亚洲年轻女性的乳腺癌发病率正在上升，但她们在全球数据中的代表性仍然不足。我们分析了不同亚型的 40 岁以下亚洲乳腺癌患者的流行病学和结果，以确定其临床未满足的需求。对亚洲乳腺癌合作组织前瞻性队列中诊断为早期乳腺癌的 20 岁以上女性患者进行了分析（ABCCG）。为了进行比较，使用了监测、流行病学和最终结果计划 (SEER) 癌症登记处的数据。患者被分为三个年龄组：年轻组（<40岁）、所谓绝经前中年组（40-49岁）和所谓绝经后组（年龄≥50岁）。针对生存的多变量 Cox 比例风险模型根据亚型、组织学分级、T 分期、淋巴结状态和研究中心进行了调整。 共有来自亚洲研究中心的 45 021 名乳腺癌患者、496 332 名 SEER-White 患者和 18 279 名 SEER 患者-亚洲患者被纳入分析中。与 SEER 白人（62 岁）和 SEER 亚洲人（58 岁）相比，亚洲人群的诊断中位年龄（51 岁）更年轻；P < 0.0001）。在年轻群体中，与 SEER 白人相比，激素受体阳性/人表皮生长因子受体 2 阴性 (HR /HER2-) 乳腺癌在亚洲人和 SEER 亚洲人中更为常见（61.2% 和 59.8% vs 54.7%） ）。在亚洲人群中，年轻HR/HER2-乳腺癌患者的总生存率明显低于中年组（6年总生存率94.4% vs 96.6%；中青年组风险比0.62；P < 0.001)。同样，与中年组相比，SEER-Whites 中的年轻患者的生存率下降得更早（89.1% 对比 94.0%；P < 0.001）。ABCCG-年龄 <40 岁的 HR /HER2- 亚型乳腺癌亚裔患者与中年人相比，他们的生存结果更有可能更差。我们的研究强调了年轻患者的预后较差，并强调需要量身定制的治疗方法，例如卵巢功能抑制，特别是考虑到种族因素。版权所有 © 2024 作者。由爱思唯尔有限公司出版。保留所有权利。

The incidence of breast cancer among young Asian women is increasing, yet they remain underrepresented in global data. We analyzed the epidemiology and outcomes of Asian patients with breast cancer <40 years old across different subtypes to identify their clinical unmet needs.Female patients aged ≥20 years diagnosed with early breast cancer were analyzed from the prospective cohort of the Asian Breast Cancer Cooperative Group (ABCCG). For comparison, data from the Surveillance, Epidemiology, and End Results Program (SEER) cancer registry were used. Patients were categorized into three age groups: young (<40 years), alleged premenopausal mid-age (40-49 years), and alleged postmenopausal (aged ≥50 years). Multivariable Cox proportional hazards models for survival were adjusted for subtypes, histologic grade, T stage, nodal status, and study centers.A total of 45 021 patients with breast cancer from Asian study centers, 496 332 SEER-White patients, and 18 279 SEER-Asian patients were included in the analysis. The median age at diagnosis was younger in the Asian cohort (51 years) compared with SEER-Whites (62 years) and SEER-Asians (58 years; P < 0.0001). In the young-age group, hormone receptor-positive/human epidermal growth factor receptor 2 negative (HR+/HER2-) breast cancer was more prevalent among Asians and SEER-Asians compared with SEER-Whites (61.2% and 59.8% versus 54.7%). In the Asian population, young patients with HR+/HER2- breast cancer exhibited significantly inferior overall survival than the mid-age group (6-year overall survival 94.4% versus 96.6%; mid-age to young-age group hazard ratio 0.62; P < 0.001). Similarly, young patients in SEER-Whites showed an earlier decline in survival compared with the mid-age group (89.1% versus 94.0%; P < 0.001).ABCCG-Asian patients with breast cancer <40 years old with HR+/HER2- subtypes were more likely to have worse survival outcomes than their mid-age counterparts. Our study highlights the poorer prognosis of young patients and underscores the need for a tailored therapeutic approach, such as ovarian function suppression, particularly considering ethnic factors.Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.