Prognostic Indicators After Surgery for Thymoma

Background: We undertook a 20-year retrospective institutional study to investigate prognostic indicators after surgery for thymoma. Methods: From 1989 to 2009, 83 patients underwent surgical resection of thymoma or thymic carcinoma at our institution. Twelve of these patients were determined to have either World Health Organization type C disease or Masaoka stage IV-B disease and were excluded from analysis. The remaining 71 patients were reviewed. Results: The majority of patients in this series were female 64.7% (n = 46) with an overall average age of 51.0 years. The distribution of Masaoka stages I, II, III, and IV-A was 40.8% (n = 29), 19.7% (n = 14), 18.3% (n = 13), and 21.1% (n = 15), respectively. Thirteen of the 28 (46.2%) patients who presented with stage III or IV-A disease received preoperative chemotherapy. After a mean follow-up of 66 months (range, 6 to 241 months), 54 (75.3%) patients are alive and well while six are alive with disease. Eleven (16.0%) patients have died, but only 3 (4.3%) of these patients died of thymoma. The overall disease-specific survival was 97% and 89% at 5 and 10 years. Of the variables analyzed, only age was predictive of overall survival (p = 0.03). Masaoka stages I to III as compared with stage IV-A was significantly predictive of disease-free survival (p < 0.01). Conclusions: Long-term disease-specific survival can be expected not only after surgery for early stage thymoma but also after surgery for advanced disease, including patients with pleural metastases. However, patients who undergo surgery for stage IV-A disease have reduced disease-free survival. Late mortality due to secondary cancers and associated immunologic disorders was more frequent than mortality from thymoma in this series.