Patients who take commonly prescribed drugs for high blood pressure and other conditions may also be getting protected against colorectal cancer, according to a new study published in the American Heart Association (AHA) journal Hypertension.
The class of drugs in the study include angiotensin-converting enzyme inhibitors (ACE-i) and angiotensin II receptor blockers (ARB), which relax and open blood vessels to reduce blood pressure. Previous studies have been conflicting—some have even found that they increased cancer risk—possibly because they had too few subjects for reliable conclusions. These new findings point to the medications’ potential benefits in lowering one’s risk of developing this colorectal cancer.
For the study, researchers reviewed the health records of nearly 188,000 adults in Hong Kong with a negative colonoscopy between 2005 and 2013.
Findings revealed that patients who took hypertension meds such as ACE-i or ARB were 22% less likely to develop colorectal cancer in the three years after a colonoscopy. Furthermore, ACE-i and ARBs were beneficial to patients age 55 and older as well as those with a history of colon polyps.
The study was retrospective, meaning it looked back at whether patients taking these meds developed colorectal cancer. To confirm the findings, the researchers recommend that there also be a prospective study, which would follow patients to determine the potential benefits of these medications on disease risk. But they suggest that the current findings are strong enough for physicians to consider as they counsel patients who need high blood pressure medications.
“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 antihypertensive medications,” said Wai K. Leung, MD, clinical professor of medicine at the University of Hong Kong and one of the study’s authors.
According to the American Cancer Society (ACS), an estimated 147,950 people will be diagnosed with colorectal cancer in 2020. It is the third most common cancer among men and women (excluding skin cancers) and the third leading cause of cancer-related deaths. Experts now recommend that people at average risk for colorectal cancer begin screening at age 45 instead of the previously recommended age 50, as rates have started to rise among young and middle-aged people.
For related coverage, read “How Can I Reduce My Risk of Colorectal Cancer?” and “Negative Colonoscopy Predicts Lower Cancer and Death Risk Well Past 10 Years.”