Colorectal cancer in relation to postmenopausal estrogen and estrogen plus progestin in the Women's Health Initiative clinical trial and observational study.

ABSTRACT:

Background

Colorectal cancer incidence was reduced among women assigned to active treatment in the Women's Health Initiative (WHI) estrogen plus progestin-randomized trial, but the interpretation was obscured by an associated later stage of diagnosis. In contrast, the estrogen-alone trial showed no incidence reduction or differential stage at diagnosis. Here, data from the WHI observational study are considered, in conjunction with colorectal cancer mortality data from the hormone therapy trials, in an attempt to clarify postmenopausal hormone therapy effects.

Participants and methods

Postmenopausal women ages 50 to 79 years at WHI enrollment. Estrogen-alone analyses include 21,552 and 10,739 women who were posthysterectomy from the observational study and clinical trial, re

SUBMITTER: Prentice RL 

PROVIDER: S-EPMC2689377 | biostudies-literature | 2009 May

REPOSITORIES: biostudies-literature