Breast Cancer Research and Treatment

, Volume 135, Issue 2, pp 571–580

Mammographic density and breast cancer risk in White and African American Women

  • Hilda Razzaghi
  • Melissa A. Troester
  • Gretchen L. Gierach
  • Andrew F. Olshan
  • Bonnie C. Yankaskas
  • Robert C. Millikan

DOI: 10.1007/s10549-012-2185-3

Cite this article as:
Razzaghi, H., Troester, M.A., Gierach, G.L. et al. Breast Cancer Res Treat (2012) 135: 571. doi:10.1007/s10549-012-2185-3


Mammographic density is a strong risk factor for breast cancer, but limited data are available in African American (AA) women. We examined the association between mammographic density and breast cancer risk in AA and white women. Cases (n = 491) and controls (n = 528) were from the Carolina Breast Cancer Study (CBCS) who also had mammograms recorded in the Carolina Mammography Registry (CMR). Mammographic density was reported to CMR using Breast Imaging Reporting and Data System (BI-RADS) categories. Increasing mammographic density was associated with increased breast cancer risk among all women. After adjusting for potential confounders, a monotonically increasing risk of breast cancer was observed between the highest versus the lowest BI-RADS density categories [OR = 2.45, (95 % confidence interval: 0.99, 6.09)]. The association was stronger in whites, with ~40 % higher risk among those with extremely dense breasts compared to those with scattered fibroglandular densities [1.39, (0.75, 2.55)]. In AA women, the same comparison suggested lower risk [0.75, (0.30, 1.91)]. Because age, obesity, and exogenous hormones have strong associations with breast cancer risk, mammographic density, and race in the CBCS, effect measure modification by these factors was considered. Consistent with previous literature, density-associated risk was greatest among those with BMI > 30 and current hormone users (P value = 0.02 and 0.01, respectively). In the CBCS, mammographic density is associated with increased breast cancer risk, with some suggestion of effect measure modification by race, although results were not statistically significant. However, exposures such as BMI and hormone therapy may be important modifiers of this association and merit further investigation.


Mammographic breast densityBreast cancerRaceAfrican AmericanEpidemiology

List of abbreviations


African American


Breast Imaging Reporting and Data System


Body mass index


Carolina Breast Cancer Study


Confidence interval


Carolina Mammography Registry


Hormone therapy


Likelihood ratio test


National Heart, Lung, and Blood Institute


Odds ratio


Waist-to-hip ratio

Supplementary material

10549_2012_2185_MOESM1_ESM.doc (40 kb)
Supplementary material 1 (DOC 40 kb)

Copyright information

© Springer Science+Business Media, LLC. 2012

Authors and Affiliations

  • Hilda Razzaghi
    • 1
  • Melissa A. Troester
    • 1
    • 2
  • Gretchen L. Gierach
    • 3
  • Andrew F. Olshan
    • 1
    • 2
  • Bonnie C. Yankaskas
    • 4
  • Robert C. Millikan
    • 1
    • 2
  1. 1.Department of EpidemiologyGillings Global School of Public Health, University of North CarolinaChapel HillUSA
  2. 2.Linberger Comprehensive Cancer CenterUniversity of North CarolinaChapel HillUSA
  3. 3.Hormonal and Reproductive Epidemiology Branch, Division of Cancer Epidemiology and GeneticsNational Cancer Institute, National Institutes of HealthRockvilleUSA
  4. 4.Department of Radiology, School of MedicineUniversity of North CarolinaChapel HillUSA