Acute Heart Attack Does Not Increase Risk of Breast Cancer, Study Shows

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Patients with a history of myocardial infarction (MI) do not necessarily develop breast cancer, the results of a new study of over 60,000 women show. This is contrary to previous research that showed that MI accelerated the growth of preexisting breast cancer cells in both mice and humans.

The prior research was based on the hypothesis that a disruption of homeostasis (like surgery or a medical event) alters cancer pathogenesis. Stress can weaken the immune system and stress hormones can halt anoikis, a complex process by the body kills diseased cells.

For this study, a total of 66,445 women were identified using nationwide Taiwanese databases called the National Health Insurance Research Database (NHIRD) and the Longitudinal Health Insurance Database 2000 (LHID2000) from Jan. 1, 2001, to Dec. 31, 2021. Of those women, 15,263 had a history of MI, and 51,182 had no history of MI. Women were followed up with 5 years later to see if they had developed breast cancer. Results were published yesterday in Scientific Reports.

During the follow-up, 712 patients with a history of MI received a breast cancer diagnosis and 594 with no history of MI were diagnosed with breast cancer.

“The development of cancer is a cumulative, time-dependent process, and the incidence of cancer diagnosis may be influenced by detection bias, which refers to a patient with some diseases receiving a diagnosis for some other diseases due to the increased medical surveillance they are under for the first disease, lead authors Chia-Pin Lin, M.D., Shing-Hsien Chou, M.D., and Pao-Hsien Chu, M.D., FCCP, FACC, FESC, FAPSC from the Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital in Linkou, Taiwan write. “In the present study, we demonstrated that acute MI does not increase the risk of breast cancer over times by including multiple lag periods in the sensitivity analysis.”

Cardio-oncology is a new subspecialty of cardiology, thanks to a growing interest in noncardiac causes of death after acute MI. Common cardiovascular risk factors such as cigarette smoking, diabetes and obesity are also risk factors for cancer.

Coronary artery disease is one of the leading causes of death worldwide. Although mortality rates are lower today due to medical advancements, survivors are often left with complications, which can include cancer.

Breast cancer is currently the most diagnosed cancer worldwide with 2.3 million cases diagnosed in 2020. Cases are expected to rise to 4.4 million globally by 2070.