Survival impact of adjuvant radiotherapy in Masaoka stage II-IV thymomas – A systematic review and meta-analysis
A partir d'une revue systématique de la littérature publiée jusqu'en août 2015 (7 études incluant au total 1 724 patients), cette méta-analyse évalue le bénéfice, en termes de survie globale, d'une radiothérapie chez les patients atteints d'un thymome de stade II à IV (selon la classification de Masaoka)
Purpose : Due to the lack of randomized evidence, no conclusion has been made concerning the role of postoperative radiotherapy (PORT) in thymomas. This systematic review and meta-analysis evaluated the survival impact of PORT in stage II-IV thymomas. Methods and Materials : A database search was conducted with EMBASE, PubMed, Web of Science, Cochrane Library, and Ovid from inception to August 2015. Thymic carcinomas were excluded, and studies comparing overall survival (OS) with and without PORT in thymomas were included. The hazard ratios (HRs) of OS were extracted, and a random-effects model was used in the pooled analysis. Results : Seven retrospective series with a total of 1,724 patients were included and analyzed. Almost all of the patients underwent macroscopically complete resection, and thymoma histology was confirmed by the World Health Organization criteria. In the overall analysis of stage II-IV thymomas, OS was not altered with the receipt of PORT (HR 0.79, 95% confidence interval [CI] 0.58‒1.08). Although PORT was not associated with survival difference in Masaoka stage II disease (HR 1.45, 95% CI 0.83‒2.55), improved OS was observed with the addition of PORT in the discrete pooled analysis of stage III-IV (HR 0.63, 95% CI 0.40‒0.99). Significant heterogeneity and publication bias were not found in the analyses. Conclusions : From the present meta-analysis of the sole primary thymomas, we suggest the potential OS benefit of PORT in locally advanced tumors with macroscopically complete resection, but not in stage II disease. Further investigations with sufficient survival data are needed to establish detailed treatment indications.