Breast cancer risk varies in young women with benign breast disease

MedWire News: Young woman diagnosed with atypical hyperplasia (AH) of the breast have a substantially elevated risk for developing cancer, even if they have no history of the disease in their family, say researchers.

Reporting their findings at the 2008 San Antonio Breast Cancer Symposium in Texas, USA, the investigators note that women with AH were almost seven times more likely to develop breast cancer than women with negative biopsy results.

For the study, Karthik Ghosh (Mayo Clinic, Rochester, Minnesota) and co-workers followed-up 4460 women aged less than 50 years who were diagnosed with benign breast disease. The mean age at diagnosis was 39.4 years. Benign breast disease was classified as non-proliferative disease (NPD; n=72%), proliferative disease without atypia (PDWA; n=26%), or AH (n=2%).

After a median follow-up of 20 years, 326 breast cancer cases were identified.

The relative risk (RR) for breast cancer in the overall cohort of young women with BBD was 1.5 when compared with a control population with negative biopsy findings. Notably the RR among those with AH was 6.9, compared with a RR of 2.0 for PDWA, and a RR of 1.2 for NPD.

Furthermore, they found that a strong family history of breast cancer was associated with a 2.2 times greater relative risk for cancer development in women with NPD or PDWA compared with AH patients.

They also found that the 5% of women who had complete lobular involution had a reduced RR of 0.68 for developing breast cancer.

"The impact of lobular involution on risk, even in young women with benign breast disease, is an interesting finding," Ghosh said, adding: "It suggests that future research could potentially think about ways of promoting lobular involution as a means to reduce breast cancer risk."