Adjuvant radiotherapy for thymic epithelial tumors: a systematic review and meta-analysis.

Adjuvant radiotherapy after complete resection of localized, invasive thymic epithelial tumors is considered by many to be the standard of care, despite little supporting literature. We hypothesized that individual studies may lack statistical power to demonstrate a reduction in recurrence with this approach, but meta-analysis of published data may allow for more adequate statistical evaluation. Analysis of data from 592 patients with completely resected stage II or III thymic epithelial tumors, however, revealed no statistically significant reduction in recurrence after adjuvant radiotherapy (odds ratio 1.05; 95% confidence interval: 0.63 to 1.75; p = 0.840). Additionally, the majority of publications suggest that the most common sites of recurrence are the lung, pleura, and diaphragm, even when incompletely resected patients are included.