Menstrual and reproductive characteristics and breast cancer risk by hormone receptor status and ethnicity: The Breast Cancer Etiology in Minorities study.

ABSTRACT: We pooled multiethnic data from four population-based studies and examined associations of menstrual and reproductive characteristics with breast cancer (BC) risk by tumor hormone receptor (HR) status [defined by estrogen receptor (ER) and progesterone receptor (PR)]. We estimated odds ratios and 95% confidence intervals using multivariable logistic regression, stratified by age (<50, ≥50 years) and ethnicity, for 5,186 HR+ (ER+ or PR+) cases, 1,365 HR- (ER- and PR-) cases and 7,480 controls. For HR+ BC, later menarche and earlier menopause were associated with lower risk in non-Hispanic whites (NHWs) and Hispanics, and higher parity and longer breast-feeding were associated with lower risk in Hispanics and Asian Americans, and suggestively in NHWs. Positive associations with later first f

SUBMITTER: John EM 

PROVIDER: S-EPMC8784189 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature