Breast density alone found not to be a factor for breast cancer risk

http://www.eurekalert.org/pub_releases/2015-12/jhm-bda120215.php

Public Release: 2-Dec-2015
Breast density alone found not to be a factor for breast cancer risk
Age and body fat are more important co-factors, study suggests
Johns Hopkins Medicine

Although several studies suggest that women with denser breast tissue have an increased risk of breast cancer, a new study by Johns Hopkins researchers discredits breast density as a risk factor in and of itself, instead concluding that age and body fat, especially in the upper belly, contribute to the breast cancer seen in many patients.

"Many studies that link breast density to breast cancer risk used data from mammograms, which can't accurately measure breast density," says Wenlian Zhu, Ph.D., a research associate in the Johns Hopkins University School of Medicine and a member of the team reporting the study results online Oct. 21, 2015, in European Radiology. "Our research may help dispel the assertion that breast density alone is something women should be worried about with regard to their breast cancer risk, and it may help minimize confusion and unnecessary concern."

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Zhu says one likely explanation for their finding is that women with the densest breasts tended to be young and lean, both factors aligned with lower breast cancer risk. "Grouping all women with dense breasts into an elevated risk category could therefore be misleading and may cause unnecessary anxiety for many women," she says. "If further studies expand and confirm our research, we may be able to offer reassurance to many young and lean women with dense breasts."

Zhu cautions that her study did not specifically examine the interactions among age, adiposity and breast density for older women. Testing whether breast density is associated with breast cancer in this population will be the subject of future research, she says.