University of Virginia Health System, Division of Endocrinology & Metabolism, Charlottesville, Virginia.
Southern Methodist University Department of Statistical Science and University of Texas Southwestern Department of Population & Data Sciences, Dallas, Texas.
J Clin Endocrinol Metab. 2020 Jun 1;105(6). doi: 10.1210/clinem/dgaa073.
The recent Collaborative Group on Hormonal Factors in Breast Cancer (CGHFBC) publication calculated the attributable risk of breast cancer from use of estrogen alone and estrogen plus a synthetic progestogen for less than 5 to 15 or more years of use. This CGHFB report calculated attributable risk based on their findings of relative risk from pooled data from 58 studies. Notably, neither the CGHFBC nor other previous studies have examined the effect of underlying risk of breast cancer on attributable risk. This omission prompted us to determine the magnitude of the effect of underlying risk on attributable risk in this perspective. Meaningful communication of the potential risk of menopausal hormonal therapy requires providing women with the estimated risk above their existing underlying risk (ie, attributable risk). Therefore, we have estimated attributable risks from the data published by the CGHFBC, taking into account varying degrees of underlying risk. Based on the Endocrine Society Guideline on Menopausal Hormone Therapy (MHT), we divided groups into 3 categories of risk: low (1.5%), intermediate (3.0%), and high (6.0%) underlying risk of breast cancer over 5 years. In women taking estrogen plus a synthetic progestogen for 5 to 9 years, the attributable risks of MHT increased from 12, to 42, to 85 additional women per 1000 in the low-, intermediate-, and high-risk groups, respectively. The attributable risks for estrogen alone were lower but also increased based on underlying risk. Notably, the attributable risks were amplified with duration of MHT use, which increased both relative risk and breast cancer incidence.
最近的乳腺癌激素因素协作组（CGHFBC）出版物计算了单独使用雌激素和雌激素加合成孕激素不到 5 至 15 年或更长时间使用的乳腺癌归因风险。该 CGHFB 报告基于对来自 58 项研究的汇总数据的相对风险的发现来计算归因风险。值得注意的是，CGHFBC 或其他先前的研究都没有检查乳腺癌潜在风险对归因风险的影响。这种遗漏促使我们确定潜在乳腺癌风险对归因风险的影响程度。为了使绝经后激素治疗的潜在风险得到有意义的沟通，需要向女性提供其现有潜在风险之上的估计风险（即归因风险）。因此，我们根据 CGHFBC 发布的数据，考虑到潜在风险的不同程度，估计了归因风险。基于内分泌学会绝经激素治疗指南（MHT），我们将组分为 3 个风险类别：低（1.5%）、中（3.0%）和高（6.0%）乳腺癌风险超过 5 年。在接受雌激素加合成孕激素治疗 5 至 9 年的女性中，MHT 的归因风险分别从每 1000 名女性中的 12 人增加到 42 人，再增加到 85 人，在低风险、中风险和高风险组中分别增加。单独使用雌激素的归因风险较低，但也会随着潜在风险的增加而增加。值得注意的是，归因风险随着 MHT 使用时间的延长而放大，这增加了相对风险和乳腺癌发病率。
