Very High Antibiotic Use May Up Risk for Proximal Colon Cancer
Inverse association seen for antibiotic use and rectal cancer, which seems to be driven by women
THURSDAY, Sept. 9, 2021 (HealthDay News) -- There is a positive association between antibiotic use and proximal colon cancer and an inverse association with rectal cancer in women, according to a study published online Aug. 30 in the Journal of the National Cancer Institute.
Sai San Moon Lu, M.B.B.S., M.P.H., from Umeå University in Sweden, and colleagues conducted a nationwide, population-based study with matched case-control design with 40,545 colorectal cancer (CRC) cases and 202,720 controls to examine antibiotic use in relation to subsequent CRC risk.
The researchers observed a positive association between more frequent antibiotic use and CRC using the full dataset; the results were attenuated toward null when excluding antibiotics prescribed within two years of diagnosis. Excluding the two-year washout, the positive association was confined to the proximal colon in site-specific analyses (adjusted odds ratio for very high use versus no use, 1.17). An inverse association was seen for rectal cancer, which seemed to be driven by women. There was a positive association observed for quinolones and sulfonamides and/or trimethoprim with proximal colon cancer, while across antibiotics classes, a more general inverse association was seen for rectal cancer.
"There is absolutely no cause for alarm simply because you have taken antibiotics," a coauthor said in a statement. "The increase in risk is moderate and the [effect] on the absolute risk to the individual is fairly small."
One author disclosed financial ties to AstraZeneca; a second author disclosed ties to Quretec Bio AB.