Background Women treated for breast cancer (BC) often suffer genitourinary syndrome of menopause. These symptoms may be alleviated by vaginal estrogen therapy (VET) or menopausal hormone therapy (MHT). However, there are concerns of risks of recurrence of BC and death following treatment. Methods Our study included longitudinal data from a national cohort of postmenopausal women, diagnosed 1997-2004 with early-stage invasive estrogen receptor–positive nonmetastatic BC, who received no treatment or 5 years of adjuvant endocrine therapy. We ascertained prescription data on hormone therapy, VET or MHT, from a national prescription registry. We evaluated mortality and risk of recurrence associated with use of VET and MHT vs non-use using multivariable models adjusted for potential confounders. Results Among 8461 women who had not received VET or MHT before BC diagnosis, 1957 and 133 used VET and MHT, respectively, after diagnosis. Median follow-up was 9.8 years for recurrence and 15.2 years for mortality. The adjusted relative risk of recurrence was 1.08 (95% confidence interval [CI] = 0.89 to 1.32) for VET (1.39 [95% CI = 1.04 to 1.85 in the subgroup receiving adjuvant aromatase inhibitors]) and 1.05 (95% CI = 0.62 to 1.78) for MHT. The adjusted hazard ratios for overall mortality were 0.78 (95% CI = 0.71 to 0.87) and 0.94 (95% CI = 0.70 to 1.26) for VET and MHT, respectively. Conclusions In postmenopausal women treated for early-stage estrogen receptor–positive BC, neither VET nor MHT was associated with increased risk of recurrence or mortality. A subgroup analysis revealed an increased risk of recurrence, but not mortality, in patients receiving VET with adjuvant aromatase inhibitors.

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早期乳腺癌后的全身或阴道激素治疗：丹麦观察队列研究

背景 接受乳腺癌（BC）治疗的女性经常患有更年期泌尿生殖综合症。这些症状可以通过阴道雌激素治疗（VET）或绝经期激素治疗（MHT）得到缓解。然而，人们担心治疗后乳腺癌复发和死亡的风险。方法 我们的研究包括来自全国绝经后妇女队列的纵向数据，这些妇女于 1997 年至 2004 年被诊断为早期侵入性雌激素受体阳性非转移性 BC，未接受任何治疗或接受了 5 年辅助内分泌治疗。我们从国家处方登记处确定了激素治疗、VET 或 MHT 的处方数据。我们使用针对潜在混杂因素进行调整的多变量模型评估了使用 VET 和 MHT 与不使用相关的死亡率和复发风险。结果 在 BC 诊断前未接受 VET 或 MHT 的 8461 名女性中，诊断后分别有 1957 名和 133 名女性使用了 VET 和 MHT。复发中位随访时间为 9.8 年，死亡率中位随访时间为 15.2 年。VET 的调整后相对复发风险为 1.08（95% 置信区间 [CI] = 0.89 至 1.32）（接受辅助芳香酶抑制剂的亚组为 1.39 [95% CI = 1.04 至 1.85]）和 1.05（95% CI = 0.62）至 1.78) 对于 MHT。VET 和 MHT 的总死亡率调整后风险比分别为 0.78（95% CI = 0.71 至 0.87）和 0.94（95% CI = 0.70 至 1.26）。结论 在接受早期雌激素受体阳性 BC 治疗的绝经后妇女中，VET 和 MHT 均与复发或死亡风险增加无关。亚组分析显示，接受辅助芳香酶抑制剂 VET 的患者复发风险增加，但死亡风险没有增加。