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

Publication Type:

Journal Article


Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, Volume 18, Issue 5, p.1531-7 (2009)


2009, Aged, Center-Authored Paper, Colorectal Neoplasms, Estrogen Replacement Therapy, Female, Follow-Up Studies, Humans, Hysterectomy, Incidence, Middle Aged, Observation, Postmenopause, Progesterone, Proportional Hazards Models, Public Health Sciences Division, RISK


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