While recent advances in breast cancer therapy have resulted in survival gains, many patients and survivors have an increased risk of cardiovascular adverse events following treatment.
A new study presented at the American Heart Association’s recent annual Scientific Sessions meeting, however, shows that the angiotensin receptor blocker (ARB) candesartan (Atacand) may preserve cardiac function during treatment.
The double-blind, placebo-controlled PRADA trial compared administering the beta blocker metoprolol, candesartan, or a combination of both in conjunction with breast cancer therapy.
The women were randomized by factorial design to receive 100 mg daily of metoprolol succinate versus placebo or 32 mg daily of candesartan versus placebo.
Using an MRI of the heart before and after treatment, investigators found that there was a 0.8 percent decline in left ventricular ejection fraction (LVEF) from baseline in the group taking candesartan versus a 2.6 percent decline in the placebo group. Metoprolol did not yield a change in LVEF versus placebo.
“We want to do our best to optimally treat our patients’ cancer, while minimizing the risks of long-term toxicities from their cancer treatments,” oncologist Erica Mayer, a senior physician in the Susan F. Smith Center for Women’s Cancers at the Dana-Farber Cancer Institute, said in a statement.
Researchers enrolled 120 women (average age of 51 years) who were undergoing post-surgery treatment for early breast cancer and had no prior history of cancer or heart disease.
The women received up to 16 months of anthracyclines, a class of strong chemotherapy drugs that includes doxorubicin. Some of the patients were also treated with Herceptin (trastuzumab), radiotherapy and taxane chemotherapy. Researchers concluded that preventive therapy may be indicated as standard care if they can confirm a sustained, long-term effect of early angiotensin inhibition, but lead investigator Geeta Gulati, Akershus University Hospital in Lorenskog, Norway, cautioned that further studies are needed.
“What we found was just after chemotherapy,” she said at the 2015 American Heart Association Scientific Sessions. “So, the long-term implications we don’t know. We’re doing a follow up study to see where this goes.”
There is a consensus among oncologists about the potential cardiotoxicity of some cancer treatments. The targeted drug Herceptin, which is used to treat patients with aggressive HER2-positive breast cancer, carries a risk of heart toxicity and radiation therapy to the chest can also cause subsequent heart problems.
But the probable causes of cardiovascular disease are multifactorial and can vary based on a person’s age and other medical conditions. “The best way to prevent toxicity is to prevent the exposure in the first place,” Mayer said.
A recent trend is to offer patients nonanthracycline 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.
Mayer said that although the results of the trial were positive overall, 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.