Programmed Cell Death 1 Receptor / Programmed Death-Ligand1 (PD‐1/PD‐L1 ) Inhibitors Alone or with Conventional Therapy versus Standard of Care for Head and Neck Cancer: A Systematic Review and Meta-Analysis

Abstract

Objectives As a pivotal part of precision therapy, PD‐1/PD‐L1\nimmunotherapy has been gradually used in head and neck cancer (HNC). We\ninvestigated the effect and adverse events of PD‐1/PD‐L1 inhibitors\nalone or with conventional therapy. Design The groups using PD-1/PD-L1\nimmunotherapy or combining with conventional therapy were defined as the\nexperimental groups, while the standard of care were the control groups.\nCochrane Library, Embase, PubMed, and Web of Science were undertaken to\nidentify literature up to November 20, 2020. Overall survival (OS) and\nprogression-free survival (PFS) were the primary outcome measures.\nSecondary outcome measures included objective response rate (ORR),\ndisease control rate (DCR), any grade and grade≥3 adverse events (AE).\nResults Five randomized controlled trials (RCTs) and nine single-arm\ntrials were included in the systematic review. The OS of the\nexperimental groups was better than the control groups (OR = 0.63,\n95%CI: 0.49‐0.82, I²=35%, P=0.0004), particularly in patients who\nsmoke current/former or with human papillomavirus negative (HPV-). The\nexperimental groups had longer OS than the control groups in patients\nwith PD-L1 positive (OR = 0.75, 95% CI: 0.65‐0.85, I²=0%,\nP<0.0001). Patients with HPV positive (HPV+) had more\nfavorable OS than those with HPV- (OR = 0.56, 95%CI:0.44-0.71, I²=39%,\nP<0.00001). There were statistical differences in AEs (e.g.,\nfatigue, rash, hypothyroidism, etc.) and no statistical differences in\nPFS, ORR, and DCR. Conclusion PD-1/PD-L1 immunotherapy or combining with\nconventional therapy can improve the treatment effect and induce fewer\nadverse events of digestion and blood system, except for hypothyroidism.