Long-term outcome after multimodality treatment for stage III thymic tumors

Background Surgery remains the cornerstone of therapy for thymic tumors, but the optimal treatment for advanced, infiltrative lesions is still controversial. The introduction of multimodality protocols has substantially modified survival and recurrence rate. We reviewed our 13-year prospective experience with multimodality treatment of stage III thymoma and thymic carcinoma. Methods Since 1989 we have prospectively used a multimodality approach in 45 stage III thymic tumors. Sixteen patients (35%) had myasthenia gravis. Twenty-three patients (51%) had pure or predominantly cortical thymoma (group 1), 11 (24.5%) had well-differentiated thymic carcinoma (group 2), and 11 (24.5%) had thymic carcinoma (group 3). Tumors that were not considered radically resectable at preoperative workup underwent biopsy and induction chemotherapy (15 patients, 33%) followed by surgical resection; all patients were referred for adjuvant chemoradiotherapy. Results No operative mortality was recorded; 1 treatment-related death during adjuvant chemotherapy was observed in group 1. Complete resection was feasible in 91% of patients in groups 1 and 2 and 82% in group 3. The overall 10-year survival was 78%. Ten-year survival for groups 1 and 2 was 90% and 85%, respectively; 8-year survival for group 3 was 56%. During follow-up, tumor recurrence was noted in 3 patients (13%) from group 1, 3 (27%) from group 2, and 3 (27%) from group 3. Conclusions Multimodality treatment with induction chemotherapy (when required) and adjuvant chemoradiotherapy offers encouraging results for stage III thymic tumors; the outcome is more favorable for cortical thymoma and well-differentiated thymic carcinoma.