Antibiotic use and risk of colorectal cancer: a meta-analysis of 412 450 participants

We read with interest the study by Zhang et al 1 which investigated the associations between oral antibiotic use and risk of colorectal cancer (CRC). The study included 166 057 participants and found that antibiotic use was associated with an increased risk of colon cancer but a reduced risk of rectal cancer. We also noticed another study by Armstrong et al 2 reporting that patients prescribed antibiotics in up to 15 years preceding diagnosis were associated with a higher risk of CRC. However, the study by Armstrong et al did not analyse the risk of colon cancer and rectal cancer, respectively. Considering current studies about antibiotic use and risk of CRC were inconsistent, we conducted this meta-analysis. The PubMed and Web of Science were …