A study led by Mayo Clinic Cancer Center adds evidence to a growing body of knowledge that shows women with benign breast disease have a higher risk for breast cancer, and that certain types of breast disease may predict the near-term development of breast cancer. The findings will be published in the July 21 issue of The New England Journal of Medicine.
"Our findings indicate a link between select types of benign breast lesions and the later development of breast cancer," says Lynn Hartmann, M.D., Mayo Clinic oncologist and lead investigator of the study. "Women who have a breast biopsy that is benign must discuss the possibility of additional risks with their doctors."
Benign breast disease refers to any lumps or mammographically-detected abnormalities that have been biopsied and found to not contain cancerous cells. Each year in the United States it is estimated that more than 1 million women have a breast biopsy with benign findings, and Dr. Hartmann encourages clinicians to look more closely at the type of lesions they find. The Mayo team is evaluating various possible risk factors for a later breast cancer, including age at benign biopsy, family history of breast cancer and the pathologic findings of the benign lesion. "Our goal is to do a better job of risk prediction for women with various types of benign breast conditions," says Dr. Hartmann.
Dr. Hartmann and her co-investigators were heartened to find convincing evidence that women with the most common, non-proliferative forms of benign findings had no increased risk of developing breast cancer -- as long as they did not have a strong family history of breast cancer. However, for proliferative and atypical types, the opposite was true, and these lesions pointed to an increased risk of a future breast cancer, even when the family history of breast cancer was negative. Dr. Hartmann and her colleagues say continued studies of this kind are necessary to help understand the process of breast cancer development.