Thymic carcinoma outcomes and prognosis: Results of an international analysis

Objectives The objectives of this collaborative study were to characterize patients with thymic carcinoma, their treatment patterns, and association with overall survival (OS) and recurrence-free survival (RFS). Methods Clinical, pathologic, treatment, and follow-up information were analyzed. OS and RFS were the primary outcome measures. Results In 1042 cases of thymic carcinoma, 42 (5%) patients had pathologic Masaoka stage I, 138 (17%) had stage II, 370 (45%) had stage III, and 274 (33%) had stage IV disease. Overall, 166 patients (22%) underwent induction chemotherapy and 48 (6%) had preoperative radiation therapy. An R0 resection was performed in 447 cases (61%), R1 in 102 cases (14%), and R2 in 184 cases (25%). Squamous cell carcinoma was the predominant histologic subtype (n = 560; 79%). Adjuvant chemotherapy was administered to 237 (31%) patients, and 449 (60%) received adjuvant radiation therapy. The median OS was 6.6 years (95% confidence interval [CI], 5.8-8.3) and the cumulative incidence of recurrence at 5 years was 35% (95% CI, 30%-40%). In univariate analysis, early Masaoka stage, R0 resection, chemotherapy, and radiation therapy were associated with OS. Early Masaoka stage and R0 resection were also associated with RFS. On multivariable analysis, R0 resection and radiation therapy were associated with prolonged OS. Radiation therapy and male gender were associated with prolonged RFS. Conclusions R0 resection and radiation therapy are associated with improved OS, whereas radiation therapy and male gender are associated with longer RFS.