Correspondence to proton pump inhibitors and risk of colorectal cancer

We have read with interest the paper by Abrahami et al on the risk of colorectal cancer (CRC) with long-term proton pump inhibitor (PPI) usage with a new user and active comparator design (PPI users n=1 293 749 and histamine-2 receptor antagonist (H2RA) users n=292 387, from 1 January 1990 to 30 April 2018 with 1-year follow-up).1 The authors found that overall use of PPI did not increase the risk of CRC (HR 1.02, 95% CI 0.92 to 1.14). However, the HR increased by 2–4 years (HR 1.45, 95% CI 1.28 to 1.60) and more than 4 years (HR 1.60, 95% CI 1.42 to 1.80) with cumulative duration of PPI usage. Similar patterns were …