Statin use tied to lower colorectal-cancer risk after negative colonoscopy

Last Updated: 2019-03-15

By Will Boggs MD

NEW YORK (Reuters Health) - Statin use is associated with a reduced risk of colorectal cancer between six and 36 months after an initial negative colonoscopy, according to a retrospective study.

"Interestingly, the effects of statins appear to be specific to a group of cancers that developed within three years after colonoscopy, but not for cancers that developed beyond 3 years," Dr. Wai Keung Leung from La Ka Shing Faculty of Medicine at the University of Hong Kong told Reuters Health by email.

Postcolonoscopy colorectal cancer (PCCRC), most commonly involving the proximal colon, accounts for 9% of all diagnosed colorectal cancers. Several meta-analyses have found an association between statin use and a reduced risk of colorectal cancer (but not adenoma).

Dr. Leung's team used data from Hong Kong Hospital Authority's Clinical Data Analysis and Reporting System electronic healthcare database to investigate the potential effect of statins in reducing PCCRC.

Of the nearly 187,900 patients included in the analysis, 0.45% developed PCCRC within three years after their initial negative colonoscopy, an incidence of 15.2 per 10,000 person-years, the researchers report in Gut, online February 26.

In a propensity score-matched analysis of 17,662 statin users and 30,304 non-statin users, the risk of PCCRC at three years was 28% lower among statin users than among nonusers, with a number needed to treat to prevent one PCCRC case of 498.

The reduced risk associated with statin use was significant in proximal but not distal colon cancers.

In subgroup analyses, statins were associated with a significantly lower three-year risk of PCCRC in patients aged 60 years and older, in women, in nondiabetic patients and in patients without a history of polyps and/or polypectomy.

There was no significant association between statins and the CRC detection rate within six months or beyond three years after the index colonoscopy or between statins and the development of any adenoma.

"Our findings not only demonstrate the chemopreventive effects of statins on postcolonoscopy colorectal cancer development, but also implicate that statins mostly act by reducing the progression from adenoma to cancer," Dr. Leung said. "These findings may further suggest the potential beneficial effects of statins on reducing the progression of colonoscopy-missed lesions and, hence, interval-cancer development."

"Our results may, however, still require further prospective studies to be confirmed," he said.

SOURCE: https://bit.ly/2CdjfQB

Gut 2019.