BY AMERICAN HEART ASSOCIATION NEWS
ORLANDO, Florida – Adding the heart failure drug candesartan to breast cancer therapy lessened damage to the heart over the short term in a small study reported Wednesday at the American Heart Association’s Scientific Sessions 2015.
The number of cancer survivors is on the rise, meaning more Americans may face health problems later in life as a direct cause of cancer treatment, including heart disease, said oncologist Erica Mayer, M.D., a senior physician in the Susan F. Smith Center for Women’s Cancers at the Dana-Farber Cancer Institute and an assistant professor of medicine at Harvard Medical School in Boston.
“We want to do our best to optimally treat our patients’ cancer, while minimizing the risks of long-term toxicities from their cancer treatment,” Mayer said.
In the study, researchers enrolled 120 women an average age of 51 who were undergoing post-surgery treatment for early breast cancer. They had no prior history of cancer or heart disease.
Researchers tested whether giving the beta blocker metoprolol, the angiotensin receptor blocker candesartan, or a combination of both alongside breast cancer treatment could lessen the toxic effects of cancer therapy to the heart. Beta blockers work by slowing the heart rate, while ARBs prevent a natural substance from tightening blood vessels, easing blood flow.
The women received up to 16 months of cancer treatment, during which all received anthracyclines – a class of strong chemotherapy drugs that includes doxorubicin, also known as Adriamycin. Some also received Herceptin (trastuzumab), radiation and another class of chemotherapy drugs called taxanes.
Magnetic resonance imaging of the heart before and after cancer treatment found that candesartan helped protect the heart from damage, but the metoprolol did not.
Oncologists have long known that some cancer treatments can be toxic to the heart, although the risks can vary based on a person’s age and other medical conditions.
A recent trend is to offer patients non-anthracycline chemotherapy drugs that pose less risk to the heart, or to use genomic tumor tests to identify patients who do not need chemotherapy for their specific cancer.
“The best way to prevent toxicity is to prevent the exposure in the first place,” Mayer said.
The targeted drug Herceptin – used to treat the roughly one-fifth of breast cancer patients diagnosed with an aggressive type that overexpresses a protein called HER2 – also carries a risk of heart toxicity. Radiation therapy to the chest can also cause later heart problems.
Mayer said that although the trial was overall positive, it was a small study and does not yet provide long-term follow-up data on patients. But it also demonstrates the importance of the emerging subspecialty of cardio-oncology and the need for collaborative research, she said.
Oncologists have learned a lot about the collateral damage of some cancer treatments since Stacy Leitner was diagnosed with Hodgkin lymphoma at 19 and treated with radiation therapy. Now 42, she’s had a stroke, heart attack and triple bypass surgery. Today, she’s being treated for heart valve disease.
“Twenty years later and being 20 years smarter, I’m telling people, ‘If you have an oncologist, you should have a cardiologist,’ ” she said.