Gene Polymorphisms Identified That Are Responsible for Breast Density and Cancer Risk
Date: 25.10.2012
It has long been known that breast density, or mammographic density, is a strong risk factor for breast cancer, and that estrogen and progestin hormone therapy increases dense breast tissue. Now, a study published in BioMed Central's open access journal Breast Cancer Research has identified several gene variants in hormone metabolism and growth factor pathways that may be associated with breast density and, hence, breast cancer risk.
Women with a breast density of 75% or more have a 4-5 times higher risk of developing breast cancer than women of the same age with little or no density.
Controversy exists over why breast density is a cancer risk. Many studies suggest that density is at least partially inherited, and twin studies show that genetic factors do play a role in the variation observed. Breast density decreases naturally with older age and menopause, but also increases with hormone therapy.
The findings suggest that several genes in hormone metabolism and growth factor pathways are indeed implicated in determining breast density, and might increase breast cancer risk.
