Breast Density Contributes to Breast Cancer Risk

Recently there has been some discussion regarding inclusion of breast density in breast cancer prediction models. In a recent issue of the Journal of the National Cancer Institute this issue is highlighted. The discussion revolves around the question: should breast density be added to the Gail model in predicting breast cancer occurrence?

The Gail model is a breast cancer prediction tool that is widely used. Gail model estimates a woman's risk of developing breast cancer taking into account several factors like age, family history of breast cancer, reproductive history and history of previous biopsies. This model is widely used to identify the group of women who have high risk of developing breast cancer. This model was originally introduced for evaluation of Caucasian women and is yet to be validated in other ethnic groups.

Researchers have recently identified other risk factors like breast density and postmenopausal hormone replacement therapy. In continuing effort to improve the accuracy of the Gail model experts are suggesting that these new risk factors should be included in calculation of the risk.

The term breast density refers to the extent of glandular and connective tissue in the breast. Breasts with more glandular and connective tissue are denser by definition. A mammogram gives an estimate of breast density. Increased breast density is linked to increased risk of breast cancer. Breast density is estimated on a scale of one to four, with one being "almost entirely fat" and four being "extremely dense."

In a recent study among premneopausal women, factors that were associated with an increased risk of breast cancer were increasing age, higher breast density, family history of breast cancer, and a prior breast procedure (such as a prior biopsy). In the group of postmenopausal women, factors that were linked with an increased risk of breast cancer were increasing age, higher breast density, higher body mass index, no live birth or older age at first birth, family history of breast cancer, prior breast procedure, current postmenopausal hormone use, natural (as opposed to surgical) menopause, and previous false-positive mammogram).

Asian/Pacific Islanders and Native-Americans have much lower risk of developing breast cancer compared to white women. Hispanic women have a lower risk than non-Hispanic women.

Breast density was the strongest predictor of breast cancer in both pre- and postmenopausal women. Among premneopausal women, the risk of breast cancer was almost four times higher in those with the highest breast density than in those with the lowest breast density. In postmenopausal women, the risk of breast cancer was roughly three-times higher in those with the highest breast density.

Written by Medicineworld Reporter


Posted by: Janet