Parity and breastfeeding among African-American women: differential effects on breast cancer risk by estrogen receptor status in the Women’s Circle of Health Study
- 19 November 2013
- journal article
- research article
- Published by Springer Science and Business Media LLC in Cancer Causes & Control
- Vol. 25 (2), 259-265
- https://doi.org/10.1007/s10552-013-0323-9
Abstract
Purpose It has long been held that parity reduces risk of breast cancer. However, accumulating evidence indicates that the effects of parity, as well as breastfeeding, may vary according to estrogen receptor (ER) status. We evaluated these associations in a case–control study among African-American women in New York City and New Jersey. Methods In the Women’s Circle of Health Study, including 786 African-American women with breast cancer and 1,015 controls, data on reproductive histories were collected from in-person interviews, with tumor characteristics abstracted from pathology reports. We calculated number of live births and months breastfeeding for each child, and examined each in relation to breast cancer by ER status, and for triple-negative (TN) breast cancer. Results Although associations were not statistically significant, having children was associated with reduced risk of ER+ breast cancer [odds ratio (OR) 0.82, 95 % confidence interval (CI) 0.58–1.16], but increased risk of ER− tumors, with associations most pronounced for TN breast cancer (OR 1.81, 95 % CI 0.93–3.51). Breastfeeding gave no additional benefit for ER+ cancer, but reduced the risk of ER− disease associated with parity. Conclusions Accumulating data from a number of studies, as well as our own in African-American women, indicate that the effects of parity and breastfeeding differ by ER status. African-American women are more likely to have children and not to breastfeed, and to have ER− and TN breast cancer. It is possible that breastfeeding in this population could reduce risk of more aggressive breast cancers.Keywords
This publication has 20 references indexed in Scilit:
- Rethinking sources of representative controls for the conduct of case–control studies in minority populationsBMC Medical Research Methodology, 2013
- Reproductive factors and risk of estrogen receptor positive, triple-negative, and HER2-neu overexpressing breast cancer among women 20–44 years of ageBreast Cancer Research and Treatment, 2012
- Variants in the vitamin D pathway, serum levels of vitamin D, and estrogen receptor negative breast cancer among African-American women: a case-control studyBreast Cancer Research, 2012
- Parity and Lactation in Relation to Estrogen Receptor Negative Breast Cancer in African American WomenCancer Epidemiology, Biomarkers & Prevention, 2011
- Associations of Breast Cancer Risk Factors With Tumor Subtypes: A Pooled Analysis From the Breast Cancer Association Consortium StudiesJNCI Journal of the National Cancer Institute, 2010
- Conducting Molecular Epidemiological Research in the Age of HIPAA: A Multi-Institutional Case-Control Study of Breast Cancer in African-American and European-American WomenJournal of Oncology, 2009
- Pregnancy and Breast Cancer: when They CollideJournal of Mammary Gland Biology and Neoplasia, 2009
- Epidemiology of basal-like breast cancerBreast Cancer Research and Treatment, 2007
- Pregnancy-associated breast cancer and metastasisNature Reviews Cancer, 2006
- Immunohistochemical and Clinical Characterization of the Basal-Like Subtype of Invasive Breast CarcinomaClinical Cancer Research, 2004