Is antibiotics use really associated with increased risk of colorectal cancer? An updated systematic review and meta-analysis of observational studies

• Published in: International journal of colorectal disease 2020-08, Vol.35 (8), p.1397-1412
• Main Authors: Qu, Guangbo, Sun, Chenyu, Sharma, Monica, Uy, John Patrick, Song, Evelyn J., Bhan, Chandur, Shu, Liqin
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - adverse effects; Antibiotics; Colon cancer; Colonic Neoplasms; Colorectal cancer; Colorectal carcinoma; Colorectal Neoplasms - chemically induced; Colorectal Neoplasms - epidemiology; Gastroenterology; Health risk assessment; Hepatology; Humans; Internal Medicine; Medicine; Medicine & Public Health; Meta-analysis; Observational studies; Observational Studies as Topic; Proctology; Quinolones; Rectal Neoplasms; Rectum; Review; Risk Factors; Surgery; Systematic review
• ISSN: 0179-1958; 1432-1262
• DOI: 10.1007/s00384-020-03658-z

Purpose The association between antibiotics and colorectal cancer (CRC) risk has drawn increasing attention but remains controversial. This study was performed to clarify the association. Methods A systematic review and meta-analysis was performed on seven electronic databases. The pooled odds ratios (OR) with a 95% confidence interval (CI) were calculated to estimate the association using the fixed-effects model or the random-effects model. Results Ten studies that contained 4,853,289 participants were included in our study. We found that antibiotics use was associated with a higher risk of CRC (OR 1.09, 95%CI 1.02–1.17, I 2 = 92.8%). More than 60 days of antibiotics use and 5 prescriptions of antibiotics were significantly associated with a higher risk of CRC. Sub-analysis on different types of antibiotics found that anti-anaerobic antibiotics, penicillins, and quinolones use led to increased risk of CRC (OR 1.22, 95% CI 1.04–1.44, I 2 = 89.1%; OR 1.09, 95% CI 1.04–1.13, I 2 = 69.2%; OR 1.15, 95% CI 1.03–1.35, I 2 = 88.2%; respectively) and colon cancer (OR 1.28, 95% CI 1.04–1.58, I 2 = 98.5%; OR 1.09, 95% CI 1.05–1.12, I 2 = 0; OR 1.09, 95% CI 1.04–1.15, I 2 = 0; respectively). However, antibiotics use was not significantly associated with rectal cancer (OR 1.03, 95% CI 0.92–1.16, I 2 = 77.6%). Conclusion It needs attention that antibiotics use is associated with a higher risk of CRC, especially for colon cancer. Clinicians should be aware of the potential risk of CRC when prescribing anti-anaerobic antibiotics, penicillins, and quinolones in the future. Further studies are needed to assess any potential differences by tumor sites and class of antibiotics.