Blood Pressure Drug Linked to Risk of Breast Cancer

A new study study suggests that women who takes calcium channel blockers, a common type of blood pressure drug for 10 years or more are over twice as probable to be at risk of breast cancer than those not taking the medication.

Dr. Christopher Li, lead researcher at the Fred Hutchinson Cancer Research Center in Seattle clarified that their research doesn't aim to recommend any changes in existing clinical practices.

About 2,851 women between the ages 55 to 74 years old participated in the study. 905 of which were diagnosed with ductal breast cancer between 2000 to 2008, 1,055 were diagnosed with lobular breast cancer and 891 without cancer.

Almost 40 percent of participants in each group took anti-hypertensive drugs, 85 with ductal breast cancer, 91 with lobular breast cancer, and 70 without cancer.

Twenty-five women with ductal breast cancer and 26 women with lobular breast cancer had been using the medication for a decade or longer which was compared to 11 women without cancer. That concludes that with the long-term use of calcium channel blockers, the risk of cancer had increased by 2.4 to 2.6 fold.

Patricia Coogan, an epidemiologist from Boston University who wrote a commentary published with the new report said, “The study raises a hypothesis for researchers to test in the future. The drugs have now been around long enough that plenty of women have taken them for a decade or more.”

Coogan told Reuters Health, "If other large studies start finding the same thing, then a serious discussion needs to take place. But for now, women who get their blood pressure under control using calcium channel blockers shouldn't stop taking them, or be too concerned about any extra risk of breast cancer.”

She added, "A far more immediate health risk is uncontrolled high blood pressure, and that is the most important thing to have in mind.”

Yet, no other hypertensive drugs and diuretics were tied to breast cancer, the researchers wrote in JAMA Internal Medicine on Monday.