Molecular Genetics of Lung AdenoCA : KRAS
About 30% of lung adenocarcinomas, especially the invasive mucinous adenocarcinomas, show activation of KRAS oncogene. This is an adverse prognostic indicator and is believed to be an early event in the carcinogenesis. Interestingly, KRAS mutations and EGFR mutations in lung adenocarcinomas are mutually exclusive and generally not seen together. The presence of a KRAS mutation is usually associated with lack of response to EGFR tyrosine kinase inhibitor therapy.