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