biostudies-literatureUnknown63(8)Aoki TProgrammed death 1 (PD-1)/programmed death ligand 1 (PD-L1) pathway blockade has become a promising therapeutic target in adult cancers. We evaluated PD-L1 expression and tumor-infiltrating CD8(+) T cells in formalin-fixed, paraffin-embedded tumor specimens from 53 untreated pediatric patients with eight cancer types: neuroblastoma, extracranial malignant germ cell tumor, hepatoblastoma, germinoma, medulloblastoma, renal tumor, rhabdomyosarcoma, and atypical teratoid/rhabdoid tumor. One rhabdomyosarcoma with the shortest survival exhibited membranous PD-L1 expression and germinoma contained abundant tumor-infiltrating CD8(+) T cells and PD-L1-positive macrophages. The PD-1/PD-L1 pathway tended to be inactive in pediatric cancers.Pediatric blood & cancer1461-4https://www.ebi.ac.uk/biostudies/studies/S-EPMC5074238biostudies-literatureLow Frequency of Programmed Death Ligand 1 Expression in Pediatric Cancers.PMC5074238Hanada RKurihara JKishimoto HKawashima HHino MAoki TKoh KMotohashi SKyushiki MArakawa YShimojo NfalseLow Frequency of Programmed Death Ligand 1 Expression in Pediatric Cancers.Programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) pathway blockade has become a promising therapeutic target in adult cancers. We evaluated PD-L1 expression and tumor-infiltrating CD8(+) T cells in formalin-fixed, paraffin-embedded tumor specimens from 53 untreated pediatric patients with eight cancer types: neuroblastoma, extracranial malignant germ cell tumor, hepatoblastoma, germinoma, medulloblastoma, renal tumor, rhabdomyosarcoma, and atypical teratoid/rhabdoid tumor. One rhabdomyosarcoma with the shortest survival exhibited membranous PD-L1 expression and germinoma contained abundant tumor-infiltrating CD8(+) T cells and PD-L1-positive macrophages. The PD-1/PD-L1 pathway tended to be inactive in pediatric cancers.2016-01-01T00:00:00Z2016 Aug2025-06-01T12:02:49.123Z2025-06-01T12:02:49.123ZS-EPMC50742382713565610.1002/pbc.26018