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Despite breast cancer being the most common among Japanese women, the risk of developing noncancer diseases among female breast cancer survivors has not been explored in detail. Therefore, researchers at the University of Tsukuba analyzed medical claims data to determine the timing and extent of noncancer disease risks among female breast cancer survivors in comparison with age-matched women without breast cancer.

Tsukuba, Japan—Breast cancer is the most common cancer among women in several countries around the world, including Japan, where one in nine women has the risk of developing the disease. In recent years, early detection and advancements in treatment strategies have enabled patients with breast cancer to live longer. Studies from western countries suggest that, for breast cancer survivors to live long and lead healthy lives, it is important to focus not only on the treatment and follow-up of breast cancer itself but also on their overall health. Nevertheless, the risk of developing various diseases among breast cancer survivors in Asian populations, including the Japanese, has not been thoroughly investigated.

In this study, researchers analyzed medical claims data (anonymous information) collected by JMDC, Inc. from Health Insurance Societies for employee insurance nationwide. They clarified the extent to which the risk of developing 12 representative diseases other than cancer (myocardial infarction, heart failure, atrial fibrillation/flutter, ischemic stroke, intracranial hemorrhage, pulmonary embolism, major osteoporotic fractures, other fractures, gastrointestinal bleeding, infectious pneumonia, urinary tract infections, and anxiety/depression) increased.

A comparison of 24,017 breast cancer survivors and 96,068 age-matched women without breast cancer (mean age 50.5 years) revealed that breast cancer survivors had a higher risk of developing heart failure, atrial fibrillation, major osteoporotic fractures, other fractures, gastrointestinal bleeding, infectious pneumonia, urinary tract infections, and depression/anxiety than women without breast cancer. Moreover, the risks of developing most diseases increased steeply during the first year of the diagnosis of breast cancer, whereas the risk of developing fractures increased in the later period.

Hence, this study also suggests that for breast cancer survivors in Japan to live long and lead healthy lives, it is important to focus not only on breast cancer treatment and follow-up care but also on the prevention, early detection, and treatment of other diseases.

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Competitive research funding from Pfizer Health Research Foundation in Japan.

Original Paper

Title of original paper:

Non-cancer risks among female breast cancer survivors: a matched cohort study in Japan.

Journal:

The Lancet Regional Health - Western Pacific

DOI:

10.1016/j.lanwpc.2025.101519

Correspondence

Professor IWAGAMI Masao
Department of Digital Health/Department of Health Services Research, Institute of Medicine, University of Tsukuba

Related Link

Institute of Medicine