Smoking history and frequency of somatic KRAS mutations in adenocarcinoma of the lung

7573 Background: Somatic mutations in the epidermal growth factor receptor (EGFR) gene are more common in patients with adenocarcinoma, especially those who smoked < 15 pack years (py). KRAS mutations are found in ∼25% of lung adenocarcinomas, most commonly in codons 12 and 13 of exon 2 (∼85%) and have been associated with poor prognosis in resected disease [Winton NEJM 2005] and resistance to EGFR tyrosine kinase inhibitors [Pao PLoS Med 2005]. KRAS mutations are uncommon in non-small cell lung cancer histologies other than adenocarcinoma. We sought to determine the association between quantitative measures of cigarette smoking and presence of KRAS mutations in lung adenocarcinomas. Methods: Standard direct sequencing techniques were used to identify KRAS codon 12 and 13 mutations in lung adenocarcinoma specimens from surgical resections between 2001 and 2006 and tumor specimens sent for KRAS molecular analysis in 2006. Surgical specimens were obtained from an institutional tumor bank. Detailed smoking h...