Nationwide Incidence of Sarcomas and Tumors of Intermediate Malignancy in France

Background: Since 2010, presentation to a designated sarcoma tumor board and pathological review by an expert network are mandatory for sarcoma patients in France. NETSARC+ (merging the 3 initial RREPS, RESOS & NETSARC) collected prospectively all cases of reviewed sarcomas and tumors of intermediate malignancy (TIM) nationwide. We report on the incidence of subtypes according to WHO classification from 2013 to 2016. Methods: Sarcoma or TIM confirmed by review of expert sarcoma pathologists were all prospectively integrated in the database; the results using the latest WHO classification are presented for the years 2013 to 2016, including yearly variations. Correlation of the incidence of each histotype with dedicated published clinical trials was conducted. Results: 139 different histological subtypes are reported among the 25172 patients with sarcomas (n = 18710, 64%) or TIM (n = 6460, 36%), respectively n = 5838, n = 6153, n = 6654, and n = 6527 yearly from 2013 to 2016. Over these 4 years, the observed yearly incidence of sarcomas, TIM, and both was therefore 79.7, 24.9 and 95.1/106/year, above that previously reported. GIST, liposarcoma, leiomyosarcomas, undifferentiated sarcomas represented 13%, 13%, 11% and 11% of all sarcomas. Only GIST, as a single entity exceeded a yearly incidence above 10/million per year. There were respectively 30, 63 and 66 different histological subtypes of sarcomas or TIM (single entities or lumped together, e.g. MPNST, or vascular sarcomas...) with an incidence ranging from 10 to 1/106/year, 1-0.1/106 per year, or < 0.1/106/year respectively. The 2 later “incidence groups” included 21% of the patients. The incidence of 8 histotypes varied significantly over this 4 years. Patients with tumors with an incidence above 1/106 per year have significantly higher numbers of dedicated published phase III and phase II clinical trials (p < 10-6). Conclusions: This nationwide registry of sarcoma patients with an histology reviewed by sarcoma experts shows that the incidence of sarcoma and TIM is higher than previously reported, may vary over years for some histotypes, and that tumors with an incidence < 10e6 have a much lower access to clinical trials. Funding Statement: NetSARC (INCA & DGOS) and RREPS (INCA & DGOS), RESOS (INCA & DGOS) and LYRICAN (INCA-DGOSINSERM 12563), Institut Convergence PLASCAN (17-CONV-0002), Association DAM’s, Ensemble contre Le GIST, Eurosarc (FP7-278742), la Fondation ARC, Infosarcome, InterSARC (INCA), LabEx DEvweCAN (ANR-10-LABX-0061), Ligue de L’Ain contre le Cancer, La Ligue contre le Cancer, EURACAN (EC 739521) funded this study. Declaration of Interests: The funders had no role in the study design, data collection, data analysis, data interpretation, or writing of the report.