Some of the chemotherapy drugs commonly used in breast cancer, including doxorubicin, can also harm the heart and surrounding tissue. "People who have cancer syndromes because of not having the BRCA1 gene may also be highly susceptible to the cardiac toxicity of the chemotherapy that they are receiving," Dr. Verma explained. "In some ways, this finding may help define what kind of chemotherapy such an individual should get."

The study may also point to new factors in the treatment of heart disease. "For millions of people in the world who have heart failure, repairing DNA may be very important, especially for younger people with heart failure that may be terminal," Dr. Verma said.

The study also linked the BRCA1 gene to development of atherosclerosis, or hardening of the arteries. "Cardiac infarction and heart failure represent the world's number one killer, and finding that a cancer gene may be implicated in both heart failure and cardiac infarction/ atherosclerosis is a very important observation," said Dr. Verma.

The study authors have started to investigate the incidence of BRCA1 gene mutations and heart disease in human population databases. However, clinical trials of BRCA1 gene therapy in people with heart disease may be at least two years away.

Source: St. Michael's Hospital