Body Mass Index Genotype Linked to Breast Cancer Risk

Premenopausal, overweight women have a decreased risk of breast cancer, while postmenopausal women have an increased risk.

Women with a high body mass index (BMI) before menopause was associated with a decreased risk of breast cancer, but an increased risk of the disease after menopause.

In a study published in PLOS Medicine, researchers used data from 145,056 women. They also used a list of genetic variants found to be associated with BMI in genomic studies.

Each woman’s BMI was estimated based solely on genotype. The results of the study showed that genetically predicted high BMI was associated with a reduce risk of breast cancer in both premenopausal and postmenopausal women.

“It is likely that genetically predicted BMI may be more closely related to body weight in early life, which is negatively associated with breast cancer risk,” said researcher Wei Zheng, PhD, MD. “Measured high BMI later in life may be influenced primarily by environmental factors that are associated with increased risk of breast cancer. For breast cancer prevention, the study provides evidence for lifestyle modification to reduce weight gain in adults.”