Predictors of recurrence in thymic tumors: Importance of invasion, World Health Organization histology, and size

This study sought to define predictors of recurrence after resection of thymic tumors. A single-institution retrospective study was performed of 179 patients who underwent resection of a thymic tumor from 1972 through 2003. Resection was complete in 90% (161/179) of patients. After a median follow-up of 115 months, the recurrence rate was 11% (20/179), the tumor-related death rate was 7.8% (14/179), and the overall death rate was 36.3% (65/179). Tumor recurrence correlated with advanced stage and histology ( P < .0001). The difference in recurrence between Masaoka stage I (0) and II (1.7% [1/59]) was insignificant. Recurrence rates correlated with World Health Organization tumor type: A and AB, 0%; B1 and B2, 8% (4/51); B3, 27% (14/51); and C, 50% (2/4; P < .0001). Tumor size separation into quintiles demonstrated a step-up of recurrence at 8 cm (