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Retroperitoneal sarcoma comprises a small subset of all soft tissue sarcoma and includes various histopathologic subtypes, each with unique patterns of behavior and differential risks for local recurrence and hematogenous metastatic spread. The primary treatment modality is surgery, although even with complete macroscopic resection, recurrence is common. The rationale for the addition of radiotherapy to resection is to improve local control; however, the use of radiation therapy for retroperitoneal sarcoma is controversial, and existing data are suboptimal to guide management. Treatment decisions should be determined with multidisciplinary input and shared decision-making. When used in selected patients, radiation therapy should be delivered preoperatively; postoperative treatment is not recommended.

Patients with locally advanced non-small cell lung cancer (LA-NSCLC) have a high prevalence of pre-existing coronary heart disease and face excess cardiac risk after thoracic radiation therapy. We sought to assess whether statin therapy is a predictor of overall survival (OS) after thoracic radiation therapy.We performed a retrospective analysis of 748 patients with LA-NSCLC treated with thoracic radiation therapy, using Kaplan-Meier OS estimates and Cox regression.Statin use among high cardiac risk patients (Framingham risk ≥20% or pre-existing coronary heart disease; n = 496) was 51.2%. After adjustment for baseline cardiac risk and other prognostic factors, statin therapy was associated with a significantly increased risk of all-cause mortality (adjusted hazard ratio, 1.39; 95% confidence interval [CI], 1.00-1.91; P = .048) but not major adverse cardiac events (adjusted hazard ratio, 1.18; 95% CI, 0.52-2.68; P = .69). Among statin-naïve patients, mean heart dose ≥10 Gy versus10 Gy was associated with a significantly increased risk of all-cause mortality (hazard ratio, 1.32; 95% CI, 1.04-1.68; P = .022), with 2-year OS estimates of 46.9% versus 60.0%, respectively. However, OS did not differ by heart dose among patients on statin therapy (hazard ratio, 1.00; 95% CI, 0.76-1.32; P = 1.00; P-interaction = .031), with 2-year OS estimates of 46.9% versus 50.3%, respectively.Among patients with LA-NSCLC, only half of statin-eligible high cardiac risk patients were on statin therapy, reflecting the highest cardiac risk level of our cohort. Statin use was an independent predictor of all-cause mortality but not major adverse cardiac events. Elevated mean heart dose (≥10 Gy) was associated with increased risk of all-cause mortality in statin-naïve patients but not among those on statin therapy, identifying a group of patients in which early intervention with statins may mitigate the deleterious effects of high heart radiation therapy dose. This warrants evaluation in prospective trials.

Purpose This guideline provides evidence-based recommendations addressing the indications for radiation therapy (RT), sequencing of local therapies, and appropriate dose and planning techniques for management of primary, operable, localized, soft tissue sarcoma (STS) in adults. Methods The American Society for Radiation Oncology convened a task force to address 5 key questions focused on the use of RT for management of STS. These questions included indications for RT for STS of the extremity and superficial trunk; considerations for sequencing of RT with respect to surgery, dose of RT, appropriate treatment volumes and techniques; and the role of RT in management of retroperitoneal sarcoma. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and system for grading evidence quality and recommendation strength. Results Multidisciplinary evaluation and decision making are recommended for all cases of STS. RT is recommended for patients in whom there is increased risk of local recurrence of resected STS, particularly if close or microscopically positive margins are anticipated or have occurred. When RT is indicated, preoperative RT is strongly recommended over postoperative RT. Postoperative RT is conditionally recommended in specific clinical circumstances (eg, uncontrolled pain or bleeding) or when the risk of wound complications outweighs that of late toxicity from RT. Routine use of RT in addition to oncologic resection for retroperitoneal sarcoma is conditionally not recommended. When RT is used for retroperitoneal sarcoma, preoperative RT is recommended, whereas postoperative RT is not recommended. Conclusions Based on currently published data, the American Society for Radiation Oncology task force has proposed evidence-based recommendations regarding the use of RT for STS in adults. Future studies will ascertain whether alterations in dosing and sequencing may optimize outcomes and quality of life.

Mean heart dose (MHD) over 10 Gy and left anterior descending (LAD) coronary artery volume (V) receiving 15 Gy (V15Gy) greater than 10% can significantly increase the risk of major adverse cardiac events (MACE) in patients with non-small cell lung cancer (NSCLC). We sought to characterize the discordance between MHD and LAD dose and the association of this classification on the risk of MACE after radiation therapy.The coefficient of determination for MHD and LAD V15Gy was calculated in this retrospective analysis of 701 patients with locally advanced NSCLC treated with radiation therapy. Four groups were defined on the basis of high or low MHD (≥10 Gy vs10 Gy) and LAD V15Gy (≥10% vs10%). MACE (unstable angina, heart failure, myocardial infarction, coronary revascularization, and cardiac death) cumulative incidence was estimated, and Fine and Gray regressions were performed.The proportion of variance in LAD V15Gy predictable from MHD was only 54.5% (RMHD is insufficient to predict LAD V15Gy with confidence. When MHD and LAD V15Gy dose exposure is discordant, isolated low LAD V15Gy significantly reduces the risk of MACE in patients with locally advanced NSCLC after radiation therapy, suggesting that the validity of whole heart metrics for optimally predicting cardiac events should be reassessed.

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.

The aim of the present study was to compare the effect of radiotherapy (RT) on abdominal recurrence-free survival (ARFS) in patients with primary retroperitoneal sarcoma treated in the EORTC-STBSG-62092 (STRASS) phase 3 randomized controlled trial (STRASS cohort) and off-trial (STREXIT cohort) and to pool STRASS and STREXIT data to test the hypothesis that RT improves ARFS in patients with liposarcoma.The STRASS trial did not show any difference in ARFS between patients treated with preoperative radiotherapy+surgery (RT+S) versus surgery alone (S).All consecutive adult patients not enrolled in STRASS and underwent curative-intent surgery for a primary retroperitoneal sarcoma with or without preoperative RT between 2012 and 2017 (STRASS recruiting period) among ten STRASS-recruiting centres formed the STREXIT cohort. The effect of RT in STREXIT was explored with a propensity score (PS)-matching analysis. Primary endpoint was ARFS defined as macroscopically incomplete resection or abdominal recurrence or death of any cause, whichever occurred first.STRASS included 266 patients, STREXIT included 831 patients (727 after excluding patients who received preoperative chemotherapy, 202 after 1:1 PS-matching). The effect of RT on ARFS in STRASS and 1:1 PS-matched STREXIT cohorts, overall and in patients with liposarcoma, was similar. In the pooled cohort analysis, RT administration was associated with better ARFS in patients with liposarcoma [N=321, hazard ratio (HR), 0.61; 95% confidence interval (CI), 0.42-0.89]. In particular, patients with well-differentiated liposarcoma and G1-2 dedifferentiated liposarcoma (G1-2 DDLPS, n=266) treated with RT+S had better ARFS (HR, 0.63; 95% CI, 0.40-0.97) while patients with G3 DDLPS and leiomyosarcoma had not. At the current follow-up, there was no association between RT and overall survival or distant metastases-free survival.In this study, preoperative RT was associated with better ARFS in patients with primary well-differentiated liposarcoma and G1-2 DDLPS.

Purpose Angiosarcoma is a sub-type of soft tissue sarcoma, often presenting as a multifocal or diffuse disease process with poor prognosis. This study presents outcomes of a single institution cohort of patients with angiosarcoma of the scalp and face following treatment with multimodality therapy, including high-dose-rate surface applicator (HDR-SA) brachytherapy, and represents the largest cohort utilizing this therapeutic approach. Material and methods Twenty patients with primary or recurrent angiosarcoma of the face or scalp were treated with HDR-SA brachytherapy between 2003-2018, with clinical characteristics and outcomes collected from medical records and used to identify prognostic features. Results Median follow-up was 45 months. Patients treated with HDR-SA brachytherapy had a 4-year local control rate of 63%, a 4-year progression-free survival (PFS) rate of 20%, and a 4-year overall survival rate of 54%. Disease features associated with worse loco-regional control (LRC) included location on the scalp (vs. face, p = 0.04) and tumor size ≥ 5 cm (p = 0.0099). Outcomes after HDR-SA brachytherapy for salvage therapy vs. HDR-SA brachytherapy as a component of an initial treatment approach were also significantly different, with worse LRC (p = 0.0084) and worse overall survival (OS) (p = 0.0019) in a setting of salvage therapy. Conclusions Local control rates following HDR-SA brachytherapy for scalp or face angiosarcoma are moderate and similar to what is described in the literature using a variety of local control treatment modalities. Smaller tumors and those involving the face rather than scalp had better outcomes. PFS rates were poor and there is a pressing need for treatment intensification and novel therapeutic options.

Background Patients undergoing surgery for soft tissue sarcoma have high morbidity rates, particularly after preoperative radiation therapy (RT). An enhanced recovery after surgery (ERAS) programme may improve perioperative outcomes in abdominal surgery. This study reported outcomes of an ERAS programme tailored to patients with soft tissue sarcoma. Methods A prospective ERAS protocol was implemented in 2015 at a high-volume sarcoma centre. Patients treated within the ERAS programme from 2015 to 2018 were case-matched retrospectively with patients treated between 2012 and 2018 without use of the protocol, matched by surgical site, surgeon, sarcoma histology and preoperative RT treatment. Postoperative outcomes, specifically wound complications and duration of hospital stay, were reported. Results In total, 234 patients treated within the ERAS programme were matched with 237 who were not. The ERAS group had lower wound dehiscence rates overall (2 of 234 (0·9 per cent) versus 31 of 237 (13·1 per cent); P < 0·001), after preoperative RT (0 of 41 versus 11 of 51; P = 0·004) and after extremity sarcoma surgery (0 of 54 versus 6 of 56; P = 0·040) compared with the non-ERAS group. Rates of postoperative ileus or obstruction were lower in the ERAS group (21 of 234 (9·9 per cent) versus 40 of 237 (16·9 per cent); P = 0·016) and in those with retroperitoneal sarcoma (4 of 36 versus 15 of 36; P = 0·007). Duration of hospital stay was shorter in the ERAS group (median 5 (range 0–36) versus 6 (0–67) days; P = 0·003). Conclusion Treatment within an ERAS protocol for patients with soft tissue sarcoma was associated with lower morbidity and shorter hospital stay.

Background In prior reports from population-based databases, black patients with extremity soft tissue sarcoma (ESTS) have lower reported rates of limb-sparing surgery and adjuvant treatment. The objective of this study was to compare the multimodality treatment of ESTS between black and white patients within a universally insured and equal-access health care system. Methods Claims data from TRICARE, the US Department of Defense insurance plan that provides health care coverage for 9 million active-duty personnel, retirees, and dependents, were queried for patients younger than 65 y with ESTS who underwent limb-sparing surgery or amputation between 2006 and 2014 and identified as black or white race. Multivariable logistic regression analysis was used to evaluate the impact of race on the utilization of surgery, chemotherapy, and radiation. Results Of the 719 patients included for analysis, 605 patients (84%) were white and 114 (16%) were black. Compared with whites, blacks had the same likelihood of receiving limb-sparing surgery (odds ratio [OR], 0.861; 95% confidence interval [95% CI], 0.284-2.611; P = 0.79), neoadjuvant radiation (OR, 1.177; 95% CI, 0.204-1.319; P = 0.34), and neoadjuvant (OR, 0.852; 95% CI, 0.554-1.311; P = 0.47) and adjuvant (OR, 1.211; 95% CI, 0.911-1.611; P = 0.19) chemotherapy; blacks more likely to receive adjuvant radiation (OR, 1.917; 95% CI, 1.162-3.162; P = 0.011). Conclusions In a universally insured population, racial differences in the rates of limb-sparing surgery for ESTS are significantly mitigated compared with prior reports. Biologic or disease factors that could not be accounted for in this study may contribute to the increased use of adjuvant radiation among black patients.

Background Solitary fibrous tumor (SFT) is a rare mesenchymal malignancy. Although surgery is potentially curative, the local relapse risk is high after marginal resections. Given the lack of prospective clinical trial data, the objective of the current study was to better define the role of perioperative radiotherapy (RT) in various SFT presentations by location. Methods This was retrospective study performed across 7 sarcoma centers. Clinical information was retrieved from all adult patients with extrameningeal, primary, localized SFT who were treated between 1990 and 2018 with surgery alone (S) compared with those who also received perioperative RT (S+RT). Differences in treatment characteristics between subgroups were tested using analysis of variance statistics and propensity score matching. Local control and overall survival rates were calculated from the start of treatment until progression or death from any cause. Results Of all 549 patients, 428 (78%) underwent S, and 121 (22%) underwent S+RT. The median follow‐up was 52 months. After correction for mitotic count and surgical margins, S+RT was significantly associated with a lower risk of local progression (hazard ratio, 0.19: P = .029), an observation further confirmed by propensity score matching (P = .012); however, this association did not translate into an overall survival benefit. Conclusions The results from this retrospective study investigating perioperative RT in patients with primary extrameningeal SFT suggest that combining RT with surgery in the management of this patient population is significantly associated with a reduced risk of local failures, especially in patients who have less favorable resection margins and in those who have tumors with a high mitotic count., This retrospective study of perioperative radiotherapy in patients with primary extrameningeal solitary fibrous tumors suggests that combining radiotherapy with surgery in the management of this population significantly reduces the risk of local failures, especially in patients who have less favorable resection margins or tumors with a high mitotic count.

Surgery is the mainstay of treatment for retroperitoneal sarcoma (RPS), but local recurrence is common. Biologic behavior and recurrence patterns differ significantly among histologic types of RPS, with implications for management. The Transatlantic Australasian RPS Working Group (TARPSWG) published a consensus approach to primary RPS, and to complement this, one for recurrent RPS in 2016. Since then, additional studies have been published, and collaborative discussion is ongoing to address the clinical challenges of local recurrence in RPS.An extensive literature search was performed, and the previous consensus statements for recurrent RPS were updated after review by TARPSWG members. The search included the most common RPS histologic types: liposarcoma, leiomyosarcoma, solitary fibrous tumor, undifferentiated pleomorphic sarcoma, and malignant peripheral nerve sheath tumor.Recurrent RPS management was evaluated from diagnosis to follow-up evaluation. For appropriately selected patients, resection is safe. Nomograms currently are available to help predict outcome after resection. These and other new findings have been combined with expert recommendations to provide 36 statements, each of which is attributed a level of evidence and grade of recommendation. In this updated document, more emphasis is placed on histologic type and clarification of the intent for surgical treatment, either curative or palliative. Overall, the fundamental tenet of optimal care for patients with recurrent RPS remains individualized treatment after multidisciplinary discussion by an experienced team with expertise in RPS.Updated consensus recommendations are provided to help guide decision-making for treatment of locally recurrent RPS and better selection of patients who would potentially benefit from surgery.

In 699 patients with locally advanced non-small-cell lung cancer (NSCLC) treated with radiation therapy as part of combined modality therapy, we compared outcomes among genotyped and ungenotyped patients and by tumor genotype status (Genotyping was performed in 250 patients:With a median follow-up of 48.2 months among genotyped patients, median overall survival (OS) was significantly longer forIn this series of locally advanced NSCLC treated with combined modality therapy

Opinion statement Soft tissue sarcomas (STS) are rare, aggressive, and heterogenous tumors, comprising approximately 1% of adult cancers with over 50 different subtypes. The mainstay of treatment for retroperitoneal sarcomas (RPS) includes surgical resection. The addition of radiation therapy (RT), either preoperatively or postoperatively, has been used to potentially decrease the risk of local recurrence. The recently published results from STRASS (EORTC-STBSG 62092-22092), which randomized patients to receive or not receive preoperative radiation, indicate no abdominal recurrence-free survival benefit (primary endpoint) nor overall survival benefit to date from the addition of preoperative RT prior to surgical resection in patients with RPS. Keeping in mind caveats of subgroup analyses, the data show a significant reduction in local recurrence with radiation therapy in resected patients and non-significant trends toward improved abdominal recurrence-free survival in all patients and improved local control and abdominal recurrence-free survival in patients with liposarcoma and low-grade sarcoma. Given the high rate of local failure with surgery alone, it is possible that higher RT dose and/or selective RT dose painting may improve outcomes. Prior to treatment, the authors encourage multidisciplinary review and discussion of management options at a sarcoma center for patients with RPS. Selective use of RT may be considered for patients at high risk of local recurrence.

Highlights • Locally advanced EGFR+ NSCLC patients have a high likelihood of brain metastasis. • The high likelihood of EGFR+ brain metastasis is independent of survival duration. • Surveillance MRI may allow early identification and treatment of brain metastasis., Background and purpose Small studies of primarily metastatic non-small cell lung cancer (NSCLC) have suggested an association between EGFR mutation (EGFR+) and likelihood of brain metastasis. However, these studies are confounded by follow-up time bias. We performed a competing risk analysis of brain metastasis in a more uniform locally advanced NSCLC (LA-NSCLC) cohort with known tumor genotype. Materials and methods Between 2002 and 2014, 255 patients with LA-NSCLC underwent tumor genotyping for EGFR, ALK and/or KRAS (180 patients had follow-up brain imaging). Cumulative incidence and Fine-Gray regression were performed on clinical variables including genotype and risk of brain metastasis, with death as a competing event. Results The proportion of tumors with aberrations in EGFR, ALK and KRAS were 17%, 4% and 28%, respectively. The median follow-up was 68 months. On multivariate analysis, EGFR+ was significantly associated with risk of brain metastasis in the full patient cohort (HR 2.04, 95% CI 1.22–3.39, p = 0.006) as well as in the subset of patients with brain follow-up imaging (HR 1.91. 95% CI 1.17–3.13, p = 0.01). This translated to a higher cumulative incidence of brain metastasis in EGFR+ patients at 3 and 5 years (33.3% vs. 23.2 and 43.8% vs. 24.2%, p = 0.006). Conclusion Patients with EGFR+ LA-NSCLC have a significantly higher likelihood of developing brain metastasis after standard combined modality therapy, independent of their longer overall survival. This high-risk genotypic subgroup may benefit from routine surveillance with brain MRI to allow early salvage with targeted systemic- and/or radiation-therapies.

Soft tissue sarcomas (STS) are a rare and diverse group of tumors that affect both adult and pediatric populations. This review discusses current screening recommendations for populations at increased risk for STS, including those with genetic predispositions. We also review surveillance guidelines for those at risk for recurrence following curative-intent surgery.

PURPOSE Radiation-associated sarcomas (RAS) are considered to have a poor prognosis. Although the incidence is anticipated to rise, contemporary data regarding predictors of outcomes are few. We performed a retrospective analysis to identify RAS prognostic factors and subset analyses for radiation-associated angiosarcoma arising after treatment for breast cancer (RAAB) and other RAS subtypes (other-RAS). METHODS AND MATERIALS Patients with localized RAS evaluated at an institutional multidisciplinary sarcoma clinic were identified. Clinical and histologic review was performed, and outcomes were assessed to identify prognostic features. A subset of cases underwent molecular analysis by next-generation sequencing. RESULTS Among 176 patients, histologic subtypes of RAS included angiosarcoma (41%), undifferentiated/unclassified sarcoma (40%), leiomyosarcoma (8%), malignant peripheral nerve sheath tumor (6%), and osteosarcoma (2%). Sixty-seven patients (38%) had RAAB, and 109 (62%) had other-RAS. RAAB had significantly shorter latency from time of initial radiation compared with other-RAS (8 vs. 15 years; P

Background Radiotherapy-associated cardiac toxicity studies in patients with locally advanced non–small cell lung cancer (NSCLC) have been limited by small sample size and nonvalidated cardiac endpoints. Objectives The purpose of this analysis was to ascertain whether cardiac radiation dose is a predictor of major adverse cardiac events (MACE) and all-cause mortality (ACM). Methods This retrospective analysis included 748 consecutive locally advanced NSCLC patients treated with thoracic radiotherapy. Fine and Gray and Cox regressions were used to identify predictors for MACE and ACM, adjusting for lung cancer and cardiovascular prognostic factors, including pre-existing coronary heart disease (CHD). Results After a median follow-up of 20.4 months, 77 patients developed ≥1 MACE (2-year cumulative incidence, 5.8%; 95% confidence interval [CI]: 4.3% to 7.7%), and 533 died. Mean radiation dose delivered to the heart (mean heart dose) was associated with a significantly increased risk of MACE (adjusted hazard ratio [HR]: 1.05/Gy; 95% CI: 1.02 to 1.08/Gy; p Conclusions Despite the competing risk of cancer-specific death in locally advanced NSCLC patients, cardiac radiation dose exposure is a modifiable cardiac risk factor for MACE and ACM, supporting the need for early recognition and treatment of cardiovascular events and more stringent avoidance of high cardiac radiotherapy dose.

Soft tissue sarcomas (STS) are rare, aggressive, and heterogenous tumors, comprising approximately 1% of adult cancers with over 50 different subtypes. The mainstay of treatment for retroperitoneal sarcomas (RPS) includes surgical resection. The addition of radiation therapy (RT), either preoperatively or postoperatively, has been used to potentially decrease the risk of local recurrence. The recently published results from STRASS (EORTC-STBSG 62092-22092), which randomized patients to receive or not receive preoperative radiation, indicate no abdominal recurrence-free survival benefit (primary endpoint) nor overall survival benefit to date from the addition of preoperative RT prior to surgical resection in patients with RPS. Keeping in mind caveats of subgroup analyses, the data show a significant reduction in local recurrence with radiation therapy in resected patients and non-significant trends toward improved abdominal recurrence-free survival in all patients and improved local control and abdominal recurrence-free survival in patients with liposarcoma and low-grade sarcoma. Given the high rate of local failure with surgery alone, it is possible that higher RT dose and/or selective RT dose painting may improve outcomes. Prior to treatment, the authors encourage multidisciplinary review and discussion of management options at a sarcoma center for patients with RPS. Selective use of RT may be considered for patients at high risk of local recurrence.

Epithelioid hemangioendothelioma (EHE) is an ultra-rare, translocated, vascular sarcoma. EHE clinical behavior is variable, ranging from that of a low-grade malignancy to that of a high-grade sarcoma and it is marked by a high propensity for systemic involvement. No active systemic agents are currently approved specifically for EHE, which is typically refractory to the antitumor drugs used in sarcomas. The degree of uncertainty in selecting the most appropriate therapy for EHE patients and the lack of guidelines on the clinical management of the disease make the adoption of new treatments inconsistent across the world, resulting in suboptimal outcomes for many EHE patients. To address the shortcoming, a global consensus meeting was organized in December 2020 under the umbrella of the European Society for Medical Oncology (ESMO) involving >80 experts from several disciplines from Europe, North America and Asia, together with a patient representative from the EHE Group, a global, disease-specific patient advocacy group, and Sarcoma Patient EuroNet (SPAEN). The meeting was aimed at defining, by consensus, evidence-based best practices for the optimal approach to primary and metastatic EHE. The consensus achieved during that meeting is the subject of the present publication., Highlights • This consensus paper provides key recommendations on the management of epithelioid hemangioendothelioma (EHE). • Recommendations followed a consensus meeting between experts and a representative of the EHE advocacy group and SPAEN. • Authorship includes a multidisciplinary group of experts from different institutions from Europe, North America and Asia.

Background Among sarcomas, which are rare cancers, many types are exceedingly rare; however, a definition of ultra-rare cancers has not been established. The problem of ultra-rare sarcomas is particularly relevant because they represent unique diseases, and their rarity poses major challenges for diagnosis, understanding disease biology, generating clinical evidence to support new drug development, and achieving formal authorization for novel therapies. Methods The Connective Tissue Oncology Society promoted a consensus effort in November 2019 to establish how to define ultra-rare sarcomas through expert consensus and epidemiologic data and to work out a comprehensive list of these diseases. The list of ultra-rare sarcomas was based on the 2020 World Health Organization classification, The incidence rates were estimated using the Information Network on Rare Cancers (RARECARENet) database and NETSARC (the French Sarcoma Network's clinical-pathologic registry). Incidence rates were further validated in collaboration with the Asian cancer registries of Japan, Korea, and Taiwan. Results It was agreed that the best criterion for a definition of ultra-rare sarcomas would be incidence. Ultra-rare sarcomas were defined as those with an incidence of approximately ≤1 per 1,000,000, to include those entities whose rarity renders them extremely difficult to conduct well powered, prospective clinical studies. On the basis of this threshold, a list of ultra-rare sarcomas was defined, which comprised 56 soft tissue sarcoma types and 21 bone sarcoma types. Conclusions Altogether, the incidence of ultra-rare sarcomas accounts for roughly 20% of all soft tissue and bone sarcomas. This confirms that the challenges inherent in ultra-rare sarcomas affect large numbers of patients.

Background We evaluated the efficacy and safety of the nontaxane microtubule dynamics inhibitor eribulin plus the humanized anti-VEGF monoclonal antibody bevacizumab in a novel second-line chemotherapy scheme in HER2-negative metastatic breast cancer (MBC) patients progressing after first-line paclitaxel and bevacizumab. Patients and methods This is a multicenter, single-arm, Simon's two-stage, phase II study. The primary endpoint was the overall response rate, considered as the sum of partial and complete response based on the best overall response rate (BORR). The secondary endpoints were progression-free survival (PFS), overall survival (OS), and clinical benefit rate. Results A total of 58 of the 61 patients enrolled in the study were evaluable for efficacy. The BORR was 24.6% (95% CI 14.5-37.3). The clinical benefit rate was 32.8% (95% CI 21.3-46.0). The median PFS was 6.2 months (95% CI 4.0-7.8), and median OS was 14.8 months (95% CI 12.6-22.8). Overall, adverse events (AEs) were clinically manageable and the most common AEs were fatigue, paresthesia, and neutropenia. Quality of life was well preserved in most patients. Conclusions The results of this study suggest that second-line therapy with bevacizumab in combination with eribulin has a meaningful clinical activity and may represent a potential therapeutic option for patients with HER2-negative MBC., Highlights • Bevacizumab + chemotherapy improved progression-free survival in HER2-negative metastatic breast cancer (MBC) patients. • Eribulin monotherapy improved overall survival in patients with anthracycline- and taxane-pretreated MBC. • The GIM11-BERGI trial assessed the efficacy and safety of eribulin + bevacizumab as second-line treatment for HER2-MBC. • Eribulin + bevacizumab showed to be a safe and active treatment after progression to first-line paclitaxel + bevacizumab.

Item does not contain fulltext IMPORTANCE: Currently, preoperative radiotherapy for all soft-tissue sarcomas is identical at a 50-Gy dose level, which can be associated with morbidity, particularly wound complications. The observed clinical radiosensitivity of the myxoid liposarcoma subtype might offer the possibility to reduce morbidity. OBJECTIVE: To assess whether a dose reduction of preoperative radiotherapy for myxoid liposarcoma would result in comparable oncological outcome with less morbidity. DESIGN, SETTING, AND PARTICIPANTS: The Dose Reduction of Preoperative Radiotherapy in Myxoid Liposarcomas (DOREMY) trial is a prospective, single-group, phase 2 nonrandomized controlled trial being conducted in 9 tertiary sarcoma centers in Europe and the US. Participants include adults with nonmetastatic, biopsy-proven and translocation-confirmed myxoid liposarcoma of the extremity or trunk who were enrolled between November 24, 2010, and August 1, 2019. Data analyses, using both per-protocol and intention-to-treat approaches, were conducted from November 24, 2010, to January 31, 2020. INTERVENTIONS: The experimental preoperative radiotherapy regimen consisted of 36 Gy in once-daily 2-Gy fractions, with subsequent definitive surgical resection after an interval of 4 or more weeks. MAIN OUTCOMES AND MEASURES: As a short-term evaluable surrogate for local control, the primary end point was centrally reviewed pathologic treatment response. The experimental regimen was regarded as a success when 70% or more of the resection specimens showed extensive treatment response, defined as 50% or greater of the tumor volume containing treatment effects. Morbidity outcomes consisted of wound complications and late toxic effects. RESULTS: Among the 79 eligible patients, 44 (56%) were men and the median (interquartile range) age was 45 (39-56) years. Two patients did not undergo surgical resection because of intercurrent metastatic disease. Extensive pathological treatment response was observed in 70 of 77 patients (91%; posterior mean, 90.4%; 95% highest probability density interval, 83.8%-96.4%). The local control rate was 100%. The rate of wound complication requiring intervention was 17%, and the rate of grade 2 or higher toxic effects was 14%. CONCLUSIONS AND RELEVANCE: The findings of the DOREMY nonrandomized clinical trial suggest that deintensification of preoperative radiotherapy dose is effective and oncologically safe and is associated with less morbidity than historical controls, although differences in radiotherapy techniques and follow-up should be considered. A 36-Gy dose delivered in once-daily 2-Gy fractions is proposed as a dose-fractionation approach for myxoid liposarcoma, given that phase 3 trials are logistically impossible to execute in rare cancers. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02106312.

Introduction A meningeal solitary fibrous tumor (SFT), also called hemangiopericytoma, is a rare mesenchymal malignancy. Due to anatomic constrains, even after macroscopic complete surgery with curative intent, the local relapse risk is still relatively high, thus increasing the risk of dedifferentiation and metastatic spread. This study aims to better define the role of postoperative radiotherapy (RT) in meningeal SFTs. Patients and methods A retrospective study was performed across seven sarcoma centers. Clinical information was retrieved from all adult patients with meningeal primary localized SFT treated between 1990 and 2018 with surgery alone (S) compared to those that also received postoperative RT (S + RT). Differences in treatment characteristics between subgroups were tested using independent samplest-test for continuous variables and chi-square tests for proportions. Local control (LC) and overall survival (OS) rates were calculated as time from start of treatment until progression or death from any cause. LC and OS in groups receiving S or S + RT were compared using Kaplan-Meier survival curves. Results Among a total of 48 patients, 7 (15%) underwent S and 41 (85%) underwent S + RT. Median FU was 65 months. LC was significantly associated with treatment. LC after S at 60 months was 60% versus 90% after S + RT (p = 0.052). Furthermore, R1 resection status was significantly associated with worse LC (HR 4.08,p = 0.038). OS was predominantly associated with the mitotic count (HR 3.10,p = 0.011). Conclusion This retrospective study, investigating postoperative RT in primary localized meningeal SFT patients, suggests that combining RT to surgery in the management of this patient population may reduce the risk for local failures.

Introduction Limited stage small cell lung cancer (LS-SCLC) has a poor prognosis. Additional prognostic markers are needed for risk-stratification and treatment intensification. This study compares quantitative CT-based volumetric tumor measurements versus International Association for the Study of Lung Cancer (IASLC) TNM staging to predict outcomes. Materials & methods A cohort of 105 patients diagnosed with LS-SCLC and treated with chemoradiation (CRT) from 2000 to 2013 were analyzed retrospectively. Patients were staged by the Union for International Cancer Control (UICC) TNM Classification, 8th edition. Tumor volumes and diameters were extracted from radiation planning CT imaging. Univariable and multivariable models were used to analyze relationships between CT features and overall survival (OS), locoregional recurrence (LRR), in-field LRR, any progression, and distant metastasis (DM). Results Median follow-up was 21.3 months. Two-year outcomes were as follows: 38% LRR, 31% in-field LRR, 52% DM, 62% any progression, and 47% OS (median survival 16.5 months). On univariable analysis, UICC T-stage and N-stage were not associated with any clinical outcome. UICC overall stage was only statistically associated with in-field LRR. One imaging feature (3D maximum tumor diameter) was found to be significantly associated with LRR (HR 1.10, p = 0.003), in-field LRR (HR 1.10, p = 0.007), DM (HR 1.10, p = 0.02), any progression (HR 1.10, p = 0.008), and OS (HR 1.10, p = 0.03). On multivariable analysis, this feature remained significantly associated with all outcomes. Conclusion For LS-SCLC, quantitative CT-based volumetric tumor measurements were significantly associated with outcomes after CRT and may be better predictors of outcome than TNM stage.

Approximately one-third of all non-small-cell lung cancer (NSCLC) are locally-advanced at diagnosis, and 15–17% of these tumors are unresectable at presentation. Definitive chemo-radiotherapy (CRT) represents the standard therapeutic approach. However, the literature has shown that only 15% of patients are alive at 5 years and this percentage has remained unchanged despite various attempts of improvement. The recent introduction of immunotherapy has not only strongly changed the clinical scenario but has also drawn attention to a stage of disease apparently forgotten for decades. Stage III NSCLC can represent an interesting setting for the combined use of chemo-radiation and immunotherapy, due to the potential synergistic effect between radiation and immune checkpoint inhibitors. We reviewed the available literature in order to report the state of art of stage III NSCLC, by focusing on trials that evaluate different combinations of CRT and new drugs of PD-1/PD-L1 axis, and anti-CTLA-4. The future goal in the management of unresectable stage III NSCLC will be the optimal patients’ selection combined with the use of individualized immuno/chemotherapies that could potentially improve clinical outcomes.

We analyzed data from 738 HER2‐positive metastatic breast cancer (mbc) patients treated with pertuzumab‐based regimens and/or T‐DM1 at 45 Italian centers. Outcomes were explored in relation to tumor subtype assessed by immunohistochemistry (IHC). The median progression‐free survival at first‐line (mPFS1) was 12 months. Pertuzumab as first‐line conferred longer mPFS1 compared to other first‐line treatments (16 vs. 9 months, p = 0.0001), regardless of IHC subtype. Median PFS in second‐line (mPFS2) was 7 months, with no difference by IHC subtype, but it was more favorable with T‐DM1 compared to other agents (7 vs. 6 months, p = 0.03). There was no PFS2 gain in patients with tumors expressing both hormonal receptors (HRs; p = 0.17), while a trend emerged for tumors with one HR (p = 0.05). Conversely, PFS2 gain was significant in HRs‐negative tumors (p = 0.04). Median overall survival (mOS) was 74 months, with no significant differences by IHC subtypes. Survival rates at 2 and 3 years in patients treated with T‐DM1 in second‐line after pertuzumab were significantly lower compared to pertuzumab‐naïve patients (p = 0.01). When analyzed by IHC subtype, the outcome was confirmed if both HRs or no HRs were expressed (p = 0.02 and p = 0.006, respectively). Our results confirm that HRs expression impacts the clinical behavior and novel treatment‐related outcomes of HER2‐positive tumors when treatment sequences are considered. Moreover, multivariate analysis showed that HRs expression had no effect on PFS and OS. Further studies are warranted to confirm our findings and clarify the interplay between HER2 and estrogen receptor pathways in HER2‐positive (mbc) patients., What's new? About half of breast cancers positive for human epidermal growth factor (HER2) also express hormone receptors but the impact of hormone receptor status on the success of HER2‐directed treatments is not fully explored. Here the authors retrospectively assessed tumor behavior and treatment outcomes in 738 women with HER2+ metastatic breast cancer treated with new generation anti‐HER2 agents. Distinct hormone receptor expression patterns significantly affected the progression free and overall survival, justifying further studies to define optimal treatment regimens and the interplay between hormone receptor and HER2 signaling.

Purpose. Angiosarcoma of the face and scalp is a rare disease with high rates of recurrence. The optimal treatment approach is not well defined. This study presents a dosimetric comparison of high-dose-rate surface applicator (HDR-SA) brachytherapy to volumetric-modulated arc therapy (VMAT). Methods. Between 2011 and 2018, 12 patients with primary or recurrent angiosarcoma of the face or scalp were treated with HDR-SA brachytherapy using CT-based planning at our institution. For comparison, deliverable VMAT plans for each patient were generated, and dose distribution was compared to the delivered HDR-SA brachytherapy plans. Results. Both VMAT and HDR-SA brachytherapy plans delivered good coverage of the clinical target. However, the dose distribution of VMAT was significantly different from HDR-SA brachytherapy across a variety of parameters. Mean doses to the lacrimal gland, orbit, lens, and cochlea were significantly higher with HDR-SA brachytherapy vs. VMAT. Brain Dmax, V80%, and V50% were also significantly higher with HDR-SA brachytherapy. Conclusions. There may be dosimetric advantages to VMAT over HDR-SA brachytherapy for many patients. However, individual tumor location, patient anatomy, and treatment reproducibility may result in HDR-SA brachytherapy being the preferred technique in a subset of patients. Ultimately, a personalized approach is likely to be the optimal treatment plan.

Summary Background Unlike for extremity sarcomas, the efficacy of radiotherapy for retroperitoneal sarcoma is not established. The aim of this study was to evaluate the impact of preoperative radiotherapy plus surgery versus surgery alone on abdominal recurrence-free survival. Methods EORTC-62092 is an open-label, randomised, phase 3 study done in 31 research institutions, hospitals, and cancer centres in 13 countries in Europe and North America. Adults (aged ≥18 years) with histologically documented, localised, primary retroperitoneal sarcoma that was operable and suitable for radiotherapy, who had not been previously treated and had a WHO performance status and American Society of Anesthesiologists score of 2 or lower, were centrally randomly assigned (1:1), using an interactive web response system and a minimisation algorithm, to receive either surgery alone or preoperative radiotherapy followed by surgery. Randomisation was stratified by hospital and performance status. Radiotherapy was delivered as 50·4 Gy (in 28 daily fractions of 1·8 Gy) in either 3D conformal radiotherapy or intensity modulated radiotherapy, and the objective of surgery was a macroscopically complete resection of the tumour mass with en-bloc organ resection as necessary. The primary endpoint was abdominal recurrence-free survival, as assessed by the investigator, and was analysed in the intention-to-treat population. Safety was analysed in all patients who started their allocated treatment. This trial is registered with ClinicalTrials.gov , NCT01344018 . Findings Between Jan 18, 2012 and April 10, 2017, 266 patients were enrolled, of whom 133 were randomly assigned to each group. The median follow-up was 43·1 months (IQR 28·8–59·2). 128 (96%) patients from the surgery alone group had surgery, and 119 (89%) patients in the radiotherapy and surgery group had both radiotherapy and surgery. Median abdominal recurrence-free survival was 4·5 years (95% CI 3·9 to not estimable) in the radiotherapy plus surgery group and 5·0 years (3·4 to not estimable) in the surgery only group (hazard ratio 1·01, 95% CI 0·71–1·44; log rank p=0·95). The most common grade 3–4 adverse events were lymphopenia (98 [77%] of 127 patients in the radiotherapy plus surgery group vs one [1%] of 128 patients in the surgery alone group), anaemia (15 [12%] vs ten [8%]), and hypoalbuminaemia (15 [12%] vs five [4%]). Serious adverse events were reported in 30 (24%) of 127 patients in the radiotherapy plus surgery group, and in 13 (10%) of 128 patients in the surgery alone group. One (1%) of 127 patients in the radiotherapy plus surgery group died due to treatment-related serious adverse events (gastropleural fistula), and no patients in the surgery alone group died due to treatment-related serious adverse events. Interpretation Preoperative radiotherapy should not be considered as standard of care treatment for retroperitoneal sarcoma. Funding European Organisation for Research and Treatment of Cancer, and European Clinical Trials in Rare Sarcomas.

Purpose In 699 patients with locally advanced non–small-cell lung cancer (NSCLC) treated with radiation therapy as part of combined modality therapy, we compared outcomes among genotyped and ungenotyped patients and by tumor genotype status ( EGFR, KRAS, and ALK). Patients and Methods Genotyping was performed in 250 patients: EGFR+ (19%), KRAS+ (32%), ALK+ (9%), and wild type (WT−/−/−; 40%). Outcomes were analyzed using the Kaplan-Meier method and Cox regression. Results With a median follow-up of 48.2 months among genotyped patients, median overall survival (OS) was significantly longer for EGFR+ and ALK+ compared with KRAS+ and WT−/−/− (55.8 months v not reached v 28.0 v 33.2 months; P = .02). There was no difference in progression-free survival (median, 15.3 v 13.7 v 13.0 v 14.5 months; P = .47) or in freedom from distant metastases by genotype (3-year estimates: 42% v 49% v 27% v 25%; P = .25). There was higher freedom from locoregional recurrence (LRR) for EGFR+ tumors and lower freedom from LRR in ALK+ tumors, compared with KRAS+ and WT−/−/− tumors (3-year: 77% v 38% v 49% v 46%). In multivariable analysis, ALK+ remained associated with increased OS (HR, 0.32; 95% CI, 0.12 to 0.87; P = .03), and EGFR+ was associated with decreased LRR (HR, 0.47; 95% CI, 0.24 to 0.92; P = .03). Analysis of post-recurrence survival demonstrated that EGFR+/ ALK+ patients treated with appropriate tyrosine kinase inhibitors had higher OS compared with other groups. Conclusion In this series of locally advanced NSCLC treated with combined modality therapy, EGFR+ and ALK+ were associated with higher OS, whereas LRR was lower in EGFR+ patients, and the risk of distant metastases was high in all subgroups. The outcomes and patterns of failure in genotypic subgroups of NSCLC from this study can inform the design of future trials integrating targeted therapies.

Standard treatment of large intermediate- and high-grade extremity soft tissue sarcoma (ESTS) typically includes wide excision and radiation therapy. Many patients do well with this approach, but for those with unfavorable features, risk for distant recurrence and, ultimately, mortality can exceed 50%. Unfortunately, universally accepted data elucidating effective treatments to prevent recurrences and improve survival for such high-risk patients are lacking. Accordingly, opinions about the appropriate role of systemic therapy for patients with high-risk localized ESTS vary. This article reviews the current literature pertaining to neoadjuvant chemotherapy, concurrent chemoradiation, and adjuvant chemotherapy for high-risk ESTS. All of these approaches are feasible and reasonable to consider. Ultimately, the decision to incorporate chemotherapy into the treatment regimen is best reached by discussion among an experienced multidisciplinary sarcoma team and should be tailored to the individual patient risk profile.

Amputation for localized extremity sarcoma (ES), once the primary therapy, is now rarely performed. We reviewed our experience to determine why patients with sarcoma still undergo immediate or delayed amputation, identify differences based on amputation timing, and evaluate outcomes. Records of patients with primary, nonmetastatic ES who underwent amputation at our institution from 2001 to 2011 were reviewed. Univariate analysis was performed, and survival outcomes were calculated. We categorized 54 patients into three cohorts: primary amputation (A1, n = 18, 33%), secondary amputation after prior limb-sparing surgery (A2, n = 22, 41%), and hand and foot sarcomas (HF, n = 14, 26%). Median age at amputation was 54 years (range 18–88 years). Common indications for amputation (> 40%) were loss of function, bone involvement, multiple compartment involvement, and large tumor size (A1); proximal location, joint involvement, neurovascular compromise, multiple compartment involvement, multifocal or fungating tumor, loss of function, and large tumor size (A2); and joint involvement and prior unplanned surgery (HF). There was no difference in disease-specific survival (DSS) (p = 0.19) or metastasis-free survival (MFS) (p = 0.31) between early (A1) and delayed (A2) amputation. Compared with cohorts A1/A2, HF patients had longer overall survival (OS) (p = 0.04). Indications for amputation for extremity sarcoma vary between those who undergo primary amputation, delayed amputation, and amputation for hand or foot sarcoma. Amputations chosen judiciously are associated with excellent disease control and survival. For patients who ultimately need amputation, timing (early vs. delayed) does not affect survival.

Purpose To conduct phase 1 and 2 trials with photon intensity modulated radiation therapy and intensity modulated proton therapy (IMPT) arms to selectively escalate the retroperitoneal sarcoma preoperative radiation dose to tumor volume (clinical target volume [CTV] 2) that is judged to be at a high risk for positive margins and aim to reduce local recurrence. We report on the IMPT study arm in phase 1. Methods and materials Patients aged ≥18 years with primary or locally recurrent retroperitoneal sarcoma were treated with preoperative IMPT, 50.4 GyRBE in 28 fractions, to CTV1 (gross tumor volume and adjacent tissues at risk of subclinical disease) with a simultaneous integrated boost to CTV2 to doses of 60.2, 61.6, and 63.0 GyRBE in 28 fractions of 2.15, 2.20, and 2.25 GyRBE, respectively. The primary objective of the phase 1 study was to determine the maximum tolerated dose to CTV2, which will be further tested in the phase 2 study. Results Eleven patients showed increasing IMPT dose levels without acute dose limiting toxicities that prevented dose escalation to maximum tolerated dose. Acute toxicity was generally mild with no radiation interruptions. No unexpected perioperative morbidity was noted. Eight months postoperatively, one patient developed hydronephrosis that was treated by stent with ureter dissected off tumor and received 57.5 GyRBE. Retained ureter(s) was (were) subsequently constrained to 50.4 GyRBE without further problem. With an 18-month median follow-up, there were no local recurrences. Conclusions IMPT dose escalation to CTV2 to 63 GyRBE was achieved without acute dose limiting toxicities. The phase 2 study of IMPT will accrue patients to that dose. Parallel intensity modulated radiation therapy phase 1 arm is currently accruing at the initial dose level. Ureters that undergo a high dose radiation and/or surgery are at risk for late hydro-ureter. Future studies will constrain retained ureters to 50.4 GyRBE to avoid ureteral stricture.

Background The incidence of histopathologic organ invasion (HOI) in retroperitoneal sarcoma (RPS) is not well described. We reviewed our experience to investigate the rate and prognostic implications of HOI. Study Design Patients with primary RPS who underwent surgery at our institution were reviewed. Histopathologic organ invasion was defined as microscopic organ invasion confirmed by re-review of pathology slides by an expert sarcoma pathologist. Impact of HOI on the crude cumulative incidence of locoregional recurrence, distant recurrence, and overall survival rates was analyzed. Results Between 2002 and 2011, one hundred and eighteen patients underwent resection for primary RPS; 99 had at least 1 organ resected and, among those, HOI was present in 58% (57 of 99). Among the 77 patients with the 3 most common histologies, rates of HOI were 61% for dedifferentiated liposarcoma, 56% for leiomyosarcoma, and 40% for well-differentiated liposarcoma. In this subset, HOI was associated with no difference in 2-year crude cumulative incidence of locoregional recurrence (48% vs 47%; p = 0.55) or distant recurrence (46% vs 22%; p = 0.2). With a median follow-up of 33.6 months, HOI was an independent predictor of worse 5-year overall survival (34% vs 62%; p = 0.04; hazard ratio = 2.3; 95% CI 1.2 to 4.4; p = 0.02). Conclusions The likelihood of organ invasion can be predicted by histologic subtype of primary RPS. To the best of our knowledge, this is the first study to demonstrate that HOI is associated with worse overall survival. These data can help guide the minimal extent of surgical resection required for RPS.

Optimal surveillance imaging (SI) regimens following radiation therapy (RT) and radical resection for localized soft tissue sarcoma (STS) are unknown and practice patterns vary.Between 2006 and 2014, 94 patients with localized STS of the extremity/trunk treated with preoperative RT and radical resection were identified. Timing of local recurrence (LR), distant recurrence (DR), and SI were evaluated. The Kaplan-Meier method was used to determine recurrence-free and overall survival (OS), and the method of recurrence detection (SI or due to signs/symptoms) was determined.Median tumor size was 7.5 cm, and 92% were intermediate/high grade. After a median follow-up of 60 months for surviving patients, 30 patients (32%) recurred, including 5 LRs and 26 DRs. The median time to LR and DR was 36.2 months (range 14.4-65.7) and 10.4 months (range 5.2-76.9), respectively, and the 5-year local recurrence-free survival (RFS), distant RFS, and OS was 95, 71, and 76%, respectively. Local SI was performed for 90% of patients, mostly by magnetic resonance imaging (MRI; 91%). Of the five LRs, two were detected by SI and three had signs/symptoms preceding imaging. All patients underwent distant SI. Of the 26 DRs, 23 (88%) were in the lung. SI detected 22 (85%) DRs, and only 4 of 26 had signs/symptoms prompting imaging.Given excellent local control with RT and radical resection for intermediate/high-grade STS of the extremity/trunk, SI of the primary site should be reserved for select patients at high risk of LR. Conversely, due to frequent occurrence of asymptomatic DR in the lungs, periodic lung SI is appropriate. Routine abdominopelvic SI may not be indicated for most histologies.

Purpose To conduct phase 1 and 2 trials with photon intensity modulated radiation therapy and intensity modulated proton therapy (IMPT) arms to selectively escalate the retroperitoneal sarcoma preoperative radiation dose to tumor volume (clinical target volume [CTV] 2) that is judged to be at a high risk for positive margins and aim to reduce local recurrence. We report on the IMPT study arm in phase 1. Methods and materials Patients aged ≥18 years with primary or locally recurrent retroperitoneal sarcoma were treated with preoperative IMPT, 50.4 GyRBE in 28 fractions, to CTV1 (gross tumor volume and adjacent tissues at risk of subclinical disease) with a simultaneous integrated boost to CTV2 to doses of 60.2, 61.6, and 63.0 GyRBE in 28 fractions of 2.15, 2.20, and 2.25 GyRBE, respectively. The primary objective of the phase 1 study was to determine the maximum tolerated dose to CTV2, which will be further tested in the phase 2 study. Results Eleven patients showed increasing IMPT dose levels without acute dose limiting toxicities that prevented dose escalation to maximum tolerated dose. Acute toxicity was generally mild with no radiation interruptions. No unexpected perioperative morbidity was noted. Eight months postoperatively, one patient developed hydronephrosis that was treated by stent with ureter dissected off tumor and received 57.5 GyRBE. Retained ureter(s) was (were) subsequently constrained to 50.4 GyRBE without further problem. With an 18-month median follow-up, there were no local recurrences. Conclusions IMPT dose escalation to CTV2 to 63 GyRBE was achieved without acute dose limiting toxicities. The phase 2 study of IMPT will accrue patients to that dose. Parallel intensity modulated radiation therapy phase 1 arm is currently accruing at the initial dose level. Ureters that undergo a high dose radiation and/or surgery are at risk for late hydro-ureter. Future studies will constrain retained ureters to 50.4 GyRBE to avoid ureteral stricture.