Which stages of thymoma benefit from adjuvant chemotherapy post-thymectomy?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'Which stages of thymoma benefit from adjuvant chemotherapy post thymectomy?' Altogether more than 150 papers were found using the reported search, of which only eight represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated; these studies have mainly reported the survival and recurrence rates of post-thymectomy patients who received adjuvant radiotherapy or chemoradiotherapy, and adjuvant radiotherapy alone was only used in a small group of patients in these studies. We did not find any randomized controlled trials comparing adjuvant chemotherapy with chemo/radiotherapy and, due to a very small incidence of this tumour, it is unlikely to see any trials in future. Studies were mainly retrospective or institutional reports and showed that, despite the high sensitivity of this tumour to chemotherapy agents and the use of chemotherapy as one of the main treatment modalities in the advanced stages of thymoma, current data are not supporting postoperative chemotherapy as a sole adjuvant treatment in advanced stages of thymoma. We conclude that, in patients with thymoma, surgical resection with or without radiation therapy is the gold standard treatment for early-stage disease (I and II). Adjuvant radiotherapy/chemoradiotherapy should be considered for Masaoka stage III (A and B) or above, and it is also advised to add adjuvant therapy for all patients with cortical fenestration, even in stages I and II. But there is no evidence that chemotherapy alone improves the survival in patients with completely resected stage III and IV thymomas and thymic carcinoma. In patients with extra-radiation field disease, however, the use of chemotherapy can potentially improve survival but no follow-up data on this group of patients are available.