EJMS

Abstract

Background: Non-small cell lung carcinoma (NSCLC) is predicted to claim over 3 million lives worldwide each year and comprises over 80% of lung cancer subtypes. It is usually only detected at an advanced stage of development, and is almost invariably already disseminated at diagnosis. Optimal treatment decisions and patient selection rely strongly on prognostic factors. The clinical stage, determined by imaging methods and endoscopic evaluation, is the most important guideline for surgical treatment decisions. Understanding the molecular basis of carcinogenesis has led to the development of “molecular staging” techniques to predict cancer aggressiveness. Methods: The current study analyzed the immunohistochemical expression of p53 and Bcl-2 proteins in 60 cases diagnosed as non-small cell lung carcinoma including 26 adenocarcinomas, 23 squamous cell carcinomas, 9 large cell carcinomas and 2 bronchial carcinoid tumors. Both proteins were expressed in 48.3% and 33.3% of cases respectively. Results: P53 expression was significantly associated with tumor grade and nodal status (p=0.045 and 0.01, respectively). Bcl-2 overexpression was significantly associated with histological type (p= 0.02) where a significantly higher expression rate was seen in squamous cell carcinoma compared to other types. Bcl-2 protein expression was also significantly associated with early tumor stages (p=0.02). No significant association was noted between the expression of p53 and Bcl-2 and any other clinicopathological features. No significant correlations between the expression of p53 and Bcl-2 could be identified in this series of NSCLC. Conclusions: P53 expression in NSCLC is more pronounced in tumors showing moderate or poor differentiation and those having hilar lymph node involvement; hence it is related to some of the poor prognostic factors in NSCLC. Bcl-2 over-expression appears to be an important event in tumorigenesis of NSCLC and loss of Bcl-2 expression could be a late event occurring mostly in the late stages of the disease.