Does your blood pressure pill increase your cancer risk?

If you have to choose between stroke and cancer, which would it be? Touch choice, eh?

Unfortunately, health professionals as well as patients might be forced to make the choice. A recent meta- analysis of studies on popular drugs used against hypertension brings some worrying news. These blood pressure pills actually increase the risk of developing cancer.

The five randomized controlled trials analyzed contained data of more than 60,000 patients who were taking the drugs called angiotensin-receptor blockers (ARBs) for hypertension, heart disease, and chronic kidney disease. The results of the analysis showed that patients on ARBs have about 1% higher risk for developing different types of cancers than those who are not taking the drugs. The cancers associated with this increased risk are prostate, breast and lung cancers.

Now, we may think that 1% is not much. But if we consider the number of people worldwide taking ARBs – estimated to be up to millions – then we can see how this 1% can actually translate to a large number of people who will be getting cancer.

According to study author Ilke Sipahi, associate director of heart failure and transplantation at University Hospitals Case Medical Center in Cleveland:

“The risk for the individual patient is modest. However, when you look at it from the population level, millions and millions of people are on these drugs and it can cause a lot of excess cancer worldwide.”

The authors estimate that for every 105 patients who take ARB for 4 years, one extra case of cancer will be diagnosed. However, the author cannot tell whether this increased risk is reversible after cessation. Also, there is no significant difference between cancer mortality between people on ARB and people who are not.

The bestselling drug in this class is telmisartan (Micardis), which was taken by about 85.7% of the patients in the studies. It is no wonder that its manufacturer Boehringer Ingelheim Corp is not too happy about the report which was published in Lancet Oncology.

Why do ARBs increase cancer risk? The experts do not know exactly why but it might have something to do with the drugs’ ability to enhance growth of new blood, the same enhancement that can promote tumor growth.

So what now?

Well, the study authors are cautious enough to tell patients on ARB not to stop their medications. In most cases, “their chances of dying from heart failure outweighed their chances of getting cancer”

The study conclusions are:

This meta-analysis of randomized controlled trials suggests that ARBs are associated with a modestly increased risk of new cancer diagnosis. Given the limited data, it is not possible to draw conclusions about the exact risk of cancer associated with each particular drug. These findings warrant further investigation.

Their ultimate advice: if in doubt, talk to your doctor about it.