Prognostic and predictive role of soluble programmed death ligand-1 in head and neck cancer

Abstract Objectives The aim of the study was to investigate clinical significance of soluble PD-L1 (sPD-L1) serum level in head and neck cancer and to evaluate its role as a possible prognostic and predictive biomarker. Methods A prospective analysis of sPD-L1 levels in 60 patients diagnosed and treated due to malignant and non-malignant lesions in the region of head and neck was performed in peripheral blood by an ELISA test. Results The range of sPD-L1 in the study group was 0.16-1.63 ng/mL, mean 0.64 ± 0.32. There were no differences in the mean sPD-L1 regarding patients’ age, sex, and the localization of the lesion. Statistically significant difference was revealed in the average sPD-L1 level (p = 0.006) depending on the histopathological advancement of the lesions, 0.704 ± 0.349 and 0.512 ± 0.177 respectively in the malignant and benign group. The separate analysis of laryngeal lesions confirmed statistical difference in sPD-L1 (p = 0.002) for the malignant lesions (0.741 ± 0.353) compared with the benign (0.489 ± 0.175). The sPD-L1 level of 0.765 ng/mL or higher, revealed 35% sensitivity and 95.5% specificity for the diagnosis of head and neck malignant lesions (AUC = 0.664, 95% CI 0.529‒0.8, p-value = 0.039). The 1-year DFS was 83.3% in the group of patients with low sPD-L1 levels (< 0.765 ng/mL) and 53.8% in patients with high sPD-L1 (≥0.765 ng/mL). The 2-year OS were 68% and 69.2% respectively in both groups. The log-rank test confirmed statistically significant prognostic value of sPD-L1 level for 1-year DFS (p-value = 0.035). Conclusions sPD-L1 is a promising prognostic and early recurrence predictive biomarker for head and neck cancers, most significantly for laryngeal lesions. Level of evidence 3.

摘要 研究目的：本研究旨在探讨血清可溶性PD-L1（soluble PD-L1，sPD-L1）水平在头颈部恶性肿瘤中的临床意义，并评估其作为潜在预后与预测生物标志物的应用价值。
研究方法：本研究采用前瞻性分析方案，通过酶联免疫吸附试验（ELISA）检测60例因头颈部良恶性病变接受诊断与治疗的患者外周血中的sPD-L1水平。
研究结果：本研究队列中sPD-L1水平范围为0.16~1.63 ng/mL，均值为0.64±0.32 ng/mL。患者年龄、性别及病变部位与sPD-L1平均水平无显著统计学差异。但根据病变的组织病理学性质，sPD-L1平均水平存在显著统计学差异（p=0.006）：恶性病变组为0.704±0.349 ng/mL，良性病变组为0.512±0.177 ng/mL。针对喉部病变的亚组分析进一步证实，恶性病变组sPD-L1水平（0.741±0.353 ng/mL）显著高于良性病变组（0.489±0.175 ng/mL），差异具有统计学意义（p=0.002）。当sPD-L1水平≥0.765 ng/mL时，其对头颈部恶性病变的诊断灵敏度为35%，特异度为95.5%（曲线下面积AUC=0.664，95%置信区间CI：0.529~0.8，p=0.039）。sPD-L1水平<0.765 ng/mL的患者1年无病生存期（Disease-Free Survival，DFS）为83.3%，而sPD-L1水平≥0.765 ng/mL的患者1年无病生存期为53.8%；两组患者2年总生存期（Overall Survival，OS）分别为68%和69.2%。对数秩检验（log-rank test）证实sPD-L1水平对1年无病生存期具有显著的预后价值（p=0.035）。
研究结论：sPD-L1是一种极具潜力的头颈部恶性肿瘤预后及早期复发预测生物标志物，在喉部病变中其预测价值尤为显著。本研究证据等级为3级。