New research warns that, after completing breast cancer treatment, women aged 45 and over face a heightened risk of developing cardiovascular disease.

According to the World Health Organization (WHO), breast cancer is the most commonly diagnosed cancer among women worldwide. At the same time, it remains one of the most treatable forms of cancer. Life expectancy for women who undergo treatment is improving, yet they still face long-term health risks following therapy. Late side effects can include bone damage, premature menopause symptoms, and poor heart health.

A new study from Botucatu Medical School at Paulista State University in Sao Paulo, Brazil, confirms that women over 45 who have completed breast cancer treatment have an increased likelihood of developing cardiovascular problems. The findings, published online ahead of print in the journal Menopause of the North American Menopause Society (NAMS), help explain why women with a history of breast cancer are at higher risk of heart disease.

In addition to toxicity from chemotherapy or radiation therapy, many women with estrogen-sensitive breast cancer take antiestrogens. Loss of estrogen may contribute to a higher risk of heart disease, explained Dr. JoAnn Pinkerton, executive director of NAMS, although she was not involved in the current study.

The study, led by first author Dr. Daniel de Araujo Brito Butters, included 288 female participants. Of these, 96 had successfully completed breast cancer treatment, while 192 were healthy women who had never experienced breast cancer. All participants were 45 years or older, postmenopausal, and without established cardiovascular disease.

Analysis showed that women who had undergone breast cancer treatment were significantly more likely to have metabolic syndrome, diabetes, atherosclerosis, hypertriglyceridemia (elevated blood levels of fatty molecules), and abdominal obesity. These conditions are major risk factors for cardiovascular disease. The study also found that the risk of death from cardiovascular events in these women was increased to levels similar to those associated with a breast cancer diagnosis.

Dr. Pinkerton noted that about one in eight women in the United States will develop invasive breast cancer in their lifetime. In 2019, an estimated 268,600 new cases of invasive breast cancer and 62,930 new cases of noninvasive (in situ) breast cancer were expected to be diagnosed in the U.S. As of January 2019, more than 3.1 million women in the U.S. had a history of breast cancer, including those currently undergoing treatment and those who had completed it.

Given the high number of women receiving breast cancer treatment, it is important for survivors to speak with their doctors about late side effects and long-term health risks. Doing so can help them take appropriate measures to prevent cardiovascular disease and protect their overall health.