ACE inhibitors and ARBs lower colorectal cancer risk in some patients

Article written by Bruce Sylvester

Patients being treated with angiotensin converting enzyme inhibitors (ACE-i) or angiotensin II receptor blockers (ARBs) for high blood pressure and other conditions appear to be less likely to develop colorectal cancer within 3 years of a negative colonoscopy.

Researchers reported the findings on July 6, 2020 in Hypertension.

The authors said, “To our knowledge, this is the first study that specifically characterized the effect of ACE inhibitors/ARBs on PCCRC [post-colonoscopy colorectal cancer] developing within 3 years after a baseline colonoscopy negative for cancer. ACE inhibitors/ARBs were associated with a 22% lower PCCRC-3y risk in a duration-response manner. Our study was the largest reported study, including >180000 subjects with baseline colonoscopy negative for cancer, to show a significant chemoprotective effect of ACE inhibitors/ARBs.”

The researchers reviewed retrospectively health records of 187,897 adult patients (above 40 years old) in Hong Kong from 2005 to 2013.  All subjects had a negative baseline colonoscopy for colorectal cancer.

The investigators reported that subjects treated with ACE inhibitors or ARBs achieved a 22% lower risk of developing colorectal cancer during the three years after the baseline screening.

This benefits from ACE inhibitors and ARB therapy appeared in patients 55 or older and in those with a history of colon polyps.

They noted that the benefit was limited to three years after the baseline colonoscopy.

“The roles of ACE inhibitors and ARBs on cancer development are controversial and, in some cases, study findings are conflicting. Results of previous studies have been limited by several factors including a small number of patients and data only on short-term follow-ups. Our results provide new insights on a potential role of these medications for colorectal cancer prevention,” said author Wai K. Leung, M.D., clinical professor of medicine at the University of Hong Kong in Hong Kong, China. “This is the first study to show the potential beneficial effects of ACE inhibitors and ARBs on colorectal cancer development, based on a large group of patients who were colorectal cancer-free at the beginning of the study.” 

Leung continued, “While ACE-i and ARBs are taken by patients with high blood pressure, heart failure and kidney diseases, the reduction in colorectal cancer risk may be an additional factor for physicians to consider when choosing anti-hypertensive medications.”