The level of stromal tumor-infiltrating lymphocytes (sTILs) in triple-negative (TNBC) and HER2-positive breast cancers convey prognostic information. The importance of systemic immunity to local immunity is unknown in breast cancer. We previously demonstrated that histological alterations in axillary lymph nodes (LNs) carry clinical relevance. Here, we capture local immune responses by scoring TILs at the primary tumor and systemic immune responses by recording the formation of secondary follicles, also known as germinal centers, in 2,857 cancer-free and involved axillary LNs on haematoxylin and eosin (H&E) stained sections from a retrospective cohort of 161 LN-positive triple-negative and HER2-positive breast cancer patients. Our data demonstrate that the number of germinal center formations across all cancer-free LNs, similar to high levels of TILs, is associated with a good prognosis in low TILs TNBC. This highlights the importance of assessing both primary and LN immune responses for prognostication and for future breast cancer research.

三阴性 (TNBC) 和 HER2 阳性乳腺癌中的间质肿瘤浸润淋巴细胞 (sTIL) 水平可传达预后信息。全身免疫对局部免疫的重要性在乳腺癌中尚不清楚。我们之前证明腋窝淋巴结（LN）的组织学改变具有临床相关性。在这里，我们通过对原发肿瘤的 TIL 进行评分来捕获局部免疫反应，并通过在苏木精和伊红 (H&E) 染色切片上记录 2,857 个无癌和受累腋窝 LN 中次级卵泡（也称为生发中心）的形成来捕获全身免疫反应来自 161 名 LN 阳性三阴性和 HER2 阳性乳腺癌患者的回顾性队列。我们的数据表明，所有无癌淋巴结中生发中心形成的数量与高水平 TIL 类似，与低 TIL 的 TNBC 的良好预后相关。这凸显了评估原发性和淋巴结免疫反应对于预后和未来乳腺癌研究的重要性。