Adverse Outcomes in Breast Cancer Are Magnified When Patients Have Poor Heart Health

Female survivors of breast cancer total over 3.5 million in the United States alone. Coronary heart disease (CHD) is a leading cause of death among this patient group, as it is for all women. This especially holds true for women with already poor cardiovascular health (CVH) who receive a breast cancer diagnosis and undergo cardiotoxic treatments for the disease.

“A better understanding of synergistic associations between poor CVH and breast cancer treatments on CHD risk after breast cancer has the potential to guide CHD and cancer treatment, [and] posttreatment cancer-related follow-up care is warranted,” noted the authors of a recent study published in BMC Medical Informatics and Decision Making. They had already seen results from their work with the Women’s Health Initiative that demonstrate poor CVH equates to more cases of cardiovascular disease (CVD) and breast cancer.

Due to a lack of concrete data on the joint effect of poor CVH and treatment for breast cancer (eg, chemotherapy, left-sided radiation, hormone-related or anti-estrogen pills, Herceptin), they wanted to quantify the data on both among these women, noting how shared risk factors for cancer and CHD are often not accounted for in survivorship care. They used electronic health records for 1934 women, with an average age of 58.5 years, who received their breast cancer diagnosis in 2006 or 2007 at a midwestern medical center to evaluate the 10-year risk of mortality and CHD.

Overall, the results are not surprising. A total of 341 (17.6%) women underwent treatment for breast cancer with cardiotoxic therapies; one-third developed CHD, a measure that increased concurrently with age; and 19% died. In addition, women in better CVH developed CHD at a lower rate compared with those in worse CVH: 24.0% versus 61.9%, respectively.

Also, treatment with any potentially cardiotoxic treatment meant a greater chance of developing CHD during the 10 years of follow-up compared with the women whose cancer was not treated: 58.9% versus 29.1%. There was an even wider gap in the development of CHD among the women in good CVH who did not undergo cardiotoxic therapy and those in poor CVH who did: 20.8% versus 75.9% respectively. The authors described this as a “synergistic effect.”

“Our results indicated women with ideal CVH scores, and those who did not receive potentially cardiotoxic cancer treatments had the lowest risk of posttreatment CHD or death, while the joint effects of poor CVH and exposure to cancer treatments significantly increased the risk of post-treatment CHD or death,” they concluded.

To make progress in the treatment of poor CVH and CHD among patients with breast cancer, the authors recommend the following:

1. Screen and begin to treat for proven poor CVH when breast cancer is diagnosed, as this could lead to gains in morbidity and mortality.
2. Investigate individual variables of specific breast cancer treatments (eg, hormone therapy) and CVH measures (eg, blood pressure and body mass index) on how they affect CHD
3. Target and prevent CVD and manage cancer survivorship through a validated cardiovascular risk algorithm

Reference

Guo A, Zhang KW, Reynolds K, Foraker RE. Coronary heart disease and mortality following a breast cancer diagnosis. BMC Med Inform Decis Mak. 2020;20(1):88. doi:10.1186/s12911-020-1127-y