Hormone replacement therapy in breast cancer survivors: a cohort study.

OBJECTIVE: Our purpose was to measure any adverse effect (if one exists) of hormone replacement therapy administered to breast cancer survivors. STUDY DESIGN: Forty-one patients from a group of 77 patients who received hormone replacement therapy after therapy for breast cancer were matched with 82 comparison patients not receiving hormone replacement therapy. Both groups were taken from the same population on the basis of cancer registry of the Cancer Surveillance Program of Orange County and were compared with regard to survival results. RESULTS: An analysis of survival time and disease-free time revealed no statistically significant difference between the two groups. CONCLUSIONS: No obvious adverse effect of hormone replacement therapy could be shown in this pilot study. A case is made for a prospective randomized trial.