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Simple Summary: Congenital dermatofibrosarcoma protuberans (DFSP) is a rare skin cancer in infants that often mimics benign lesions such as birthmarks or hemangiomas, leading to misdiagnosis and treatment delays. Early biopsy and accurate diagnosis are essential to prevent aggressive growth and recurrence. Multidisciplinary management and clinician awareness are essential to improve outcomes in affected children. Dermatofibrosarcoma protuberans (DFSP) is a rare low-grade soft tissue sarcoma. Its congenital form poses distinct diagnostic and therapeutic challenges, often resembling benign entities like hemangiomas or vascular malformations, which can lead to misdiagnosis and treatment delays. This review delves into the epidemiology, clinical manifestations, and diagnostic strategies for DFSP, with an emphasis on the use of advanced molecular techniques, such as FISH and RT-PCR, for the detection of the COL1A1-PDGFB fusion gene, a definitive marker of DFSP. We also explore emerging non-invasive imaging technologies, including multispectral and optical coherence, which, while promising, still require further validation. This review underscores the importance of differential diagnosis from similar conditions, such as medallion-like dermal dendritic hamartoma (MLDDH), through an integrated approach that combines histopathology, immunohistochemistry, and molecular testing. Surgical excision, particularly using Mohs micrographic surgery, is preferred to achieve oncologic safety while preserving aesthetic and functional results in pediatric cases. Furthermore, we discuss the potential of adjuvant therapies like tyrosine kinase inhibitors in treating advanced or inoperable cases. Highlighting the critical role of early detection and a collaborative treatment strategy, this review aims to enhance diagnostic precision and access to innovative treatments, ensuring optimal management for this severe, yet rare, condition. [ABSTRACT FROM AUTHOR]

Background: The authors report the prospective evaluation of reduced dose alkylator chemotherapy combined with radiotherapy for European Pediatric Soft Tissue Sarcoma Study Group (EpSSG) standard risk nonalveolar rhabdomyosarcoma (NA‐RMS). Patients and Methods: Localized node negative Intergroup Rhabdomyosarcoma Study (IRS) II/III NA‐RMS at favorable sites (subgroup C), <25 years old, received five cycles of ifosfamide, vincristine, and dactinomycin (IVA) chemotherapy (30 g/m2 ifosfamide) and four cycles of vincristine and dactinomycin (if receiving radiotherapy), or nine cycles of IVA (54 g/m2 ifosfamide) ± radiotherapy. Delayed primary tumor excision was considered for IRS III tumors. The primary end points were event‐free survival (EFS) and overall survival (OS). Results: From October 2005 to December 2016, 359 evaluable patients were recruited: orbit, 164 (45.7%); head and neck nonparameningeal, 77 (21.4%); and genitourinary non–bladder/prostate, 118 (32.9%). EFS and OS were 77.4% (95% confidence interval [CI], 72.5–81.6) and 93.5% (95% CI, 90.1–95.8), respectively. Lower dose alkylator chemotherapy and radiotherapy achieved 5‐year OS of 93.7% but the difference with higher dose alkylator chemotherapy +/‐ radiotherapy was not significant (p = 0.8003). Adjuvant radiotherapy improved EFS with 5‐year estimates of 84.7% versus 65.2% for nonirradiated (p <.0001), but not OS (p =.9298). Omitting radiotherapy for orbital tumors reduced OS (5‐year was 87.1% vs. 97.3% for irradiated, p =.0257). Following R0 resection (n = 60), radiotherapy did not significantly improve EFS or OS. Conclusions: Radiotherapy for local tumor control allows for reduction of cumulative dose of alkylators in EpSSG standard risk subgroup C RMS patients. The omission of radiotherapy did not affect OS in all patients except those with orbital RMS and was associated with inferior EFS. Radiotherapy allowed effective reduction in cumulative dose of alkylators for localized Intergroup Rhabdomyosarcoma Study II/III nonalveolar rhabdomyosarcoma (RMS) at favorable sites in the European Pediatric Soft Tissue Sarcoma Study Group RMS 2005 trial. The omission of radiotherapy is associated with inferior event‐free survival but not overall survival (OS), although inferior OS was observed for orbital RMS. [ABSTRACT FROM AUTHOR]

Background: Rhabdomyosarcoma (RMS) is a rare malignant soft tissue sarcoma (STS), accounting for almost 50% of pediatric STSs. Due to its heterogeneity, RMS presents challenges in diagnosis and treatment, with prognosis varying depending on multiple factors. Tumors localized in the other site (OTH)—including the paraspinal, perianal, thoracic, abdominal, pelvic, and perineal regions—are generally classified as unfavorable. This study assesses the clinical features and prognoses of RMS in OTH locations depending on its site of origin. Methods: An explorative analysis of RMS cases from the SEER 17 database 2000–2020 was conducted. Patients of all ages with histologically confirmed RMS as primary malignant disease classified under OTH, were included. OTH was categorized in four granular site classifications. Overall survival (OS) and disease‐specific survival (DSS) were analyzed using Kaplan–Meier estimators. Factors independently influencing survival, including a site classification model presented in this study, were identified through Cox regression analysis. Results: Out of 4168 patients with RMS, 990 cases of RMS with the OTH site met the inclusion criteria. The median age was 16 years. The predominant histological subtypes were embryonal (33.0%) and alveolar (25.5%). Most tumors were ≥ 5 cm (median 9 cm) and located primarily in the pelvic region (41.5%). The 3‐, 5‐, and 10‐year OS rates were 45.4% ± 3.332 (95% CI), 40.7 ± 3.332, and 38.6% ± 3.332, respectively, while DSS rates were 43.3% ± 3.136 (95% CI), 38.3% ± 3.136, and 35.1% ± 3.332. In the multivariate analysis age, histological type, site in a granular categorization, stage, regional lymph node examination, and regional lymph node involvement (pathologically proven) were independently associated with survival. Through both univariate and multivariate analyses, an OTH favorable group could be established. The OTH favorable group consists of the anal region, gallbladder and biliary tract, and breast. Conclusion: RMS in OTH shows significant differences in prognosis, putting the current categorization as unfavorable into question and making a more detailed classification necessary. Furthermore, pathological regional lymph node assessment is specifically in the OTH localization recommended. [ABSTRACT FROM AUTHOR]

Indocyanine green (ICG) is a fluorescent dye with increasing use for adult sentinel lymph node biopsy (SLNB). The utility of ICG in pediatric oncology remains understudied. We aim to describe our experience using ICG for SLNB in pediatrics versus standard blue dye. A retrospective review of pediatric patients with melanoma or sarcoma who underwent SLNB with technetium plus ICG or blue dye from 2014 to 2023 at a large academic children's hospital was conducted. Twenty-four patients were included; 58.3% were male with median age 13 years (range 4–21 years). The majority had a melanocytic tumor (91.7%) and 8.3% had sarcoma. All patients received technetium with concomitant blue dye (62.5%) or ICG (37.5%). ICG more reliably identified radioactive SLNs, compared to blue dye (mean 100% vs 78.3 ± 8.3%, p = 0.03). There was no significant difference in median operative time (ICG 82 min [68–203] vs blue dye 93 min [78–105], p = 0.84). Seven patients had positive SLNs (29.2%), with recurrence in 2 patients (8.3%) and 1 death (4.2%). There were no adverse events. ICG-directed SLNB in children is a safe and effective alternative to blue dye. Use of ICG did not add to operative time, and more often identified sentinel nodes versus blue dye. Original Research Article, Retrospective Comparative Study. III. • Indocyanine Green (ICG) is a safe, effective dye for augmenting the surgeon's visual field and has broad utility in adult oncology, particularly for sentinel lymph node biopsies and staging procedures. However, the safety and efficacy of ICG in the pediatric oncology population remains understudied. • We demonstrate that ICG in combination with technetium is a safe and effective method for identifying sentinel lymph nodes in pediatric patients. ICG more reliably identified radioactive lymph nodes versus conventional blue dye, without lengthening operating time. [ABSTRACT FROM AUTHOR]

Introduction: Chest wall reconstruction in children continues to be a challenging undertaking, aiming to restore both form and function. An optimal chest wall reconstruction material has not been identified that would provide dynamic chest function and would ideally avoid potential long-term sequelae. Case presentation: A 15-year-old female with Li Fraumeni syndrome and a history of hepatic rhabdomyosarcoma presented with increasing left back and left scapular pain initially attributed to her known scoliosis. Computed tomography revealed a 12 x 6 × 7 cm mass encasing ribs 3–5 extending into the left chest wall and axilla. Image-guided biopsy confirmed a high-grade osteosarcoma without extra-thoracic metastatic disease. She underwent neoadjuvant chemotherapy after which a three-dimensional (3D) anatomic model of the tumor was printed using the post-therapy imaging reconstruction. The surgical team collaborated with Osteobionix (Osteobionics S.L., Santa Lucia de Tirajana, Spain) to create a patient-specific dynamic chest wall reconstruction implant, based on 3D modeling of the planned resection zone. The final implant was 3D printed with a titanium alloy using electron-beam manufacturing technology, sterilized prior to implantation. She underwent left thoracotomy and rib resection with prosthesis fixation to the T3, T4, and T5 vertebral bodies posteriorly and to the sternum anteriorly. More than2 years after the operation, she is doing well without evidence of recurrent disease. She has an excellent cosmetic result, there has been no progression of her scoliosis, and she has returned to competitive sports. Conclusion: Our titanium-based 3D-printed, patient-specific implant seems to be a valuable option for the reconstruction of the chest wall in children who require an extensive chest wall resection.

BackgroundExpandable endoprostheses can be used to equalize limb length for pediatric patients requiring reconstruction following large bony oncologic resections. Outcomes of the Compress® Compliant Pre-Stress (CPS) spindle paired with an Orthopedic Salvage System expandable distal femur endoprosthesis have not been reported.MethodsWe conducted a multi-institutional retrospective study of pediatric patients with distal femoral bone sarcomas reconstructed with the above endoprostheses. Statistical analysis utilized Kaplan-Meier survival technique and competing risk analysis.ResultsThirty-six patients were included from five institutions. Spindle survivorship was 86.3% (95% confidence interval [CI], 67.7-93.5) at 10 years. Two patients had a failure of osseointegration (5.7%), both within 12 months. Twenty-two (59%) patients had 70 lengthening procedures, with mean expansions of 3.2 cm (range: 1-9) over 3.4 surgeries. The expandable mechanism failed in eight patients with a cumulative incidence of 16.1% (95% CI, 5.6-31.5) at 5 years. Twenty-nine patients sustained International Society of Limb Salvage failures requiring 63 unplanned surgeries. Periprosthetic joint infection occurred in six patients (16.7%). Limb preservation rate was 91% at 10 years.ConclusionsThere is a high rate of osseointegration of the Compress® spindle among pediatric patients when coupled with an expandable implant. However, there is a high rate of expansion mechanism failure and prosthetic joint infections requiring revision surgery.Level of evidenceLevel IV, therapeutic study.

Pediatric sarcomas, rare malignancies of mesenchymal origin, pose diagnostic and therapeutic challenges. In this review, we explore the role of radiomics in reshaping our understanding of pediatric sarcomas, emphasizing methodological considerations and applications such as diagnostics and predictive modeling. A systematic review conducted up to November 2023 identified 72 papers on radiomics analysis in pediatric sarcoma from PubMed/MEDLINE, Web of Knowledge, and Scopus. Following inclusion and exclusion criteria, 10 reports were included in this review. The studies, predominantly retrospective, focus on Ewing sarcoma and osteosarcoma, utilizing diverse imaging modalities, including CT, MRI, PET/CT, and PET/MRI. Manual segmentation is common, with a median of 35 features extracted. Radiomics Quality Score (RQS) and Methodological Radiomics Score (METRICS) assessments reveal a consistent emphasis on non-radiomic features, validation criteria, and improved methodological rigor in recent publications. Diagnostic applications dominate, with innovative studies exploring prognostic and treatment response aspects. Challenges include feature heterogeneity and sample size variations. The evolving landscape underscores the need for standardized methodologies. Despite challenges, the diagnostic and predictive potential of radiomics in pediatric oncology is evident, paving the way for precision medicine advancements. [ABSTRACT FROM AUTHOR]

Alveolar soft-part sarcoma (ASPS) is a rare soft tissue tumor with a broad morphologic differential diagnosis. While histology and immunohistochemistry can be suggestive, diagnosis often requires exclusion of other entities followed by confirmatory molecular analysis for its characteristic ASPSCR1-TFE3 fusion. Current stain-based biomarkers (such as immunohistochemistry for cathepsin K and TFE3) show relatively high sensitivity but may lack specificity, often showing staining in multiple other entities under diagnostic consideration. Given the discovery of RNA in situ hybridization (RNA-ISH) for TRIM63 as a sensitive and specific marker of MiTF-family aberration renal cell carcinomas, we sought to evaluate its utility in the workup of ASPS. TRIM63 RNA-ISH demonstrated high levels (H-score greater than 200) of expression in 19/20 (95%) cases of ASPS (average H-score 330) and was weak or negative in cases of paraganglioma, clear cell sarcoma, rhabdomyosarcoma, malignant epithelioid hemangioendothelioma, as well as hepatocellular and adrenal cortical carcinomas. Staining was also identified in tumors with known subsets characterized by TFE3 alterations such as perivascular epithelioid cell neoplasm (PEComa, average H-score 228), while tumors known to exhibit overexpression of TFE3 protein without cytogenetic alterations, such as melanoma and granular cell tumor, generally showed less TRIM63 ISH staining (average H-scores 147 and 96, respectively). Quantitative assessment of TRIM63 staining by RNA-ISH is potentially a helpful biomarker for tumors with molecular TFE3 alterations such as ASPS. [ABSTRACT FROM AUTHOR]

Oncolytic viruses (OVs) selectively replicate in tumor cells resulting in lysis, spreading of new infectious units and induction of antitumor immune responses through abrogating an immunosuppressive tumor microenvironment (TME). Due to their mode of action, OVs are ideal combination partners with targeted immunotherapies. One highly attractive combination is the inhibition of the 'don't-eat-me'-signal CD47, which is known to increase the phagocytic potential of tumor-associated macrophages. In this work, we analyzed the combination approach consisting of the YB-1-based oncolytic adenovirus XVir-N-31 (XVir) and the CD47 inhibitor (CD47i) B6.H12.2 concerning its phagocytic potential. We investigate phagocytosis of XVir-, adenovirus wildtype (AdWT)-, and noninfected established pediatric sarcoma cell lines by different monocytic cells. Phagocytes (immature dendritic cells and macrophages) were derived from THP-1 cells and healthy human donors. Phagocytosis of tumor cells was assessed via FACS analysis in the presence and absence of CD47i. Additional characterization of T cell-stimulatory surface receptors as well as chemo-/cytokine analyses were performed. Furthermore, tumor cells were infected and studied for the surface expression of the 'eat-me'-signal calreticulin (CALR) and the 'don't-eat-me'-signal CD47. We herein demonstrate that (1) XVir-infected tumor cells upregulate both CALR and CD47. XVir induces higher upregulation of CD47 than AdWT. (2) XVir-infection enhances phagocytosis in general and (3) the combination of XVir and CD47i compared to controls showed by far superior enhancement of phagocytosis, tumor cell killing and innate immune activation. In conclusion, the combination of CD47i and XVir causes a significant increase in phagocytosis exceeding the monotherapies considerably accompanied by upregulation of T cell-stimulatory receptor expression and inflammatory chemo/-cytokine secretion. [ABSTRACT FROM AUTHOR]

Dermatofibrosarcoma protuberans (DFSP) is a locally aggressive intermediate soft tissue neoplasm that occurs in the dermis. DFSP generally occurs in young to middle-aged adults and rarely in infancy. Because of its extreme rarity, DFSP is difficult to diagnose and treat, especially when it occurs in infancy. In this paper, we reported a case of infantile DFSP in which we performed additional wide resection with a 3-cm horizontal margin for a mass that had previously undergone unplanned excision. No tumor recurrence has been seen for 3 years postoperatively. We suggest that the possibility of DFSP should always be considered when an enlarging superficial mass is identified on the trunk, even in an infant. Additionally, radical local treatment is as important for DFSP in infancy as it is for DFSP in adults, even after unplanned excision.

BackgroundEwing sarcoma (EwS) is an aggressive and highly metastatic bone and soft tissue tumor in pediatric patients and young adults. Cure rates are low when patients present with metastatic or relapsed disease. Therefore, innovative therapy approaches are urgently needed. Cellular- and oncolytic virus-based immunotherapies are on the rise for solid cancers.MethodsHere, we assess the combination of EwS tumor-associated antigen CHM1319-specific TCR-transgenic CD8+ T cells and the YB-1-driven (i.e. E1A13S-deleted) oncolytic adenovirus XVir-N-31 in vitro and in a xenograft mouse model for antitumor activity and immunostimulatory properties.ResultsIn vitro both approaches specifically kill EwS cell lines in a synergistic manner over controls. This effect was confirmed in vivo, with increased survival using the combination therapy. Further in vitro analyses of immunogenic cell death and antigen presentation confirmed immunostimulatory properties of virus-infected EwS tumor cells. As dendritic cell maturation was also increased by XVir-N-31, we observed superior proliferation of CHM1319-specific TCR-transgenic CD8+ T cells only in virus-tested conditions, emphasizing the superior immune-activating potential of XVir-N-31.ConclusionOur data prove synergistic antitumor effects in vitro and superior tumor control in a preclinical xenograft setting. Combination strategies of EwS-redirected T cells and YB-1-driven virotherapy are a highly promising immunotherapeutic approach for EwS and warrant further evaluation in a clinical setting.

Oncolytic viruses (OVs) selectively replicate in tumor cells resulting in lysis, spreading of new infectious units and induction of antitumor immune responses through abrogating an immunosuppressive tumor microenvironment (TME). Due to their mode of action, OVs are ideal combination partners with targeted immunotherapies. One highly attractive combination is the inhibition of the ‘don’t-eat-me’-signal CD47, which is known to increase the phagocytic potential of tumor-associated macrophages. In this work, we analyzed the combination approach consisting of the YB-1-based oncolytic adenovirus XVir-N-31 (XVir) and the CD47 inhibitor (CD47i) B6.H12.2 concerning its phagocytic potential. We investigate phagocytosis of XVir-, adenovirus wildtype (AdWT)-, and non-infected established pediatric sarcoma cell lines by different monocytic cells. Phagocytes (immature dendritic cells and macrophages) were derived from THP-1 cells and healthy human donors. Phagocytosis of tumor cells was assessed via FACS analysis in the presence and absence of CD47i. Additional characterization of T cell-stimulatory surface receptors as well as chemo-/cytokine analyses were performed. Furthermore, tumor cells were infected and studied for the surface expression of the ‘eat-me’-signal calreticulin (CALR) and the ‘don’t-eat-me’-signal CD47. We herein demonstrate that (1) XVir-infected tumor cells upregulate both CALR and CD47. XVir induces higher upregulation of CD47 than AdWT. (2) XVir-infection enhances phagocytosis in general and (3) the combination of XVir and CD47i compared to controls showed by far superior enhancement of phagocytosis, tumor cell killing and innate immune activation. In conclusion, the combination of CD47i and XVir causes a significant increase in phagocytosis exceeding the monotherapies considerably accompanied by upregulation of T cell-stimulatory receptor expression and inflammatory chemo/-cytokine secretion.

Low-grade fibromyxoid sarcoma (LGFMS) is a rare malignant fibroblastic tumor, principally affecting the deep tissues of the proximal trunk and extremities in young adults. However, primary pleural LGFMS is extremely rare, and only three cases have been reported in the previous English literature without genetic confirmation. Furthermore, the historical pleural LGFMS cases were all adults, and the primary pleural LGFMS in children has never been reported to date. Here, we presented a primary pleural LGFMS in a 4-year-old boy with detailed clinical, pathological, and molecular results. Histologically, the current tumor showed typical alternating collagenous and myxoid areas, containing spindled or oval tumor cells arranged in a whorled and short fascicular pattern. In some areas, the tumor cells exhibited moderate atypia, and mitotic figures were identified but without the identification of giant collagen rosettes. Immunohistochemically, all the neoplastic cells showed strong and diffuse positivity for MUC4. Genetically, FUS gene rearrangement was revealed by fluorescence in-situ hybridization (FISH), and subsequently, next-generation sequencing (NGS) and polymerase chain reaction (PCR) further demonstrated the FUS::CREB3L2 fusion transcript. To the best of our knowledge, this is the first case of primary pleural LGFMS with the identification of FUS gene rearrangement and FUS::CREB3L2 fusion in a 4-year-old child. Our study expands the age range of pleural LGFMS and highlights the combination of morphological, immunohistochemical, and molecular analyses in such challenging cases.

Phyllodes tumor (PT) is an infrequent type of breast neoplasm, constituting a mere 0.5%-1.5% of the entirety of breast tumors. The malignant phyllodes tumor (MPT) comprises only 15% of all phyllodes tumors, and its transformation into rhabdomyosarcoma (RMS) is exceedingly rare in clinical practice. Given its insensitivity to chemotherapy and radiotherapy, treatment options for MPT patients are limited, leaving complete surgical resection as the only option. Therefore, it is imperative to investigate the effective utilization of the heterogeneous differentiation characteristics of MPT to expand treatment alternatives for these patients. In this case report, we represent a 13-year-old adolescent diagnosed with giant breast MPT with RMS differentiation and pulmonary metastasis. The initial step in the treatment process involved radical surgical resection, followed by the administration of four cycles of VDC/IC chemotherapy, which is widely recognized as the standard chemotherapy for RMS. Regrettably, the delay in initiating chemotherapy resulted in minimal observable changes in the size of the pulmonary metastatic nodule. Additionally, a comprehensive literature review on the characterization of MPT with heterogeneous differentiation was conducted to enhance comprehension of the diagnosis and treatment of this uncommon disease in clinical practice. Meanwhile, this case also reminds the doctors that when we diagnose a patient as MPT, it is crucial to consider its heterogenous nature and promptly initiate adjuvant treatment. By targeting the differentiation element of MPT, it becomes feasible to overcome the previously perceived limitation of surgical intervention as the sole treatment option. [ABSTRACT FROM AUTHOR]

Background. For children with non-rhabdomyosarcoma soft tissue sarcomas, a risk-adapted treatment approach is generally used in order to minimize treatment-related morbidity and mortality in low-risk patients and maximize the benefit in high-risk patients. Our aim in this review is to discuss the prognostic factors, riskadapted treatment options and the details of radiotherapy. Methods. The publications reached by searching the keywords 'pediatric soft tissue sarcoma', 'nonrhabdomyosarcoma soft tissue sarcoma (NRSTS)', and 'radiotherapy' in Pubmed database were evaluated in detail. Results. Today, based on prospective COG-ARST0332 and EpSSG studies, a risk-adapted multimodal treatment approach has become the standard in pediatric NRSTS. According to them, adjuvant chemotherapy/ radiotherapy can be safely omitted in low-risk patients, while adjuvant chemotherapy/radiotherapy or both are recommended in intermediate and high-risk groups. Recent prospective studies for pediatric patients have reported excellent treatment outcomes with smaller radiotherapy fields and lower doses than adult series. The primary goal of surgery is maximal tumor resection with negative margins. In cases that are initially unresectable, neoadjuvant chemotherapy and radiotherapy should be considered. Conclusions. A risk-adapted multimodal treatment approach is the standard in pediatric NRSTS . Surgery alone is sufficient in low-risk patients, and adjuvant therapies may safely be omitted. On the contrary, in intermediateand high-risk patients, adjuvant treatments should be applied to reduce recurrence rates. In unresectable patients, the chance of surgery increases with the neoadjuvant treatment approach and thus treatment results may improve. In the future, outcome might be improved with further clarification of molecular features and targeted therapies in such patients. [ABSTRACT FROM AUTHOR]

Background: Dermatofibrosarcoma protuberans (DFSP) is an uncommon cutaneous tumor in children. Most published articles are sporadic or small series and lack systematically molecular analyses. The aim of our study is to better understand the clinicopathologic and genetic features of these rare lesions. Methods: All patients diagnosed with DFSP aged = 18 years were retrospectively reviewed from January 2006 to May 2022. Results: A total of 66 cases (32 male and 34 female patients) were identified, with ages ranging from 0.3 to 18 years (median, 13 years). Tumor locations predominantly occurred on the trunk (38/66, 57.6%), followed by the extremities (20/66, 30.3%) and head/neck (8/66, 12.1%). Histological findings revealed classic (41/66, 62.1%), myxoid (4/66, 6.1%), pigmented (6/66, 9.1%), plaque-like (3/66, 4.5%), giant cell fibroblastoma (GCF; 6/66, 9.1%), and fibrosarcomatous (6/66, 9.1%) variants of DFSP. Immunochemistry revealed minority tumors (9/66, 13.6%) showing patchy or negative staining for CD34. Fluorescence in situ hybridization (FISH) indicated that 49 of 53 tested cases including all detected biopsy specimens (11/11) contained COL1A1-PDGFB fusion, in which the average copy number gain of COL1A1-PDGFB was 0.68. There were four cases negative for COL1A1-PDGFB rearrangement, one of which was found to harbor a novel COL3A1-PDGFB fusion by next-generation sequencing (NGS). Treatment for 63 patients comprised 40 marginal excisions and 23 wide local excisions (WLEs), including 1 with imatinib therapy. Follow-up information was available on 49 patients with a duration of 12-161 months (median, 60 months). Fourteen patients developed tumor recurrence, all with initial marginal excisions. The others survived with no evidence of disease. Conclusions: This study of pediatric DFSP indicates certain discrepancies in clinicopathologic characteristics between children and adults. The majority of pediatric DFSPs contain COL1A1-PDGFB fusion, the same as their adult counterparts. The COL3A1-PDGFB chimerism might be associated with the special morphology of GCF, which needs further investigation. FISH is valuable in biopsy tissues and cases with atypical CD34 immunostaining, while supplementary NGS could be helpful to identify the cytogenetically cryptic DFSP. Overall, an urgent accurate diagnosis is needed to formulate an optimal therapeutic strategy in the pediatric population. [ABSTRACT FROM AUTHOR]

In children and adolescents, most sarcoma subtypes have a simple karyotype with a single genetic alteration; cytologic findings combined with ancillary testing can lead to a specific diagnosis. The goal of this study was to review the use of fine-needle aspiration in conjunction with immunohistochemistry and molecular studies as a part of an integrated, multidisciplinary diagnostic workup for bone and soft tissue sarcomas in this population. We searched for cases aged ≤18 years old with a malignant bone or soft tissue tumor that had corresponding cytology specimens from 3 institutions. Clinical data, cytologic findings and diagnoses, histologic diagnoses, and ancillary testing were documented. Of 99 cases, 55% were male with a mean age of 12 years. Ninety-four cases (95%) had a specific histologic diagnosis, and 84 cases (85%) were primary neoplasms. Ninety-four cases (95%) had a malignant cytologic diagnosis, and 71 cases (72%) had a specific cytologic diagnosis concordant with the histologic diagnosis. Among primary tumors with a specific histologic diagnosis, a specific cytologic diagnosis was made in 63 cases (79%). After excluding osteosarcoma, 74% of the tumors (n = 50) had molecular studies. Specific genetic alterations supporting a definitive diagnosis were found in 42 cases (84%), the majority of which were demonstrated using Fluorescence In Situ Hybridization (n = 33, 79%). We found that fine-needle aspiration in conjunction with core needle biopsy, immunohistochemistry, and molecular studies allowed cytopathologists to accurately classify sarcomas in a pediatric age group. • Fine-needle aspiration in conjunction with immunohistochemistry and molecular studies as a part of an integrated, multidisciplinary diagnostic workup for bone and soft tissue sarcoma allows cytopathologists to accurately classify sarcomas in a pediatric age group. • Making a diagnosis of conventional osteosarcoma from fine-needle aspiration in this age group is usually straightforward, especially with characteristic radiologic appearance; aspirates frequently contain malignant cells with overt pleomorphism, which limit diagnostic considerations, particularly in the presence of osteoid. • A pattern-based approach is often helpful in guiding differential diagnosis and determining appropriate ancillary testing in soft tissue tumors; most pediatric sarcomas fall into 1 of the 3 patterns: round cell, epithelioid, and spindle cell. [ABSTRACT FROM AUTHOR]

Dermatofibrosarcoma protuberans (DFSP) is a locally aggressive intermediate soft tissue neoplasm that occurs in the dermis. DFSP generally occurs in young to middle-aged adults and rarely in infancy. Because of its extreme rarity, DFSP is difficult to diagnose and treat, especially when it occurs in infancy. In this paper, we reported a case of infantile DFSP in which we performed additional wide resection with a 3-cm horizontal margin for a mass that had previously undergone unplanned excision. No tumor recurrence has been seen for 3 years postoperatively. We suggest that the possibility of DFSP should always be considered when an enlarging superficial mass is identified on the trunk, even in an infant. Additionally, radical local treatment is as important for DFSP in infancy as it is for DFSP in adults, even after unplanned excision. [ABSTRACT FROM AUTHOR]

BackgroundPrognosis of children with primary disseminated or metastatic relapsed sarcomas remains dismal despite intensification of conventional therapies including high-dose chemotherapy. Since haploidentical hematopoietic stem cell transplantation (haplo-HSCT) is effective in the treatment of hematological malignancies by mediating a graft versus leukemia effect, we evaluated this approach in pediatric sarcomas as well.MethodsPatients with bone Ewing sarcoma or soft tissue sarcoma who received haplo-HSCT as part of clinical trials using CD3+ or TCRα/β+ and CD19+ depletion respectively were evaluated regarding feasibility of treatment and survival.ResultsWe identified 15 patients with primary disseminated disease and 14 with metastatic relapse who were transplanted from a haploidentical donor to improve prognosis. Three-year event-free survival (EFS) was 18,1% and predominantly determined by disease relapse. Survival depended on response to pre-transplant therapy (3y-EFS of patients in complete or very good partial response: 36,4%). However, no patient with metastatic relapse could be rescued.ConclusionHaplo-HSCT for consolidation after conventional therapy seems to be of interest for some, but not for the majority of patients with high-risk pediatric sarcomas. Evaluation of its future use as basis for subsequent humoral or cellular immunotherapies is necessary.

Abstract Background Pediatric sarcomas are divided into two major groups of soft‐tissue sarcomas (STSs) and malignant bone tumors (MBTs). Aims The aim of the present study was to determine the incidence and survival rate of STSs and MBTs in the Iranian population based on diagnosis date, gender, age, and histological types. Methods and Results Data was retrieved from Iran National Cancer Registry between 2008 and 2015. The dataset was classified according to the third edition of the International Classification of Childhood Cancer. The survival information was merely available for 291 (21% of total data), including 142 (49%) MBTs and 149 (51%) STSs. The age‐standardized incidence rates (ASIRs) and five‐year survival rates were calculated. Conclusion The present study is the first comprehensive study of pediatric sarcomas in Iran, in which a lower incidence and survival rate of MBTs and STSs compared with high‐income countries were found. However, the survival rates of these malignancies were higher in high‐income countries compared to Iran. This study showed the need to improve the quantity and quality of the population‐based registry in Iran for acquiring progress in the prevention and control of sarcomas.

Survivors of pediatric sarcomas often experience greater psychological and psychosocial difficulties than their non-afflicted peers. We consider findings related to poorer outcomes from a developmental cascade perspective. Specifically, we discuss how physical, neurocognitive, psychological, and psychosocial costs associated with pediatric sarcomas and their treatment function transactionally to degrade well-being in long-term pediatric sarcoma survivors. We situate the sarcoma experience as a broad developmental threat – one stemming from both the presence and treatment of a life-imperiling disease, and the absence of typical childhood experiences. Ways in which degradation in one developmental domain spills over and effects other domains are highlighted. We argue that the aggregate effect of these cascades is two-fold: first, it adds to the typical stress involved in meeting developmental milestones and navigating developmental transitions; and second, it deprives survivors of crucial coping strategies that mitigate these stressors. This position suggests specific moments of intervention and raises specific hypotheses for investigators to explore. [ABSTRACT FROM AUTHOR]

BackgroundMultimodal risk-adapted treatment is used in paediatric protocols for synovial sarcoma (SS). Retrospective analyses suggest that low-risk SS patients can be safely treated with surgery alone, but no prospective studies have confirmed the safety of this approach. This analysis pooled data from the two prospective clinical trials to assess outcomes in SS patients treated with a surgery-only approach and to identify predictors of treatment failure.MethodsPatients with localised SS enrolled on the European paediatric Soft tissue sarcoma Study Group (EpSSG) NRSTS2005 and on the Children Oncology Group (COG) ARST0332 trials, treated with surgery alone were eligible for this analysis. Patients must have undergone initial complete resection with histologically free margins, with a grade 2 tumour of any size or a grade 3 tumour ≤5 cm.ResultsSixty patients under 21 years of age were eligible for the analysis; 36 enrolled in the COG (from 2007 to 2012) and 24 in the EpSSG study (from 2005 to 2012). The 3-year event-free survival was 90% (median follow-up 5.2 years, range 1.9-9.1). All eight events were local tumour recurrence, whereas no metastatic recurrences were seen. All patients with recurrence were effectively salvaged, resulting in 100% overall survival.ConclusionThis joint prospective analysis showed that patients with adequately resected ≤5 cm SS, regardless of grade, can be safely treated with a surgery-only approach. Avoiding the use of adjuvant chemotherapy and radiotherapy in this low-risk patient population may decrease both short- and long-term morbidity and mortality.

A 5-year-old male child was diagnosed with interdigitating dendritic cell sarcoma (IDCS) during his maintenance therapy for B-cell precursor acute lymphoblastic leukemia (B-ALL). Multiplex lymph node involvements of the neck were found by positron emission tomography CT (PET-CT). Treatments, including surgical and chemotherapy, resulted in complete remission. Four years later, systemic bone infiltration was discovered. Surgical resection of the IV rib and intensive chemotherapy led to a complete morphological remission, and allogeneic bone marrow transplantation was performed. Comprehensive genomic profiling of the formalin fixed the tumor tissue, and the cryopreserved leukemic cells revealed several common alterations and divergent clonal evolution with a novel MAP2K1 mutation of the IDCS, which is responsible for the trans-differentiation of the common lymphoid-committed tumor progenitor.

Chest wall reconstruction in children continues to be a challenging undertaking, aiming to restore both form and function. An optimal chest wall reconstruction material has not been identified that would provide dynamic chest function and would ideally avoid potential long-term sequelae. A 15-year-old female with Li Fraumeni syndrome and a history of hepatic rhabdomyosarcoma presented with increasing left back and left scapular pain initially attributed to her known scoliosis. Computed tomography revealed a 12 x 6 × 7 cm mass encasing ribs 3–5 extending into the left chest wall and axilla. Image-guided biopsy confirmed a high-grade osteosarcoma without extra-thoracic metastatic disease. She underwent neoadjuvant chemotherapy after which a three-dimensional (3D) anatomic model of the tumor was printed using the post-therapy imaging reconstruction. The surgical team collaborated with Osteobionix (Osteobionics S.L., Santa Lucia de Tirajana, Spain) to create a patient-specific dynamic chest wall reconstruction implant, based on 3D modeling of the planned resection zone. The final implant was 3D printed with a titanium alloy using electron-beam manufacturing technology, sterilized prior to implantation. She underwent left thoracotomy and rib resection with prosthesis fixation to the T3, T4, and T5 vertebral bodies posteriorly and to the sternum anteriorly. More than2 years after the operation, she is doing well without evidence of recurrent disease. She has an excellent cosmetic result, there has been no progression of her scoliosis, and she has returned to competitive sports. Our titanium-based 3D-printed, patient-specific implant seems to be a valuable option for the reconstruction of the chest wall in children who require an extensive chest wall resection. [ABSTRACT FROM AUTHOR]

Sarcomas are a rare subgroup of pediatric cancers comprised of a variety of bone and soft-tissue tumors. While significant advances have been made in improving outcomes of patients with localized pediatric sarcomas since the addition of systemic chemotherapy to local control many decades ago, outcomes for patients with metastatic and relapsed sarcoma remain poor with few novel therapeutics identified to date. With the advent of new technologies to study cancer genomes, transcriptomes and epigenomes, our understanding of sarcoma biology has improved tremendously in a relatively short period of time. However, much remains to be accomplished in this arena especially with regard to translating all of this new knowledge to the bedside. To this end, a meeting was convened in Philadelphia, PA, on April 18, 2015 sponsored by the QuadW foundation, Children's Oncology Group and CureSearch for Children's Cancer that brought together sarcoma clinicians and scientists from North America to review the current state of pediatric sarcoma biology and ongoing/planned genomics based clinical trials in an effort to identify and bridge knowledge gaps that continue to exist at present. At the conclusion of the workshop, three key objectives that would significantly further our understanding of sarcoma were identified and a proposal was put forward to develop an all-encompassing pediatric sarcoma biology protocol that would address these specific needs. This review summarizes the proceedings of the workshop.

Simple Summary: There has been an incredible amount of discovery in pediatric sarcomas, but much remains to be accomplished. Clinical challenges include diagnostic heterogeneity and the poor outcome of patients with high risk, metastatic, and relapsed disease. The emergence of single cell sequencing has allowed the ability to document tumor cell heterogeneity in amazing detail, but it does not allow the ability to visualize spatial orientation. This problem has been solved by spatial multi-omics, which can be used to map tumors and visualize the distribution of critical transcripts, mutations, and proteins. However, these tools only offer observational data. High-throughput functional genomics provides a powerful way to highlight oncogenic drivers and potential therapy opportunities. Research has been hamstrung by a need for annotated specimens, particularly in post-therapy, relapsed, and metastatic disease, and initial biopsies offer only limited data opportunities. Data complexity, variability, and inconsistency present problems best approached with AI/machine learning. We stand on the threshold of a revolution in cancer cell biology that has the potential for translation into more effective and more directed therapies, particularly for previously recalcitrant diseases. Pediatric sarcomas constitute one of the largest groups of childhood cancers, following hematopoietic, neural, and renal lesions. Partly because of their diversity, they continue to offer challenges in diagnosis and treatment. In spite of the diagnostic, nosologic, and therapeutic gains made with genetic technology, newer means for investigation are needed. This article reviews emerging technology being used to study human neoplasia and how these methods might be applicable to pediatric sarcomas. Methods reviewed include single cell RNA sequencing (scRNAseq), spatial multi-omics, high-throughput functional genomics, and clustered regularly interspersed short palindromic sequence-Cas9 (CRISPR-Cas9) technology. In spite of these advances, the field continues to be challenged by a dearth of properly annotated materials, particularly from recurrences and metastases and pre- and post-treatment samples. [ABSTRACT FROM AUTHOR]

Abstract Background Metastasectomy is performed on a select cohort of patients with advanced and/or recurrent bone and soft tissue sarcomas because of the potential for long term relapse free and overall survival associated with the procedure. However, the evidence supporting metastasectomy is difficult to summarize without a systematic examination of existing literature. The objective of this systematic review will be to examine survival among both adults and children with advanced and recurrent bone and STS who undergo metastasectomy. Methods We designed and registered a study protocol for a systematic review and meta-analysis. We will include data from survival studies (e.g., randomized trials, cohort studies, routine case registries, and case control) conducted in children and adults with advanced and recurrent bone and soft tissue sarcoma who undergo metastasectomy. The primary outcome will be overall survival. Secondary outcomes will be 30-day post-operative mortality, recurrence-free survival, time off systemic therapy, and patient-reported outcomes including quality of life end points where available. Literature searches will be performed in multiple electronic databases including Ovid MEDLINE ® (1946 to present), Ovid EMBASE (1974 to present), Web of Science, and Cochrane Library. Grey literature will be identified through searching references, conference abstracts, Papers First, and Google Scholar. Two investigators will independently screen all citations, full-text articles, and abstract data. Full-text articles selected for analysis will be assessed for quality and risk of bias. If feasible, we will conduct a random effects meta-analysis. Estimates will be stratified according to histology comparing survival based on organ of metastasectomy. Additional analysis will be conducted to explore the potential sources of heterogeneity according to various patient, disease, and treatment characteristics (e.g., metastasis status, age, disease burden, and concomitant interventions). Discussion This systematic review and meta-analysis will identify, evaluate, and integrate data on survival of metastasectomy of bone and soft tissue sarcoma by organ of metastasis. Our findings may have implications for clinicians, patients, and their families when considering selection for resection of oligometastatic disease in de novo, or recurrent bone and soft tissue sarcoma. Implications for future research will be identified to improve the outcomes of these complex patients. Systematic review registration PROSPERO CRD42019126906

Purpose: To report a rare case of primary orbital pleomorphic liposarcoma and present a relevant literature review. Observations: An 11-year-old boy presented with an enlarging, painless lower right eyelid mass that was noted 4 months ago. Imaging revealed a 3.2 × 2.1 × 3.7-cm-sized well-circumscribed lobulated mass. Biopsy revealed a pleomorphic spindle cell neoplasm that was consistent with a pleomorphic liposarcoma. A systemic evaluation found no evidence of distant metastasis. Despite four chemotherapy cycles, the mass size increased at follow-up. Total orbital exenteration was performed 1 year after confirming a diagnosis of pleomorphic liposarcoma. At the 6-month follow-up, the patient was alive with no signs of recurrence. Conclusions: Pediatric pleomorphic liposarcoma is a very rare entity. Its definite diagnosis relies on histopathological results. In the absence of systemic metastasis, total orbital exenteration is the optimal approach for local control.

Pediatric sarcomas are rare entities. Bone sarcomas and rhabdomyosarcoma are most common, whereas primary sarcoma of the lung is extremely uncommon. Pneumonectomy is only very infrequently performed in the pediatric population. We report on a 16-year-old girl with an undifferentiated high-grade pleomorphic sarcoma of the left lung. There was no comorbidity and no history of previous malignant disease. The huge tumor originated from the left lower lobe and had spread to the left pleura. As part of a multimodal approach, she underwent extrapleural pneumonectomy with en bloc resection of the pleura, lung, pericardium, and diaphragm.

Background: The benefit of adjuvant therapy in synovial sarcoma (SS) treatment is under debate. Long-term follow-up data are missing. Methods: SS patients treated in the consecutive trials CWS-81, CWS-86, CWS-91, CWS-96, CWS-2002-P, and the SoTiSaR-registry till 2013 were analyzed. Results: Median age of 185 patients was 13.9 years (0.1–56)—with median follow-up of 7.4 years for 163 survivors. Most tumors (76%) were located in extremities. Size was < 3 cm in 58 (31%), 3–5 cm in 59 (32%), 5–10 cm in 42 (23%), and > 10 cm in 13 (7%) (13 missing). In 84 (45%) tumors, first excision was complete (R0 corresponding to IRS-I-group) and in 101 (55%) marginal (R1 corresponding to IRS-II-group). In a subsequent surgical intervention during chemotherapy, R0-status was accomplished in 23 additional IRS-II-group patients with secondary surgery. Radiotherapy was administered to 135 (73%), thereof 62 with R0-status and 67 R1-status (6 missing information). Adjuvant chemotherapy was administered to all but six patients. 5-year event-free (EFS) and overall survival (OS) was 82.9% ± 5.7 (95%CI) and 92.5% ± 3.9. Local and metastatic relapse-free survival was 91.3% ± 4.3 and 92.3% ± 4.1 at 5 years, respectively. In the multivariate analysis, tumor size and no chemotherapy were independently associated with EFS. Size and site were associated with OS. In a detailed analysis of local and metastatic events, tumor size was associated with an independent risk for developing metastases. No independent factor for suffering local recurrence could be identified. Discussion: Omission of chemotherapy in a non-stratified way seems not justified. Size governs survival due to high linear association with risk of suffering metastatic recurrence in a granular classification. [ABSTRACT FROM AUTHOR]

Pediatric sarcomas are the most common malignancies of bones in childhood. With advances in adjuvant treatment, limb salvage surgery has become common, increasing the demand of skeletal reconstruction. Traditional practice included bone grafting and transport. Recently, microsurgical tissue transfer in pediatric patients has become a well-accepted practice, with the fibula as an ideal biologic construct for long bone reconstruction. We aim to assess the success rate of this operation, including flap survival, bony union, weight-bearing ambulation, and complications. We identified 10 pediatric patients who underwent reconstruction of long bones (femur, humerus, or tibia) with a free fibula flap from January 2015 to January 2020. All patients received neoadjuvant chemotherapy 4 weeks prior to the surgical procedure followed by adjuvant chemotherapy. The average follow-up time was 15 months. We had no partial or total flap loss. Three of our patients passed away in the first post-operative year due to metastatic disease. In the remaining 7 patients, we had two long-term complications. The fibula of one patient did not exhibit hypertrophy, yet weight-bearing ambulation was achieved. The other patient had nonunion proximally that required bone grafting at 8 months post-operatively. After that, the same patient fractured her fibula and required surgical fixation. She was eventually able to achieve weight-bearing ambulation. The vascularized fibula flap is a reliable tool for reconstruction in children. Flap survival is similar to that of adults. Complication rate is low compared to that for other forms of reconstruction. [ABSTRACT FROM AUTHOR]

The incidence of pediatric liposarcoma is rare and most published cases lack systematic genetic analyses. We present clinicopathologic and genetic features of 23 liposarcomas aged <22 years. The study cohort comprised 10 males and 13 females (M:F=1:1.3) aged 11–21 years (median 17 years). The tumors predominantly occurred at the extremities (16/23; 69.6%), followed by the head/neck (2/23; 8.7%), chest (2/23; 8.7%), waist (2/23, 8.7%), and retroperitoneum (1/23; 4.3%). The tumor subtypes were sixteen myxoid liposarcoma (ML), one well-differentiated liposarcoma (WDL), two dedifferentiated liposarcoma (DDL), one pleomorphic liposarcoma (PL), and three myxoid pleomorphic liposarcoma (MPL) cases. Fluorescence in situ hybridization analysis identified MDM2/CDK4 amplification in all WDL/DDL cases (3/3; 100%) and DDIT3 rearrangement in all ML cases (13/13; 100%). Whole-exome sequencing indicated that one PL case and one MPL case exhibited RB1 loss. The two tested MPL cases had TP53 mutation and one of them harbored a TP53 germline mutation. Follow-up information was available for 20 patients (20/23; 87.0%) with a median follow-up duration of 42.5 months (range, 13–120 months). Three patients exhibited tumor progression (3/20;15.0%). Seventeen patients (17/20; 85.0%) survived with no evidence of disease. One MPL case (1/20; 5.0%) died of the disease. In conclusion, despite some overlaps, the occurrence, distribution of subtype, and prognosis of liposarcoma are overall different in children and adults. Most MLs and ALT/WDL/DDLs showed similar genetic aberrations with adult counterparts. Molecular features of MPL overlapped with those of conventional PL. The genetic characteristics including Tp53 status of MPL need further investigation. [ABSTRACT FROM AUTHOR]

Abstract Background In pediatric sarcomas, outcomes of established therapies still remain poor, especially due to high-grade resistances to chemotherapeutic compounds. Taking novel biological approaches into account, virotherapy was found to be efficient in many pediatric sarcoma types. Also NK cell therapy was denoted to represent a promising upcoming strategy for pediatric sarcoma patients. We here investigated a combinatorial approach employing oncolytic measles vaccine virotherapeutics (MeV) together with activated human NK cells (or PBMCs). Methods The human sarcoma cell lines A673 and HT1080 were used to evaluate the efficacy of this combinatorial treatment modality. Oncolysis was determined by measuring real-time cell proliferation using the xCELLigence RTCA SP system. Furthermore, expression of receptors on NK cells and the respective ligands on A673 cells was analyzed by flow cytometry. To measure the protein release of activated NK cells a LEGENDplex™ assay was performed. Results Monotherapy with MeV led to a time- and dose-dependent oncolytic reduction of A673 and HT1080 sarcoma tumor cell masses. Concurrently, such MeV infections did not change the expression of NK cell ligands MICA/B, ULBP1, 2, and 3, CD112, and CD155. As shown by real-time proliferation assays, infections of A673 and HT1080 sarcoma cells with MeV followed by co-culture with activated NK cells or PBMCs led to enhanced sarcoma cell destruction when compared to the respective monotherapies. In parallel, this dual therapy resulted in an increased release of granzymes, perforin, and granulysin from NK cells. In contrast, expression of activation and ontogenesis receptors on NK cells was not found to be altered after co-culture with MeV-infected A673 sarcoma cells. Conclusions Taken together, the combined treatment strategy comprising oncolytic MeV and activated NK cells resulted in enhanced oncolysis of A673 and HT1080 cells when compared to the respective monotherapies. In parallel, we observed an increased release of NK cell activation markers upon co-culture with MeV-infected A673 human sarcoma cells. These results support the onset of clinical trials combining oncolytic virotherapy with NK cell based immunotherapies.

Abstract While promising, immunotherapy has yet to be fully unlocked for the preponderance of cancers where conventional chemoradiation reigns. This remains particularly evident in pediatric sarcomas where standard of care has not appreciably changed in decades. Importantly, pediatric bone sarcomas, like osteosarcoma and Ewing’s sarcoma, possess unique tumor microenvironments driven by distinct molecular features, as do rhabdomyosarcomas and soft tissue sarcomas. A better understanding of each malignancy’s biology, heterogeneity, and tumor microenvironment may lend new insights toward immunotherapeutic targets in novel platform technologies for cancer vaccines and adoptive cellular therapy. These advances may pave the way toward new treatments requisite for pediatric sarcomas and patients in need of new therapies.

Purpose of Review: Osteosarcoma (OSA) is the most common primary tumor of bone, mainly affecting children and adolescents. Here we discuss recent advances in surgical and systemic therapies, and highlight potentially new modalities in preclinical evaluation and prognostication. Recent Findings: The advent of neoadjuvant and adjuvant chemotherapy has markedly improved the disease-free recurrence and overall survival of OSA. However, treatment efficacy has been stagnant since the 1980s. This plateau has prompted preclinical and clinical research into in precision surgery, inhaled chemotherapy to increase pulmonary drug concentration without systemic side effects, and novel immunomodulators intended to block molecular pathways associated with OSA proliferation and metastasis. Summary: With the advent of novel surgical techniques and new forms and vectors for chemotherapy, it is hoped that OSA treatment outcomes will exceed their currently sustained plateau in the near future. [ABSTRACT FROM AUTHOR]

Purpose: To assess the relationship between apparent diffusion coefficients (ADC) and standard uptake values (SUV) of pediatric sarcomas at staging by using volumetric histograms analyses. Methods: Children with histologically proven sarcoma, referring to our tertiary center for a whole-body 18F-FDG PET/MRI for staging and including diffusion weighted imaging in the MRI protocol were investigated. Firstly, turbo inversion recovery magnitude (TIRM) and PET images were resliced and resampled according to the ADC maps. Regions of interests were drawn along tumor margins on TIRM images and then copied on PET and ADC datasets. Pixel-based SUVs and ADCs were collected from the entire volume of each lesion. Mean, median, skewness, and kurtosis of SUVs and ADCs values were computed, and the Pearson correlation coefficient was then applied (for the entire population and for histological subgroups with more than five patients). Results: Thirteen patients met the inclusion criteria (six females; mean age 8.31 ± 6.03 years). Histology revealed nine rhabdomyosarcomas, three Ewing sarcomas, and one chondroblastic osteosarcoma. A significant negative correlation between ADCs' and SUVs' mean (rmean = − 0.501, P < 0.001), median (rmedian = − 0.519, P < 0,001), and skewness (rskewness = − 0.550, P < 0.001) emerged for the entire population and for rhabdomyosarcomas (rmean = − 0.541, P = 0.001, rmedian = − 0.597, P < 0.001, rskewness = − 0.568, P < 0.001), whereas a significant positive correlation was found for kurtosis (rkurtosis = 0.346, P < 0.001, and rkurtosis = 0.348, P < 0.001 for the entire population and for rhabdomyosarcomas, respectively). Conclusion: Our preliminary results demonstrate that, using volumetric histograms, simultaneously collected SUVs and ADCs are dependent biomarkers in pediatric FDG-avid sarcomas. Further studies, on a larger population, are necessary to confirm this evidence and assess its clinical implications. [ABSTRACT FROM AUTHOR]

Abstract This case report demonstrates the possibility of sarcoma biopsy needle track seeding from FNA/Core Needle Biopsy during the workup of a pediatric head and neck mass. Though not currently widely practiced in head and neck tumors, surgeons may consider placing biopsy tracks in the area of planned resection for suspected head and neck malignancies as is more common in approaches to extremity sarcoma.

This case report demonstrates the possibility of sarcoma biopsy needle track seeding from FNA/Core Needle Biopsy during the workup of a pediatric head and neck mass. Though not currently widely practiced in head and neck tumors, surgeons may consider placing biopsy tracks in the area of planned resection for suspected head and neck malignancies as is more common in approaches to extremity sarcoma. [ABSTRACT FROM AUTHOR]

For many pediatric sarcoma patients, multi-modal therapy including chemotherapy, radiation, and surgery is sufficient to cure their disease. However, event-free and overall survival rates for patients with more advanced disease are grim, necessitating the development of novel therapeutic approaches. Within many pediatric sarcomas, the normal immune response, including recognition and destruction of cancer cells, is lost due to the highly immune suppressive tumor microenvironment (TME). In this setting, tumor cells evade immune detection and capitalize on the immune suppressed microenvironment, leading to unchecked proliferation and metastasis. Recent preclinical and clinical approaches are aimed at understanding this immune suppressive microenvironment and employing cancer immunotherapy in an attempt to overcome this, by renewing the ability of the immune system to recognize and destroy cancer cells. While there are several factors that drive the attenuation of immune responses in the sarcoma TME, one of the most remarkable are tumor associated macrophage (TAMs). TAMs suppress immune cytolytic function, promote tumor growth and metastases, and are generally associated with a poor prognosis in most pediatric sarcoma subtypes. In this review, we summarize the mechanisms underlying TAM-facilitated immune evasion and tumorigenesis and discuss the potential therapeutic application of TAM-focused drugs in the treatment of pediatric sarcomas.

Cyclin-Dependent Kinases (CDKs) are well-known reliable targets for cancer treatment being often deregulated. Among them, since the transcription-associated CDK9 represents the sentry of cell transcriptional homeostasis, it can be a valuable target for managing cancers in which the transcriptional machinery is dysregulated by tumor-driver oncogenes. Here we give an overview of some natural compounds identified as CDK inhibitors with reported activity also against CDK9, that were taken as a model for the development of highly active synthetic anti-CDK9 agents. After, we summarize the data on CDK9 inhibition in a group of rare pediatric solid tumors such as rhabdomyosarcoma, Ewing’s sarcoma, synovial sarcoma and malignant rhabdoid tumors (soft tissue sarcomas), highlighting the more recent results in this field. Finally, we discuss the perspective and challenge of CDK9 modulation in cancer.

For many pediatric sarcoma patients, multi-modal therapy including chemotherapy, radiation, and surgery is sufficient to cure their disease. However, event-free and overall survival rates for patients with more advanced disease are grim, necessitating the development of novel therapeutic approaches. Within many pediatric sarcomas, the normal immune response, including recognition and destruction of cancer cells, is lost due to the highly immune suppressive tumor microenvironment (TME). In this setting, tumor cells evade immune detection and capitalize on the immune suppressed microenvironment, leading to unchecked proliferation and metastasis. Recent preclinical and clinical approaches are aimed at understanding this immune suppressive microenvironment and employing cancer immunotherapy in an attempt to overcome this, by renewing the ability of the immune system to recognize and destroy cancer cells. While there are several factors that drive the attenuation of immune responses in the sarcoma TME, one of the most remarkable are tumor associated macrophage (TAMs). TAMs suppress immune cytolytic function, promote tumor growth and metastases, and are generally associated with a poor prognosis in most pediatric sarcoma subtypes. In this review, we summarize the mechanisms underlying TAM-facilitated immune evasion and tumorigenesis and discuss the potential therapeutic application of TAM-focused drugs in the treatment of pediatric sarcomas. [ABSTRACT FROM AUTHOR]

Background and purpose: Radiotherapy (RT) is persistently gaining significance in the treatment of pediatric tumors. However, individual features of a growing body and multifocal stages complicate this approach. Tomotherapy offers advantages in the treatment of anatomically complex tumors with low risks of side effects. Here we report on toxicity incidence and outcome of tomotherapy with a focus on multitarget RT (mtRT). Materials and methods: From 2008 to 2017, 38 children diagnosed with sarcoma were treated with tomotherapy. The median age was 15 years (6–19 years). Toxicity was graded according to the Common Terminology Criteria for Adverse Events v.4.03 and classified into symptoms during RT, acutely (0–6 months) and late (>6 months) after RT, and long-term sideeffects (>24 months). Results: The main histologies were Ewing sarcoma (n = 23 [61%]) and alveolar rhabdomyosarcoma (n = 5 [13%]). RT was performed with a median total dose of 54 Gy (40.5–66.0 Gy) and a single dose of 2 Gy (1.80–2.27 Gy). Twenty patients (53%) received mtRT. Median follow-up was 29.7 months (95% confidence interval 15.3–48.2 months) with a 5-year survival of 55.2% (±9.5%). The 5‑year survival rate of patients with mtRT (n = 20) was 37.1 ± 13.2%, while patients who received single-target RT (n = 18) had a 5-year survival rate of 75 ± 10.8%. Severe toxicities (grade 3 and 4) emerged in 14 patients (70%) with mtRT and 7 patients (39%) with single-target RT. Two non-hematological grade 4 toxicities occurred during RT: one mucositis and one radiodermatitis. After mtRT 5 patients had grade 3 toxicities acute and after single-target RT 4 patients. One patient had acute non-hematological grade 4 toxicities (gastritis, pericarditis, and pericardial effusion) after mtRT. Severe late effects of RT occurred in 2 patients after mtRT and in none of the single-target RT patients. No severe long-term side effects appeared. Conclusion: Our results showed acceptable levels of acute and late toxicities, considering the highly advanced diseases and multimodal treatment. Hence, tomotherapy is a feasible treatment method for young patients with anatomically complex tumors or multiple targets. Especially mtRT is a promising and innovative treatment approach for pediatric sarcomas, delivering unexpectedly high survival rates for patients with multifocal Ewing sarcomas in this study, whereby the limited number of patients should invariably be considered in the interpretation. [ABSTRACT FROM AUTHOR]

Primary superficial Ewing sarcoma (psES) cases are exceedingly rare, with fewer than 150 cases reported in the literature. Small case series have suggested differences between psES and Ewing sarcoma (ES) of bone or deep soft tissues: psES appears to have a more indolent course and a higher 5‐year overall survival rate. PsES is more common in older adolescent females as opposed to younger males in their peak growth velocity years in bone or deep soft tissue ES. We present a case report of a 17‐year‐old female with a relatively static nodule on her left thigh for 4 years. Morphologic, immunohistochemical, and molecular evaluations confirmed ES. Patient underwent a gross‐total resection and a shortened course of adjuvant chemotherapy without radiation. Cancer gene panel testing found three gene abnormalities (in addition to EWSR1‐FLI1 fusion): CCND1 copy number gain, ELF3 copy number loss, and TNFRSF14 copy number loss. To our knowledge, this is the first published case report of psES to include genomic sequencing and the first to report ELF3 and TNFRSF14 abnormalities in ES. Larger series of psES cases with genomic profiling are needed to elucidate a possible genetic etiology for its more indolent clinical course and favorable outcomes. [ABSTRACT FROM AUTHOR]

Cyclin-Dependent Kinases (CDKs) are well-known reliable targets for cancer treatment being often deregulated. Among them, since the transcription-associated CDK9 represents the sentry of cell transcriptional homeostasis, it can be a valuable target for managing cancers in which the transcriptional machinery is dysregulated by tumor-driver oncogenes. Here we give an overview of some natural compounds identified as CDK inhibitors with reported activity also against CDK9, that were taken as a model for the development of highly active synthetic anti-CDK9 agents. After, we summarize the data on CDK9 inhibition in a group of rare pediatric solid tumors such as rhabdomyosarcoma, Ewing's sarcoma, synovial sarcoma and malignant rhabdoid tumors (soft tissue sarcomas), highlighting the more recent results in this field. Finally, we discuss the perspective and challenge of CDK9 modulation in cancer. [ABSTRACT FROM AUTHOR]

Aim: Scarce data assessing the real value of whole lung irradiation (WLI) in Ewing's sarcoma (ES) with lung-only metastasis, with published conflicting results. We studied the impact of WLI in a homogenous pediatric population. Materials & methods: Retrospective study evaluating the survival outcomes of WLI in these patients. Results: Out of 163 metastatic ES; 41 patients were eligible for WLI. 30 patients (73.1%) received WLI (+ve) while 11 patients (26.8%) did not receive WLI (-ve). Five-year event-free survival was statistically significant in WLI (+ve). Five-year pulmonary relapse-free survival showed trend for improvement with WLI (+ve), while 5-year overall survival was not statistically significant between the two arms. Conclusion: WLI added significantly to the long term clinical outcome of metastatic ES patients, with no irreversible toxicity. [ABSTRACT FROM AUTHOR]

Background: Older age is associated with worse outcome in synovial sarcoma (SS) patients. Differences in disease presentation among distinct age groups, however, are currently unknown. Methods: SS patients < 21 years registered in consecutive CWS trials over the period of 1981–2018 were evaluated. Characteristics were analyzed according to age groups using the Fisher's exact test. Results: The study population included 432 SS patients. Disease characteristics differed according to age groups of children (0–12 years, n = 176), adolescents (13–16 years, n = 178), and young adults (17–21 years, n = 78). The proportion of invasive tumors (T2) was significantly higher in older patients: children 33%, adolescents 39% and young adults 54%, p = 0.009805. Similarly, the proportion of tumors > 10 cm was higher (13%, 21%, 31%; p = 0.005657) whereas conversely, the proportion of small tumors < 3 cm was lower in older patients (29%, 24%, 6%; p = 0.000104). The presence of metastases at first diagnosis was also highest in older patients (6%, 10%, 21%, p = 0.000963). Notably, the proportion of thigh tumors was higher in older patients (p = 0.04173), whereas the proportion of head–neck tumors was lower in older patients (p = 0.08896). Conclusions: The rates of large, invasive tumors and the presence of metastases are significantly associated with older patient age. Localization to the thigh is more frequent in older patients. Discussion: The causes for these variations require further exploration. [ABSTRACT FROM AUTHOR]

Monocyte-derived dendritic cell (DC)-based vaccines loaded with tumor self-antigens represent a novel approach in anticancer therapy. We evaluated DC-based anticancer immunotherapy (ITx) in an academic Phase I/II clinical trial for children, adolescent, and young adults with progressive, recurrent, or primarily metastatic high-risk tumors. The primary endpoint was safety of intradermal administration of manufactured DCs. Here, we focused on relapsing high-risk sarcoma subgroup representing a major diagnosis in DC clinical trial. As a part of peripheral blood immunomonitoring, we evaluated quantitative association between basic cell-based immune parameters. Furthermore, we describe the pattern of these parameters and their time-dependent variations during the DC vaccination in the peripheral blood immunograms. The peripheral blood immunograms revealed distinct patterns in particular patients in the study group. As a functional testing, we evaluated immune response of patient T-cells to the tumor antigens presented by DCs in the autoMLR proliferation assay. This analysis was performed with T-cells obtained prior to DC ITx initiation and with T-cells collected after the fifth dose of DCs, demonstrating that the anticancer DC-based vaccine stimulates a preexisting immune response against self-tumor antigens. Finally, we present clinical and immunological findings in a Ewing's sarcoma patient with an interesting clinical course. Prior to DC therapy, we observed prevailing CD8+ T-cell stimulation and low immunosuppressive monocytic myeloid-derived suppressor cells (M-MDSC) and regulatory T-cells (Tregs). This patient was subsequently treated with 19 doses of DCs and experienced substantial regression of metastatic lesions after second disease relapse and was further rechallenged with DCs. In this patient, functional ex vivo testing of autologous T-cell activation by manufactured DC medicinal product during the course of DC ITx revealed that personalized anticancer DC-based vaccine stimulates a preexisting immune response against self-tumor antigens and that the T-cell reactivity persisted for the period without DC treatment and was further boosted by DC rechallenge.Trial Registration Number: EudraCT 2014-003388-39.