Sex hormone associations with breast cancer risk and the mediation of randomized trial postmenopausal hormone therapy effects.

ABSTRACT:

Introduction

Paradoxically, a breast cancer risk reduction with conjugated equine estrogens (CEE) and a risk elevation with CEE plus medroxyprogesterone acetate (CEE + MPA) were observed in the Women's Health Initiative (WHI) randomized controlled trials. The effects of hormone therapy on serum sex hormone levels, and on the association between baseline sex hormones and disease risk, may help explain these divergent breast cancer findings.

Methods

Serum sex hormone concentrations were measured for 348 breast cancer cases in the CEE + MPA trial and for 235 cases in the CEE trial along with corresponding pair-matched controls, nested within the WHI trials of healthy postmenopausal women. Association and mediation analyses, to examine the extent to which sex hormone levels and

SUBMITTER: Zhao S 

PROVIDER: S-EPMC4053241 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature