Introduction:Breast cancer (BC) is one of the commonest cancers among women worldwide. Differences regarding tumor biology, presentation, genetics, and molecular subtypes may contribute to the relatively poorer prognosis among younger women. Limited information exists regarding pathologic characteristics and long-term outcomes among this group.Methods:This retrospective cohort study included 695 BC patients diagnosed over a 10-year period and investigated the clinicopathological characteristics and long-term disease outcomes among patients diagnosed at age less than or equal to 40 years compared with older ones. Cox regression analysis was performed, and Kaplan-Meier curves were generated to assess overall survival (OS).Results:Compared with the younger patients (⩽40 years) estrogen receptor (ER) and progesterone receptor (PR) expression was mainly positive in older patients (>40 years) (76.2% vs 61.3% and 64.2% vs 49.6%, respectively). The most common molecular subtype in both age groups was luminal B (44.1% in older and 40.3% in younger). A clinical complete remission after neoadjuvant therapy was observed more frequently in older patients (76.7%; N = 442) in comparison with the younger patients (66.4%; N = 79) ( P = .018). Recurrence and disease progression were significantly more likely to occur among younger patients accounting for 12.6% and 29.4% of the cases, compared with 6.3% and 18.2% in older patients ( P = .016 and P = .006, respectively). The overall mortality was 132 (19%) of 695, with 88% cancer-related deaths. Estrogen receptor and PR expression ( P ⩽ .001 and P = .003, respectively), molecular subtype ( P = .002), tumor grade ( P = .002), and N stage ( P = .038) were the variables that were found to be significantly influenced by age. The OS was not statistically different among 2 age groups, but younger patients with luminal A molecular subtype showed significantly poor outcome ( P = .019).Conclusion:Overall survival in women diagnosed with BC at age less than or equal to 40 years is not significantly worse than older patients. However, among patients with luminal A subtype, younger women had relatively poor survival. Further research is needed to understand this age-based disparity in outcomes.

中文翻译：

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年轻女性乳腺癌：有什么不同吗？单中心回顾性队列研究

简介：乳腺癌（BC）是全世界女性最常见的癌症之一。肿瘤生物学、表现、遗传学和分子亚型方面的差异可能导致年轻女性的预后相对较差。关于该组的病理特征和长期结果的信息有限。方法：这项回顾性队列研究纳入了 10 年内诊断的 695 名 BC 患者，并调查了年龄小于 5 岁诊断的患者的临床病理特征和长期疾病结果。或与年长者相比等于40岁。进行Cox回归分析，并生成Kaplan-Meier曲线评估总生存期（OS）。结果：与年轻患者（≤40岁）相比，老年患者雌激素受体（ER）和孕激素受体（PR）表达以阳性为主患者（> 40 岁）（分别为 76.2% vs 61.3% 和 64.2% vs 49.6%）。两个年龄组中最常见的分子亚型是 Luminal B（老年人为 44.1%，年轻人为 40.3%）。与年轻患者 (66.4%; N = 79) 相比，老年患者 (76.7%; N = 442) 更频繁地观察到新辅助治疗后临床完全缓解 (P = .018)。年轻患者中复发和疾病进展的可能性明显更高，占病例的 12.6% 和 29.4%，而老年患者中这一比例为 6.3% 和 18.2%（分别为 P = .016 和 P = .006）。695 人中，总死亡率为 132 人（19%），其中 88% 与癌症相关。雌激素受体和 PR 表达（分别为 P ≤ .001 和 P = .003）、分子亚型（ P = .002）、肿瘤分级（ P = .002）和 N 分期（ P = .038）是变量发现受年龄影响显着。2 个年龄组之间的 OS 没有统计学差异，但较年轻的 Luminal A 分子亚型患者的预后显着较差 ( P = .019)。结论：年龄小于或等于 40 岁诊断为 BC 的女性的总生存期并不长明显比老年患者差。然而，在 Luminal A 亚型患者中，年轻女性的生存率相对较差。需要进一步的研究来了解这种基于年龄的结果差异。