Antibiotic Use Impacts Colorectal Cancer: A Double-Edged Sword by Tumor Location?

The authors identified a positive dose-response antibiotic-cancer association primarily confined to the proximal colon with an inverse association between antibiotic exposure and rectal cancer. Given that most people are exposed to more than 1 antibiotic class over time (7), the independent effect of antibiotic class might be best revealed by studying prescriptions of single antibiotic classes. The authors report that antibiotics with anti-aerobic activity (eg, quinolones, trimethoprim-sulfonamide) seemed to drive the increased proximal colon risk, whereas multiple antibiotic classes associated with diminished rectal cancer risk. [Extracted from the article]