Apoptosis-Related (Survivin, Bcl-2), Tumor Suppressor Gene (p53), Proliferation (Ki-67), and Non-Receptor Tyrosine Kinase (Src) Markers Expression and Correlation With Clinicopathologic Variables in 60 Thymic Neoplasms

Abstract

Our objective was to investigate the expression of survivin, Bcl-2, p53, Ki-67, and Src in thymic neoplasms and analyze their interrelationship with clinicopathologic variables. A series of 60 thymic neoplasms was reviewed and classified according to the World Health Organization (WHO) scheme. Key clinical information, including Masaoka stage, recurrence-free survival (RFS), and overall survival (OS) was obtained. The percentage and staining intensity of listed markers were recorded. The correlation of markers and clinicopathologic variables was statistically analyzed using the Fisher exact test and log-rank test. There were 7 type A, 15 type AB, 8 type B1, 5 type B2, 17 type B3 thymomas, and 8 thymic carcinomas. Seven patients (11.7%) died of the disease. Tumors recurred in eight patients (13.3%). Although p53 expression alone was found to be correlated with RFS with borderline significance (p = 0.056), patients with Src-positive and p53-positive coexpression had a shorter OS time than the other groups (p < 0.008). Cytoplasmic expression of survivin was present in 5 of 60 thymic neoplasms (8.3%), 4 of which were thymic carcinomas that all recurred. Regardless of WHO type and/or tumor stage, although p53 expression may predict recurrence in thymomas, p53 and Src coexpression can predict shorter OS, and cytoplasmic localization of survivin may predict recurrence in thymic carcinoma. These findings make thymic tumors a prime target for newly developed anti-Src and anti-survivin therapies.