Surgical Treatment and Assessment of Prognostic Factors of Thymoma

The relative importance of various factors influencing the prognosis and survival in the treatment of thymoma is still controversial. Sixty ave patients operated on for thymoma from Jan. 1981 to Dec. 1994 were evaluated, 28 patients (43.1 %) with myasthenia gravis and 37 patients (56.9%) without. Masaoka staging revealed stage I disease in 28 patie ts(4).1%) , stage ll in 1) patients(20.0%), stage 111 In 22 patients(33.8%), stage IVa in 1 patients(1.5%), and stage IVb in 1 patient(1.5%). There was no operative mortality. A complete resection was performed in 48 patients (73.8%) patients, associated in 10 patients (15.4%) with postoperative adjuvant treatment(radiotherapy 5; chemotherapy 1: radio- and chemotherapy 4). Thymomas were found to be predominantly of the epithelial type in 16 patients(24.6%), predominantly Iymphocytic type in 18 patients(27.7%), and mlxed in 22 patients (33.9%). The overall 5- and 10-year survival rates were 87% and 82%, respectively, Factors indicating a poor prognosis included local invasion, incomplete excision, thymic carcinoma, advanced staging and myasthenia gravis. The de- gree of tumor invasion turned out to be the main prognostic factor, and treatment should be planned ac- cordingly. The prognosis is best predicted by the stage of the tumor as determined intraoperatively and is poorer in patie ts with incomplete resection than in those with complete resection of the thynoma. No recurrence developed In patients with stage I disease.ope