Prognostic factors in thymic epithelial neoplasms.

Abstract

The primary thymic epithelial neoplasms (PTENs) are uncommon tumours with a broad spectrum of both biological and morphological features. The aim of this study is to analyse the prognostic factors that influence survival. Forty-four patients with a complete follow-up were analysed. Nine patients (20.5%) were asymptomatic, the most common symptoms in the rest being myasthenia gravis and dyspnoea. All the patients underwent surgery, 30 cases (68.2%) receiving total thymectomy and the rest a partial resection or biopsy. Marino-Müller's histological classification showed the mixed type to be the most common (52.3%). Clinical staging was done according to the Masaoka classification, which gave the most common stage as stage III (34.1%). Twelve patients died during a mean follow-up of 8.2 +/- 3.5 years. The accumulated survival rate was 77% at 5 years and 60% at 10 years. Analysis of the survival curves shows significant differences (P<0.05) when considering surgical technique, clinical staging and histological subtype. The multivariate analysis shows the only parameters with prognostic significance in PTENs to be clinical staging and histological type (P<0.001). The most important prognostic factors in PTENs are Masaoka's clinical staging and Marino-Müller's histological subtype.