Larger breasts confer higher breast cancer risk

Women with larger breasts have a greater risk of developing breast cancer before menopause than smaller-breasted women do, a new study shows.
Studies investigating the association between breast size and breast cancer risk have had mixed results. To provide a more definitive answer, they looked at 89,268 women between the ages of 29 and 47, all of whom reported their bra cup size at age 20. The study was prospective, meaning that participants were followed over time to see if they developed breast cancer.
Women with bra sizes of D or larger had an 80-percent greater risk of developing breast cancer during the study's follow-up period than those with a smaller cup size. However, there was no link between bra cup size and breast cancer risk among overweight or obese women.
This is because cup size is most accurate for measuring breast size in thinner women. Increased risk with larger breasts most likely occurs for all women, but bra size is a less accurate gauge of breast size among heavier women.
The findings are simple, "The bigger the breast, the more breast cells. The more cells you have, the more cells are at risk for a potential mutation or malignant change."