Statin use reduces post-colonoscopy CRC risk

Individuals who use statins for ≥90 days before colonoscopy have a significantly reduced risk of colorectal cancer (CRC) after a negative procedure, a large retrospective cohort study in Hong Kong has shown.

The results, from 187,897 patients aged ≥40 years who underwent colonoscopy between 2005 and 2013, showed that pre-colonoscopy use of statins for ≥90 days was associated with a significant 28 percent reduction in risk of post-colonoscopy CRC for up to 3 years (subdistribution hazard ratio [SHR], 0.72; 95 percent confidence interval [CI], 0.55 to 0.95; p=0.018). [Gut 2019;68:1979-1985]

Of note, patients ≥60 years of age, women, and those without diabetes or polyps appeared to benefit more from statin use.

In the study, patients’ data were retrieved from the Hong Kong Hospital Authority’s Clinical Data Analysis and Reporting System. The data were analyzed for drug prescriptions up to 5 years before index colonoscopy, as well as post-colonoscopy CRC diagnosed at 6–36 months in the absence of a CRC diagnosis during the index procedure (PCCRC-3y). The patients’ (48.9 percent male) mean age was 62.1 years at index colonoscopy, and the follow-up duration was 560,471 person-years.

PCCRC-3y was diagnosed in 0.45 percent of patients, with 82.8 percent of the cases being distal cancers and 17.2 percent being proximal cancers. The median age at PCCRC-3y diagnosis was 75.9 years, and the median time from index colonoscopy to diagnosis of PCCRC-3y was 1.2 years.

The results showed a dose-related chemopreventive effect of statins, with a 7 percent reduction in risk of PCCRC-3y for every 100 increase in cumulative defined daily dose of statins used (SHR, 0.93; 95 percent CI, 0.87 to 0.99; p=0.023). The number needed to treat to prevent one case of PCCRC-3y was 498.

Of note, statin use was associated with a significant reduction in risk of PCCRC-3y in the proximal colon (SHR, 0.50; 95 percent CI, 0.28 to 0.91), but not in the distal colon (SHR, 0.80; 95 percent CI, 0.59 to 1.09).

“Subgroup analysis showed that statins were associated with a lower PCCRC-3y risk in patients ≥60 years of age [SHR, 0.72; 95 percent CI, 0.56 to 0.92], women [SHR, 0.35; 95 percent CI, 0.22 to 0.58], nondiabetic patients [SHR, 0.59; 95 percent CI, 0.42 to 0.81], and those without a history of polyps and/or polypectomy [SHR, 0.58; 95 percent CI, 0.41 to 0.83],” reported the investigators from the University of Hong Kong.

Among the 25,447 statin users, the most commonly used statin was simvastatin (59.7 percent), followed by atorvastatin (7.3 percent) and rosuvastatin (2.1 percent), while 20.9 percent of statin users changed agents.

Pre-colonoscopy use of statins for ≥90 days was also associated with a significant reduction in risk of all PCCRC that developed 6 months after the index colonoscopy (SHR, 0.75; 95 percent CI, 0.61 to 0.93; p<0.001). However, no significant association was seen between statin use and the development of any adenoma (odds ratio, 1.08; 95 percent CI, 0.97 to 1.20).