Common hypertension medicine may reduce risk of colorectal cancer

There is hope that ACE inhibitors and ARBs, medications that are commonly prescribed for high blood pressure, may be helpful for lowering the risk of colorectal cancer. A study reporting these findings are published in the American Heart Association journal, Hypertension. 

ACE stands for angiotensin-converting enzyme inhibitor (ACE-i) while ARB means angiotensin II receptor blocker (ARB). Both classes of medication are often used to treat heart failure, high blood pressure, or heart disease. As the video above explains, they work by blocking angiotensin, which is a chemical that causes stenosis (narrowing) of the arteries. But now researchers think they might have other benefits, too. 

"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 the potential role of these medications for colorectal cancer prevention," said study author Wai K. Leung, M.D., who is a clinical professor of medicine at the University of Hong Kong. "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."

Colorectal cancer is the third most common cancer and takes the place as the second leading cause of cancer death around the globe. As such, the desire to decrease the risk of the disease remains high.

In this retrospective study, the researchers reviewed whether patients on these medications developed colorectal cancer. They analyzed the health records of 187,897 adult patients in Hong Kong from 2005 to 2013, with a negative baseline colonoscopy for colorectal cancer. According to Science Daily, the study determined that:

• those who took hypertension medications such as ACE-i or ARBs had a 22% lower risk of developing colorectal cancer in the subsequent three years;
• the benefits of ACE-i and ARBs were seen in patients 55 or older and those with a history of colon polyps; and
• the benefit associated with the medications was limited to the first three years after the negative baseline colonoscopy.

"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," concludes Leung.

Sources: Hypertension, Science Daily