(HealthDay News) — High mammographic breast density is not associated with an increased risk of breast cancer-related or all-cause mortality, according to a study published online Aug. 21 in the Journal of the National Cancer Institute.
Gretchen L. Gierach, Ph.D., M.P.H., from the National Cancer Institute in Rockville, Md., and colleagues utilized data from 9,232 women diagnosed with primary invasive breast carcinoma from 1996 to 2005 in the U.S. Breast Cancer Surveillance Consortium. The Breast Imaging Reporting and Data System (BI-RADS) density classification was used to assess mammographic density.
The researchers found that, over a mean of 6.6 years of follow-up, 1,795 women died; of these, 889 died from breast cancer. High density (BI-RADS 4) was not associated with risk of death from breast cancer (hazard ratio [HR], 0.92; 95 percent confidence interval [CI], 0.71 to 1.19) or death from all causes (HR, 0.83; 95 percent CI, 0.68 to 1.02) after adjusting for other factors, including site, age at diagnosis, year of diagnosis, cancer stage, body mass index, mode of detection, treatment, and income. Stratifying the data by stage and other prognostic factors showed similar results, except for a significantly increased risk of breast cancer mortality among women with low density (BI-RADS 1) who either had tumors of at least 2.0 cm (HR, 1.55) or were obese (HR, 2.02).
“High mammographic breast density was not associated with risk of death from breast cancer or death from any cause after accounting for other patient and tumor characteristics,” the authors write.