Heart Disease May Increase Risk of Advanced Breast Cancer

Older people with cardiovascular disease may be at a higher risk of advanced breast cancer than people without cardiovascular disease, a study has found. 

“The study could help inform personalized screening strategies, as it suggests that individuals with [cardiovascular disease] may benefit from earlier or more frequent breast cancer screenings to catch the disease at an earlier, more treatable stage,” study author Kevin Nead, M.D., said in a statement. 

Researchers have long known that people with an increased risk of cancer are at greater risk of heart problems and vice versa. But they thought this was caused by shared risk factors (for example, smoking increases the risk of both heart disease and cancer). 

A study in animals showed that mice who experienced a heart attack had more rapid growth and spread of breast cancer than mice who didn’t have a heart attack. The immune system of the mice who had a heart attack was less able to do important things, such as break down abnormal cells. The study is among a few to suggest a direct link between heart disease and cancer in mice. This inspired Nead, an assistant professor of epidemiology and radiation oncology at MD Anderson, to investigate evidence of the link in humans. 

Nead and his team identified women from a large dataset who were 65 years of age and older, had received regular screening mammograms, and had been diagnosed with breast cancer. When they compared those diagnosed with early-stage breast cancer to those with advanced disease — breast cancer that has spread to nearby tissue or other parts of the body — they found that women with a diagnosis of advanced breast cancer were 10% more likely to have a history of heart disease. They also found that women who are diagnosed with breast cancer that was the hormone receptor-positive and HER2-negative were most likely to have been diagnosed with cardiovascular disease before developing breast cancer.

Before researchers can feel confident that cardiovascular disease increases the risk of advanced breast cancers, they’ll need to conduct more studies of larger groups of people with breast cancer. But if more studies support a link between cardiovascular disease and advanced breast cancer, it suggests that people with cardiovascular disease might benefit from more frequent breast cancer screenings.

The results were published in JAMA Network Open.