While adjuvant treatment with the selective-estrogen receptor modulator (SERM) tamoxifen has been the standard of care for pre-menopausal patients with hormone receptor (HR) positive breast cancer, recent trials showed a benefit of aromatase inhibitors (AI) and ovarian function suppression (OFS) for some patients. The approach to endocrine therapy has not been well studied in pre-menopausal patients with invasive lobular carcinoma (ILC). We identified 202 pre-menopausal patients with HR positive stage I-III ILC in an institutional database. We investigated factors associated with endocrine therapy type and determined changes in systemic therapy from 1990–2021. We evaluated associations between endocrine therapy type and disease-free survival (DFS) with a multivariate Cox proportional hazards model. Of 202 patients, most (69.3%) were prescribed a SERM (99.3% tamoxifen). Those who received an AI had significantly higher stage disease. Over time, use of OFS and AI increased significantly in stage II or III cases (from 0% in 1990 to 56% after 2015 for stage II; from 0% to 80% after 2015 for stage III). Concurrently, adjuvant chemotherapy use significantly decreased in stage II cases (from 67% to 19%). In an exploratory multivariable model, longer duration of AI compared to tamoxifen was associated with significantly improved DFS (HR 0.31; 95% CI 0.11–0.86; p = 0.025). While most pre-menopausal patients received adjuvant tamoxifen, the use of OFS and AIs increased significantly over time. The association between AI use and improved DFS may be consistent with prior randomized trials and warrants further investigation into predictive factors to guide treatment selection.

虽然选择性雌激素受体调节剂 (SERM) 他莫昔芬的辅助治疗一直是绝经前激素受体 (HR) 阳性乳腺癌患者的标准治疗，但最近的试验显示芳香酶抑制剂 (AI) 和卵巢功能抑制的益处(OFS) 对于某些患者。绝经前浸润性小叶癌 (ILC) 患者的内分泌治疗方法尚未得到充分研究。我们在机构数据库中确定了 202 名 HR 阳性 I-III 期 ILC 绝经前患者。我们调查了与内分泌治疗类型相关的因素，并确定了 1990 年至 2021 年全身治疗的变化。我们使用多变量 Cox 比例风险模型评估了内分泌治疗类型与无病生存 (DFS) 之间的关联。在 202 名患者中，大多数（69.3%）接受了 SERM（99.3% 他莫昔芬）。接受 AI 治疗的患者的疾病阶段明显较高。随着时间的推移，OFS 和 AI 在 II 期或 III 期病例中的使用显着增加（II 期从 1990 年的 0% 增加到 2015 年之后的 56%；III 期从 0% 增加到 2015 年之后的 80%）。与此同时，II 期病例的辅助化疗使用率显着下降（从 67% 降至 19%）。在探索性多变量模型中，与他莫昔芬相比，AI 持续时间较长与 DFS 显着改善相关（HR 0.31；95% CI 0.11–0.86；p = 0.025）。虽然大多数绝经前患者接受他莫昔芬辅助治疗，但 OFS 和 AI 的使用随着时间的推移显着增加。 AI 使用和 DFS 改善之间的关联可能与之前的随机试验一致，并需要进一步研究预测因素以指导治疗选择。