Surgical treatment of recurrent thymoma: is it worthwhile?†

Radical resection of thymoma is the most important predictor of survival; despite a complete resection, 10-30% of patients develop a recurrence. The surgical treatment of thymic relapses is an accepted therapeutic approach; however, no clear data are available yet regarding the indication for surgery and the long-term prognosis of this subset of patients. The aim of our work was to review the data of a group of recurrent thymomas treated by surgery, comparing it with non-surgical therapy, and analysing the outcome and the prognostic factors.

Between 1980 and 2010, 880 patients with thymoma underwent complete macroscopical resection and were followed up for recurrence. Masaoka stage IVa and type C thymic tumours were excluded from the study. A total of 82 (9.3%) patients developed a recurrence, and 52 (63.4%) were reoperated. The other 21 patients, originally operated outside, underwent surgical resection of recurrence. Finally, 73 patients were operated on for recurrent thymoma and 30 received medical treatment. This entire cohort represents the subject of the study.

There were 57 (55.3%) males and 46 (44.7%) females. The median time to relapse was 50 months. Sixty-three (61.2%) recurrences were regional, 17 (16.5%) local, 14 (13.6%) distant, 6 (5.8%) regional and distant, and 3 (2.9%) local, regional and distant. No operative mortality was observed. In 50 (68.5%) patients, a macroscopic complete resection was accomplished. The 5- and 10-year overall survival rates from recurrence were 63 and 37%, respectively. Complete surgical resection was associated with a significant better survival when compared with incomplete surgical resection and non-surgical treatment (P < 0.0001). A significant poorer prognosis was observed for multiple versus single relapses (P < 0.0001), Masaoka stage III primary tumour versus Masaoka stage I-II primary tumour (P = 0.02), distant versus loco-regional relapses (P = 0.05) and B3 histotype versus other (P = 0.02). On multivariate analysis, completeness of resection, number of metastases, Masaoka stage of primary tumour and site of relapse were identified as the only independent predictors of prognosis.

Reoperation for recurrent thymoma is effective and safe, achieving a prolonged survival. Complete macroscopic resection and single recurrence are associated with better prognosis.