MONDAY, Nov. 1 (HealthDay News) -- Women with dense breasts and
no lobular involution -- an age-related change in breast tissue --
are at increased risk for breast cancer, a new study finds.
It included 2,666 women, aged 18 to 85, with benign breast
disease who were followed for an average of 13.3 years. During that
time, 172 (6.5 percent) of the women developed breast cancer.
The Mayo Clinic researchers found that breast density and
lobular involution were independent risk factors for breast
The study appears online in the
Journal of the National Cancer Institute.
"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," they wrote in a news release from the publisher.
"Lobular involution is the physiological atrophy of the breast epithelium [the top layer of cells] and is known to increase with increasing age," the news release explained.
Breast density and lobular involution are factors that "hold
promise for improving [breast cancer] risk prediction, particularly
since they reflect the cumulative interplay of numerous genetic and
environmental breast cancer risk factors over time," Gretchen L.
Gierach, of the U.S. National Cancer Institute, and colleagues
wrote in the news release.
Other known breast cancer risk factors are age, family history
and age at first menstrual cycle.
The U.S. National Cancer Institute has more about
breast cancer risk.