Chemo + checkpoint inhibitor (PD-1/PD-L1) extends OS vs chemo alone in metastatic head & neck PD-NEC (NCDB)

In this NCDB real‑world cohort (2018–2023) of metastatic poorly differentiated head and neck neuroendocrine carcinomas (HN‑NECs; n=275; survival data available for 227), systemic chemotherapy (typical backbone in this disease is platinum/etoposide) was associated with longer median OS vs no chemo (11.3 vs 3.4 months; HR 0.53; p<0.001), and immune checkpoint inhibitor immunotherapy (IO; PD‑1/PD‑L1 agents, not specified) was associated with longer OS vs no IO (13.0 vs 8.1 months; HR 0.63; p=0.005). Among patients receiving chemo (n=174), adding concurrent IO (chemoIO; n=73) improved median OS vs chemo alone (14.1 vs 9.9 months; HR 0.67; p=0.03), remaining significant on multivariable analysis (HR 0.57; p=0.003); this size of benefit is directionally similar to first‑line ES‑SCLC chemo‑IO benchmarks (e.g., IMpower133 atezolizumab+carboplatin/etoposide mOS 12.3 vs 10.3 months; HR 0.76), while RT and surgery were not significantly associated with OS in this metastatic cohort (p=0.17 and p=0.18).