Objective: To explore the expression of programmed cell death ligand 1 (PD-L1) in patients with locally advanced and non-EGFR-mutated non-small cell lung cancer (LA-NSCLC) undergoing concurrent chemoradiotherapy (cCRT) and its association with clinical outcome of patients. Methods: The basic clinical information of 19 patients with unresectable, non-EGFR mutated LA-NSCLC receiving radical cCRT in Cancer Hospital Chinese Academy of Medical Sciences from January 2016 to December 2017 was retrospectively analyzed. The rabbit monoclonal antibody SP263 was used for immunohistochemical analysis to detect the expression of PD-L1 in LA-NSCLC tissues and the tumor proportion score (TPS) equal to or greater than 1% was defined as PD-L1 positive. The associations between PD-L1 ≥1% and PD-L1 ≥25% with the clinical characteristics and clinical outcome of LA-NSCLC patients were evaluated respectively. Results: Among 19 LA-NSCLC patients, 13 had PD-L1 positive expression, and 4 had PD-L1 expression greater than or equal to 25%. No significant difference was observed between patients with PD-L1 positive and negative expressions regarding the distribution of age, smoking history, pathological classification, and TNM staging (P>0.05). A total of 15 patients could be evaluated for therapeutic effect, including 7 patients with partial response (PR), 7 patients with stable disease (SD), and 1 patient with progressive disease (PD). In the group with PD-L1 expression<1%, 3 patients were in objective response, and 4 patients were in disease control. In the group with PD-L1 expression ≥1%, 4 patients were in objective response, and 10 patients were in disease control. When the PD-L1 expression was less than 25%, 6 patients gained the objective response, and 11 patients gained the disease control. When the PD-L1 expression was greater than or equal to 25%, 1 patient gained the objective response, and 3 patients gained the disease control. The median overall survival (OS) was 35 (95%CI: 12.7-57.3) months for patients with PD-L1 ≥1% and 40 (95%CI: not reaching the end point) months for patients with PD-L1<1% (P=0.284). Patients with PD-L1 ≥25% had a median survival time of 12 (95%CI:0.0-34.5) months, and patients with PD-L1<25% had a median survival time of 40 (95%CI: 27.4-52.6) months (P=0.241). Conclusions: The prognosis of LA-NSCLC patients with PD-L1 positive and no-EGFR mutation receiving concurrent chemoradiation has a trend of poor prognosis. A larger sample size study is warranted to explore the prognostic value of PD-L1 expression in inoperable LA-NSCLC patients and to further explore the effect of immunotherapy on patients with different PD-L1 expression levels.
目的： 探讨程序性细胞死亡配体1（PD-L1）在同步放化疗非表皮生长因子受体（EGFR）突变局部晚期非小细胞肺癌（NSCLC）中的表达及其与患者预后的关系。 方法： 回顾性分析中国医学科学院肿瘤医院放疗科2016年1月至2017年12月收治的根治性同步放化疗非EGFR突变局部晚期不可手术的19例NSCLC患者的临床资料。采用免疫组化方法以兔单克隆抗体SP263检测PD-L1在NSCLC组织中的表达，以肿瘤阳性细胞比例≥1%为PD-L1阳性表达，分别分析PD-L1表达≥1%和≥25%与NSCLC患者临床特征和预后的关系。 结果： 19例NSCLC患者中，PD-L1阳性表达13例，其中PD-L1表达≥25%者4例。PD-L1表达≥1%和PD-L1表达<1%组年龄、吸烟史、病理类型和TNM分期差异均无统计学意义（均P>0.05）。15例患者可进行疗效评价，其中部分缓解（PR）7例，疾病稳定（SD）7例，疾病进展（PD）1例。PD-L1表达<1%组患者客观缓解3例，疾病控制4例；PD-L1表达≥1%组患者客观缓解4例，疾病控制10例。PD-L1表达<25%组患者客观缓解6例，疾病控制11例；PD-L1表达≥25%组患者客观缓解1例，疾病控制3例。PD-L1表达≥1%组患者的中位生存时间为35个月（95%CI：12.7~57.3个月），PD-L1表达<1%组患者的中位生存时间为40个月（95%CI未达终点），差异无统计学意义（P=0.284）；PD-L1≥25%组患者的中位生存时间为12个月（95%CI：0.0~34.5个月），PD-L1<25%组患者的中位生存时间为40个月（95%CI：27.4~52.6个月），差异无统计学意义（P=0.241）。 结论： PD-L1阳性接受同步放化疗非EGFR突变局部晚期NSCLC患者的预后有不良趋势，有必要扩大样本量探索PD-L1在局部晚期不可手术NSCLC患者中的预后意义，并探讨免疫治疗对不同PD-L1表达水平患者的疗效。.