Association between Smoking and Molecular Subtypes of Colorectal Cancer

Background Smoking is associated with colorectal cancer (CRC) risk. Previous studies suggested this association may be restricted to certain molecular subtypes of CRC while large-scale comprehensive analysis is lacking. Methods A total of 9,789 CRC cases and 11,231 controls of European ancestry from 11 observational studies were included. We harmonized smoking variables across studies and derived sex-study-specific quartiles of pack-years of...