Surgical treatment of stage III thymic tumors: a multi-institutional review from four Italian centers

OBJECTIVE: Radical surgery is the cornerstone of treatment for thymic tumors, but a complete surgical resection in stage III is not always achievable; and recurrence of disease is not rare. We reviewed the results of four centers with large experience in multimodality treatment of stage III thymic tumors. METHODS: Between 1980 and 2009, 249 patients (137 males: 112 females; median age 50 years) with stage III thymic tumors underwent surgery. Myasthenia gravis (MG) was present in 110 (44.2%) patients. A total of 94 (37.7%) patients received induction chemotherapy and 205 (82.7%) had adjuvant treatments. RESULTS: Thirty-day mortality was 0.8%. A total of 203 (81.6%) had R0, 26 (10.4%) R1 and 20 (8%) R2 resection. World Health Organization (WHO) histotype was: A in 2.4%, AB in 15.3%, B1 in 16.5%, B2 in 31.3%, B3 in 22.1%, and thymic carcinoma in 12.4%. The R0 rate was lower in patients who received induction chemotherapy (p=0.04), in B1-B2-thymic carcinoma histotypes (p = 0.05), and in patients without MG (p = 0.04). Overall 10-year survival rate was 64%; tumor-related and disease-free survival were 76% and 74%, respectively. At univariate analysis, R2 resection (p < 0.0001), recurrence of disease (p < 0.0001), absence of MG (p = 0.0009), thymic carcinoma (p = 0.002), age more than 50 years (p = 0.01), and vascular invasion (p < 0.0001) were predictors of poor survival. At multivariate analysis, type of resection (p < 0.0001), vascular involvement (p = 0.007), and recurrent disease (p < 0.0001) were independent predictors of prognosis. During follow-up, 43 (21.2%) patients developed recurrence. Patients with recurrence, who underwent redo surgery (n = 24), showed a similar survival to patients without recurrence. CONCLUSIONS: Multimodality treatment of stage III thymic tumors achieved good survival. Radical surgery, even at recurrence, seems to be the most important prognostic factor.