Many breast cancer survivors live only to face life-threatening heart disease due to treatments that vanquished their cancer but damaged their hearts. However, Canadian researchers found that heart medication taken at the time of chemo can reduce the risk of serious cardiovascular damage.

Although some cancer therapies such as Herceptin greatly improve survival rates for early-stage breast cancer, they also increase the risk of heart failure by fivefold — a devastating condition that is as life-threatening as the cancer itself.

Canadian researchers found that two types of heart drugs, beta blockers and ACE inhibitors, help prevent damage from cancer treatment.

In the double-blind trial, 100 patients from Alberta and Manitoba with early-stage breast cancer were selected at random to receive either a beta blocker, ACE inhibitor, or placebo for one year. Beta blockers and ACE inhibitors are drugs used to treat several conditions, including heart failure.

Cardiac MRI images taken over a two-year period showed that patients who received the beta blockers showed fewer signs of heart weakening than the placebo group. The ACE inhibitor drug also showed protective benefits.

In addition to protecting the heart, these medications may also improve breast cancer survival rates, says lead Ian Paterson, a cardiologist at the Mazankowski Alberta Heart Institute and associate professor with the University of Alberta's Department of Medicine.

When a patient shows signs of heart weakening, Mazankowski said, chemotherapy is stopped immediately, until heart function returns to normal. This can take a couple of months, so the heart drugs may increase breast cancer survival rates by limiting interruptions to chemotherapy treatment.

"We are aiming for two outcomes for these patients — we're hoping to prevent heart failure and we're hoping for them to receive all the chemotherapy that they are meant to get, when they are supposed to get it — to improve their odds of remission and survival."
The study was published in the Journal of Clinical Oncology.

Breast cancer is the second leading cause of cancer deaths in American women, after lung cancer, and about 12 percent of women will develop breast cancer during their lifetime. In 2016, 246,000 new cases of invasive cancer are projected to be diagnosed, along with 61,000 new cases of non-invasive (in situ) breast cancer.