Postgraduate Program in Tocogynecology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, 13083-887, Brazil.
Multipat Anatomic Pathology Laboratory, Campinas, 13086-130, Brazil.
Sci Rep. 2021 Nov 18;11(1):22478. doi: 10.1038/s41598-021-00944-w.
Herein it was evaluated the impact of PD-L1 immunohistochemical expression and stromal tumor-infiltrating lymphocyte (sTIL) counts in pretreatment needle core biopsy on response to neoadjuvant chemotherapy (NACT) for patients with breast carcinomas (BC). In 127 paired pre- and post-NACT BC specimens, immunohistochemical expression of PD-L1 was evaluated in stroma and in neoplastic cells. In the same samples sTILs were semi-quantified in tumor stroma. Post-NACT specimens were histologically rated as having residual cancer burden (RCB of any degree), or with complete pathological response (pCR). PD-L1 expression and higher sTIL counts were associated with histological grade 3 BC. PD-L1 expression was also associated with the non-luminal-HER2+ and triple negative immunohistochemical profiles of BC. Pathological complete response was associated with histological grade 3 tumors, and with the non-luminal-HER2+ and triple negative profiles. Additionally, our results support an association between PD-L1 expression and pCR to NACT. It was also observed that there is a trend to reduction of sTIL counts in the post-NACT specimens of patients with pCR. Of note, PD-L1 was expressed in half of the hormone receptor positive cases, a finding that might expand the potential use of immune checkpoint inhibitors for BC patients.
本研究评估了乳腺癌（BC）患者新辅助化疗（NACT）前针芯活检中 PD-L1 免疫组化表达和肿瘤间质浸润淋巴细胞（sTIL）计数对化疗反应的影响。在 127 对 NACT 前后 BC 标本中，评估了 PD-L1 在基质和肿瘤细胞中的免疫组化表达。在相同的样本中，在肿瘤基质中对 sTIL 进行半定量评估。对 NACT 后标本进行组织学分级，分为残留肿瘤负荷（任何程度的 RCB）或完全病理缓解（pCR）。PD-L1 表达和较高的 sTIL 计数与组织学 3 级 BC 相关。PD-L1 表达还与 BC 的非腔面-HER2+和三阴性免疫组化特征相关。病理完全缓解与组织学 3 级肿瘤以及非腔面-HER2+和三阴性特征相关。此外，我们的结果支持 PD-L1 表达与 NACT 后 pCR 之间的关联。还观察到，pCR 患者的 NACT 后标本中 sTIL 计数呈下降趋势。值得注意的是，半数激素受体阳性病例表达 PD-L1，这一发现可能扩大免疫检查点抑制剂在 BC 患者中的潜在应用。
