The main study population was recruited from a prospective cohort study, the Nord-Trøndelag Health study
(HUNT). In this population, we found 1206 cases of lung cancer. Adding the 436 cases from the Pemetrexed Gemcitabine
study (PEG study) and the 210 cases of lung cancer from the Norwegian Lung Cancer Biobank study (NLCB
registry study), we identified a total of 1852 cases of lung cancer that were evaluated for inclusion into our study.