Heidi D Lehrke1, Rondell P Graham1, Robert R McWilliams2, Dora M Lam-Himlin3, Thomas C Smyrk1, Sarah Jenkins4, Haidong Dong5, Lizhi Zhang1.
Abstract
OBJECTIVES: Programmed death ligand 1 (PD-L1) expression in pancreatic ductal adenocarcinoma (PDA) has been described, but unselected PDAs have shown limited clinical responsiveness to anti-programmed death 1 (PD-1)/PD-L1 therapy.
METHODS: We studied 24 cases of undifferentiated pancreatic carcinoma (UPC) using immunohistochemistry for PD-L1 (E1L3N clone), CD3, CD20, CD68, and DNA mismatch repair proteins in this study. Slides were scored for extent of PD-L1 expression on tumor cells and tumor-infiltrating immune cells.
RESULTS: PD-L1 expression was more frequent in UPCs than in PDAs (63% vs 15%, P < .01). The extent of PD-L1 expression was greater in UPCs, with 13 (87%) of 15 cases containing 10% or more positive tumor cells compared with three of seven PDAs (P = .05). Both tumor groups showed similar numbers of tumor-infiltrating T cells, B cells, and macrophages.
CONCLUSIONS: UPC is enriched for PD-L1 expression in frequency and extent, relative to conventional PDA. Anti-PD-1/PD-L1 agents may represent a valuable therapeutic approach for this subset of highly aggressive pancreatic carcinoma. © American Society for Clinical Pathology, 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com
OBJECTIVES: Programmed death ligand 1 (PD-L1) expression in pancreatic ductal adenocarcinoma (PDA) has been described, but unselected PDAs have shown limited clinical responsiveness to anti-programmed death 1 (PD-1)/PD-L1 therapy.
METHODS: We studied 24 cases of undifferentiated pancreatic carcinoma (UPC) using immunohistochemistry for PD-L1 (E1L3N clone), CD3, CD20, CD68, and DNA mismatch repair proteins in this study. Slides were scored for extent of PD-L1 expression on tumor cells and tumor-infiltrating immune cells.
RESULTS: PD-L1 expression was more frequent in UPCs than in PDAs (63% vs 15%, P < .01). The extent of PD-L1 expression was greater in UPCs, with 13 (87%) of 15 cases containing 10% or more positive tumor cells compared with three of seven PDAs (P = .05). Both tumor groups showed similar numbers of tumor-infiltrating T cells, B cells, and macrophages.
CONCLUSIONS: UPC is enriched for PD-L1 expression in frequency and extent, relative to conventional PDA. Anti-PD-1/PD-L1 agents may represent a valuable therapeutic approach for this subset of highly aggressive pancreatic carcinoma. © American Society for Clinical Pathology, 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com
Entities:
Keywords:
Immunohistochemistry; PD-L1; Pancreatic ductal adenocarcinoma; Undifferentiated pancreatic carcinoma
Mesh:
Substances:
Year: 2017
PMID: 29069274 DOI: 10.1093/ajcp/aqx092
Source DB: PubMed Journal: Am J Clin Pathol ISSN: 0002-9173 Impact factor: 2.493