Background The influence of the breast as the primary site on the outcome of diffuse large B-cell lymphoma (DLBCL) and further changes in therapeutic strategies remain unclear. We aimed to compare the outcomes between primary breast and non-breast DLBCL and analyze the genetic profiles of some of the study cohorts using next-generation sequencing. Methods This matched-pair study reviewed the medical records of 19 patients with stage I and II primary breast DLBCL diagnosed between January 2005 and December 2021 on the basis of the Wiseman and Liao criteria, and we used 1:4 propensity score matching to identify patients with non-breast DLBCL as the control group. The overall response rate, progression-free survival (PFS), and overall survival (OS) were the outcome measures. Results Patients with primary breast and non-breast DLBCL had a 5-year PFS of 72.6% and 86.9%, respectively (P = .206). These 2 groups also had comparable 5-year OS (86.9% vs 87.8%; P = .772). The breast as the primary site was not associated with inferior PFS (hazard ratio [HR]: 2.14; 95% CI: 0.66-6.96; P = .206) and OS (HR: 1.26; 95% CI: 0.27-5.93; P = .772). Conclusion Patients with primary breast DLBCL and those with non-breast DLBCL had comparable PFS and OS under rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) or R-CHOP-like regimens. Further investigations of the mutation profile, its clinical impact, potential central nervous system relapse, and prognosis of primary breast DLBCL are required.

中文翻译：

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原发性乳腺弥漫性大 B 细胞淋巴瘤的临床特征和结果：一项配对研究。

背景 乳房作为原发部位对弥漫性大 B 细胞淋巴瘤 (DLBCL) 结局的影响以及治疗策略的进一步变化仍不清楚。我们的目的是比较原发性乳腺癌和非乳腺癌 DLBCL 之间的结果，并使用下一代测序分析一些研究队列的遗传图谱。方法 这项配对研究回顾了 2005 年 1 月至 2021 年 12 月期间根据 Wiseman 和 Liao 标准诊断的 19 例 I 期和 II 期原发性乳腺 DLBCL 患者的病历，并采用 1:4 倾向评分匹配来识别患者以非乳腺DLBCL作为对照组。总体缓解率、无进展生存期（PFS）和总体生存期（OS）是结果指标。结果 原发性乳腺和非乳腺 DLBCL 患者的 5 年 PFS 分别为 72.6% 和 86.9% (P = .206)。这两组的 5 年 OS 也相当（86.9% vs 87.8%；P = .772）。乳房作为主要部位与较差的 PFS（风险比 [HR]：2.14；95% CI：0.66-6.96；P = 0.206）和 OS（HR：1.26；95% CI：0.27-5.93；P）无关。 = .772)。结论 原发性乳腺 DLBCL 患者和非乳腺 DLBCL 患者在利妥昔单抗、环磷酰胺、阿霉素、长春新碱和泼尼松 (R-CHOP) 或 R-CHOP 样方案下具有相当的 PFS 和 OS。需要进一步研究原发性乳腺 DLBCL 的突变谱、其临床影响、潜在的中枢神经系统复发和预后。