MULTIMODALITY TREATMENT OF THYMOMA - A PROSPECTIVE-STUDY

Background. Thymomas are a heterogeneous group of tumors. Treatment of invasive lesions is not well standardized. The aim of this study is t o propose a clinicopathologically based protocol for multimodality the rapy. Methods. Between 1965 and 1988, we operated on 83 patients with thymoma who did not receive standardized adjuvant therapy. In 1989, on the basis of the retrospective analysis of the data, we started a mul timodality therapy protocol and used it for 65 patients. Twelve patien ts had medullary thymoma (11 stage I and 1 stage II), 13 had mixed typ e (6 stage I and 7 stage II), and 40 had cortical thymoma (4 stage I, 11 stage II, 12 stage III, and 13 stage IV). We considered three group s. Group I(n = 18 patients), benign thymoma, included stage I and II m edullary and stage I mixed thymomas; radical resection with no adjuvan t therapy was performed. Group II (n = 22), invasive thymoma, included stage I and II cortical and stage II mixed thymomas; postoperative ch emotherapy plus radiotherapy was always administered. Group III (n = 2 5), malignant thymoma, comprised stage III and IV cortical thymomas an d stage III mixed thymomas; resectable stage III lesions were removed, and highly invasive stage III and stage IV lesions underwent biopsy, neoadjuvant chemotherapy, and surgical resection; postoperative chemot herapy and radiotherapy was administered to all patients. Results. The 8-year survival rate for patients in stages I, II, III, and IV was 95 %, 100%, 92%, and 68%, respectively. Patients with medullary thymoma h ad a 92% 8-year survival rate; those with mixed type, 100%; and those with cortical thymoma, 85%. Group I had an 8-year survival rate of 94% ; group II, 100%; and group III, 76%. Survival was compared with that of patients operated on before 1989: differences were not significant for group I; survival improved in group II (100% versus 81%; p = not s ignificant); and group III showed significant improvement (76% versus 43%; p < 0.049). Conclusions. Multimodality treatment with neoadjuvant chemotherapy and adjuvant chemotherapy plus radiotherapy may improve the results of radical resection and the survival of patients with inv asive and malignant thymoma. (C) 1997 by The Society of Thoracic Surge ons.