Prognostic value of K-ras mutations, ras oncoprotein, and c-erb B-2 oncoprotein expression in adenocarcinoma of the lung.

Abstract

This trial was undertaken to determine the prognostic role of K-ras (p21), c-erb B-2 (p185) protein expression, and the presence or nonpresence of a K-ras gene mutation in patients with adenocarcinoma of the lung. This was a retrospective study of 103 patients with adeno- or large-cell carcinoma of the lung who had available paraffin-stored tumor material. The relation of several clinical variables to survival was analyzed. Immunohistochemical techniques were used to determine expression of p21 and p185. Polymerase chain reaction (PCR) and sequencing were used to determine K-ras mutation status. Tumor stage was the only nonmolecular clinical variable predictive of survival (p=0.0001). A combination of K-ras mutation and p 185 expression (p=0.0144), ras mutation and strong p21 expression (p=0.0137), and K-ras mutation and the combined expression of p21 and p185 were predictive of poor survival (p=0.0415) in univariate analysis of all patients. The sole presence of K-ras mutation was predictive of survival. Additionally, when combined with elevated p21 or p185 expression in a subset of patients with 4 or more years of follow-up, negative correlation with survival was observed.