Photo Credit: Artur Plawgo

Optimizing modifiable CVD risk factors management offers an opportunity to address the leading cause of noncancer mortality for survivors of breast cancer.

A majority of patients have an elevated risk for atherosclerotic cardiovascular disease (ASCVD) at the time of breast cancer diagnosis, explained John W. Melson, MD. Compared with those without breast cancer, Dr. Melson notes, long-term survivors have nearly twice the risk for cardiovascular disease (CVD)-related mortality. Furthermore, for older patients with underlying CVD, the competing risk for or death from CVD is greater.

“[Patients with breast cancer] are at increased risk [for] CVD relative to the general population, likely due to several mechanisms, including shared risk factors and exposure to cardiotoxic therapies during breast cancer treatment,” Dr. Melson writes. “ A more details understanding of the CVD risk factor burden these patients face is a key initial step in identifying opportunities to improve our clinical practice.”

There Is Limited Research on ASCVD Estimated Risk for Survivors

Since there is limited data on ASCVD estimated risk and the use of preventive medication, Dr. Melson and colleagues sought to evaluate a cohort of patients (N=362) with nonmetastatic breast cancer or ductal carcinoma in situ to determine the risk for ASCVD and to examine the use of longitudinal preventive medication. The study team collected clinical characteristics, demographics, medical exposure, laboratory studies, and incident cardiovascular outcomes. They calculated all patients’ estimated 10-year ASCVD risk; the median follow-up time was 6.5 years.

The findings were published in Clinical Breast Cancer.

Dr. Melson and colleagues observed that 7.1% of patients presented with ASCVD at cancer diagnosis. Among those without ASCVD, the 10-year estimated ASCVD risk was 20% or more for 25.4% of patients and 7.5% to 20% or less for 37.6% of patients. At diagnosis, 66.3% of patients had an indication for lipid-lowering therapy, 57.0% of who were administered a statin during the study. During the study period, 15% of patients were diagnosed with incident hyperlipidemia, 10.4% with incident hypertension, and 5.2% with incident diabetes (Table).

Of 100 patients with ASCVD or an estimated 10-year ASCVD risk of 20% or more, 92.0% received an antihypertensive medication during the study. In 33.0% to 55.6% of these patients at each follow-up assessment, the researchers observed clinic blood pressure of 140/90 mmHg or greater.

Substandard Management of ASCVD Risk Factors Exist After Treatment

For survivors of breast cancer, CVD is the leading obstacle to their well-being and long-term health, according to Dr. Melson and colleagues. In addition to a high estimated 10-year risk for ASCVD at the time of their diagnosis, many patients have substandard management of ASCVD risk factors after completion of their breast cancer treatment.

The study team observed that modifiable ASCVD risk factors were frequently untreated or uncontrolled in the years following cancer treatment. Therefore, Dr. Melson writes, “[ASCVD] risk estimation is recommended to guide preventive medication use. Two-thirds of patients [in this cohort] had an elevated estimated 10-year ASCVD risk and were eligible for lipid-lowering therapy at the time of cancer diagnosis.”  However, he adda, after cancer treatment, many patients did not receive lipid-lowering therapy during follow-up.

Elevated clinic blood pressure is also a concern for many high-risk patients despite the use of antihypertensive medication. Therefore, Dr. Melson notes that aggressive blood pressure control is recommended for improved ASCVD-associated outcomes.

Based on their findings, Dr. Melson and colleagues agree that oncologists and other healthcare professionals who treat patients with breast cancer should prioritize increased attention to CVD prevention. In this way, they can improve long-term CVD-associated outcomes and mortality among survivors of breast cancer.

While this study focused exclusively on several pharmacologic preventive measures, Dr. Melson and colleagues would like to see a detailed accounting of the use of nonpharmacologic preventive measures, such as dietary modification, exercise, and smoking cessation efforts, among this population. These measures, he says, may provide a more complete understanding of the opportunity to improve patients’ cardiovascular health.

“As oncologists, we seek to understand how our cancer-directed treatments impact the overall health of each patient,” Dr. Melson notes. “We have an opportunity to identify cardiovascular health as a critical component of cancer survivorship care and discuss its importance with our patients. This emphasis has the potential to improve the management of modifiable cardiovascular risk factors and reduce the burden of CVD for cancer survivors.”