The prognostic value of the level of programmed death ligand 1 (PD-L1) expression in non-Hodgkin lymphoma (NHL) is still debatable. This study examined the effect of the level of PD-L1 expression on the clinicopathological characteristics and prognosis of diffuse large B cell lymphoma (DLBCL). A retrospective study was conducted on formalin-fixed paraffin-embedded tissue blocks of one hundred de novo DLBCL patients diagnosed from 2013 to 2016. PD-L1 expression was defined by a modified Combined-Positive Score (CPS) and their medical records were reviewed to collect their clinical, laboratory and radiological data, treatment, and outcome. The included patients were aged from 23 to 85 years and treated by rituximab- cyclophosphamide, doxorubicin, oncovin, prednisone (R-CHOP); 49% were males; 85% of the cases were presented at Ann Arbor stages III, IV; 33% of patients were seropositive for HCV and 87% of cases were presented with intermediate and high IPI. All included cases expressed PD-L1 using modified CPS. 27% of patients showed low PD-L1 expression (≥ 5% to < 50% of total tumor cellularity) while 73% of patients showed high PD-L1expression (≥ 50% of total tumor cellularity). High PD-L1 expression is statistically correlated with advanced stage (p 0.01), high IPI score (p 0.017), high incidence of stationary and progressive disease (p 0.002) and high incidence of relapse (p value 0.01). Five-year disease-free survival (DFS) was 29% for patients with high PD-L1 expression compared with 84.8% for patients with low PD-L1 expression (p 0.001). This study suggests that high PD-L1 expression in DLBCL is associated with aggressive clinicopathological features and a decreased response to R-CHOP. The level of PD-L1 expression could be an independent predictor of DFS of DLBCL. More research is mandatory to standardize the cutoff value and scoring methods.

中文翻译：

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程序性死亡配体 1 在弥漫性大 B 细胞淋巴瘤中的表达：与临床病理预后因素的相关性

程序性死亡配体 1 (PD-L1) 表达水平在非霍奇金淋巴瘤 (NHL) 中的预后价值仍有争议。本研究探讨了 PD-L1 表达水平对弥漫性大 B 细胞淋巴瘤 (DLBCL) 临床病理特征和预后的影响。对 2013 年至 2016 年确诊的 100 名新发 DLBCL 患者的福尔马林固定石蜡包埋组织块进行了回顾性研究。PD-L1 表达由改良的联合阳性评分 (CPS) 定义，并回顾了他们的医疗记录以收集他们的临床、实验室和放射学数据、治疗和结果。纳入的患者年龄在 23 至 85 岁之间，接受利妥昔单抗-环磷酰胺、多柔比星、癌瘤素、泼尼松 (R-CHOP) 治疗；49% 是男性；85% 的病例出现在 Ann Arbor III 期，四；33% 的患者为 HCV 血清阳性，87% 的病例表现为中度和高度 IPI。所有包含的病例都使用改良的 CPS 表达 PD-L1。27% 的患者表现出低 PD-L1 表达（≥ 5% 至 < 50% 的肿瘤细胞总数），而 73% 的患者表现出高 PD-L1 表达（≥ 50% 的肿瘤细胞总数）。PD-L1 高表达与晚期 (p < 0.01)、高 IPI 评分 (p = 0.017)、静止和进展性疾病高发生率 (p < 0.002) 和高复发率 (p 值 0.01) 具有统计学相关性。PD-L1 高表达患者的五年无病生存率 (DFS) 为 29%，而 PD-L1 低表达患者的五年无病生存率 (DFS) 为 84.8% (p < 0.001)。这项研究表明，DLBCL 中 PD-L1 的高表达与侵袭性临床病理学特征和对 R-CHOP 的反应降低有关。PD-L1表达水平可能是DLBCL DFS的独立预测因子。必须进行更多研究以标准化临界值和评分方法。