Does hormone replacement therapy cause breast cancer? An application of causal principles to three studies Part 4. The Million Women Study

作者：Shapiro Samuel^*; Farmer Richard D T; Stevenson John C; Burger Henry G; Mueck Alfred

来源：Journal of Family Planning and Reproductive Health Care, 2012, 38(2): 102-109.

DOI：10.1136/jfprhc-2011-100229

Background Based principally on findings in three studies, the collaborative reanalysis (CR), the Women%26apos;s Health Initiative (WHI) and the Million Women Study (MWS), it is claimed that hormone replacement therapy (HRT) with estrogen plus progestogen (E+P) is now an established cause of breast cancer; the CR and MWS investigators claim that unopposed estrogen therapy (ET) also increases the risk, but to a lesser degree than does E+P. The authors have previously reviewed the findings in the CR and WHI (Parts 1-3). %26lt;br%26gt;Objective To evaluate the evidence for causality in the MWS. %26lt;br%26gt;Methods Using generally accepted causal criteria, in this article (Part 4) the authors evaluate the findings in the MWS for E+P and for ET. %26lt;br%26gt;Results Despite the massive size of the MWS the findings for E+P and for ET did not adequately satisfy the criteria of time order, information bias, detection bias, confounding, statistical stability and strength of association, duration-response, internal consistency, external consistency or biological plausibility. Had detection bias resulted in the identification in women aged 50-55 years of 0.3 additional cases of breast cancer in ET users per 1000 per year, or 1.2 in E+P users, it would have nullified the apparent risks reported. %26lt;br%26gt;Conclusion HRT may or may not increase the risk of breast cancer, but the MWS did not establish that it does.

• 出版日期2012-4
• 单位河北医科大学