharm Pharmaceuticals, Novartis, Pfizer, PharmaMar. GGB—outside the submitted work: consulting fees from Eli Lilly, PharmaMar, AboutEvents; honoraria from PharmaMar, Eli Lilly, Glaxo Smith Kline, Merck Sharp & Dome, Eisai, Istituto Gentili; support for attending meetings and/or travels from Novartis, PharmaMar, Eli Lilly; participation on advisory board from PharmaMar, Eli Lilly, Glaxo Smith Kline, Merck Sharp & Dome, Eisai. AMF—outside the submitted work: institutional financial interests: Advenchen Laboratories, Amgen Dompe’, Bayer, Blueprint Medicines, Daiichi Sankyo, Deciphera, Eisai, Eli Lilly, Epizyme Inc, Glaxo Smith Kline, Karyopharm Pharmaceuticals, Novartis, Pfizer, PharmaMar. IP—outside the submitted work: institutional financial interests: Advenchen Laboratories, Amgen Dompe', Bayer, Blueprint Medicines, Daiichi Sankyo, Deciphera, Eisai, Eli Lilly, Epizyme Inc, Glaxo Smith Kline, Karyopharm Pharmaceuticals, Novartis, Pfizer, PharmaMar. PGC—outside the submitted work: institutional financial interests: Advenchen Laboratories, Amgen Dompe', Bayer, Blueprint Medicines, Daiichi Sankyo, Deciphera, Eisai, Eli Lilly, Epizyme Inc, Glaxo Smith Kline, Karyopharm Pharmaceuticals, Novartis, Pfizer, PharmaMar. TDP—outside the submitted work: participation on advisory board from Glaxo Smith Kline, Boehringer Ingelheim. Trial support from: Pfizer, BluPrint Medicine, Gilead, Amgen, Merck. SS—outside the submitted work: personal financial interests (honoraria, consultancy or advisory role): Aadi, Astex Pharmaceuticals, Bavarian Nordic, Bayer, Boehringer Ingelheim, Daiichi Sankyo, Deciphera, Epizyme, Gentili, GSK, Agenus, Ikena, MaxiVAX, Novartis, PharmaMar, Pharma Essentia, Rain Therapeutics, Servier; support for attending meetings and/or travel PharmaMar; institutional financial interests: Advenchen, Bayer, Blueprint, Daiichi Sankyo, Deciphera, Epizyme, Eli Lilly, GSK, Hutchinson, Inhibrx, Karyopharm, Novartis, PharmaMar, Rain Therapeutics, SpringWorks; unpaid Member of the Scientific Advisory Board of the Chordoma Foundation, Member of the Scientific Advisory Board of the Desmoid Foundation, Member of the Scientific Advisory Board of the Epithelioid Hemangioendothelioma Group, Member of the Scientific Advisory Board of the Leiomyosarcoma Foundation. All other authors have declared no conflicts of interest., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Angiosarcoma (AS) represents a rare and aggressive vascular sarcoma, posing distinct challenges in clinical management compared to other sarcomas. While the current European Society of Medical Oncology (ESMO) clinical practice guidelines for sarcoma treatment are applicable to AS, its unique aggressiveness and diverse tumor presentations necessitate dedicated and detailed clinical recommendations, which are currently lacking. Notably, considerations regarding surgical extent, radiation therapy (RT), and neoadjuvant/adjuvant chemotherapy vary significantly in localized disease, depending on each different site of onset. Indeed, AS are one of the sarcoma types most sensitive to cytotoxic chemotherapy. Despite this, uncertainties persist regarding optimal management across different clinical presentations, highlighting the need for further investigation through clinical trials. The Italian Sarcoma Group (ISG) organized a consensus meeting on April 1st, 2023, in Castel San Pietro, Italy, bringing together Italian sarcoma experts from several disciplines and patient representatives from "Sofia nel Cuore Onlus" and the ISG patient advocacy working group. The objective was to develop specific clinical recommendations for managing localized AS within the existing framework of sarcoma clinical practice guidelines, accounting for potential practice variations among ISG institutions. The aim was to try to standardize and harmonize clinical practices, or at least highlight the open questions in the local management of the disease, to define the best evidence-based practice for the optimal approach of localized AS and generate the recommendations presented herein., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: None of the authors has any interests to report directly related to this manuscript. Outside the scope of this manuscript: Elena Palassini, Institutional Research Funding: Deciphera Pharmaceuticals, Blueprint Medicines, Cogent Biosciences, Amgen/Dompè, Bayer, GlaxoSmith Kline, Novartis, Pfizer, PharmaMar, Eisai, Eli Lilly, Advenchen Laboratories , Arog, Epizyme, Karyopharm Therapeutics, SpringWorks Ther,Daiichi Sankyo, Boehringer Ingelheim, Rain Therapeutics, Foghorn Ther Inc, Hutchinson MediPharam Lt, INBRX, PTC Ther. Giacomo Giulio Baldi, consulting fees from Eli Lilly, Pharmamar, AboutEvents; honoraria from Pharmamar, Eli Lilly, Glaxo Smith Kline, Merck Sharp & Dome, Eisai, Istituto Gentili; support for attending meetings and/or travels from Novartis, Pharmamar, Eli Lilly; participation on advisory board from Pharmamar, Eli Lilly, Glaxo Smith Kline, Merck Sharp & Dome, Eisai. Sara Sulfaro, Marta Barisella, Giuseppe Bianchi, Domenico Campanacci, Marco Fiore, Marco Gambarotti, Massimiliano Gennaro, Carlo Morosi, no conflict of interests to declare. Federico Navarria, travel grants from Pharmamar, Boehringer Ingelheim. Claudia Sangalli, advisory board from Boehringer Ingelheim, Astra Zeneca. Rossella Bertulli, travel grants from PharmaMar. Institutional Research Funding: Deciphera Pharmaceuticals, Blueprint Medicines, Cogent Biosciences, Amgen/Dompè, Bayer, GlaxoSmith Kline, Novartis, Pfizer, PharmaMar, Eisai, Eli Lilly, Advenchen Laboratories , Arog, Epizyme, Karyopharm Therapeutics, SpringWorks Ther,Daiichi Sankyo, Boehringer Ingelheim, Rain Therapeutics, Foghorn Ther Inc, Hutchinson MediPharam Lt, INBRX, PTC Ther. Alexia Bertuzzi, Roberto Biagini, Angela Bonadonna, Antonella Brunello, Dario Callegaro, no conflict of interests to declare. Ferdinando Cananzi, speaking fee from Istituto Gentili. Marco Cianchetti, Paola Collini(,) Danila Comandini, Annalisa Curcio, no conflict of interests to declare. Lorenzo D’Ambrosio, advisory board: PSI CRO Italy, GSK, AstraZeneca, Boehringer Ingelheim, Eisai. Meeting participation: GSK, AstraZeneca, PharmaMar. Martino De Pas, participation on advisory board from Glaxo Smith Kline, Boehringer Ingelheim. Trial support from: Pfizer, BluPrint Medicine, Gilead, Amgen, Merck. Angelo Paolo Dei Tos, no conflict of interests to declare. Virginia Ferraresi, Travel grants from PharmaMar, Gentili, Boehringer Ingelheim. Advisory Board: SERB Pharmaceuticals. Andrea Ferrari, Alessandro Franchi, no conflict of interests to declare. Anna Maria Frezza, Institutional Research Funding: Deciphera Pharmaceuticals, Blueprint Medicines, Cogent Biosciences, Amgen/Dompè, Bayer, GlaxoSmith Kline, Novartis, Pfizer, PharmaMar, Eisai, Eli Lilly, Advenchen Laboratories , Arog, Epizyme, Karyopharm Therapeutics, SpringWorks Ther,Daiichi Sankyo, Boehringer Ingelheim, Rain Therapeutics, Foghorn Ther Inc, Hutchinson MediPharam Lt, INBRX, PTC Ther. Elena Fumagalli, Advisory Board from Deciphera Pharmaceuticals. Institutional Research Funding: Deciphera Pharmaceuticals, Blueprint Medicines, Cogent Biosciences, Amgen/Dompè, Bayer, GlaxoSmith Kline, Novartis, Pfizer, PharmaMar, Eisai, Eli Lilly, Advenchen Laboratories , Arog, Epizyme, Karyopharm Therapeutics, SpringWorks Ther,Daiichi Sankyo, Boehringer Ingelheim, Rain Therapeutics, Foghorn Ther Inc, Hutchinson MediPharam Lt, INBRX, PTC Ther. Matteo Ghilli, Daniela Greto, no conflict of interests to declare. Giovanni Grignani, advisory board from Pharmamar, Incyte, Merck, Novartis, Deciphera,Bayer. Michele Guida, advisory board from Bristol Myers Squibb, Merck Sharp & Dohme, Novartis, Pierre Fabre. Toni ibrahim, advisory board and consultation fees from Amgen, Glaxosmithkline, PharMamar and Istituto Gentili. Travel grants from Istitaka Gentili and Pharmamar. Marco Krengli, Roberto Luksch, Andrea Marrari, Marinella Mastore, Alessandra Merlini, no conflict of interests to declare. Giuseppe Maria Milano, Advisory board from Bayer, GSK, SERBS Pharmaceuticals. Piera Navarria, Maria Abbondanza Pantaleo, Antonina Parafioriti, no conflict of interests to declare. Ilaria Pellegrini, Institutional Research Funding: Deciphera Pharmaceuticals, Blueprint Medicines, Cogent Biosciences, Amgen/Dompè, Bayer, GlaxoSmith Kline, Novartis, Pfizer, PharmaMar, Eisai, Eli Lilly, Advenchen Laboratories , Arog, Epizyme, Karyopharm Therapeutics, SpringWorks Ther,Daiichi Sankyo, Boehringer Ingelheim, Rain Therapeutics, Foghorn Ther Inc, Hutchinson MediPharam Lt, INBRX, PTC Ther. Elisabetta Pennacchioli, Marco Rastrelli, Elisabetta Setola, Salvatore Tafuto, Salvatore Turano, Sergio Valeri, Bruno Vincenzi, Viviana Vitolo, Andrei Ivanescu, Fiammetta Paloschi, no conflict of interests to declare. Paolo Giovanni Casali, Institutional Research Funding: Deciphera Pharmaceuticals, Blueprint Medicines, Cogent Biosciences, Amgen/Dompè, Bayer, GlaxoSmith Kline, Novartis, Pfizer, PharmaMar, Eisai, Eli Lilly, Advenchen Laboratories , Arog, Epizyme, Karyopharm Therapeutics, SpringWorks Ther,Daiichi Sankyo, Boehringer Ingelheim, Rain Therapeutics, Foghorn Ther Inc, Hutchinson MediPharam Lt, INBRX, PTC Ther. Alessandro Gronchi, no conflict of interests to declare. Silvia Stacchiotti, personal financial interests (honoraria, consultancy or advisory role): Aadi, Astex Pharmaceuticals, Bavarian Nordic, Bayer, Boehringer Ingelheim, Daiichi Sankyo, Deciphera, Epizyme, Gentili, GSK, Agenus, Ikena, MaxiVAX, Novartis, PharmaMar, Pharma Essentia, Rain Therapeutics, Servier. Support for attending meetings and/or travel Pharmamar; Institutional financial interests: Advenchen, Bayer, Blueprint, Daiichi Sankyo, Deciphera, Epizyme, Eli Lilly, GSK, Hutchinson, Inhibrx, Karyopharm, Novartis, PharmaMar, Rain Therapeutics, SpringWorks; unpaid Member of the Scientifc Advisory Board of the Chordoma Foundation, Member of the Scientifc Advisory Board of the Desmoid Foundation, Member of the Scientifc Advisory Board of the Epithelioid Hemangioendothelioma Group, Member of the Scientifc Advisory Board of the Leiomyosarcoma Foundation., (Copyright © 2024. Published by Elsevier Ltd.)

Background: Epithelioid hemangioendothelioma (EHE) is an ultra-rare, vascular sarcoma with clinical presentation ranging from an indolent to an aggressive form. Over 50% of patients present with metastatic disease, requiring systemic therapy, although no systemic therapies are specifically approved for EHE. Retrospective evidence supports the activity of mTOR inhibitors (e.g. sirolimus), although available only off-label. EHE patients and advocates are therefore working to support approval of effective treatments by collecting data on patient perspectives and experiences., Materials and Methods: In February 2023, the EHE Rare Cancer Charity (UK) and The EHE Foundation (US), with other advocates, conducted a survey of perspectives and experiences of EHE patients regarding the use and accessibility of sirolimus. The survey consisted of 20 questions designed for individuals undergoing treatment, those who had been treated, or had never been treated with the drug. Widely promoted within the patient community, the online survey categorized patients into three cohorts for the analysis: liver transplant patients, non-transplant patients who had ever taken sirolimus and sirolimus-naïve non-transplant patients., Results: The survey evaluated data from 129 patient responses from 21 countries, mostly from USA, UK, Australia, and Canada (70%). The liver transplant, sirolimus and non-sirolimus cohorts were 16%, 25% and 59%, respectively. In the sirolimus group 66% reported treatment durations exceeding one year, with 16% exceeding five years, indicating the drug's efficacy. In the non-sirolimus group, the drug was not available for 42% and for 11% sirolimus was available but not selected for treatment because of its off-label status. Overall, 87% of all patients across all cohorts expressed the importance of the drug's availability as hugely or very important., Conclusion: The survey responses highlight the activity of sirolimus for EHE and the importance of securing a label extension for the drug delivering equitable access to this treatment for patients., Competing Interests: GB: Consulting fees from Eli Lilly, PharmaMar, AboutEvents; Honoraria from Pharmamar, Eli Lilly, GlaxoSmithKline, Merck Sharp & Dome, Eisai, Istituto Gentili; Support for attending meetings and/or travels from Novartis, Pharmamar, Eli Lilly; Participation on the advisory board from PharmaMar, Eli Lilly, GlaxoSmithKline, Merck Sharp & Dome, Eisai. WT: COI related to the submitted work: Member of the Scientifc Advisory Board of The EHE Foundation; Consulting fees and honoraria: Adaptimmune, Eli Lilly, C4 Therapeutics, Daiichi Sankyo, Deciphera, Adcendo, Ayala Pharmaceuticals, Kowa, Servier, Bayer Pharmaceuticals, Epizyme, Cogent, Medpacto, Foghorn Therapeutics, Amgen, AmMax Bio, Boehringer Ingelheim, BioAtla, Inhibrx, PharmaEssentia, Avacta, Ipsen, Sonata, Curadev, Nuvation Bio, Abbisko; Advisory roles: Certis Oncology – stock ownership, Atropos Therapeutics, co-founder, stock ownership, Innova Therapeutics, Osteosarcoma Institute. RJ: COI related to the submitted work: Member of the Scientific Advisory Board of the EHE Rare Cancer Charity UK; Receipt of grants/research support: MSD, GSK; Receipt of consultation fees: Adaptimmune, Astex, Athenex, Bayer, Boehringer Ingelheim, Blueprint, Clinigen, Eisai, Epizyme, Daichii, Deciphera, Immunedesign, Immunicum, Karma Oncology, Lilly, Merck, Mundipharma, Pharmamar, Springworks, SynOx, Tracon, Up to Date. SS: COI related to the submitted work: Member of the Scientifc Advisory Board of The EHE Foundation and EHE Rare Cancer Charity UK; Consulting fees and honoraria, or advisory role: Aadi, Astex Pharmaceuticals, Bavarian Nordic, Bayer, Boehringer Ingelheim, Daiichi Sankyo, Deciphera, Epizyme, Gentili, GSK, Agenus, Ikena, MaxiVAX, Novartis, PharmaMar, Pharma Essentia, Rain Therapeutics, Servier. Support for attending meetings and/or travel Pharmamar; Institutional financial interests: Advenchen, Bayer, Blueprint, Daiichi Sankyo, Deciphera, Epizyme, Eli Lilly, GSK, Hutchinson, Inhibrx, Karyopharm, Novartis, PharmaMar, Rain Therapeutics, SpringWorks; unpaid Member of the Scientific Advisory Board of the Chordoma Foundation, Member of the Scientific Advisory Board of the Desmoid Foundation, Member of the Scientific Advisory Board of the Leiomyosarcoma Foundation. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Robinson, Leonard, Baldi, Tap, Jones, Stacchiotti and Pantziarka.)

Background: To investigate the activity of regorafenib in advanced solitary fibrous tumour (SFT)., Methods: An Italian monocentric investigator-initiated exploratory single-arm Phase II trial was conducted of regorafenib in adult patients with advanced and progressive SFT, until progression or limiting toxicity. Prior treatment with antiangiogenics was allowed. Primary and secondary end-points were: overall response rate (ORR) by Choi criteria, and ORR by RECIST, progression-free survival (PFS), overall survival (OS)., Results: From January 2016 to February 2021, 18 patients were enroled [malignant-SFT = 13; dedifferentiated-SFT (D-SFT) = 4; typical-SFT (T-SFT) = 1]. Fourteen patients were pre-treated, in 12 cases with antiangiogenics (median [m-] lines of treatment = 3). Sixteen patients were evaluable for response (one screening failure; one early discontinuation). Six/16 (35.2%) required a definitive dose reduction. ORR by Choi was 37.5% (95% CI: 15.2-64.6), with 6/16 (37.5%) partial responses (PR), 6/16 (37.5%) stable disease (SD) and 4/16 (25%) progressions; 5/6 responses occurred in patients pre-treated with antiangiogenics. No responses were detected in D-SFT. Best RECIST responses were: 1/16 (6.2%) PR, 12/16 (75%) SD, 3/16 (18.8%) progressions. At 48.4 month m-FU, m-PFS by Choi was 4.7 (inter-quartile range: 2.4-13.1) months, with 31.2% patients progression-free at 1 year., Conclusion: Regorafenib showed activity in SFT, with 30% patients free-from-progression at one year. Responses were observed also in patients pretreated and refractory to another antiangiogenic agents. However, ORR and m-PFS were lower than reported with other antiangiogenics, and this was possibly due to discrepancies in the patient population and the high-rate of dose reductions., Competing Interests: Declaration of Competing Interest SS: related to the submitted work: Bayer Institutional financial interest; outside the submitted work: personal financial interests (honoraria, consultancy or advisory role): Aadi, Astex Pharmaceuticals, Bavarian Nordic, Bayer, Boehringer Ingelheim, Daiichi Sankyo, Deciphera, Epizyme, Gentili, GSK, Agenus, Ikena, MaxiVAX, Novartis, PharmaMar, Pharma Essentia, Rain Therapeutics, Servier. Support for attending meetings and/or travel Pharmamar; Institutional financial interests: Advenchen, Bayer, Blueprint, Daiichi Sankyo, Deciphera, Epizyme, Eli Lilly, GSK, Hutchinson, Inhibrx, Karyopharm, Novartis, PharmaMar, Rain Therapeutics, SpringWorks; unpaid Member of the Scientifc Advisory Board of the Chordoma Foundation, Member of the Scientifc Advisory Board of the Desmoid Foundation, Member of the Scientifc Advisory Board of the Epithelioid Hemangioendothelioma Group, Member of the Scientifc Advisory Board of the Leiomyosarcoma Foundation. GGB: related to the submitted work: Bayer Institutional financial interest; outside the submitted work: consulting fees from Eli Lilly, Pharmamar, AboutEvents; honoraria from Pharmamar, Eli Lilly, Glaxo Smith Kline, Merck Sharp & Dome, Eisai, Istituto Gentili; support for attending meetings and/or travels from Novartis, Pharmamar, Eli Lilly; participation on advisory board from Pharmamar, Eli Lilly, Glaxo Smith Kline, Merck Sharp & Dome, Eisai. AMF: related to the submitted work: Bayer Institutional financial interest; outside the submitted work: institutional research funding from Advenchen Laboratories, Amgen Dompé, AROG Pharmaceuticals, Bayer, Blueprint Medicines, Boehriger Ingelheim, Daiichi Sankyo, Deciphera, Eisai, Eli Lilly, Epizyme Inc, Foghorn Therapeutics Inc., Glaxo, Hutchison MediPharma. Limited, Inhibrx, Inc., Karyopharm Pharmaceuticals, Novartis, Pfizer, PharmaMar, PTC Therapeutics, Rain Oncology, SpringWorks Therapeutics. CM: related to the submitted work: Bayer Institutional financial interest; outside the submitted work: no COIs to declare. FGG: related to the submitted work: Bayer Institutional financial interest; outside the submitted work: no COIs to declare. PC: related to the submitted work: Bayer Institutional financial interest; outside the submitted work: no COIs to declare. MB: related to the submitted work: Bayer Institutional financial interest; outside the submitted work: no COIs to declare. GPD: related to the submitted work: Bayer Institutional financial interest; outside the submitted work: no COIs to declare. NZ: related to the submitted work: Bayer Institutional financial interest; outside the submitted work: institutional research funding from Ikena Oncology, Astex therapeutics. SP: related to the submitted work: Bayer Institutional financial interest; outside the submitted work: institutional research funding from Ikena Oncology, Pharmamar, Astex therapeutics. AG: related to the submitted work: Bayer Institutional financial interest; outside the submitted work: compensations for advisory boards from Novartis, Pfizer, Bayer, Lilly, PharmaMar, SpringWorks, Boehringer Ingelheim; Honoraria from Deciphera; Research grants from PharmaMar and Nanobiotix. PH: Patent patient stratification methods for antiangiogenic agents (Patent number: EPS3665307B1). MI: related to the submitted work: Bayer Institutional financial interest; outside the submitted work: institutional research funding from Advenchen Laboratories, Amgen Dompé, AROG Pharmaceuticals, Bayer, Blueprint Medicines, Boehriger Ingelheim, Daiichi Sankyo, Deciphera, Eisai, Eli Lilly, Epizyme Inc, Foghorn Therapeutics Inc., Glaxo, Hutchison MediPharma Limited, Inhibrx, Inc., Karyopharm Pharmaceuticals, Novartis, Pfizer, PharmaMar, PTC Therapeutics, Rain Oncology, SpringWorks Therapeutics. GT: related to the submitted work: Bayer Institutional financial interest; outside the submitted work: no COIs to declare. RM: related to the submitted work: Bayer Institutional financial interest; outside the submitted work: no COIs to declare. PGC: related to the submitted work: Bayer Institutional financial interest; outside the submitted work: institutional research funding from Advenchen Laboratories, Amgen Dompé , AROG Pharmaceuticals, Bayer, Blueprint Medicines, Boehriger Ingelheim, Daiichi Sankyo, Deciphera, Eisai, Eli Lilly, Epizyme Inc, Foghorn Therapeutics Inc., Glaxo, Hutchison MediPharma Limited, Inhibrx, Inc., Karyopharm Pharmaceuticals, Novartis, Pfizer, PharmaMar, PTC Therapeutics, Rain Oncology, SpringWorks Therapeutics., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Importance: Gastrointestinal stromal tumor (GIST) follow-up is recommended by international guidelines, but data on the role of follow-up in patients with low relapse risk are missing. For these patients, the potential benefit of anticipating recurrence detection should be weighed against psychological burden and radiologic examination loads in terms of costs and radiation exposure., Objective: To evaluate the outcomes of guideline-based follow-up in low-risk GIST., Design, Setting, and Participants: This multi-institutional retrospective cohort study involving Italian Sarcoma Group reference institutions evaluated patients with GIST who underwent surgery between January 2001 and June 2019. Median follow-up time was 69.2 months. Data analysis was performed from December 15, 2022, to March 20, 2023. Patients with GIST at low risk according to Armed Forces Institute of Pathology criteria were included provided adequate clinical information was available: primary site, size, mitotic index, surgical margins, and 2 or more years of follow-up., Exposures: All patients underwent follow-up according to European Society for Medical Oncology (ESMO) guidelines., Main Outcomes and Measures: The primary outcome was the number of tests needed to identify a relapse according to ESMO guidelines follow-up plan. Secondary outcomes included relapse rate, relapse timing, disease-free survival (DFS), overall survival (OS), GIST-specific survival (GIST-SS), postrelapse OS, secondary tumor rates, and theoretical ionizing radiation exposure. An exploratory end point, new follow-up schedule proposal for patients with low-risk GIST according to the observed results, was also assessed., Results: A total of 737 patients (377 men [51.2%]; median age at diagnosis, 63 [range, 18-86] years) with low-risk GIST were included. Estimated 5-year survival rates were 95.5% for DFS, 99.8% for GIST-SS, and 96.1% for OS. Estimated 10-year survival rates were 93.4% for DFS, 98.1% for GIST-SS, and 91.0% for OS. Forty-two patients (5.7%) experienced disease relapse during follow-up (9 local, 31 distant, 2 both), of which 9 were detected after 10 or more years. This translated into approximately 1 relapse detected for every 170 computed tomography scans performed, with a median radiation exposure of 80 (IQR, 32-112) mSv per patient. Nongastric primary tumor (hazard ratio [HR], 2.09; 95% CI, 1.14-3.83; P = .02), and KIT mutation (HR, 2.77; 95% CI, 1.05-7.27; P = .04) were associated with a higher risk of relapse. Second tumors affected 187 of 737 patients (25%), of which 56 were detected during follow-up and represented the primary cause of death in these patients., Conclusions and Relevance: In this cohort study on patients affected by low-risk GISTs, the risk of relapse was low despite a follow-up across 10 or more years. These data suggest the need to revise follow-up schedules to reduce the anxiety, costs, and radiation exposure of currently recommended follow-up strategy.

Background: After a huge efficacy of imatinib in treating patients with gastrointestinal stromal tumors (GISTs) was proven, a maximum effort was made to make a differential diagnosis between GISTs and gastrointestinal leiomyosarcomas (GI-LMS), showing the latter to be an extremely rare tumor entity. Limited data on GI-LMS biology, clinical behavior and drug-sensibility are available, and the clinical decision-making in this subgroup of patients is usually challenging., Methods: We conducted a multicenter, retrospective observational study on patients with diagnosed GI-LMS from 2004 to 2020 within six high-volume referral centers in Italy., Results: Thirty-three patients had diagnosis of KIT-negative GI-LMS confirmed by sarcoma-expert pathologist. The most common site of origin was the intestine. Twenty-two patients had localized disease and underwent surgery: with a median follow-up of 72 months, median disease-free survival was 42 months. Overall survival (OS)-rate at 5 years was 73% and median OS was 193 months. Five out of 10 patients with local relapse received a salvage surgery, and 2/5 remained with no evidence of disease. Thirteen patients received neoadjuvant (6) or adjuvant (7) chemotherapy, and 2/13 patients remained free from relapse. The median OS for patients with metastatic LMS was 16.4 months., Conclusion: GI-LMS is very rare and extremely aggressive subgroup of sarcomas with a high tendency to systemic spread. Localized GI-LMS at diagnosis may be cured if treated with adequate surgery with or without (neo) adjuvant chemotherapy, while de-novo metastatic disease appeared to have a poor prognosis. Clinical effort to understand GI-LMS biology and clinical behavior and to develop active treatment strategy, especially for metastatic-disease, is warranted., (© 2023 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Retroperitoneal soft tissue sarcomas mainly consist histologically of liposarcomas and leiomyosarcomas. For the liposarcoma subgroup, the local relapse rate seems to determine patients' overall prognosis. In contrast, leiomyosarcoma patients are challenged by the development of metastatic disease; therefore, effective systemic therapies are the cornerstone to improve patients' outcome. No doubt, the limited number of active regimens currently available makes the treatment of patients with locally advanced and/or metastatic disease challenging and results in the overall poor prognosis of this population. In this European Journal of Surgical Oncology Educational Special Issue from the Transatlantic Australasian RetroPeritoneal Sarcoma Working Group (TARPSWG), we aim to summarize state-of-the-art systemic treatments for patients with retroperitoneal sarcomas with a focus on the locally advanced and metastatic disease setting including conventional standard chemotherapies as well as new innovative treatment approaches in order to identify current unmet medical needs guiding the sarcoma community to initiate appropriate translational research projects and design innovative clinical trials., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2021 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.)

Opinion Statement: Epithelioid hemangioendothelioma (EHE) is an ultra-rare, translocated vascular sarcoma. EHE can have different clinical presentations from indolent to rapidly evolving cases, behaving as a high-grade sarcoma. Serosal effusion and systemic symptoms such as fever and severe pain are known as adverse prognostic factors; however, outcome prediction at disease onset remains a major challenge. In spite of its rarity, an international collaborative effort is in place with the support of patient advocates to increase the knowledge of EHE biology, develop new treatment options, and improve patient access to new active medications. Currently, systemic therapies are indicated only for patients suffering from progressive and/or symptomatic disease and in patients with a high risk of organ dysfunction. Standard systemic agents available so far for treatment of sarcomas, and in particular anthracycline-based chemotherapy, have marginal activity in EHE. On this background, EHE patients should be always considered for clinical study when available. The MEK inhibitor trametinib has been recently investigated prospectively in advanced EHE showing some activity, but the publication of the full dataset is still awaited to better interpret the results. Besides, there are data on response to antiangiogenics such as sorafenib and bevacizumab and, from retrospective studies, interferon, thalidomide, and sirolimus. Unfortunately, none of these agents is formally approved for EHE patients and access to treatments varies greatly between countries causing a huge disparity in patient care from one country to another., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Undifferentiated small round cell sarcomas (URCSs) represent a diagnostic challenge, and their optimal treatment is unknown. We aimed to define the clinical characteristics, treatment, and outcome of URCS patients., Methods: URCS patients treated from 1983 to 2019 at 21 worldwide sarcoma reference centres were retrospectively identified. Based on molecular assessment, cases were classified as follows: (1) CIC-rearranged round cell sarcomas, (2) BCOR::CCNB3-rearranged round cell sarcomas, (3) unclassified URCSs. Treatment, prognostic factors and outcome were reviewed., Results: In total, 148 patients were identified [88/148 (60%) CIC-rearranged sarcoma (median age 32 years, range 7-78), 33/148 (22%) BCOR::CCNB3-rearranged (median age 17 years, range 5-91), and 27/148 (18%) unclassified URCSs (median age 37 years, range 4-70)]. One hundred-one (68.2%) cases presented with localised disease; 47 (31.8%) had metastases at diagnosis. Male prevalence, younger age, bone primary site, and a low rate of synchronous metastases were observed in BCOR::CCNB3-rearranged cases. Local treatment was surgery in 67/148 (45%) patients, and surgery + radiotherapy in 52/148 (35%). Chemotherapy was given to 122/148 (82%) patients. At a 42.7-month median follow-up, the 3-year overall survival (OS) was 92.2% (95% CI 71.5-98.0) in BCOR::CCNB3 patients, 39.6% (95% CI 27.7-51.3) in CIC-rearranged sarcomas, and 78.7% in unclassified URCSs (95% CI 56.1-90.6; p < 0.0001)., Conclusions: This study is the largest conducted in URCS and confirms major differences in outcomes between URCS subtypes. A full molecular assessment should be undertaken when a diagnosis of URCS is suspected. Prospective studies are needed to better define the optimal treatment strategy in each URCS subtype., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Tenosynovial giant cell tumour (TGCT) is a rare, locally aggressive, mesenchymal tumor arising from the joints, bursa and tendon sheaths. TGCT comprises a nodular- and a diffuse-type, with the former exhibiting mostly indolent course and the latter a locally aggressive behavior. Although usually not life-threatening, TGCT may cause chronic pain and adversely impact function and quality of life (QoL). CSFR1 inhibitors are effective with benefit on symptoms and QoL but are not available in most countries. The degree of uncertainty in selecting the most appropriate therapy and the lack of guidelines on the clinical management of TGCT make the adoption of new treatments inconsistent across the world, with suboptimal outcomes for patients. A global consensus meeting was organized in June 2022, involving experts from several disciplines and patient representatives from SPAGN to define the best evidence-based practice for the optimal approach to TGCT and generate the recommendations presented herein., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: In ultra-rare sarcomas (URS) the conduction of prospective, randomized trials is challenging. Data from retrospective observational studies (ROS) may represent the best evidence available. ROS implicit limitations led to poor acceptance by the scientific community and regulatory authorities. In this context, an expert panel from the Connective Tissue Oncology Society (CTOS), agreed on the need to establish a set of minimum requirements for conducting high-quality ROS on the activity of systemic therapies in URS., Methods: Representatives from > 25 worldwide sarcoma reference centres met in November 2020 and identified a list of topics summarizing the main issues encountered in ROS on URS. An online survey on these topics was distributed to the panel; results were summarized by descriptive statistics and discussed during a second meeting (November 2021)., Results: Topics identified by the panel included the use of ROS results as external control data, the criteria for contributing centers selection, modalities for ensuring a correct pathological diagnosis and radiologic assessment, consistency of surveillance policies across centers, study end-points, risk of data duplication, results publication. Based on the answers to the survey (55 of 62 invited experts) and discussion the panel agreed on 18 statements summarizing principles of recommended practice., Conclusions: These recommendations will be disseminated by CTOS across the sarcoma community and incorporated in future ROS on URS, to maximize their quality and favor their use as control data when results from prospective studies are unavailable. These recommendations could help the optimal conduction of ROS also in other rare tumors., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: We retrospectively investigated the role of (neo)adjuvant chemotherapy in patients with primary, localized angiosarcoma., Methods: We selected all patients with primary, localized angiosarcoma, who had received radical surgery between January 2005 and December 2019 at 33 European sarcoma reference centers. The primary objective was to compare the outcome of patients who received (neo)adjuvant chemotherapy versus those who did not, in terms of overall survival (OS), disease-free survival (DFS) and distant metastasis-free survival (DMFS). To reduce the risk of confounding due to imbalance, a propensity-score matching(PSM) was performed. Finally, subgroups analysis was performed according to tumor site, tumor size (< 50 mm or ≥ 50 mm) and patients predicted 10-years OS according to the nomogram sarculator (two different cutoff-values were applied: ≤ 33% or > 33% and < 60% or ≥ 60%)., Results: 362 patients were analyzed: 149 (41.2%; treated group) received (neo) adjuvant chemotherapy and 213 (58.6%; control group) did not. The median follow-up for the OS endpoint was 5.1 years (95% CI: 4.0-5.5). The OS-HR was 0.58 (95%CI: 0.40-0.83; p-value = 0.003) in the univariate analysis and 0.74 (95% CI: 0.38-1.43; p = 0.367) in the PSM analysis. The DFS-HR was 0.75 (95% CI: 0.57-0.98; p-value = 0.036) in the univariate analysis, and 0.91 (95% CI:0.56-1.48; p-value = 0.7) in the PSM analysis. The DMFS-HR was 0.75 (95% CI: 0.55-1.02; p-value = 0.065) in univariate analysis and 0.92 (95% CI: 0.53-1.61; p-value = 0.769) in the PSM analysis. Subgroup analysis revealed no heterogeneity of results in strata of tumor site. On the contrary, there was a trend for heterogeneity according to tumor size and patient's risk of death. For all the endpoints analyzed, patients with tumors smaller than 50 mm or at lower risk of death seem to have no benefit from chemotherapy, while patients with larger tumors or at higher risk of death at 10 years seem to derive substantial benefit., Conclusion: This large, retrospective study suggests that patients affected by > 50 mm and/or high-risk primary, localized angiosarcoma could benefit from (neo)adjuvant chemotherapy., Competing Interests: Conflict of interest statement The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: Clear cell sarcoma (CCS) is a translocated aggressive malignancy with a high incidence of metastases and poor prognosis. There are few studies describing the activity of systemic therapy in CCS. We report a multi-institutional retrospective study of the outcomes of patients with advanced CCS treated with systemic therapy within the World Sarcoma Network (WSN)., Materials and Methods: Patients with molecularly confirmed locally advanced or metastatic CCS treated with systemic therapy from June 1985 to May 2021 were included. Baseline demographic and treatment information, including response by Response Evaluation Criteria in Solid Tumours (RECIST) 1.1, was retrospectively collected by local investigators. Descriptive statistics were carried out., Results: Fifty-five patients from 10 institutions were included. At diagnosis, the median age was 30 (15-73) years and 24% (n = 13/55) had metastatic disease. The median age at diagnosis was 30 (15-73) years. Most primary tumours were at aponeurosis (n = 9/55, 16%) or non-aponeurosis limb sites (n = 17/55, 31%). The most common fusion was EWSR1-ATF1 (n = 24/55, 44%). The median number of systemic therapies was 1 (range 1-7). The best response rate was seen for patients treated with sunitinib (30%, n = 3/10), with a median progression-free survival of 4 [95% confidence interval (CI) 1-7] months. The median overall survival for patients with advanced/metastatic disease was 15 months (95% CI 3-27 months)., Conclusions: Soft tissue sarcoma-type systemic therapies have limited benefit in advanced CCS and response rate was poor. International, multicentre prospective translational studies are required to identify new treatments for this ultra-rare subtype, and access to early clinical trial enrolment remains key for patients with CCS., Competing Interests: Disclosure AS has received consulting fees from Merck and Medison. RLJ is the recipient of grants/research support from MSD and GSK and is the recipient of consultation fees from Adaptimmune, Athenex, Blueprint, Clinigen, Eisai, Epizyme, Daichii, Deciphera, Immunedesign, Lilly, Merck, Pharmamar, and UptoDate. PR has received honoraria for lectures and advisory boards from BMS, MSD, Novartis, Pierre Fabre, Sanofi, Merck, Philogen, and Blueprint Medicines outside of the scope of the trial. AMC has received honoraria as invited speaker from BMS, MSD, Novartis, and Pierre Fabre. FD has received honoraria from PharmaMar, GSK, and Bayer, and travel grants from PharmaMar. GGB has received honoraria from Eli Lilly, Eisai, PharmaMar, GSK, and MSD; travel grants from PharmaMar, Pfizer, and Eli Lilly; and personal fees from AboutEvents, EditaMed, and Eli Lilly. All other authors have declared no conflicts of interest., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Introduction: In the last few years, steps forward in the knowledge of the biology of soft tissue sarcomas (STS) have led to the development of new therapeutic strategies, including immunotherapy., Areas Covered: This review outlines the recent findings on immunological features and provides a synopsis of the results of clinical trials with different immunotherapy approaches in STS, discussing criticisms, and how the efficacy of immunotherapy could be improved., Expert Opinion: The heterogeneity of STS has limited generalized approaches of immunotherapy in the disease. Clinical decisions should encompass a comprehensive characterization of the tumor microenvironment (TME), marked by intra-histotype diversity. Profiling of immune cells, checkpoint molecules, and antigen target/HLA expression is deemed to reshape the classical histotype classification for a selection of the most appropriate immune-based treatment. In a synergistic view, tumor-directed treatments, designed on the genetic and epigenetic histotype make-up, should be monitored for their immunomodulant effect and applied to ensure or amplify immunotherapy response. In light of the dynamic nature of the TME, this immunomonitoring should be conducted at baseline and during treatment, for improved therapeutic decisions and rational sequence of treatment combination, pursuing an immunological marker approach by histotype guidance.

Background: We aimed at investigating outcome of systemic treatments in advanced breast PT., Methods: All cases of advanced breast PT treated with systemic treatments from 1999 to 2019, in one of the referral sarcoma centers involved in the study, were retrospectively reviewed., Results: 56 female patients were identified. Median age was 52 (range of 25-76) years. Patients received a median number of 2 systemic treatments (range of 1-4). Best responses according to RECIST were 1 (3.7%) CR, 11 (40.7%) PR, 6 (22.2%) SD, 9 (33.3%) PD with anthracyclines plus ifosfamide (AI); 2 (16.7%) PR, 4 (33.3%) SD, 6 (50.0%) PD with anthracycline alone; 3 (18.8%) PR, 4 (25.0%) SD, 9 (56.3%) PD with high-dose ifosfamide given as a continuous infusion (HD-IFX); 3 (20.0%) SD, 12 (80.0%) PD with a gemcitabine-based regimen (with 2 patients not evaluable); 1 (8.3%) PR, 2 (16.7%) SD, 9 (75.0%) PD with trabectedin (with 1 patient not evaluable); 1 (16.7%) PR, 1 (16.7%) SD, 4 (66.7%) PD with tyrosine-kinase inhibitors (TKI). The median PFS were 5.7 (IQR 2.5-9.1) months with AI; 3.2 (IQR 2.2-5.0) months with anthracycline alone; 3.4 (IQR 1.4-6.7) months with HD-IFX; 2.1 (IQR 1.4-5.2) months with gemcitabine-based chemotherapy; 1.8 (IQR 0.7-6.6) months with trabectedin; 3.4 (IQR 3.1-3.8) months with TKI. With a median follow-up of 35.3 (IQR 17.6-66.9) months, OS from the start of first-line systemic treatment was 15.2 (IQR 7.6-39.6) months., Conclusion: In this series of advanced PT (to our knowledge, the largest reported so far), AI was associated with a high rate of responses, however, with a median PFS of 5.7 months. Other systemic treatments were poorly active., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: To report on a retrospective case-series analysis of weekly cisplatin (wCDDP) as a single agent or combined with imatinib (wCDDP/I) in patients with advanced chordoma treated within the Italian Rare Cancer Network., Methods: Adult patients with a diagnosis of advanced, brachyury-positive chordoma, treated from April 2007 to October 2020 with wCDDP or wCDDP/I were retrospectively identified. Imatinib was withheld at the same time as wCDDP. Response according to Response Evaluation Criteria in Solid Tumors, overall survival (OS), and progression-free survival (PFS) were analyzed., Results: Thirty-three consecutive patients were identified (wCDDP as front-line n = 8 [24.2%]; wCDDP as a further line n = 25 [75.8%]; prior imatinib n = 25 [75.8%]; evidence of progression before starting wCDDP n = 33). Of 32 patients evaluable for response (wCDDP, n = 22 [68.8%]; wCDDP/I, n = 10 [31.3%]), best response was stable disease (SD) in 27 patients (84.3%) and progression in 5 patients (15.6%). At a median follow-up of 54 months, the median OS (m-OS) was 30.3 months (interquartile range [IQR], 18.1-56.6), the m-PFS was 8.0 months (IQR, 5.1-17.0), the 6-month PFS rate was 65.2%, and the 12-month PFS rate was 30.3%. Of 22 patients who received wCDDP, the best response was SD in 18 patients (81.8%) and progression in 4 patients (18.2%), and the m-PFS was 8.0 months (IQR, 5.1-17.0 months). Of 10 patients who received treatment with wCDDP/I, the best response was SD in 9 patients (90%) and progression in 1 patient (10%), and the m-PFS was 9.3 months (IQR, 4.9-26.5 months)., Conclusions: This series suggests that wCDDP, both as a single agent and combined with imatinib, has antitumor activity in chordoma. Although no dimensional responses were observed, 65% and 30% of previously progressive patients were progression-free at 6 and 12 months, respectively. A prospective study is warranted., (© 2022 American Cancer Society.)

Epithelioid hemangioendothelioma (EHE) is an extremely rare vascular sarcoma with an unpredictable clinical behavior. Pleural EHEs have been associated with poor response to treatment and reduced survival. To date, no standard treatment for EHE is available. Here we report the case of a 53-year-old man who underwent radical surgery for a symptomatic primary pleural EHE. Clinical presentation was characterized by chronic pain in the left hemithorax with transitory flare, anemia, weight loss and progressive worsening of clinical conditions. After surgery, he resumed active life and normal daily activities and, at 8 months, 18F-FDG PET and computed tomography scan showed no radiological evidence of recurrent disease. Clinical signs of this rare disease, histological features, imaging findings and functional imaging are discussed. We also report a summary of other cases with resected pleural EHE and we briefly review the role of chemotherapeutic, immunomodulatory and antiangiogenic drugs for advanced disease., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Background: We aimed to investigate changes in volume and MRI T2-weighted intensity in desmoid-type fibromatosis (DF) receiving methotrexate plus vinca-alkaloids (MTX-VA) at Istituto Nazionale dei Tumori, Milan., Methods: All cases of sporadic DF treated with MTX-VA from 1999 to 2019 were reviewed. MRIs at baseline, 6 and 12 months of chemotherapy and at treatment withdrawal were retrospectively reviewed, contouring the tumor lesion and measuring diameters, volume, and mean T2-signal intensity (normalized to muscle) changes. These parameters were also evaluated according to clinical variables., Results: Thirty-two DF patients were identified. Best RECIST response was: 25% partial response, 69% stable disease, 6% progression. A ≥65% tumor volume reduction was observed in 38%, <65% reduction in 53%, an increase in 9%. 22% had RECIST stable disease with a ≥65% tumor volume reduction. T2-signal intensity decreased by ≥50% in 47%, <50% in 41% and increased in 12%. In patients with symptomatic improvement while on therapy and in patients maintaining symptomatic improvement during follow-up, median T2-signal intensity showed a reduction along the time points (3.0, 1.9, 1.2, 1.1; 2.9, 2.0, 1.2, 1.2, respectively); in patients without symptomatic improvement and in those clinically progressing during follow-up, a reduction was not observed. High T2-signal intensity at baseline was observed in patients showing RECIST progression during follow-up., Conclusions: In this series, RECIST detected a lower proportion of responses as compared to volumetric and T2-signal changes. T2-signal reduction seemed to better reflect symptomatic improvement. High T2-signal intensity at baseline was related to a higher proportion of further progression., (© 2021 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Background: This observational, retrospective effort across Europe, US, Australia, and Asia aimed to assess the activity of systemic therapies in EHE, an ultra-rare sarcoma, marked by WWTR1-CAMTA1 or YAP1-TFE3 fusions., Methods: Twenty sarcoma reference centres contributed data. Patients with advanced EHE diagnosed from 2000 onwards and treated with systemic therapies, were selected. Local pathologic review and molecular confirmation were required. Radiological response was retrospectively assessed by local investigators according to RECIST. Progression free survival (PFS) and overall survival (OS) were estimated by Kaplan-Meier method., Results: Overall, 73 patients were included; 21 had more than one treatment. Thirty-three patients received anthracyclines regimens, achieving 1 (3%) partial response (PR), 25 (76%) stable disease (SD), 7 (21%) progressive disease (PD). The median (m-) PFS and m-OS were 5.5 and 14.3 months respectively. Eleven patients received paclitaxel, achieving 1 (9%) PR, 6 (55%) SD, 4 (36%) PD. The m-PFS and m-OS were 2.9 and 18.6 months, respectively. Twelve patients received pazopanib, achieving 3 (25%) SD, 9 (75%) PD. The m-PFS and m-OS were.2.9 and 8.5 months, respectively. Fifteen patients received INF-α 2b, achieving 1 (7%) PR, 11 (73%) SD, 3 (20%) PD. The m-PFS and m-OS were 8.9 months and 64.3, respectively. Among 27 patients treated with other regimens, 1 PR (ifosfamide) and 9 SD (5 gemcitabine +docetaxel, 2 oral cyclophosphamide, 2 others) were reported., Conclusion: Systemic therapies available for advanced sarcomas have limited activity in EHE. The identification of new active compounds, especially for rapidly progressive cases, is acutely needed., (© 2021 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Background: The objective of this study was to report on a retrospective series of patients with epithelioid hemangioendothelioma (EHE) who received treatment with sirolimus within the Italian Rare Cancer Network., Methods: From January 2005, 38 adult patients with advanced EHE received continuous-dosing sirolimus, 5 mg daily, until they developed either toxicity or disease progression. Disease progression in the 6 months before the start of treatment was required. Each pathologic diagnosis was reviewed. The daily dose of sirolimus was adjusted based on plasma levels. Response was retrospectively assessed by local investigators using Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST). Survival was estimated using the Kaplan-Meier method., Results: All 38 patients (WW Domain Containing Transcription Regulator 1 [WWTR1]-positive, n = 37; transcription factor E3 [TFE3]-positive, n = 1) had disease progression before starting sirolimus (at baseline, 13 of 38 patients had the presence of serosal effusions and systemic symptoms). Thirty-seven patients were evaluable for response (there was 1 early interruption). The best RECIST responses were a partial response in 4 patients (10.8%), stable disease in 28 patients (75.7%), and disease progression in 5 patients (13.5%). At a 41.5-month median follow-up (interquartile range [IQR], 23.9-56.8 months), the median PFS was 13 months (95% CI, 3.7 months to not estimated [NE]), and the median OS was 18.8 months (95% CI, 10.6 months to NE). In patients who had serosal effusions at baseline, the median PFS was 4.8 months (IQR, 3.5-11.7 months), and the median OS was 10.6 months (IQR, 5.1-13.0 months), compared with 47.8 months (IQR, 11.4 months to NE) and 47.8 months (IQR, 15.7 months to NE), respectively, in patients without serosal effusions. Overall, sirolimus was fairly well tolerated, with 10 patients reporting irregular menstruation/ovary disfunction., Conclusions: The current results confirm that sirolimus is active in EHE, leading to prolonged stabilization in most patients who present without serosal effusions. Serosal effusions are confirmed as an unfavorable prognostic sign associated with short survival, and sirolimus displays limited activity in this subgroup., (© 2020 American Cancer Society.)

Background: This study aimed to review the activity of cytotoxic chemotherapy in patients with inflammatory myofibroblastic tumors (IMTs) treated at nine European sarcoma reference centers., Materials and Methods: Patients of any age, with histologically proven IMT, treated with anthracycline-based methotrexate plus/minus vinorelbine/vinblastine (MTX-V) or other chemotherapeutic regimens between 1996 and 2018 were retrospectively reviewed. Diagnosis was confirmed at the local level by an expert pathologist. Response was retrospectively assessed by local investigators by RECIST v1.1. Progression-free survival (PFS), relapse-free survival (RFS), and overall survival (OS) were computed by Kaplan-Meier method., Results: Thirty-eight patients were included. Twenty-five patients (8 localized, 17 advanced disease) received an anthracycline-based regimen; 21 were evaluable for response. Overall response rate (ORR) was 10/21 (47.6%). At a 70.8-month median follow-up (FU), median RFS and median OS were not reached (NR) in patients with localized disease; median PFS and median OS were 6.3 (interquartile range [IQR]: 1.9-13.4) and 21.2 (IQR: 7.7-40.7) months in patients with advanced disease. Thirteen patients received MTX-V (4 localized, 9 advanced disease), all evaluable for response. ORR was 7/13 (53.8%). At a 56.6-month median FU, median RFS and median OS were 42.5 (IQR: 12.9-61.2) months and NR (no death events) in patients with localized disease, and NR (IQR: 24.9 to NR) and 83.4 months (IQR: 83.4 to NR) in patients with advanced disease. In the "other-regimens group," responses were seen in 3/4 patients treated with oral cyclophosphamide and 1/2 with docetaxel/gemcitabine., Conclusion: Anthracycline-based and MTX-V regimens are very effective in IMT, with a similar ORR in both groups. MTX-V achieved a prolonged disease control. Responses were also seen with oral cyclophosphamide and docetaxel/gemcitabine, but few patients were treated with these schedules., Implications for Practice: Inflammatory myofibroblastic tumor (IMT) is an ultrarare sarcoma with known sensitivity to anaplastic lymphoma kinase (ALK) inhibitors in ALK-fused cases, although ALK inhibitors are not licensed in the disease. The current knowledge on the activity of cytotoxic chemotherapy is limited. This multi-institutional retrospective study on pediatric and adult patients with IMT shows that cytotoxic chemotherapy, and in particular anthracycline-based and methotrexate plus/minus vinorelbine/vinblastine regimens, represents a treatment option and can be considered in IMT patients irrespectively from ALK status. This study provides a benchmark for future studies on new medical therapies., (© AlphaMed Press 2020.)

Background: Although elderly patients (≥70 years) represent 30% of new diagnoses of soft tissue sarcoma (STS), they are underrepresented in clinical trials and are often unfit to receive standard anthracycline-based chemotherapy. Trabectedin is registered as a second-line treatment for advanced STS and is characterized by a favorable safety profile., Methods: The aim of this single-arm, phase 2 study was to investigate trabectedin (scheduled dose, 1.3-1.5 mg/m 2 ) as a first-line treatment in elderly patients with advanced stage STS who are inoperable and are unfit to receive standard anthracycline-based chemotherapy. The coprimary endpoints were progression-free survival at 3 months (PFS3) and the rate of clinically limiting toxicities (CLTs). We also conducted an ancillary study on pharmacokinetics., Results: Twenty-four patients (12 men and 12 women) with a median age of 79 years (interquartile range [IQR], 74-83 years) were enrolled. The histological subtype was leiomyosarcoma in 46%, liposarcoma in 33%, and other histotypes in 21%. The median number of trabectedin courses was 4 (IQR, 3-6), with 7 patients (29%) receiving ≥6 cycles. Eight patients (33%) required dose reductions. The most frequent grade 3/4 adverse events were neutropenia in 9 patients (38%), fatigue in 5 patients (21%), and aminotransferase elevation in 5 patients (21%). PFS3, median PFS, and overall survival were 71% (80% CI, 57%-81%), 4 months, and 12 months, respectively. Ten patients (42% [80% CI, 28%-57%]) experienced CLTs. Trabectedin C max , half-life, clearance, and distribution volume were 1.28 ng/mL (standard deviation [SD], 0.58 ng/mL), 26.70 hours (SD, 9.09 hours), 39.98 L/h/m 2 (SD, 14.08 L/h/m 2 ), and 1460 L/m 2 (SD, 561 L/m 2 ), respectively., Conclusion: Trabectedin can be administered safely to elderly patients with STS who are unfit to receive anthracyclines. Pharmacokinetics in the elderly population was superimposable to historical data., (© 2020 American Cancer Society.)

Extraskeletal myxoid chondrosarcoma (EMC) is an ultra-rare mesenchymal neoplasm with uncertain differentiation, which arises mostly in the deep soft tissue of proximal extremities and limb girdles. EMC is marked by a translocation involving the NR4A3 gene, which can be fused in-frame with different partners, most often EWSR1 or TAF1 . Although EMC biology is still poorly defined, recent studies have started shedding light on the specific contribution of NR4A3 chimeric proteins to EMC pathogenesis and clinical outcome. Standard treatment for localized disease is surgery, plus or minus radiation therapy with an expected prolonged survival even though the risk of relapse is about 50%. In advanced cases, besides the standard chemotherapy currently used for soft tissue sarcoma, antiangiogenic agents have recently shown promising activity. The aim of this review is to provide the state of the art of treatment for localized and advanced disease, with a focus on pharmacological treatments available for EMC. The biological basis of current research and future perspectives will be also discussed.

Introduction: This case-series is aimed to describe the natural history of epithelioid sarcoma (ES) and to provide insights into the differential clinical behaviour of its two variants ("classic-type" and "proximal-type"). The value of a subtype-adapted grading system based on pathological features is explored., Methods: Data from consecutive, primary, localised, INI1-deleted ES operated at three Italian sarcoma reference centres (1995-2015) were included. Centralised pathological review was performed. Classic-type ES was broken down into "high-grade" and "low-grade", according to number of mitoses, evidence of necrosis and nuclear atypia. Five- and 10-year overall survival (OS) and crude cumulative incidence (CCI) of local recurrence (LR) and distant metastasis (DM) were estimated., Results: Fifty-two patients were included. 5- and 10-year OS estimates were 70% and 47% in the whole series, 57% and 37% in patients with proximal-type ES, 77% and 54% in patients with classic-type ES (P = 0.02). In classic-type ES, 5- and 10-year OS was higher for low-grade (95% and 72%, respectively) than high-grade tumours (P = 0.002). 5- and 10-year CCI estimates for LR were 21% and 33% in the whole series. 5- and 10-year CCI estimates for DM were 35% and 39% in the whole series, both 28% in classic-type ES, 47% and 59% in proximal-type ES (P = 0.03)., Conclusions: Suffering from a proximal- or a classic-type is the stronger predictor of outcome in patients with localised ES, with proximal-type ES patients having lower survival due to a higher tendency toward metastatic spreading. However, the "high-grade" classic-type ES was associated with outcomes close to proximal-type ES., Competing Interests: Declaration of competing interest AMF received institutional clinical trials support from Amgen Dompé, AROG Bayer, Blueprint Medicines, Eli Lilly, Daiichi Sankyo Pharma, Epizyme, GlaxoSmithKline, Novartis, Pfizer, PharmaMar and travel grants from PharmaMar. GGB received travel grants and advisory honoraria from Pharmamar and Eli Lilly, advisory honoraria from Eisai. NS received institutional clinical trials support from Amgen Dompé, AROG Bayer, Blueprint Medicines, Eli Lilly, Daiichi Sankyo Pharma, Epizyme, GlaxoSmithKline, Novartis, Pfizer, PharmaMar. PGC has reported advisory roles for Deciphera Pharmaceuticals, Eisai, Eli Lilly, Nektar Therapeutics, speaker's honoraria from Eisai, Eli Lilly, Pfizer, PharmaMar, and conducted studies sponsored by Amgen Dompé, AROG Bayer, Blueprint Medicines, Eli Lilly, Daiichi Sankyo Pharma, Epizyme, GlaxoSmithKline, Novartis, Pfizer, PharmaMar. SSt has received honoraria from Eli Lilly, PharmaMar, Takeda; institutional research grants from Amgen Dompé, Advenchen, Bayer, Eli Lilly, Daiichi Sankyo Pharma, Epizyme Inc., Novartis, Pfizer and PharmaMar; travel grants from PharmaMar and has reported advisory/consultant roles for Bayer, Daiichi, Eli Lilly, Epizyme, Karyopharm, ImmuneDesign, Maxivax and PharmaMar. MS, SLV, FF, DC, DC, SP, AG, APDT, MG, MB, AP, LM have nothing to declare., (Copyright © 2020 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.)

Introduction: Tenosynovial giant cell tumor (TGCT) is a benign mesenchymal tumor arising from the synovium of tendon sheats and joints, driven by colony-stimulating factor 1 (CSF1) over-expression. Standard treatment is surgery, but local recurrences are frequent, especially in diffuse TGCT subtype, rarely cured with surgery. When TGCT becomes a chronic condition, which may severely compromise joint function and quality of life, patients may need a systemic therapy. Areas covered: We reviewed the drugs on clinical development in TGCT, focusing on the pharmacodynamics, pharmacokinetics, efficacy, and toxicity profile of pexidartinib, the first drug approved in the US for TGCT, and on the open questions about its optimal use in clinical practice., Expert Opinion: CSFR1 inhibitors have opened a new avenue for treatment of TGCT patients. Pexidartinib is the first-in-class FDA approved agent for symptomatic locally advanced TGCT, based on a phase III study where pexidartinib showed high anti-tumor activity, improved patient symptoms, and functional outcome. A few cases of potentially life-threatening hepatic toxicity were observed. TGCT patients candidate to pexidartinib need to be carefully selected by the multidisciplinary board of center of expertise, balancing the expected risk-benefit ratio. Close monitoring of liver function and adequate education on the approved indication is warranted.

Background: Intimal sarcoma (InS) is an exceedingly rare neoplasm with an unfavorable prognosis, for which new potentially active treatments are under development. We report on the activity of anthracycline-based regimens, gemcitabine-based regimens, and pazopanib in patients with InS., Methods: Seventeen sarcoma reference centers in Europe, the United States, and Japan contributed data to this retrospective analysis. Patients with MDM2-positive InS who were treated with anthracycline-based regimens, gemcitabine-based regimens, or pazopanib between October 2001 and January 2018 were selected. Local pathological review was performed to confirm diagnosis. Response was assessed by RECIST1.1. Recurrence-free survival (RFS), progression-free survival (PFS) and overall survival were computed by Kaplan-Meier method., Results: Seventy-two patients were included (66 anthracycline-based regimens; 26 gemcitabine-based regimens; 12 pazopanib). In the anthracycline-based group, 24 (36%) patients were treated for localized disease, and 42 (64%) patients were treated for advanced disease. The real-world overall response rate (rwORR) was 38%. For patients with localized disease, the median RFS was 14.6 months. For patients with advanced disease, the median PFS was 7.7 months. No anthracycline-related cardiac toxicity was reported in patients with cardiac InS (n = 26). For gemcitabine and pazopanib, the rwORR was 8%, and the median PFS was 3.2 and 3.7 months, respectively., Conclusion: This retrospective series shows the activity of anthracycline-based regimens in InS. Of note, anthracyclines were used in patients with cardiac InS with no significant cardiac toxicity. The prognosis in patients with InS remains poor, and new active drugs and treatment strategies are needed., (© 2019 American Cancer Society.)

Introduction : Liposarcomas are a heterogeneous group of soft tissue tumors that arise from adipose tissue and are one of the most common soft tissue sarcomas found in adults. Liposarcomas are subclassified into four subtypes with distinct histologic and biologic features that influence their treatment and management. Areas covered : This manuscript reviews the key clinicopathologic and cytogenic characteristics of the liposarcoma histologic subtypes and summarizes the results of recent clinical trials, treatment options, and future directions in the pharmacotherapy for the management of liposarcoma. Expert opinion : Despite significant advancements in the management of this disease, the treatment of liposarcoma continues to be a challenge. Surgical resection remains the mainstay of treatment for localized disease; however, use of systemic therapies in conjunction with surgery may be considered in patients where tumor shrinkage could reduce surgical morbidity and in patients with high-risk of micrometastatic disease. Anthracycline-based chemotherapy regimens remain the standard first-line treatment for unresectable/metastatic liposarcoma. Trabectedin and eribulin are currently the two most promising and evidenced-based second-line treatment options for liposarcomas. However, multiple clinical trials dedicated to patients with liposarcoma evaluating novel targeted agents are ongoing. Every effort should be made to enroll patients with liposarcoma into histotype-specific clinical trials.

Sarcomas are rare malignant neoplasms that develop from mesenchymal cells and include a heterogeneous and large group of histological subtypes that may occur at any anatomical site. Soft tissue sarcomas (STS), the focus of this review, account for ≈70‒80% of sarcomas and represent <1% of all cancers. The heterogeneity of STS applies to both their topography and morphology, and 5-year survival can vary widely depending on disease stage and the complex interplay between anatomical site and histology for different STS subtypes. The rarity and heterogeneity of STS, together with other factors, such as the lack of clinical expertise often lead to difficulties and delays in making an accurate diagnosis and to the inappropriate management of each STS subtype. Therefore, this group of cancers requires special attention and approaches to diagnosis and treatment. Epidemiological data on STS are limited, and concerns have been raised regarding accurate registration of STS in cancer registries, including issues related to details of the histotypes. This review provides an overview of the epidemiology of STS in Italy, focusing on data from the Italian Association of Cancer Registries (AIRTUM), and compares findings with those from other European countries. Based on these data, and considering that STS is among the most common group of rare cancers, the relevance of multidisciplinary care for STS patients through reference centres, clinical networks and collaborative disease-specific groups is discussed., (Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Introduction: in this review we discuss the standard of care for both pediatric and adult synovial sarcoma (SS), the prognostic differences between them, and the treatments available for localized and advanced diseases. We also overview the biology and the recent drugs under consideration in clinical trials on SS. Areas covered: we focus on new targeted therapies being investigated for advanced SS, especially anti-angiogenic drugs, and immunotherapy. We review all the published data and ongoing trials dedicated to SS or to soft tissue sarcoma in general, paying particular attention to the results obtained in SS patients. Expert opinion: we expect new treatment strategies to become available for SS in the near future. The ongoing and published trials on targeted therapies and immunotherapy mainly concern adult patients, but the somatic biology of pediatric SS has some similarities as in adult disease. A stronger cooperation between adult and pediatric oncologists in recent years has led to a more shared effort to find new treatment strategies for advanced SS patients, regardless of their age.

Background: Giant cell tumor of bone (GCTB) is an osteolytic, locally aggressive, rarely metastazing bone tumor. This is a retrospective study evaluating a large series of GCTB patients treated with denosumab in routine practice in 6 European reference centers., Methods: Patients with locally advanced, unresectable or metastatic GCTB, treated with denosumab outside clinical trials were eligible. Primary end-point was progression-free survival (PFS) for all patients; secondary end-points were: type of surgery, relapse rate and event-free survival for patients after preoperative denosumab + surgery., Results: We identified 138 patients treated in the period 2011-2016. In 40/43 cases the diagnosis was confirmed by H3F3A gene mutation. Median follow-up time was 23 months (range 6-48). Primary tumor was located in lower limb (38%) - mostly in femur and tibia, in upper limb (34%), and in pelvis/axial skeleton/ribs (28%). 110 (80%) patients had primary tumors, 28 (22%) recurrent tumors after previous surgical procedures (+/- radiotherapy). 89/138 patients had locally advanced GCTB and underwent neoadjuvant denosumab. The median denosumab treatment duration was 8 months (median number of cycles 11), 98% had clinical benefit from therapy. 39 (44%) had wide en-bloc resection - WE (+implantation of the prosthesis in 17 cases), the other 50 (56%) cases had intralesional curettage - C. Progression after surgical treatment was observed in 19 patients, 16 of them after C (32%); 13 patients underwent denosumab re-challenge, and all responded. Two-year progression-free survival (PFS; from denosumab start) rate was 81%; 2-year EventFS (from surgery) was significantly better in WE group (93%) vs 55% in C group (p = 0.006). Treatment was well tolerated with only 2 cases of grade 3 toxicity and one osteonecrosis of the jaw., Conclusion: Our retrospective study confirms that denosumab is extremely efficient in unresectable/metastatic disease as well as in a neoadjuvant setting. Our data confirm excellent efficacy and short-term tolerability of this drug. Our data suggest that neoadjuvant therapy with denosumab is the option for treatment of initially locally advanced tumors to facilitate complete surgical resection or avoid mutilating surgery. The risk of recurrences after curettage of GCTB following denosumab raises questions about the optimal management of such cases., (Copyright © 2018 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.)

Evidence supporting rechallenge in patients responding to first exposure to trabectedin is limited. We report on a 39-year-old woman with advanced high-grade undifferentiated sarcoma (US) retreated twice with trabectedin after first response. The patient presented in June 2006 with an abdominal mass originating from the rear fascia of the rectus abdominis. Staging examinations did not indicate metastases and she underwent surgery; pathology showed a high-grade (FNCLCC G3) US. Subsequently, the patient received five cycles of adjuvant chemotherapy with epirubicin and ifosfamide. In February 2009 a computed tomography (CT) scan showed an abdominal mass involving the transverse mesocolon. R0 surgery was performed. In September 2009, peritoneal lesions appeared. Trabectedin was initiated at a dose of 1.5 mg/m by a 24 h intravenous infusion every 3 weeks, without relevant toxicity. After six cycles (March 2010), CT and PET-CT scans showed complete disappearance of metastases. In February 2012, new secondary lesions in the subdiaphragmatic region and a peritoneal lesion appeared. We rechallenged the patient with the same schedule of trabectedin; a complete response was achieved after two cycles. In October 2013, new secondary lesions in the subdiaphragmatic region and a retroperitoneal lesion were found. We rechallenged with the same schedule of trabectedin; PET-CT scans after two cycles showed complete response on the subdiaphragmatic lesion. Radiotherapy on the retroperitoneal lesion was performed. The patient underwent a total of 18 cycles and remains free from radiologically detectable disease. We report complete radiological remission after two rechallenges with trabectedin in a patient with previously responding high-grade US.

Denosumab is a monoclonal antibody to RANK ligand approved for use in giant cell tumour (GCT) of bone. Due to its efficacy, Denosumab is recommended as the first option in inoperable or metastatic GCT. Denosumab has also been used pre-operatively to downstage tumours with large soft tissue extension to allow for less morbid surgery. The role of Denosumab for conventional limb GCT of bone is yet to be defined. Further studies are required to determine whether local recurrence rates will be decreased with the adjuvant use of Denosumab along with surgery. The long term use and toxicity of this agent is unknown as is the proportion of patients with primary or secondary resistance. It is advised that complicated cases of GCT requiring Denosumab treatment should be referred and followed up at expert centres. Collaborative studies involving further clinical trials and rigorous data collection are strongly recommended to identify the optimum use of this drug.

Aims: Denosumab, a fully human monoclonal antibody directed against RANKL, has recently been introduced in the treatment strategy of giant cell tumour of bone (GCTB). Aim of this study was to investigate the phenotypical modifications induced by denosumab treatment in a series of 15 GCTB., Methods: The tumours were characterised for histone 3.3 mutations, and studied immunohistochemically for the modifications of RANKL, RANK, SATB2 and RUNX2 expression, as well as of tumour proliferative activity and angiogenesis., Results: Nine of 11 tumours investigated presented a histone 3.3 mutation in H3F3A, and 2 of these for which the analysis was carried out in pretreatment and post-treatment specimens showed the same mutation in both. Denosumab induced the disappearance of osteoclast-like giant cells, leaving residual spindle neoplastic cells arranged in a storiform pattern, with deposition of trabecular collagen matrix and osteoid, which tended to maturation in the peripheral portions of the lesion. RANK and RANKL expression was variable, with no significant variation after treatment. Moreover, we did not observe any significant modification of the expression of the osteoblastic markers SATB2 and RUNX2. Denosumab treatment determined a significant reduction of the proliferative index and of tumour angiogenesis (p=0.001, Wilcoxon rank-sum test)., Conclusions: These results indicate that denosumab induces a partial maturation towards the osteoblastic phenotype of the neoplastic cells of GCTB, with production of fibrous and osteoid matrix, but with minor immunophenotypical changes. Finally, we first report an antiangiogenic activity of denosumab in GCTB, possibly mediated by a RANKL-dependent pathway., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Introduction: Many patients affected by desmoid-type fibromatosis (DF) are treated with a course of hormonal therapy as front line. So far, tamoxifene has been the preferred choice. Toremifene is an anti-oestrogen agent, but possible further mechanisms of action in desmoids are related to its role in regulation of transforming growth factor-beta and β-catenin pathways., Material and Methods: We retrospectively reviewed all patients treated with toremifene between 2005 and 2012 at a reference institution. Indication to toremifene was radiologically progressive disease and/or symptomatic deterioration. Progression-free survival (PFS), clinical benefit (CB) and safety profile were analysed., Results: Forty-four patients were treated with toremifene 180 mg daily, 20 for radiological progression, 16 for pain and 8 for both. In 28 patients, toremifene was offered as front-line therapy, while in 11 after tamoxifen failure. PFS was 89.6% at 2 years. According to Response Evaluation Criteria in Solid Tumours, partial response, stable disease and disease progression were observed in 25%, 65% and 10% of the patients, respectively. Symptomatic relief was obtained in 75% of patients. Median time to response was 4 months. Overall CB was 86%. Adverse events G≥2 according to National Cancer Institute Common Toxicity Criteria were recorded in ten patients., Discussion: Present series provides evidence to make toremifene an option in patients with DF, even after failure on different hormonal agents. A prospective trial is ongoing to confirm these results., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Treatment options for patients with metastatic synovial sarcoma are limited. Over recent years, trabectedin has emerged as an effective agent for patients with advanced soft tissue sarcomas resistant to anthracyclines and ifosfamide. The aim of this retrospective analysis was to study the efficacy of trabectedin in the subgroup of synovial sarcomas. A retrospective analysis was carried out on patients with advanced synovial sarcoma treated with trabectedin at four European reference sarcoma centers and within the Italian Rare Cancer Network between 2000 and 2013. Radiological response, progression-free, and overall survival, as well as serious and unexpected adverse events were retrospectively assessed. Sixty-one patients with metastatic synovial sarcoma were identified. The median number of previous chemotherapy regimens was 2 (range 1-6). Nine patients had a partial response, in addition to two minor responses, and 19 patients had stable disease, for an overall response rate of 15% and a tumor control rate of 50%. The median progression-free survival was 3 months, with 23% of patients free from progression at 6 months. The median progression-free survival in responding patients was 7 months. Trabectedin is a therapeutic option for palliative treatment of a subset of patients with metastatic synovial sarcoma.

Aims and Background: Neuroendocrine tumors are uncommon clinical entities and only a few cases of the co-occurrence of neuroendocrine tumors and retroperitoneal fibrosis have been described in the literature., Methods and Study Design: We report the promising results achieved in a case of neuroendocrine tumor complicated by retroperitoneal fibrosis causing right ureteral obstruction treated with long-acting release octreotide and tamoxifen., Results and Conclusions: The treatment resulted in a complete response without toxicity.