Genetically Predicted Body Mass Index and Breast Cancer Risk: European Descent

open access:
Genetically Predicted Body Mass Index and Breast Cancer Risk: Mendelian Randomization Analyses of Data from 145,000 Women of European Descent

What Do These Findings Mean?

• Our results from postmenopausal women contradict prior findings from population studies, which used measured, rather than genetically predicted, BMI.
• BMI predicted using genetic variants identified to date may be more closely related to body weight in early life or midlife, which is negatively associated with risk of breast cancer. Measured high BMI later in life may be influenced by environmental factors that are associated with increased risk of breast cancer.
• More research is needed on the interrelationship of genetic factors, environment, and BMI in the risk of breast cancer.