肿瘤浸润淋巴细胞（TILs）已被证明与三阴性和HER2 +亚型的系统治疗反应呈正相关，以及早期乳腺癌（BC）的改善临床结果。在转移灶中，特别是脑转移（BM）中，关于TILs的了解较少，该处独特的免疫调节统治着基质组成。反应性胶质细胞积极参与细胞因子介导的T细胞刺激。先前的医学治疗（化疗，内分泌和HER2靶向治疗）对人类乳腺癌脑转移（BCBM）中TILs和胶质细胞增生的影响尚未报告。我们检查了133名患者的先前治疗数据，他们进行了颅骨切开术切除BM，数据来自电子病历。主要终点是自BM诊断以来的总生存期（OS）。我们在单因素分析中检查了先前系统治疗暴露与BCBM切除术后的胶质化、坏死、出血和淋巴细胞浸润（LI）组织学特征之间的关系。123名患者的完整治疗数据可用。116名接受过先前系统治疗的患者中，有35人（30％）被发现有BCBM LI，而7人中有5人（71.4％）未接受过 {Fisher精确检验p = 0.045显著}。先前的系统治疗和检查的其他三个组织学变量之间没有显着的关系。该观察结果表明，系统治疗可能会干扰对BCBM的免疫应答并导致反肿瘤免疫力的枯竭。这激励着临床研究策略来增强LI，从而提高BCBM患者的治疗效果。©2023年。作者（s）独家许可Springer Science+Business Media，LLC的一部分，Springer Nature。

Tumor-infiltrating lymphocytes (TILs) have been positively correlated with response to systemic therapy for triple-negative and HER2 + subtypes and improved clinical outcomes in early breast cancer (BC). Less is known about TILs in metastatic sites, particularly brain metastases (BM), where unique immune regulation governs stromal composition. Reactive glial cells actively participate in cytokine-mediated T cell stimulation. The impact of prior medical therapy (chemotherapy, endocrine, and HER2-targeted therapy) on the presence of TILs and gliosis in human breast cancer brain metastases (BCBM) has not been previously reported.We examined prior treatment data for 133 patients who underwent craniotomy for resection of BMs from the electronic medical record. The primary endpoint was overall survival (OS) from the time of BM diagnosis. We examined the relationship between prior systemic therapy exposure and the histologic features of gliosis, necrosis, hemorrhage, and lymphocyte infiltration (LI) in BCBMs resected at subsequent craniotomy in univariate analyses.Complete treatment data were available for 123 patients. BCBM LI was identified in 35 of 116 (30%) patients who had received prior systemic treatment versus 5 of 7 (71.4%) who had not {significant by Fisher's exact test p = 0.045}. There were no statistically significant relationships between prior systemic therapy and the three other histologic variables examined.This observation suggests that systemic therapy may interfere with the immune response to BCBMs and cause exhaustion of anti-tumor immunity. This motivates clinical investigation of strategies to enhance LI for therapeutic benefit to improve outcomes for patients with BCBMs.© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.