Women with dense breast and no lobular involution were at a higher risk for developing breast cancer than those with non-dense breasts and complete involution, according to a Mayo Clinic study published online in The Journal of the National Cancer Institute.
Apart from age, family history, and age at menarche, two additional factors associated with breast cancer risk include dense breasts and no lobular involution, the latter of which is a physiological process whereby fat replaces breast stroma, occurring as women age.
The authors sought to discover if these factors are independently associated with breast cancer risk.
To determine whether lobular involution and mammographic density are independently associated with breast cancer risk, Karthik Ghosh, M.D., Mayo Clinic Breast Clinic director, and colleagues investigated the independent contributions of lobular involution and mammographic breast density to breast cancer risk in a cohort of 2666 women with benign breast disease, followed for a mean of 13.3 years.
The researchers took their cohort from the larger Mayo Breast Disease cohort, which included 9376 women between the ages of 18 and 85, with no history of breast cancer, who were diagnosed with benign breast disease between 1967 and the end of 1991.
The researchers found that breast density and amount of lobular involution pose independent risk factors for breast cancer. But combining both factors, there was a statistically significantly increased risk of breast cancer in women with no lobular involution and dense breasts compared to those with non-dense breasts and complete involution.
The authors write: “Our findings also reveal that having a combination of dense breasts and no lobular involution was associated with higher breast cancer risk than having non-dense or fatty breasts and complete involution.”
The researchers write that one of the study’s strengths is that it was conducted in large, well-organized cohort of women; however, limitations include the fact that the study population was white women from the Midwest, pointing to the need to conduct research in diverse populations.
The above news release was issued by the Journal of the National Cancer Institute.
