Lu SSM, Mohammed Z, Häggström C, et al. - This nationwide, population-based study revealed a robust link between antibiotics use and higher risk of proximal colon cancer and an inverse link with rectal cancer in women in Sweden.

• Complete-population data were obtained from Swedish national registers for the period 2005-2016, covering the entire population of Sweden.

• A total of 40,545 colorectal cancer (CRC) cases and 202,720 controls were analyzed.

• Full dataset showed more frequent antibiotics use was positively linked with CRC, excluding antibiotics prescribed within 2 years of diagnosis attenuated results toward the null.

• Excluding the 2-year washout, the positive link was restricted to the proximal colon (adjusted odds ratio for very high use vs no use = 1.17).

• An inverse link with rectal cancer was seemed to be driven by women.

• Results reinforce the evidence from earlier studies.