Antibiotic Use and Colorectal Cancer in Olmsted County, Minnesota

Area of Science:

• Gastroenterology
• Oncology
• Epidemiology

Background:

• Antibiotic use is widespread, and its potential long-term effects on cancer risk are a growing concern.
• Previous studies have yielded conflicting results regarding the association between antibiotic exposure and colorectal cancer (CRC).

Purpose of the Study:

• To investigate the association between antibiotic use and CRC risk.
• To explore potential effect modification by tumor site, age, and antibiotic class.

Main Methods:

• Retrospective case-control study using Rochester Epidemiology Project (REP) data.
• Matched 512 CRC cases with 1942 controls.
• Categorized antibiotic exposure into none, low, intermediate, and high based on prescription duration.

Main Results:

• No statistically significant association between overall antibiotic use and CRC risk was found.
• Subgroup analyses revealed no significant associations by tumor location or antibiotic class.
• Individuals younger than 65 with low to intermediate antibiotic exposure showed a significantly reduced CRC risk.

Conclusions:

• Antibiotic exposure does not appear to increase overall CRC risk.
• The observed inverse association in younger adults suggests a need for further research in larger, diverse populations.