Estrogen metabolism in menopausal hormone users in the women's health initiative observational study: Does it differ between estrogen plus progestin and estrogen alone?

ABSTRACT: The WHI found an unexpected reduced breast cancer risk in women using CEE alone. We hypothesized CEE alone induces estrogen hydroxylation along the 2-pathway rather than the competing 16-pathway, a pattern linked to reduced postmenopausal breast cancer risk. One thousand eight hundred and sixty-four women in a WHIOS case-control study of estrogen metabolism and ovarian and endometrial cancer were studied of whom 609 were current E + P users (351 used CEE + MPA), while 272 used E alone (162 used CEE). Fifteen EM were measured, and analyses were conducted for each metabolite, hydroxylation pathway (2-, 4-, or 16-pathway) and ratios of pathway concentrations using inverse probability weighted linear regression. Compared to E + P users, all EM were higher in E alone users (significant for unco

SUBMITTER: Falk RT 

PROVIDER: S-EPMC6746113 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature