Does Breast Density Affect Cancer Risk?

While most women may understand genetic and lifestyle risks for breast cancer, many do not realize that breast density also plays a significant role in breast cancer risk.

breast exam, mammogramBreasts are considered dense if they are mostly made up of glandular and fibrous tissue and not much fat. Breast density can only be seen on a mammogram; the firmness of a woman’s breasts is not an indicator. Breasts are most dense when a woman is young; for most women, dense breast tissue will be replaced by fat as women age.

“Because of new legislation that requires providers to inform patients about their breast density, more women are learning that high breast density is a predictor of breast cancer,” says Rulla Tamimi, Sc.D.

If your doctor finds you have dense breast tissue, it is important to discuss screening options for breast cancer. It is harder to spot tumors in dense breasts with mammography alone; both dense breast cells and tumors appear white on a mammogram, while the fatty tissue is dark.

“High breast density decreases mammogram sensitivity,” Tamimi says, “If a woman knows she has dense breasts, she should talk with her radiologist about using additional screening methods.”

Women with dense breasts should work with their radiologist and care team to develop a personalized strategy for breast cancer screening. This can include:

  • Monthly breast self-exams
  • An annual exam by a doctor
  • An annual digital mammogram (film mammograms are not as sensitive)

Strategies may also include regular MRIs and ultrasounds depending on the patient’s situation.