Mammographic density and breast cancer risk: a mediation analysisReport as inadecuate

Mammographic density and breast cancer risk: a mediation analysis - Download this document for free, or read online. Document in PDF available to download.

Breast Cancer Research

, 18:94

First Online: 21 September 2016Received: 10 May 2016Accepted: 23 August 2016DOI: 10.1186-s13058-016-0750-0

Cite this article as: Rice, M.S., Bertrand, K.A., VanderWeele, T.J. et al. Breast Cancer Res 2016 18: 94. doi:10.1186-s13058-016-0750-0


BackgroundHigh mammographic density MD is a strong risk factor for breast cancer. However, it is unclear whether high MD is an intermediate phenotype or whether breast cancer risk factors influence breast cancer risk and MD independently.

MethodsOur study population included 1290 invasive breast cancer cases and 3422 controls from the Nurses’ Health Studies. We estimated the percent of the total association between the risk factor and breast cancer that was mediated by MD.

ResultsIn both pre- and postmenopausal women, the association between history of biopsy-confirmed benign breast disease and risk was partially mediated by percent MD percent mediated PM = 17 %, p < 0.01 and PM = 33 %, p = 0.04, respectively. In premenopausal women, the associations between early life body size adolescent somatotype and BMI at age 18 and breast cancer risk were substantially mediated by percent MD PM = 73 %, p = 0.05 and PM = 82 %, p = 0.04, respectively. In postmenopausal women, the proportion of the associations of childhood somatotype and adolescent somatotype that were mediated by percent MD were lower PM = 26 %, p = 0.01 for both measures. Hormone therapy use at mammogram was significantly mediated by percent MD in postmenopausal women PM = 22 %, p < 0.01. Associations with other risk factors, such as age at menarche or family history of breast cancer, were not mediated by percent MD.

ConclusionsPercent MD partially mediated some of the associations between risk factors and breast cancer, though the magnitude varied by risk factor and menopausal status. These findings suggest that high MD may be an intermediate in some biological pathways for breast cancer development.

AbbreviationsBBDBenign breast disease

BMIBody mass index

HTHormone therapy

MDMammographic density

NHSNurses’ Health Study

Electronic supplementary materialThe online version of this article doi:10.1186-s13058-016-0750-0 contains supplementary material, which is available to authorized users.

Download fulltext PDF

Author: Megan S. Rice - Kimberly A. Bertrand - Tyler J. VanderWeele - Bernard A. Rosner - Xiaomei Liao - Hans-Olov Adami - Rulla


Related documents