Estrogen-alone therapy and invasive breast cancer incidence by dose, formulation, and route of delivery: findings from the WHI observational study.

ABSTRACT:

Objective

Research on the relationships between different hormone therapy doses, formulation and routes of delivery, and subsequent breast cancer incidence has been limited. This study directly compared different estrogen doses, formulations, and route of delivery of estrogen alone among women with a hysterectomy in relation to invasive breast cancer incidence.

Methods

The Women's Health Initiative Observational Study is a large multicenter prospective cohort study conducted at 40 US sites. Analyses included 26,525 postmenopausal women with a hysterectomy, aged 50 to 79 years, at study entry, recruited between September, 1993 and December, 1998, with annual follow-up through September 12, 2005.

Results

Average follow-up was 8.2 years. For conjugated equine estrogen (C

SUBMITTER: Shufelt C 

PROVIDER: S-EPMC6103839 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature