Beta-catenin expression pattern in small cell lung cancer: correlation with clinical and evolutive features.

Beta-catenin expression in small cell lung carcinomas (SCLC) was investigated by immunohistochemical method using antibodies against beta-catenin. 50 pre-treatment biopsies were examined and the relationship between beta-catenin expression and the patients' relevant clinical characteristics, response to chemotherapy, time to relapse or progression, and overall survival, were analyzed. Beta-catenin expression exhibited different intensity within each sample, predominantly localized in the cytoplasm, and no sample showed nuclear expression. There was cytoplasmic hyperexpression in 14 cases, hypoexpression in 15 cases, and normal expression in 21 cases. We did not find any association between beta-catenin expression and clinical data. Our results show, however, correlation between beta-catenin cytoplasmic hyperexpression with a shorter time to progression (p=0.0437) as well as with a shorter overall survival (p=0.0253). Beta-catenin hyperexpression could have prognostic significance in SCLC.