Expression of Immune Checkpoint Regulators, Cytotoxic T-Lymphocyte Antigen-4, and Programmed Death-Ligand 1 in Epstein-Barr Virus-associated Nasopharyngeal Carcinoma.

Nasopharyngeal carcinoma (NPC) is the most common cancer arising from the nasopharynx with a poor prognosis. Targeting immune checkpoint is one of the new promising lines in cancer treatment. Cytotoxic T-lymphocyte antigen-4 (CTLA-4) and programmed death-ligand 1 (PD-L1) are immune checkpoints that regulate T-cell immune function. This work aimed to assess the immunohistochemical expression of PD-L1 and CTLA-4 in NPC and their ability to predict survival and response therapy and to check their validity as immunotherapy targets. Twenty-six cases of NPC were studied by immunohistochemistry for PD-L1 and CTLA-4 and by nested polymerase chain reaction followed by DNA sequencing for the presence of EBNA-1 gene of Epstein-Barr virus (EBV). All investigated cases were diagnosed and treated in the Zagazig University Hospital in the period from August 2015 to July 2018. EBNA-1 gene was identified in 84.6% of the cases. Whereas the expression of PD-L1 was noted in 46.2% of all cases studied, 54.6% of EBV-associated NPCs were found to express PD-L1. There was a significant association between PD-L1 expression and the advanced stage of the tumor (P<0.001). CTLA-4 expression was observed in 88.4% of all NPC cases as cytoplasmic staining in both tumor cells and tumor-infiltrating lymphocytes. CTLA-4 expression in lymphocytes was associated with the presence of EBV. A significant association was detected between CTLA-4 and tumor-infiltrating lymphocyte expression on one side and the stage of the tumor on the other. High expression of CTLA-4 was significantly associated with disease progression and worse overall survival. PD-L1 and CTLA-4 are adverse prognostic markers in NPC. The authors propose that targeted therapy against PD-L1 and CTLA-4 will be a hopeful therapy for cases of NPC with resistance to concurrent chemoradiation treatment in Egypt, especially EBV-associated cases.

Ahmed MM ，Gebriel MG ，Morad EA ，Saber IM ，Elwan A ，Salah M ，Fakhr AE ，Shalaby AM ，Alabiad MA ... -  《-》

Characterization of PD-L1 and PD-1 Expression and CD8+ Tumor-infiltrating Lymphocyte in Epstein-Barr Virus-associated Nasopharyngeal Carcinoma.

Larbcharoensub N ，Mahaprom K ，Jiarpinitnun C ，Trachu N ，Tubthong N ，Pattaranutaporn P ，Sirachainan E ，Ngamphaiboon N ... -  《-》

PD-L1 predicts poor prognosis for nasopharyngeal carcinoma irrespective of PD-1 and EBV-DNA load.

Zhou Y ，Shi D ，Miao J ，Wu H ，Chen J ，Zhou X ，Hu D ，Zhao C ，Deng W ，Xie C ... -  《Scientific Reports》

Prognostic Value of Programmed Cell Death-Ligand 1 Expression in Tumor-Infiltrating Lymphocytes and Viral Load in Peripheral Blood Mononuclear Cells for Epstein-Barr Virus-Positive Nasopharyngeal Carcinoma.

Epstein-Barr virus (EBV) infection has a role in the development and progression of nasopharyngeal carcinoma (NPC); however, it is unclear whether EBV load correlates with tumor prognosis or the need for immunotherapy. This study evaluated whether the EBV DNA concentration in peripheral blood mononuclear cells (PBMC) or programmed cell death-ligand1 (PD-L1) expression in tumor-infiltrating lymphocytes (TIL) could predict the clinical outcomes of patients with NPC. Clinicopathological parameters of 198 patients with NPC were analyzed retrospectively from June 2012 to May 2018. Patients' EBV loads were determined by droplet digital PCR. TIL PD-L1 was analyzed by immunohistochemistry. A log value of 1.98 log IU/mL for PBMC EBV DNA and a percentage of PD-L1 expression of 15% in TILs marked distinguishing cutoffs in NPC prognosis. The 5-year progression-free survival (PFS) rates in patients with high vs low log (PBMC EBV DNA) were 68.2% and 93.1%, respectively (P = 0.002). The 5-year PFS rates in patients with high vs low TIL PD-L1 expression were 66.3% and 33.7%, respectively (P = 0.03). The 5-year PFS rates of the high-risk group (high log [PBMC EBV DNA] and low TIL PD-L1), low-risk group (low log [PBMC EBV DNA] and high TIL PD-L1), and those in between (intermediate group) were 0%, 91.9%, and 71.4%, respectively (P < 0.001). Concentrations of PBMC EBV DNA and TIL PD-L1 expression can be used as prognostic markers in NPC. The combination of both an increased EBV DNA concentration and suppressed TIL PD-L1 expression is associated with metastasis or relapse.

Hu B ，Sun M ，Wang Z ，Zheng Y ，Cai W ，Shi HH ，Zhuang Y ，Lin Q ... -  《-》

Biomarkers predicting clinical outcomes in nasopharyngeal cancer patients receiving immune checkpoint inhibitors: A systematic review and meta-analysis.

Optimal biomarkers to select patients who will benefit most from immunotherapy remain lacking in nasopharyngeal cancer (NPC). This systematic review and meta-analysis aimed to evaluate the association between various biomarkers and clinical outcomes in NPC patients treated with immune checkpoint inhibitors (ICIs). Systematic searches of PubMed, Embase, Cochrane Library, and Web of Science databases were performed up to October 2022. Studies evaluating the association between biomarkers and intended outcomes of ICIs were included. The pooled odds ratio (OR) and hazard ratio (HR) with 95% confidence intervals (CIs) were calculated, respectively, for the objective response rate (ORR) and progression-free survival (PFS) under fixed or random-effect models. A total of 15 studies involving 1,407 patients were included. The pooled analysis indicated that NPC patients with lower plasma Epstein-Barr virus (EBV) DNA level at baseline (OR = 2.14, 95% CI: 1.46-3.14, P < 0.001), decreased EBV DNA load during immunotherapy (OR = 4.57, 95% CI: 2.24-9.34, P = 0.002) and higher programmed cell death-ligand 1 (PD-L1) expression (OR = 2.35, 95% CI: 1.36-4.09, P = 0.002) had superior ORR than the counterparts. No significant differences of ORR were observed between positive PD-L1 expression and negative PD-L1 expression (OR = 1.50, 95% CI: 0.92-2.45, P = 0.104), as well as higher tumor mutation burden (TMB) and lower TMB (OR = 1.62, 95% CI: 0.41-6.44, P = 0.494). Patients with lower plasma EBV DNA level at baseline obtained a significant benefit on PFS than those with higher plasma EBV DNA level (HR = 0.52, 95% CI: 0.42-0.63, P < 0.001). There were no differences in PFS between decreased EBV DNA load and increased EBV DNA load during immunotherapy (HR = 0.51, 95% CI: 0.22-1.17, P = 0.109), higher PD-L1 expression and lower PD-L1 expression (HR = 0.65, 95% CI: 0.42-1.01, P = 0.054), positive PD-L1 expression and negative PD-L1 expression (HR = 0.90, 95% CI: 0.64-1.26, P = 0.531), lower TMB and higher TMB (HR = 0.84, 95% CI: 0.51-1.38, P = 0.684). Lower baseline plasma EBV DNA level, decreased plasma EBV DNA during immunotherapy, and higher PD-L1 expression are reliable biomarkers predicting better response to ICIs treatment. Lower baseline plasma EBV DNA level was also associated with longer PFS. It is warranted to further explore and better illuminate the utility of these biomarkers in future clinical trials and real-world practice. https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022324434.

Qian X ，Chen H ，Tao Y 《Frontiers in Immunology》