Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA.
Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA.
J Natl Cancer Inst. 2023 Jun 8;115(6):662-670. doi: 10.1093/jnci/djad038.
Gynecologic surgery is hypothesized to reduce risk of breast cancer; however, associations may be modified by subsequent hormone use. Our objective was to examine the association between gynecologic surgery and breast cancer incidence considering the use of hormone therapy.
The Sister Study is a prospective cohort of initially breast cancer-free women aged 35-74 years with a sister who had breast cancer. We used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between gynecologic surgery (no surgery, hysterectomy only, bilateral oophorectomy with or without hysterectomy) and incident breast cancer among 50 701 women.
History of gynecologic surgery was common, with 13.8% reporting hysterectomy only and 18.1% reporting bilateral oophorectomy with or without hysterectomy. During follow-up (median = 11.4 years), 3948 cases were diagnosed. Compared with no surgery, bilateral oophorectomy was inversely associated with breast cancer (HR = 0.91, 95% CI = 0.83 to 1.00), and hysterectomy alone was positively associated (HR = 1.12, 95% CI = 1.02 to 1.23). Compared with no surgery and no hormone therapy, bilateral oophorectomy combined with estrogen only therapy (HR = 0.83, 95% CI = 0.74 to 0.94) was inversely associated with breast cancer, while hysterectomy combined with estrogen plus progestin therapy was positively associated with breast cancer (HR = 1.25, 95% CI = 1.01 to 1.55).
We observed an inverse association between bilateral oophorectomy and breast cancer risk. The positive association between hysterectomy and breast cancer may be due to concomitant estrogen plus progestin therapy.
妇科手术被认为可降低乳腺癌风险；然而，这种关联可能会因后续激素使用而改变。我们的目的是在考虑激素治疗的情况下，研究妇科手术与乳腺癌发病之间的关联。
姐妹研究是一项针对最初无乳腺癌的 35-74 岁女性的前瞻性队列研究，她们有一位患有乳腺癌的姐妹。我们使用 Cox 比例风险模型来估计 50701 名女性中妇科手术（无手术、单纯子宫切除术、双侧卵巢切除术伴或不伴子宫切除术）与乳腺癌发病之间的风险比（HR）和 95%置信区间（CI）。
妇科手术史常见，13.8%的女性报告单纯子宫切除术，18.1%的女性报告双侧卵巢切除术伴或不伴子宫切除术。在随访期间（中位=11.4 年），诊断出 3948 例病例。与无手术相比，双侧卵巢切除术与乳腺癌呈负相关（HR=0.91，95%CI=0.83 至 1.00），而单纯子宫切除术呈正相关（HR=1.12，95%CI=1.02 至 1.23）。与无手术和无激素治疗相比，双侧卵巢切除术联合雌激素治疗（HR=0.83，95%CI=0.74 至 0.94）与乳腺癌呈负相关，而子宫切除术联合雌激素加孕激素治疗与乳腺癌呈正相关（HR=1.25，95%CI=1.01 至 1.55）。
我们观察到双侧卵巢切除术与乳腺癌风险呈负相关。子宫切除术与乳腺癌的正相关可能是由于同时使用雌激素加孕激素治疗。
