THYMOMA - PROGNOSTIC FACTORS

The relative importance of factors influencing prognosis and survival in the treatment of thymoma is still controversial. Fifty-three patien ts operated on for thymoma from 1966 to 1990 were evaluated, 14 with m yasthenia gravis and 39 without. Survival was analyzed as it related t o associated disease, gross invasion by the tumor and the predominant cell type. Follow-up information was obtained in all cases (mean obser vation time: 11.2 years). A high proportion (51%) of our patients had invasive forms (stages III and IV). The overall 5-, 10- and 20-year su rvival rates were 52%, 46% and 21%, respectively. Factors indicating a poor prognosis included local invasion (P < 0.0001), predominantly ep ithelial histologic features (P = 0.002), tumor-related symptoms and t he type of surgical procedure. Myasthenia gravis was not an adverse fa ctor for survival. The degree of tumor invasion was the main prognosti c factor and treatment should be planned accordingly.