NEW DELHI– Excess body weight may significantly raise the risk of breast cancer among postmenopausal women, particularly those with cardiovascular disease, according to a new study from the World Health Organization (WHO) published Monday.
While a higher body mass index (BMI) is already recognized as a risk factor for breast cancer in postmenopausal women, the study—published in the American Cancer Society’s journal CANCER—offers fresh insights into how that risk differs in women with and without pre-existing cardiovascular disease or type 2 diabetes.
Researchers found that every 5 kg/m² increase in BMI was linked to a 31% higher risk of breast cancer in women who developed cardiovascular disease during the study period. For women without heart disease, the risk increase was 13% for the same BMI gain.
Interestingly, the presence or absence of type 2 diabetes did not appear to influence the relationship between BMI and breast cancer risk. Women with or without type 2 diabetes showed similarly elevated breast cancer risks associated with higher BMI levels.
“The findings of this study could be used to inform risk-stratified breast cancer screening programs,” said Dr. Heinz Freisling, who led the research team from the WHO’s International Agency for Research on Cancer (IARC).
The study analyzed data from 168,547 postmenopausal women who were free of cardiovascular disease and type 2 diabetes at enrollment. The data came from two major research databases: the European Prospective Investigation into Cancer and Nutrition (EPIC) and the UK Biobank.
Over a median follow-up period of 10.7 years in EPIC and 10.9 years in the UK Biobank, 6,793 women developed breast cancer.
The study further estimated that the combination of being overweight (BMI ≥ 25 kg/m²) and having cardiovascular disease could result in 153 additional cases of breast cancer per 100,000 women per year than would otherwise be expected.
“This study should also inspire future research to include women with a history of cardiovascular disease in weight-loss trials for breast cancer prevention,” Freisling added.
The link between excess weight and cancer risk is already well documented. Being overweight or obese raises the risk of at least 12 types of cancer, including uterine, kidney, liver, and colorectal cancer.
A separate recent study published in Nature Communications also found that overweight and obese women are more likely to be diagnosed with larger and more advanced-stage breast tumors. (Source: IANS)
