Saller JJ, Mora LB, Nasir A, Mayer Z, Shahid M, Coppola D. Expression of DNA Mismatch Repair Proteins, PD1 and PDL1 in Barrett's Neoplasia.
Cancer Genomics Proteomics 2022;
19:145-150. [PMID:
35181584 DOI:
10.21873/cgp.20310]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 12/23/2021] [Accepted: 01/04/2022] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND/AIM
Cancers with a microsatellite instability-high (MSI-H) or deficient mismatch repair (dMMR) status respond to immune checkpoint inhibition (ICI). Regardless of the tumor type, MSI-H/dMMR status is a reliable biomarker for ICI responsiveness. This study aimed at determining the MSI-H status in precursor lesions to esophageal adenocarcinoma (EAC) such as Barrett's esophagus (BE) and BE with either low-grade dysplasia (LGD) or high-grade dysplasia (HGD).
PATIENTS AND METHODS
We performed immunohistochemical staining (IHC) for PMS2, MSH6, PD1, and PD-L1.
RESULTS
All cases of BE (50), LGD (48), and HGD (50) had intact PMS2 and MSH6 nuclear expression; were negative for PD1; and had a PD-L1 combined positive score (CPS) score <1. One EAC case (2%) was negative for PMS2 nuclear expression. One HGD case (2%) and two EAC cases (4%) were PD1 positive (CPS score <1 applied to PD1). One EAC case (2%) had a CPS score >1, and one EAC case (2%) was MSI-H. MSI-H tumors usually show PD-L1 expression, although the MSI-H EAC in this study had a PD-L1 CPS score of <1.
CONCLUSION
Further studies investigating EAC and its precursor lesions for PD1, PD-L1, and dMMR status may be informative regarding the immunogenicity of the evolution of EAC.
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