K‐ <i>ras</i> oncogene activation in lung adenocarcinomas from former smokers evidence that K‐ <i>ras</i> mutations are an early and irreversible event in the development of adenocarcinoma of the lung

Abstract excerpt

BACKGROUND: Point mutations in codon 12 of the K-ras protooncogene occur more frequently in lung adenocarcinomas from smokers (30%) than they do in lung adenocarcinomas from nonsmokers (7%), suggesting that smoking is an important factor in the induction of these mutations. The lack of well defined "early" premalignant or in situ glandular neoplasms of the lung, however, has not permitted direct evaluation of the...