Reproductive history, breast‐feeding and risk of triple negative breast cancer: The Breast Cancer Etiology in Minorities (BEM) study
Abstract
Few risk factors have been identified for triple negative breast cancer (TNBC) which lacks expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2). This more aggressive subtype disproportionately affects some racial/ethnic minorities and is associated with lower survival. We pooled data from three population‐based studies (558 TNBC and 5,111 controls) and examined associations of TNBC risk with reproductive history and breast‐feeding. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) using multivariable logistic regression. For younger women, aged vs. 0 months: OR = 0.52, 95% CI = 0.26–1.04, Ptrend = 0.06). Considering the joint effect of parity and breast‐feeding, risk was increased two‐fold for women with ≥3 full‐term pregnancies (FTPs) and no or short‐term (<12 months) breast‐feeding compared to women with 1–2 FTPs and breast‐feeding ≥12 months (OR = 2.56, 95% CI = 1.22–5.35). None of these associations were observed among older women (≥50 years). Differences in reproductive patterns possibly contribute to the ethnic differences in TNBC incidence. Among controls aged <50 years, the prevalence of no or short‐term breast‐feeding and ≥3 FTPs was highest for Hispanics (22%), followed by African Americans (18%), Asian Americans (15%) and non‐Hispanic whites (6%). Breast‐feeding is a modifiable behavioral factor that may lower TNBC risk and mitigate the effect of FTPs in women under age 50 years.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 30, 2018
- Source ID
- 10.1002/ijc.31258
Entities
People
- Amanda I. Phipps
- Anna H. Wu
- Esther M. John
- Jocelyn Koo
- Kathy B. Baumgartner
- Lisa M. Hines
- Martha L Slattery
- Sue A. Ingles
- Teri A. Longacre
Organizations
- California Breast Cancer Research Program
- Cancer Prevention Institute of California
- Fred Hutchinson Cancer Center
- National Cancer Institute
- Stanford University
- United States Department of Defense
- University of Colorado, at Colorado Springs
- University of Louisville
- University of Southern California
- University of Utah
- University of Washington