Consideration of CV health important during breast cancer treatment

BOSTON — Breast cancer and CVD are often linked together, and therefore, oncological treatments should include CVD risks, according to a presentation at the Cardiometabolic Health Congress.

There are several similarities between breast cancer and CVD, including similar patient profiles, causes and risk factors, Ana Barac, MD, PhD, associate professor of medicine at Georgetown University and director of MedStar Heart and Vascular Institute’s Cardio-Oncology Program, said during the presentation. Specifically, age, diet, family history, alcohol intake, hormone replacement, obesity and tobacco use are all common risk factors for both diseases.

During cancer treatment, patients with high doses of anthracycline and radiotherapy are at increased risk for future CV complications and CVD. The same is true for lower doses of anthracyclines or radiotherapy when the treated area is near the heart. Barac also said pre-existing CVD risk factors, older age and compromised cardiac function can increase risk for those with breast cancer, particularly when combined with anthracyclines and trastuzumab (Herceptin, Genentech).

She said, although this knowledge exists, there is not enough of a synergy between cancer treatment and maintenance of CV health. As more oncological treatment plans are introduced, there is a professional need for more CV evaluation before, during and after treatment. Barac specifically called for a multidisciplinary approach that follows through the entire cancer treatment process.

Not all patients with breast cancer need to be seen by a cardiologist but CV risk factors, medical history, physical assessment, and often an echocardiogram form a part of a comprehensive assessment of all patients. In patients with multiple CV risk factors who are planned to receive potentially cardiotoxic therapies, cardiologists need to become an active part of the oncology team, Barac said, noting that cardiologists may need to do additional testing and participate with the oncology team in decision making about the choice of oncology therapy.

Once a treatment plan is enacted, the cardiac monitoring process must continue.

Barac said cardiologists should actively screen and manage modifiable CV risk factors, with imaging a preferred means of screening.

Identifying cardiotoxicity during treatment is also important, according to Barac. Tools that exist for this are echocardiography, nuclear cardiac imaging, cardiac MRI and cardiac biomarkers. She said each approach has advantages and shortcomings and imaging and biomarkers are often used in a complementary way, particularly in patients with symptoms.

Echocardiography is a widely used option that does not lead to increased radiation. However, it has technical challenges that may reduce its accuracy in comparing serial testing. For example, breast surgery or radiation may affect the quality of images and limit the value of comparison. In these patients, physicians often consider an alternative imaging modality, Barac said, adding that nuclear cardiac imaging was first used in oncology patients and has good reproducibility but increases radiation exposure. Cardiac MRI is an accurate measure but not widely available, whereas there is not enough evidence for biomarkers alone in asymptomatic patients, according to Barac.

She said after cancer treatment is concluded, an echocardiogram should be performed within the following 6 to 12 months, especially for those with identified risk for cardiac dysfunction. Continued surveillance is recommended as well, whereas survival can be improved by active interventions. For example, a 2018 study in JAMA Oncology found an association between low-fat diet and improved the 10-year survival rates of patients with breast cancer.

“Cardiovascular disease in patients with breast cancer offers opportunities to advance patient care in cardiology and oncology,” Barac said. “Cardiac imaging offers opportunities for risk stratification and guidance of treatment as well as identification of new imaging and clinical phenotypes. We need to create a platform for collaboration on a growing number of questions.” – by Phil Neuffer

References:

Barac A. Cardio-oncology: Overview and the intersection between breast cancer and cardiovascular disease. Presented at: Cardiometabolic Health Congress; Oct. 24-27, 2018; Boston.

Chlebowski RT, et al. JAMA Oncol. 2018;doi:10.1001/jamaoncol.2018.1212.

Disclosure: Barac reports no relevant financial disclosures.