Overall survival in patients with re-excision of positive microscopic margins of limb and trunk wall soft tissue sarcoma operated outside of a reference center: a nationwide cohort analysis.

BACKGROUND: This French nationwide NETSARC exhaustive prospective cohort aims to explore the impact of systematic re-excision (RE) as adjuvant care on overall survival (OS), local recurrence free survival (LRFS), and local and distant control (RFS) in patients with soft tissue sarcoma (STS) with positive microscopic margins (R1) after initial resection performed outside of a reference center. METHODS: Eligible patients had experienced STS surgery outside a reference center from 2010 to 2017, and had R1 margins after initial surgery. Characteristics and treatment comparisons used chi-square for categorical variables and Kruskall-Wallis test for continuous data. Survival distributions were compared in patients reexcised (RE) or not (No-RE) using a log-rank test. A Cox proportional hazard model was used for subgroup analysis. RESULTS: A total of 1,284 patients had experienced initial STS surgery outside NETSARC with R1 margins, including 1,029 patients with second operation documented. Among the latter, 698 patients experienced re-excision, and 331 were not re-excised. Characteristics were significantly different regarding patient age, tumor site, tumor size, tumor depth, and histotype in the population of patients re-excised (RE) or not (No-RE). The study identified RE as an independent favorable factor for OS (HR 0.36, 95%CI 0.23-0.56, p<0.0001), for LRFS (HR 0.45, 95%CI 0.36-0.56, p<0.0001), and for RFS (HR 0.35, 95%CI 0.26-0.46, p<0.0001). CONCLUSION: This large nationwide series shows that RE improved overall survival in patients with STS of extremities and trunk wall, with prior R1 resection performed outside of a reference center. RE as part of adjuvant care should be systematically considered.

Alveolar soft part sarcomas in young patients: The French national NETSARC+ network experience.

BACKGROUND AND AIMS: Alveolar soft part sarcoma (ASPS) is an ultra-rare chemo-resistant sarcoma in children, occurring preferentially in young adults. We aimed to describe and compare its clinical presentation and behaviour in children and young adults to determine whether the same therapeutic strategy should be addressed for both populations. METHODS: National retrospective multicentre study of children (0-18 years) vs. young adults (19-30 years) included in the "ConticaBase" sarcoma database, treated for ASPS between 2010 and 2019 with pathology reviewed via the NETSARC + network. RESULTS: Overall, 45 patients were identified, 19 children (42%) and 26 young adults (58%). All ASPS diagnoses were confirmed with TFE3 rearrangement by immunohistochemistry or FISH. All clinical characteristics were balanced between both populations with frequent metastases at diagnosis (8/19 vs. 10/26). The therapeutic strategy was based on surgery (17/19 vs. 21/26), radiotherapy (8/19 vs. 12/26) ± systemic treatment (8/19 vs. 9/26). In patients with initially localized disease, metastatic relapse occurred only in adults (8/16), whereas metastatic progression was present in both metastatic groups (5/8 vs. 8/10). After a median follow-up of 5.2 years (range, 0.2-12.2), 5-year EFS was 74% [95%CI, 56-96] vs. 47% [30-74] (p = 0.071) respectively, and 5-year OS was 95% [85-100] vs. 85% [70-100] (p = 0.84). For localized tumours, 5-year MFS was 100% [100-100] vs. 60% [39-91] (p = 0.005). The 5-year OS of all patients with metastasis at diagnosis was 80.2% (62.2%-100%). CONCLUSIONS: ASPS appears to have the overall same clinical characteristics, but a more aggressive behaviour in young adults than in children. However, despite frequent metastases at diagnosis, long-term survival is high in both groups. Overall, the same therapeutic strategies may be considered for both populations.

Improved Metastatic-Free Survival after Systematic Re-Excision Following Complete Macroscopic Unplanned Excision of Limb or Trunk Soft Tissue Sarcoma.

BACKGROUND: Whether re-excision (RE) of a soft tissue sarcoma (STS) of limb or trunk should be systematized as adjuvant care and if it would improve metastatic free survival (MFS) are still debated. The impact of resection margins after unplanned macroscopically complete excision (UE) performed out of a NETSARC reference center or after second resection was further investigated. METHODS: This large nationwide series used data from patients having experienced UE outside of a reference center from 2010 to 2019, collected in a French nationwide exhaustive prospective cohort NETSARC. Patient characteristics and survival distributions in patients reexcised (RE) or not (No-RE) are reported. Multivariate Cox proportional hazard model was conducted to adjust for classical prognosis factors. Subgroup analysis were performed to identify which patients may benefit from RE. RESULTS: Out of 2371 patients with UE for STS performed outside NETSARC reference centers, 1692 patients were not reviewed by multidisciplinary board before treatment decision and had a second operation documented. Among them, 913 patients experienced re-excision, and 779 were not re-excised. Characteristics were significantly different regarding patient age, tumor site, size, depth, grade and histotype in patients re-excised (RE) or not (No-RE). In univariate analysis, final R0 margins are associated with a better MFS, patients with R1 margins documented at first surgery had a better MFS as compared to patients with first R0 resection. The study identified RE as an independent favorable factor for MFS (HR 0.7, 95% CI 0.53-0.93; p = 0.013). All subgroups except older patients (>70 years) and patients with large tumors (>10 cm) had superior MFS with RE. CONCLUSIONS: RE might be considered in patients with STS of limb or trunk, with UE with macroscopic complete resection performed out of a reference center, and also in originally defined R0 margin resections, to improve LRFS and MFS. Systematic RE should not be advocated for patients older than 70 years, or with tumors greater than 10 cm.

Impact of the coronavirus disease 2019 pandemic on sarcoma management in France: a 2019 and 2020 comparison.

Background: The coronavirus disease 2019 (COVID-19) pandemic was an unprecedented shock to the healthcare systems, and its consequences on managing rare cancers are unknown. We investigated COVID-19's impact on the activity of sarcoma-labeled networks by comparing key indicators in 2019-2020 (before and during the pandemic, respectively). Methods: We compared the incidence of limb and trunk soft tissue sarcomas, surgery rate, surgery center, surgery quality, and surgery delays nationally and in various regions, focusing on the three most severely affected regions. Findings: In this study, sarcoma incidence did not decrease, and the tumor and patient characteristics were similar in both years. The number of patients who underwent surgery in the labeled centers increased significantly (63% versus 57%, p = 0.015), the rate of R0 resection increased (55% versus 47%, p = 0.004), and the rate of re-excision decreased (12% versus 21%, p < 0.0001). In the univariate analysis, the time to surgery was similar in both years. Cox regression analysis revealed that the factors associated with a longer time to surgery were age > 70 years (p = 0.003), retroperitoneal location (p > 0.001), tumor size (p < 0.001), deep tumors (p < 0.001), and regions (p < 0.001). However, we have observed an increase in the time before surgery in the regions most stroked by the COVID-19 pandemic. Interpretation: The model of the labeled center network for managing rare tumors was resilient. Paradoxically, the quality indicators improved during the pandemic due to the direct referral of patients with sarcomas to the labeled centers. Summary: This study shows that a nationwide network organization has made it possible to maintain care for these rare tumors during the pandemic.

Locally aggressive rarely metastazing tumors and low-grade sarcoma in children, adolescents and young adults: The benefits of a national network.

INTRODUCTION: Complete surgical resection constitutes the mainstay of treatment for locally aggressive, rarely metastazing tumor and low-grade soft tissue sarcomas (LAS). Local relapse is the most common tumor event, especially in the presence of positive margins (R1 margins). The aims of this study are to assess the impact of the national network on patient care and to evaluate the role of immediate re-excision in children, adolescents and young adults with incompletely resected LAS. METHODS: National retrospective multicenter study of all young patients (≤25 years) included in the Sarcoma "ConticaBase" treated for LAS between 2005 and 2017 for whom pathology/biology review was available via the national NETSARC + network. RESULTS: A total of 96 patients were identified (median age: 16 years). Tumors were localized in 99% of cases (1 N+ tumor). With a median follow-up of 4.7 years (range: 0.1-11.9), eight local relapses and two distant metastases were observed. No patient died. Overall 5-year event-free survival (EFS) was 90.4% [95%CI, 84.3-97]. Five year EFS for R1 patients (n = 51) with (n = 24) and without (n = 27) immediate re-excision was 90.5% [95%CI, 78.8-100.0] and 80.3% [95%CI, 64.7-99.9], respectively (p = 0.34). The 37 patients directly treated in a reference center more commonly had a diagnostic biopsy (78% vs. 21%; p < 0.001), more complete surgery (R0: 65% vs. 14%; p < 0.001) and less commonly underwent re-excision (16% vs. 54%; p < 0.001). CONCLUSIONS: This large series indicates that LAS are rare in young patients and have a favorable prognosis. Immediate management in reference centers is associated with better standard of care. The main tumor events are local relapses.

Nationwide incidence of sarcomas and connective tissue tumors of intermediate malignancy over four years using an expert pathology review network.

BACKGROUND: Since 2010, nationwide networks of reference centers for sarcomas (RREPS/NETSARC/RESOS) collected and prospectively reviewed all cases of sarcomas and connective tumors of intermediate malignancy (TIM) in France. METHODS: The nationwide incidence of sarcoma or TIM (2013-2016) was measured using the 2013 WHO classification and confirmed by a second independent review by expert pathologists. Simple clinical characteristics, yearly variations and correlation of incidence with published clinical trials are presented and analyzed. RESULTS: Over 150 different histological subtypes are reported from the 25172 patients with sarcomas (n = 18712, 74,3%) or TIM (n = 6460, 25.7%), with n = 5838, n = 6153, n = 6654, and n = 6527 yearly cases from 2013 to 2016. Over these 4 years, the yearly incidence of sarcomas and TIM was therefore 70.7 and 24.4 respectively, with a combined incidence of 95.1/106/year, higher than previously reported. GIST, liposarcoma, leiomyosarcomas, undifferentiated sarcomas represented 13%, 13%, 11% and 11% of tumors. Only GIST, as a single entity had a yearly incidence above 10/106/year. There were respectively 30, 64 and 66 different histological subtypes of sarcomas or TIM with an incidence ranging from 10 to 1/106, 1-0.1/106, or < 0.1/106/year respectively. The 2 latter incidence groups represented 21% of the patients with 130 histotypes. Published phase III and phase II clinical trials (p<10-6) are significantly higher with sarcomas subtypes with an incidence above 1/106 per. CONCLUSIONS: This nationwide registry of sarcoma patients, with exhaustive histology review by sarcoma experts, shows that the incidence of sarcoma and TIM is higher than reported, and that tumors with a very low incidence (1<106/year) are less likely to be included in clinical trials.

Geographical Accessibility of the Referral Networks in France. Intermediate Results from the IGéAS Research Program.

Rare cancer patients face lower survival and experience delays in diagnosis and therapeutic mismanagement. Considering the specificities of rare cancers, referral networks have been implemented in France to improve the management and survival of patients. The IGéAS research program aims to assess the networks' ability to reduce inequalities. Data analysis of the IGéAS cohort (n = 20,590, sarcoma diagnosed between 2011 and 2014) by gathering medical data and geographical index will identify risk factors associated with the belated access to expertise or with no access to expertise. Intermediate results show that referral networks give sarcoma patients access to sarcoma expertise despite the remoteness of some of them. Regional expert centers mostly receive requests from within their area while national referral centers receive requests from the whole country. Delays in the access to expertise may be reduced by making outside practitioners more sensitive to the issues of rare cancers. The perception and involvement of outside practitioners in this device will be assessed using a qualitative survey. All the results are discussed and will contribute to design guidelines to improve early access to expertise and reduce inequalities. Results of the IGéAS research program may contribute to the assessment of referral sarcoma networks and provide some useful lessons to improve cancer care management.