Parity, Breastfeeding Tied to ER−/PR− Breast Cancer RiskLast Updated: August 17, 2011. Higher parity is associated with an increased risk of estrogen receptor-negative/progesterone receptor-negative breast cancer in African-American women, but breastfeeding ameliorates this adverse effect, according to a study published online Aug. 16 in Cancer Epidemiology, Biomarkers & Prevention.
WEDNESDAY, Aug. 17 (HealthDay News) -- Higher parity is associated with an increased risk of estrogen receptor (ER)-negative/progesterone receptor (PR)-negative (ER−/PR−) breast cancer in African-American women, but breastfeeding ameliorates this adverse effect, according to a study published online Aug. 16 in Cancer Epidemiology, Biomarkers & Prevention.
Julie R. Palmer, Sc.D., from Slone Epidemiology Center at Boston University, and colleagues examined the association between parity and lactation to incidence of ER−/PR− and ER+/PR+ breast cancer in 59,000 African-American women. Data were collected from women followed in the Black Women's Health Study between 1995 and 2009, and 457 incident cases of ER+/PR+ and 318 cases of ER−/PR− breast cancer, confirmed by review of pathology data, were identified.
The investigators found that higher parity was correlated with an increased risk of ER−/PR− breast cancer (hazard ratio [HR], 1.48; 95 percent confidence interval [CI], 0.98 to 1.84 for three or more versus zero births), and with a lowered risk of ER+/PR+ cancer (HR, 0.53; 95 percent CI, 0.39 to 0.73 for three or more versus zero births). High parity was not correlated with an increased incidence of ER−/PR− breast cancer among women who had breastfed. However, the inverse correlation between high parity and ER+/PR+ cancer remained.
"The higher incidence of ER−/PR− breast cancer in African-American women may be explained in part by their higher parity and lower prevalence of breastfeeding relative to white women," the authors write. "Increased breastfeeding may lead to a reduction in the incidence of this breast cancer subtype."
|Previous: Asymptomatic Microscopic Hematuria Ups Youth ESRD Risk||Next: AdV-tk Plus Valacyclovir Safe in New Malignant Gliomas|
Reader comments on this article are listed below. Review our comments policy.