Prospective analysis of oncogenic driver mutations and environmental factors: Japan molecular epidemiology for lung cancer study

Purpose Oncogenic driver mutations are critical for lung cancer development and serve as therapeutic targets. However, their associations with environmental factors are not fully understood. We aimed to elucidate the relationship between tumor developmental biology and exposure to environmental factors. Patients and Methods This was a prospective, multicenter, molecular epidemiology study. Eligible patients were those with newly diagnosed stages I to IIIB non-small-cell lung cancer (NSCLC) who underwent surgery. The tumors were examined for somatic mutations in 72 cancer-associated genes by targeted deep sequencing, estrogen receptorβ (ERβ) expression using immunohistochemical staining, and infection with any of 37 types of human papillomavirus (HPV) using a polymerase chain reaction-based microarray system. Detailed information on patient demographics and environmental factors was obtained from a comprehensive questionnaire. Results From July 2012 to December 2013, 957 patients were enrolled, and molecular analyses were performed on 876 samples (from 441 ever- and 435 never-smokers). Oncogenic driver mutations in P53 and KRAS increased proportionally with smoking status, whereas mutations in EGFR and SMAD4 decreased. KRAS mutations in smokers and SMAD4 mutations were observed more frequently in proportion to body mass index. TP53 and NFE2L2 mutations were observed more frequently in advanced NSCLC stages. As for never-smokers, no environmental factors were significantly associated with mutational changes. EGFR mutations and TP53 mutations were observed more frequently in women and in men, respectively. Mutations in these two genes were also potentially associated with ERβ expression. Only three patients (0.3%) were HPV positive. Conclusion The mutational spectrum is associated with smoking, body mass index, and other environmental factors, as well as with ERβ expression. Little association was observed between HPV and NSCLC.