Study: Overweight Women with Heart Disease Face Higher Breast Cancer Risk

New Delhi: A new study by the World Health Organization (WHO) has found that being overweight may significantly raise the risk of breast cancer among postmenopausal women, especially those with cardiovascular disease. The research, published in the journal CANCER, highlights how weight and health conditions like heart disease and diabetes may influence breast cancer risk.

It is already known that a higher body mass index (BMI) is a risk factor for breast cancer after menopause. This study, however, looked deeper to understand how that risk varies in women with or without heart disease and type 2 diabetes.

Researchers discovered that for every 5 kg/m² increase in BMI, the risk of developing breast cancer rose by:

31% in women who developed cardiovascular disease during the study period

13% in women who did not have cardiovascular disease

Interestingly, the presence or absence of type 2 diabetes did not seem to change the link between weight and breast cancer risk. In other words, excess weight increased the risk regardless of diabetes status.

The data comes from two major health studies: the European Prospective Investigation into Cancer and Nutrition (EPIC) and the UK Biobank. Together, they included over 168,000 postmenopausal women who were initially free of cancer, heart disease, and type 2 diabetes. After about 11 years of follow-up, nearly 6,800 of these women had developed breast cancer.

The researchers estimated that overweight women with cardiovascular disease could face an additional 153 cases of breast cancer per 100,000 people per year.

“These findings could help shape breast cancer screening strategies based on individual risk,” said lead author Heinz Freisling from the WHO’s International Agency for Research on Cancer (IARC). He also emphasized the need to include women with heart disease in weight loss trials aimed at preventing breast cancer.

The study reinforces previous research linking obesity to higher risks of 12 different cancers, including uterine, liver, and kidney cancers. It also supports recent findings that overweight and obese women tend to be diagnosed with more advanced and larger breast tumors.