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Reduced risk in colorectal cancer associated with menopausal hormone therapy We evaluated colorectal cancer risk associated with duration and recency of menopausal hormone therapy use. In this study, we abstracted data from 56,733 postmenopausal women who participated in the Breast Cancer Detection Demonstration Project follow-up study. Hormone therapy use and other risk factors were ascertained through telephone interviews and mailed questionnaires between 1979 and 1998. During an average 15 years of follow-up, we identified 960 new cases of colorectal cancer in this population.We found that ever use of any menopausal hormone therapy was associated with a reduced risk of colorectal cancer. Any use of estrogen therapy was associated with a 17 percent reduced risk in colorectal cancer. Among those who used estrogen, the largest reductions were seen among those who were current users (25 percent reduced risk) and users of ten or more years duration (26 percent reduced risk). We also found a 22 percent reduced risk among those who had ever used estrogen plus progestin in combination. Furthermore, we found a 36 percent reduction in risk among those who had used progestin sequentially, or less than 15 days per month. Past users of estrogen plus progestin, who had stopped at least five years ago, had a 45 percent risk reduction
Bibliographic Reference
Jill R. Johnson Division of
Epidemiology and Community Health, School of Public Health, University of
Minnesota, Minneapolis, Minnesota; USA
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