A recently published paper has evaluated colorectal cancer risk associated with the duration and recency of specific menopausal hormone therapy formulations viz. unopposed estrogen versus estrogen combined with continuously or sequentially administered progestin among 56,733 postmenopausal women participating in the Breast Cancer Detection Demonstration Project (BCDDP) follow-up study . There were 960 women who were identified to have developed colorectal cancer over a mean follow-up period of 15 years and mean age at commencement of follow-up of 55.7 years. Current use of estrogen (relative risk (RR), 0.75; 95% confidence interval (CI), 0.54–1.05) and duration of use of > 10 years (RR, 0.74; 95% CI, 0.56–0.96) were associated with the largest reduction of risk compared to non-users. Estrogen with sequentially administered progestin for < 15 days per cycle (RR, 0.64; 95% CI, 0.43–0.95) was more protective than continuous combined estrogen and progestin therapy.
Menopause Research Unit, University Hospitals of Leicester, Leicester, UK
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