Role of postoperative radiotherapy in non-localized thymoma - Propensity-matched analysis of Surveillance, Epidemiology, and End Results (SEER) database
Menée à partir des données des registres américains des cancers portant sur 529 patients atteints d'un thymome non localisé (âge médian : 57 ans), cette étude évalue le bénéfice, en termes de survie, d'une radiothérapie postopératoire
Introduction : Due to a lack of randomized trials, the role of postoperative radiotherapy (PORT) in thymomas has not been established. This study evaluated the prognostic impact of the adjuvant treatment insurgically resected non-localized thymomas. Methods : Patients diagnosed between 2000 and 2010 were identified from the Surveillance, Epidemiology, and End Results (SEER) database (1973-2011registry). Cases with localized or organ-confined tumors were not included. Propensity-matched analysis was conducted considering baseline characteristics. Results : A total of 529 patients were identified. The median age was 57 years (range, 18-86), and 345 (65%) patients received PORT. Before and after propensity score matching, overall survival (OS) (p = 0.018 and 0.008, respectively) and disease-specific survival (DSS) (p = 0.007 and 0.008, respectively) were better in the PORT group. In multivariate analyses of the matched population, no receipt of PORTinduced poorerOS (HR 1.98, 95% CI 1.27-3.09) and DSS (HR 2.64, 95% CI 1.32-5.29). Primary tumor extensions of adjacent organs or structures and further contiguous extensions also resulted in worse outcomes (p< 0.001 and 0.039 for OS; p = 0.006 and 0.009 for DSS, respectively). In the subgroup analyses, PORT was associated with favorable OS in stage III and IV (p= 0.049 and 0.012, respectively) and DSS in stage III (p = 0.005). Conclusion : Regarding the independent prognostic significance of PORT, this population-based analysis demonstrates the survival benefits of PORT in relation to non-localized thymomas. We recommend consideration of PORT in the poor prognostic subset of stages III-IV in the contemporary era.