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.
Original language | English (US) |
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Pages (from-to) | 441-449 |
Number of pages | 9 |
Journal | American journal of clinical pathology |
Volume | 148 |
Issue number | 5 |
DOIs | |
State | Published - Nov 1 2017 |
Keywords
- Immunohistochemistry
- PD-L1
- Pancreatic ductal adenocarcinoma
- Undifferentiated pancreatic carcinoma
ASJC Scopus subject areas
- Pathology and Forensic Medicine