Department of Pathology, Microbiology and Forensic Medicine, School of Medicine, 54658The University of Jordan, Amman, Jordan.
Department of General and Specialized Surgery, Faculty of Medicine, 34419The Hashemite University, Zarqa, Jordan.
Int J Immunopathol Pharmacol. 2022 Jan-Dec;36:3946320221078433. doi: 10.1177/03946320221078433.
To investigate the expression of programmed death-ligand 1 (PD-L1) in breast cancer in association with incomplete pathological response (PR) to neoadjuvant chemotherapy (NAC).
PD-L1 expression was evaluated using immunohistochemistry in post-operative, post-NAC samples of 60 patients ( = 60) diagnosed with breast invasive ductal carcinoma with incomplete PR to NAC, including 31 matched pre-NAC and post-NAC samples ( = 31). PD-L1 protein expression was assessed using three scoring approaches, including the tumor proportion score (TPS), the immune cell score (ICS), and the combined tumor and immune cell score (combined positive score, CPS) with a 1% cut-off.
In the post-operative, post-NAC samples ( = 60), positive expression rate of PD-L1 was observed in 18.3% (11/60) of cases by TPS, 31.7% (19/60) by ICS, and 25% (15/60) by CPS. In matched samples, positive expression rate of PD-L1 was observed in 19.3% (6/31) of patients by TPS, 51.6% (16/31) by ICS, and 19.3% (6/31) by CPS in pre-NAC specimens, while it was observed in 22.6% (7/31) of matched post-NAC samples by TPS, 22.6% (7/31) by ICS, and 19.3% (6/31) by CPS. In the matched samples, there was a significant decrease in PD-L1 immunoexpression using ICS in post-NAC specimens (McNemar's, = 0.020), while no significant differences were found using TPS and CPS between pre- and post-NAC samples ( = 1.000, = 0.617; respectively). PD-L1 immunoexpression determined by TPS or CPS was only significantly associated with ER status ( = 0.022, = 0.021; respectively), but not with other clinicopathological variables. We could not establish a correlation between PD-L1 expression and the overall survival rate ( > 0.05). There were no significant differences in the tumor infiltrating lymphocytes count between the paired pre- and post-NAC samples ( = 0.581, = 0.563 or Wilcoxon's Signed Rank test; = -0.625, = 0.529).
Our findings indicate that PD-L1 protein expression in infiltrating immune cells was significantly reduced in breast tumors that developed incomplete PR following the exposure to NAC.
探讨程序性死亡配体 1（PD-L1）在乳腺癌中的表达与新辅助化疗（NAC）不完全病理缓解（PR）的关系。
对 60 例 NAC 后诊断为乳腺浸润性导管癌且不完全 PR 的患者（ = 60）的术后、NAC 后标本进行 PD-L1 表达的免疫组化检测，包括 31 例匹配的 NAC 前、后标本（ = 31）。采用肿瘤比例评分（TPS）、免疫细胞评分（ICS）和联合肿瘤和免疫细胞评分（阳性评分，CPS）三种评分方法评估 PD-L1 蛋白表达，以 1%为截断值。
在术后、NAC 后标本（ = 60）中，TPS 检测到 PD-L1 阳性表达率为 18.3%（11/60），ICS 为 31.7%（19/60），CPS 为 25%（15/60）。在匹配标本中，TPS 检测到 NAC 前标本的 PD-L1 阳性表达率为 19.3%（6/31），ICS 为 51.6%（16/31），CPS 为 19.3%（6/31），而 NAC 后标本的阳性表达率为 22.6%（7/31），ICS 为 22.6%（7/31），CPS 为 19.3%（6/31）。在匹配样本中，NAC 后标本的 ICS 检测到 PD-L1 免疫表达显著降低（McNemar's ， = 0.020），而 TPS 和 CPS 检测到 NAC 前、后样本之间无显著差异（ = 1.000， = 0.617；分别）。TPS 或 CPS 检测到的 PD-L1 免疫表达仅与 ER 状态显著相关（ = 0.022， = 0.021；分别），而与其他临床病理变量无关。我们无法建立 PD-L1 表达与总生存率之间的相关性（ > 0.05）。配对的 NAC 前、后样本之间的肿瘤浸润淋巴细胞计数无显著差异（ = 0.581， = 0.563 或 Wilcoxon 符号秩检验； = -0.625， = 0.529）。
我们的研究结果表明，在暴露于 NAC 后发生不完全 PR 的乳腺肿瘤中，浸润免疫细胞中的 PD-L1 蛋白表达显著降低。
