New evidence for cancer-related benefit of breastfeeding in African-Americans

According to a recent study in the Journal of the National Cancer Institute, the evidence continues to mount for an association between breastfeeding and reduced risk of aggressive breast cancers in African-American women.

Led by researchers at the Roswell Park Cancer Institute, the study used questionnaire data from 2 cohort and 2 case-control studies of breast cancer in African-American women, which was subsequently combined and harmonized. Based on pathology data, breast cancer in respondents was classified as estrogen receptor-positive (ER+) (n = 2446), ER- (1252), or triple negative (ER-, progesterone receptor-negative [PR-], HER2-negative; n =567). There were 14180 control patients overall. Adjusting for study, age, and reproductive and other risk factors, polytomous logistic regression analysis was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

Stat bite: Preconception health indicators

For parity relative to nulliparity, the ORs were 0.92 (95% CI = 0.81 to 1.03) for ER+ disease, 1.33 (95% CI = 1.11 to 1.59) for ER-, and 1.37 (95% CI = 1.06 to 1.70) for triple-negative breast cancer. Breastfeeding was associated with ER- breast cancer (OR = 0.81, 95% CI 0.69 to 0.95), but not with ER+ cancer. The risk of ER- breast cancer increased with each additional birth in which the child was not subsequently breastfed, an OR of 1.68 (95% CI = 1.15 to 2.44) for 4 or more births compared to 1 birth with breastfeeding.

The investigators concluded that parous African-American women who did not breastfeed were at an increased risk of triple negative and ER- breast cancers.

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