数据不足以探索年轻乳腺癌早期(eBC)患者。我们评估了大量患者中不同年龄段的共享和内在预后因素，其中包括年龄≤35岁的患者组和年龄在36岁至50岁的对照组。这些患者在1990-2014年间进行了初次手术，其中≤50岁的患者是从一个多中心的23,134例eBC患者队列中进行回顾性挑选。我们进行了DFS和OS的多元Cox分析。通过将≤35岁和36-50岁的患者进行匹配分析，以评估年龄的独立影响力，从而进行了1到3个病例对照分析。 在6481例患者中，有556例年龄≤35岁，5925例年龄在36至50岁之间。年龄≤35岁与肿瘤更大、级别更高、ER阴性、宏观淋巴结受累（pN+宏观）、淋巴管侵犯（LVI）、乳房切除术和化疗药物使用相关。多元回归分析表明，年龄≤35岁与DFS [HR 1.56，95％CI 1.32-1.84；p < 0.001] 和OS [HR 1.29，95％CI 1.03-1.60; p = 0.025] 更差相关，与高级别、大肿瘤、LVI、pN+宏观、ER阴性、诊断期间和没有使用ET或CT (对于DFS)也相关。通过病例对照分析发现，年龄≤35岁的不良预后影响在DFS [HR 1.56，95％CI 1.28-1.91，p < 0.001] 和OS [HR 1.33，95％CI 1.02-1.73，p = 0.032]方面得以维持。当只考虑≤35岁的患者时，这个亚组中ER、肿瘤大小、淋巴结状态和LVI独立地与生存有关。年龄≤35与不利的检查结果和更积极的治疗策略相关。我们的结果支持年轻的不良预后价值，当调整其他预后因素和治疗策略时，它独立地存在。 版权所有©2023 作者。由Elsevier Ltd.出版。保留所有权利。

There is a scarcity of data exploring early breast cancer (eBC) in very young patients. We assessed shared and intrinsic prognostic factors in a large cohort of patients aged ≤35, compared to a control group aged 36 to 50.Patients ≤50 were retrospectively identified from a multicentric cohort of 23,134 eBC patients who underwent primary surgery between 1990 and 2014. Multivariate Cox analyses for DFS and OS were built. To assess the independent impact of age, 1 to 3 case-control analysis was performed by matching ≤35 and 36-50 years patients.Of 6481 patients, 556 were aged ≤35, and 5925 from 36 to 50. Age ≤35 was associated with larger tumors, higher grade, ER-negativity, macroscopic lymph node involvement (pN + macro), lymphovascular invasion (LVI), mastectomy, and chemotherapy (CT) use. In multivariate analysis, age ≤35 was associated with worse DFS [HR 1.56, 95% CI 1.32-1.84; p < 0.001], and OS [HR 1.29, 95% CI 1.03-1.60; p = 0.025], as were high grade, large tumor, LVI, pN + macro, ER-negativity, period of diagnostic, and absence of ET or CT (for DFS). Adverse prognostic impact of age ≤35 was maintained in the case control-matched analysis for DFS [HR 1.56, 95%CI 1.28-1.91, p < 0.001], and OS [HR 1.33, 95%CI 1.02-1.73, p = 0.032]. When only considering patients ≤35, ER, tumor size, nodal status, and LVI were independently associated with survival in this subgroup.Age ≤35 is associated with less favorable presentation and more aggressive treatment strategies. Our results support the poor prognosis value of young age, which independently persisted when adjusting for other prognostic factors and treatments.Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.