The majority of women at risk for hereditary breast cancer have a mutated form of the BRCA 1 or BRCA 2 gene – the genes which normally suppress the growth of breast and ovarian tumors. New research now indicates that these women, who are at risk for hereditary breast cancer, may also be at greater risk for heart disease.

A cardiac surgeon at St. Michael’s Hospital in Toronto, Dr. Subodh Verma, states that his research team has discovered that the BRCA1 and BRCA2 genes also regulate heart function.

What does that mean to women who know, or suspect, they may be compromised by mutation to the BRCA1 or BRCA2 genes? And what, if anything, can they do to diminish their risk of heart disease?

According to Dr. Verma, in laboratory studies, mice with the mutated BRCA1 gene had a three-to-five times higher rate of death after a heart attack. The mice suffered profound heart failure, probably due to the fact that their heart attacks were twice as severe as those in mice that did not have the mutated gene.

Compounding the problem, when mice with a mutated BRCA1 or BRCA2 gene were treated with doxorubicin (one of the most common chemotherapy drugs for breast cancer patients), a similar two-fold increase in heart failure was observed. The same results were verified by the research team with human tissues.
Doctors know that doxorubicin is associated with heart failure; however, the new research shows that women with the mutated BRCA1 or BRCA2 gene are even more sensitive to the drug’s toxicity.

In simple terms, the research findings suggest that the mutated BRCA1or BRCA2 genes prevent DNA repair in muscle cells that is essential to recovery after a heart attack. Therefore, women at risk for breast cancer may be at an unrecognized risk for heart disease. And it is now understood that breast cancer and heart disease have a common biological basis.

Dr. Verma stressed the important implications these findings have across the board.. Knowing that the BRCA1 and 2 genes are essential to DNA repair may lead to future treatments for anyone with heart disease, a leading cause of death worldwide. Women who carry the mutated gene(s) now know they may also be at a higher risk for developing heart disease in addition to the risk of developing cancer.

As always, bring up your concerns with your medical team. If you suspect you may carry the BRCA 1 or 2 gene mutation, or if this has been confirmed through testing, you will want to monitor your situation very carefully.