Objective: To investigate the expression of programmed death ligand-1 (PD-L1, SP142) and PD-L1 (22C3) in triple-negative breast cancer (TNBC), and analyze their correlation with the clinicopathological factors and prognosis. Methods: The clinicopathologic data of 259 patients with TNBC treated in Cancer Hospital from August 2010 to December 2013 were collected. Whole section of surgical tissue samples were collected to conduct PD-L1 (SP142) and PD-L1 (22C3) immunohistochemical (IHC) staining. The PD-L1 expression in tumor cells and tumor infiltrating immune cells were visually assessed respectively, the relationship between PD-L1 expression and clinicopathologic characterizes were analyzed. Univariable and multivariable Cox proportional hazards regression models were used to test the correlations between PD-L1 expression and disease-free survival (DFS) and overall survival (OS). Results: The positive rates of SP142 (immune cell score, ICs≥1%) and 22C3 (combined positive score, CPS≥1) were 42.1%(109/259) and 41.3%(107/259) in TNBC tissues, respectively, with a total coincidence rate of 82.3%. The Kappa value of positive expression cases was 0.571 and the distribution difference of SP142 and 22C3 positive expression cases was statistically significant (P<0.001). The PD-L1 positive patients were less likely to have vascular invasion (P<0.05), but with higher histological grade and Ki-67 proliferation index (P<0.05). The recurrence/metastasis cases(8) of the patients with positive PD-L1 (SP142) was significantly lower than that of patients with negative PD-L1(SP142, 27, P=0.016). The positive expression of PD-L1 (SP142) patients were longer DFS (P=0.019). The OS of patients with positive PD-L1 (SP142) were longer than those with negative PD-L1 (SP142), but without significance (P=0.116). The positive expression of PD-L1 (22C3) was marginally associated with DFS and OS of patients (P>0.05). Conclusions: The expression of PD-L1 (22C3) is different from that of PD-L1 (SP142) in TNBC, and the two antibodies can't be interchangeable for each other in clinical tests. PD-L1 (SP142) status is an independent prognostic factor of DFS in TNBC. The DFS is significantly prolonged in patients with positive expression of PD-L1 (SP142).
目的： 探讨程序性死亡配体1(PD-L1)不同抗体克隆SP142和22C3在三阴性乳腺癌中的表达情况，分析不同抗体表达与患者临床病理特征及预后的关系。 方法： 收集2010年8月至2013年12月于中国医学科学院肿瘤医院治疗的259例三阴性乳腺癌(TNBC)患者的临床病理资料，将患者手术组织样本切片进行SP142和22C3免疫组化染色，分别评估肿瘤细胞及肿瘤浸润免疫细胞PD-L1的表达情况，分析2种抗体表达与患者临床病理特征的关系，采用Cox比例风险回归模型分析PD-L1表达与无病生存时间(DFS)和总生存时间(OS)之间的相关性。 结果： SP142(免疫细胞表达评分≥1%)与22C3(联合阳性评分≥1分)在TNBC中的阳性表达率分别为42.1%(109/259)和41.3%(107/259)，二者总符合率为82.3%，阳性表达病例的Kappa值为0.571，差异有统计学意义(P<0.001)。PD-L1抗体阳性患者的组织学级别和Ki-67增殖指数与阴性患者比较升高，阳性患者出现脉管侵犯的概率小(均P<0.05)；PD-L1(SP142)阳性患者的复发或转移数(8例)低于阴性患者(27例，P＝0.016)。SP142阳性表达患者DFS长于阴性患者(P＝0.019)；SP142阳性表达患者的OS长于阴性患者，但差异无统计学意义(P＝0.116)。22C3阳性表达与患者DFS和OS均无关(均P>0.05)。 结论： PD-L1(22C3)和PD-L1(SP142)在TNBC中表达情况存在差异，临床检测中二者不可相互替代；PD-L1阳性表达患者预后更好，PD-L1(SP142)阳性患者DFS明显延长。.
Keywords: Breast neoplasms; PD-L1 (22C3) antibody expression; PD-L1 (SP142) antibody expression; Prognosis; Programmed death ligand 1; Triple negative breast cancer.