Breast cancer outcomes rely on “coexisting cardiovascular health” at every step in the patient journey, the American Heart Association has said in its first-ever scientific statement on the matter.
The statement, published in Circulation provides a comprehensive overview of cardiovascular disease and breast cancer prevalence and shared risk factors, as well as current recommendations on avoiding the cardiotoxic effects of some cancer treatments and strategies to prevent or treat CVD in breast cancer patients.
Cardiovascular disease and breast cancer are two entities that are frequently intertwined, Laxmi S. Mehta, MD, chair of the statement writing group, said in an interview.
“For any oncologic patient, it’s important to also consider their heart in the risk assessment because that also affects survival from the cancer,” said Dr. Mehta, the director of the Women’s Cardiovascular Health Program and an associate professor of medicine at the Ohio State University, Columbus.
Mortality risk attributable to CVD is higher in breast cancer survivors than in women who have no history of breast cancer, according to evidence Dr. Mehta and her colleagues cite in the statement.
Breast cancer and CVD share a number of common and sometimes modifiable risk factors, including dietary patterns, physical activity, and being overweight or obese, and tobacco use. There is “growing awareness” that modifying those risk factors may help prevent some cases of breast cancer.
Even in patients who have a breast cancer diagnosis, “from a cardiology standpoint, lifestyle is going to be key,” said Dr. Mehta. She said breast cancer patients can be encouraged to follow AHA recommendations to aim for 150 minutes of moderate aerobic exercise weekly and to follow an “overall healthy dietary pattern” that limits saturated and trans fats, sodium, red meat, sweets, and sugar-sweetened beverages.
Although left ventricular systolic dysfunction is the most common cardiovascular side effect associated with chemotherapy, other manifestations of early or delayed cardiotoxicity can include heart failure, hypertension, thromboembolic disease, pulmonary hypertension, pericarditis, and myocardial ischemia, according to the AHA scientific statement.
A wide range of standard breast cancer treatments cause cardiovascular adverse effects, including taxanes such as paclitaxel, anthracyclines such as doxorubicin, and alkylating agents such as cisplatin and cyclophosphamide, as outlined in the statement.
Targeted HER-2–directed therapies, including trastuzumab and pertuzumab, are associated with left ventricular dysfunction and heart failure, while emerging therapies, such as the cyclin-dependent kinase 4/6 inhibitors palbociclib and ribociclib, are associated with QTc prolongation, the statement also notes.
Current strategies for monitoring for cardiovascular toxicity, which typically involve myocardial strain imaging, assessing cardiac biomarkers, or a combination of imaging and biomarkers, are outlined in the report.
To mitigate the impact of cancer treatments on cardiovascular health, several oncologic strategies are useful, according to Dr. Mehta and colleagues.
In multiple clinical trials of breast cancer patients receiving doxorubicin or epirubicin, the iron-binding agent dexrazoxane reduced the combined endpoint of decreased left ventricular ejection fraction or development of heart failure, the authors said.
Likewise, clinical trial evidence has suggested cardiotoxicity associated with doxorubicin can be mitigated through administration via infusion as opposed to bolus and with longer versus shorter infusion durations, they continued.
Extreme cases or difficult-to-manage patients can be referred to a center that has an active program in cardio-oncology, a newer and rapidly expanding field, according to Dr. Mehta.
“That’s where there’s tight collaboration in terms of understanding the current treatments, and that’s also where research on how to best take care of these patients will be conducted,” she said.
Dr. Mehta reported no disclosures. Coauthors reported disclosures related to Amgen, Boehringer Ingelheim, Genentech, AstraZeneca, Lilly, Roche, Novartis, and others.
SOURCE: Mehta LS et al. Circulation. 2017 Jan 22. doi: 10.1161/CIR.0000000000000556.