Background: beta-Catenin has been shown to function as a Wnt signaling molecule to stimulate cyclin D1 expression and cell growth in several kinds of tumors.
Methods: The authors immunohistochemically examined specimens of 217 surgically resected primary nonsmall cell lung carcinomas (NSCLCs) for beta-catenin expression and classified them semiquantitatively into three categories, including those with high, moderate, and low scores of expression.
Results: High, moderate, and low scores of expression were found in 37 (17.1%), 145 (66.8%), and 35 (16.1%) tumors, respectively. beta-Catenin expression was not correlated with cyclin D1 expression, but was positively correlated with the Ki-67 cell growth fraction (P = 0.04). The direct sequencing analysis for the beta-catenin gene mutation of 13 specimens of 217 tumors for the current study revealed no mutations. The relation between survival and beta-catenin expression was evaluated in 148 potentially curatively resected tumors with pathologic Stages I-IIIA. A trend toward better survival was found in patients with tumors having higher scores. In multivariate analysis, high beta-catenin expression was a significant and independent favorable prognostic factor (hazards ratio, 0.31; P = 0.007) as was pathologic stage. Analyzed by cell type, in nonsquamous cell carcinomas, patients with tumors having high scores survived a significantly longer time than those with tumors having moderate or low scores (5-year survival rates, 84%, 55%, and 32%, respectively; P = 0.02), and high beta-catenin expression tended to be a favorable prognostic factor (hazards ratio, 0.32; P = 0.052).
Conclusions: These results indicate that, in NSCLCs, increased expression of beta-catenin can predict favorable prognosis of patients with resected tumors, suggesting that accumulation of beta-catenin has no or little oncogenic effect via activation of the Wnt pathway, unlike in colon carcinomas or hepatomas.
Copyright 2002 American Cancer Society.