Role of postoperative radiotherapy in the management of malignant pleural mesothelioma : A propensity score matching of the SEER database.

INTRODUCTION: This study assessed the prognostic impact of postoperative radiotherapy in patients with surgically resected malignant pleural mesothelioma (MPM).

METHODS: MPM patients diagnosed between 2000 and 2013 were identified from the SEER (Surveillance, Epidemiology, and End Results) database. A propensity-matched analysis was performed considering baseline characteristics (age, gender, race, histology, TNM stage, and type of surgery).

RESULTS: A total of 2166 patients were identified. The median age was 60 years (range 25-85 years), and 469 patients received postoperative radiotherapy. Both before and after propensity score matching, overall survival (P < 0.0001 and P = 0.012, respectively) was better in the postoperative radiotherapy group. When the overall survival was stratified by histology, postoperative radiotherapy did not improve the survival in sarcomatoid histology patients both before and after matching (P = 0.424 and P = 0.281, respectively). In multivariate analysis of the matched population, not receiving postoperative radiotherapy did not correlate with worse survival (hazard ratio: 1.175; P = 0.12). Factors associated with worse survival include sarcomatoid histology, nodal positivity, and age ≥70.

CONCLUSION: Evidence from this analysis is insufficient on its own to routinely recommend postoperative radiotherapy for surgically resected MPM. However, large-scale prospective clinical trials are warranted to further evaluate this intervention in nonsarcomatoid histology.