Prognostic significance of expression of p53 oncoprotein in primary (stage I-IIIa) non-small cell lung cancer

Mutation of the p53 gene is one of the most common genetic abnormalities found in all types of human cancer. Accumulating evidence strongly indicates that p53 alterations play a role in tumorgenesis in non-small cell lung cancer (NSCLC). However, the role of p53 as a prognostic marker in NSCLC remains unclear. The data derived from the literature on prognostic impact of p53 in NSCLC has been a matter of controversy. Among the reasons for the discrepancy, are lack of correlation with key clinical parameters, patients with different stages, different antibodies used, and insufficient sample size. The intent of this study was to evaluate the prognostic value of p53 protein in a larger cohort of stage I-IIIa patients. Clinicopathological data was obtained on 179 patients with NSCLC. These data were correlated with the p53 status on the respective surgically resected tumors, using monoclonal antibody DO7. There is a significant relationship between strong p53 expression and patient survival. In a multivariate analysis, strong expression (> 50%) of the p53 oncoprotein is an independently favorable prognostic factor. Patients with strong p53 expression had a prolonged survival (p = 0.009, RR; 0.56, 95% CI: 0.35-0.86). The median time of survival for patients with strong and negative/weak p53 expression was more than 61 and 44 months, respectively. The present study suggests that p53 protein expression in tumor tissue may serve as a prognostic biomarker for NSCLC. This information may also potentially serve as a tool for clinical decision-making when selecting patients for adjuvant treatments of NSCLC.