UCLA experts call for individualized heart monitoring in breast cancer survivors

As breast cancer survival rates continue to climb - 4.3 million women in the U.S. are currently living with a history of the disease and in the next 10 years that number is expected to rise by another million - heart health has become an increasingly important part of survivorship care. 

Certain breast cancer therapies, while lifesaving, can also place stress on the heart, raising important questions about who might benefit from closer monitoring.

But does every breast cancer survivor need to see a cardiologist?

A new editorial published in JAMA Oncology and led by UCLA Health Jonsson Comprehensive Cancer Center investigators Patricia Ganz, MD, a distinguished professor of medicine at the David Geffen School of Medicine at UCLA, and Eric Yang, MD, director and founder of the UCLA Cardio-Oncology Program, says the answer is more nuanced than many might expect. 

"Current cardio-oncology guidelines recommend cardiac imaging during and immediately following systemic cancer therapies in breast cancer and other malignant neoplasms, but long-term surveillance with these approaches has not been evaluated and evidence-based guidelines are lacking," the UCLA authors write. Biomarker tests, such as B-type natriuretic peptide, show promise, but their usefulness in cancer survivors remains uncertain. 

Understanding the link between cancer treatment and the heart

Some breast cancer therapies, including anthracycline chemotherapy and HER2-targeted drugs like Herceptin (trastuzumab), are known to stress the heart in certain patients. For years, doctors have monitored patients during treatment to catch early signs of heart dysfunction.

However, it's unclear how long survivors should continue to be monitored once treatment ends, and whether all survivors would benefit from seeing a cardiologist.

In the editorial, Dr. Ganz and Dr. Yang evaluated a study that introduced a new tool to help pinpoint which breast cancer survivors face the highest chances of developing heart failure or cardiomyopathy in the decade following treatment. The team created a risk calculator using real-world clinical data from more than 26,000 breast cancer patients within an integrated health care system in Southern California.

The findings revealed that while certain breast cancer treatments, including anthracycline chemotherapy and HER2-targeted drugs, did increase risk, most women do not go on to develop serious cardiac disease. Instead, the strongest predictors had less to do with cancer and more to do with overall health.

Most women 65 years and older included in the study were at high risk of heart disease, independent of cancer therapy. High blood pressure, diabetes, obesity, smoking, and a history of heart disease contributed more to a woman's long-term heart outlook than the chemotherapy regimen did. 

The authors also found that cancer treatment alone rarely pushed younger women into a high-risk category, with few women younger than 40 at the time of diagnosis at increased risk, suggesting that routine long-term cardiac imaging for all survivors may not be warranted.

So, who should see a cardiologist?

"It depends!" said Dr. Ganz and Dr. Yang. 

Women who may benefit from seeing a cardiologist include those who received higher-risk chemotherapy, developed heart issues during treatment, are older or have multiple cardiovascular risk factors, or report symptoms like shortness of breath, fatigue or swelling.

Instead of blanket heart screening for every survivor, the editorial highlights the importance of essentials: controlling blood pressure, managing cholesterol, maintaining a healthy weight and knowing early warning signs of heart disease.

For most survivors, regular visits with a primary care clinician, combined with an oncologist's input, may be sufficient. 

"What all breast cancer survivors need is access to primary care that focuses on prevention or management of established cardiac risk factors, as well as regular clinical assessment of their functioning," wrote Dr. Ganz and Dr. Yang. "With attention to cardiac prevention and control, heart failure/cardiomyopathy is less likely to occur."