Predictors of survival in patients with myasthenia gravis and thymoma

BACKGROUND AND OBJECTIVE: Myasthenia Gravis (MG) and Thymoma have different clinical evolutions and survival. There are few studies grying to describe the prognosis factors in patients with both thymoma and MG. We have evaluated all patients with thymoma and associated MG who were treated in our unit in order to identify possible predictors of survival. PATIENTS AND METHOD: There were 108 patients with thymoma and associated MG treated at our center from 1967 to 2000. All data were analyzed by multivariate Cox regression analysis, which allowed quantification of the independent predictive value of prognostic indicators. RESULTS: Median follow-up was 10 years. Mortality was 35.2% (38 patients). In 14 (36.8%) cases, death was related to MG, and 6 (15.8%) patients died from a cause directly related to thymoma. Cox regression analysis found a predictive value for both an age older than 55 years and the need for tracheostomy during the postoperative period. CONCLUSIONS: In our series of patients with thymoma and associated MG, age older than 55 years and the need for postoperative tracheostomy were independent predictors of poorer overall survival.