Multicenter Institutional Experience of Surgically Resected Thymic Epithelial Tumors (TETs): An Observational Report on Behalf of F.O.N.I.C.A.P. (Forza Operativa Nazionale Interdisciplinare Contro il Cancro del Polmone)

Abstract

This multicenter analysis evaluated patient outcome and clinical pathologic features of thymic epithelial tumors after complete surgical resection and adjuvant treatment. Histologic classification and clinical staging were performed according to WHO classification and Masaoka staging system, respectively. We analyzed 62 patients, 20 (32%) of whom had myasthenia at diagnosis. Clinical and pathologic staging was as follows: 31 (50%) and 30 (48%) patients had stage I disease, 19 (30%) and 22 (35%) stage II, 5 (8%) and 3 (6%) stage III, 2 (4%) and 2 (3%) stage IVa, and 5 (8%) and 5 (8%) stage IVb, respectively. Histologic examination revealed 11 (19%) type A tumors, 19 (30%) type AB tumors, 7 (12%) type B1 tumors, 11 (17%) type B2 tumors, 11 (17%) type B3 tumors, and 3 (5%) type C tumors. Adjuvant therapies comprised chemotherapy in 3 (5%) patients and radiotherapy in 16 (26%) patients. Median follow-up was 71 months (range 1-145). DFS and OS at 48, 60, and 72 months were 89 and 89%, 86 and 97%, and 95% and 92%, respectively. Myasthenia at the onset of disease (P=0.18 for DFS; P=0.97) and tumor size>5 cm (P=0.94 for DFS; P=0.56) were not prognostic factors. TETs are rare and indolent tumors. Complete surgical resection followed by adjuvant therapies, such as chemotherapy and/or radiotherapy, in patients at risk of recurrence show very good DFS and OS results, even in cases with radically resected pleural-pulmonary metastases.