Breast Cancer Risk Linked to Lobular Involution
The greater the regression of milk glands the lower the risk of cancer
WEDNESDAY, Nov. 22 (HealthDay News) -- In women with benign breast disease, the extent of lobular involution, the normal process of regression of the milk glands, is related to the risk of developing breast cancer, according to a report published in the Nov. 15 issue of the Journal of the National Cancer Institute.
Lynn C. Hartmann, M.D., of the Mayo Clinic College of Medicine in Rochester, Minn., and colleagues analyzed biopsies of 8,736 women with benign breast disease who were followed up for a mean of 17 years. Lobular involution was classified in three categories: none, partial (1 percent to 74 percent), and complete (more than 74 percent).
There were 1,627 women (18.6 percent) without lobular involution, 5,197 women (59.5 percent) with partial involution and 1,912 women (21.9 percent) with complete involution. There was an inverse association between parity and lobular involution, and involution was positively associated with increasing age.
The risk of developing breast cancer was lower as the degree of lobular involution increased, and the association applied in all subsets, such as women with atypia.
"Among women with benign breast disease, assessment of extent of involution may help to fine-tune current risk prediction approaches. Elucidation of the mechanism of lobular involution may reveal ways to promote the process as a means of risk reduction," the authors conclude.