Association between Antibiotic Use and Subsequent Risk of Prostate Cancer: A Retrospective Cohort Study in South Korea

Background: Several studies suggest that antibiotic use may affect overall cancer incidence, but the association between antibiotics and prostate cancer is still unclear. Methods: A population-based retrospective cohort study was conducted using the Korean National Health Insurance Service (NHIS) database. 1,032,397 individuals were followed up from January 1, 2007, to December 31, 2019. Multivariate Cox hazards regression was utilized to calculate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for the risk of prostate cancer according to accumulative days of antibiotic use and the number of antibiotic classes used. Results: Individuals who used antibiotics for 180 or more days had a higher risk of prostate cancer (aHR, 1.46; 95% CI, 1.11-1.91) than those who did not use antibiotics. Also, individuals who used four or more kinds of antibiotics had a higher risk of prostate cancer (aHR, 1.18; 95% CI, 1.07-1.30) than antibiotic non-users. A similar trend was observed among participants who underwent health examinations. Conclusion: Our findings suggest that long-term use of antibiotics may affect prostate cancer incidence. Further studies are needed to improve understanding of the association between antibiotic use and prostate cancer incidence.