Next Article in Journal
Relative Effects of Brachytherapy and Beam Radiation for DCIS on Subsequent Invasive Events
Previous Article in Journal
Therapeutic Potential of Gentianaceae Family Plants in the Treatment of Diabetes and Its Complications
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Biomedicines
Volume 13
Issue 11
10.3390/biomedicines13112824
biomedicines-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
This is an early access version, the complete PDF, HTML, and XML versions will be available soon.
Technical Note

Best Practice PD-L1 Staining and Interpretation in Gastric Cancer Using PD-L1 IHC PharmDx 22C3 and PD-L1 IHC PharmDx 28-8 Assays, with Reference to Common Issues and Solutions

by
Soomin Ahn
1,
Inwoo Hwang
1,
Yuyeon Kim
2,
Somin Lee
2,
Yunjoo Cho
1,
So Young Kang
1,
Deok Geun Kim
1,
Jeeyun Lee
3 and
Kyoung-Mee Kim
1,*
1
Department of Pathology and Translational Genomics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea
2
Advanced Technology Research Center for Diagnostics (ATRCD), Samsung Precision Genome Medicine Institute (SPGM), Samsung Medical Center, Seoul 06351, Republic of Korea
3
Department of Medicine, Division of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Republic of Korea
*
Author to whom correspondence should be addressed.
Biomedicines 2025, 13(11), 2824; https://doi.org/10.3390/biomedicines13112824
Submission received: 27 September 2025 / Revised: 10 November 2025 / Accepted: 11 November 2025 / Published: 19 November 2025
(This article belongs to the Topic Biomarkers of Disease: Discovery and Clinical Applications)
Review Reports Versions Notes

Abstract

Programmed death-ligand 1 (PD-L1) biomarker testing in gastric cancer is required to identify patients suitable for immunotherapy. However, the PD-L1 testing landscape is complex, with various PD-L1 tests available and multiple algorithms that combine tumor and immune cell staining. To provide guidance on the best practices for PD-L1 testing in gastric cancer, we reviewed the literature and incorporated our extensive experience using the PD-L1 IHC PharmDx 22C3 and 28-8 assays and scoring with the combined positive score (CPS) algorithm. This review summarizes inter-reader agreement and PD-L1 assay concordance studies in gastric cancer, highlights practical challenges and pitfalls encountered in our own laboratory, and proposes solutions to address them. Accurate and consistent interpretation of PD-L1 CPS in gastric cancer is challenging, but can be improved with training, experience, and close attention to interpretation guidelines. Techniques are available that can optimize the automated staining of PharmDx PD-L1 assays using the Autostainer Link 48 to ensure consistent staining performance. The PD-L1 IHC PharmDx 22C3 and PD-L1 IHC PharmDx 28-8 assays show high concordance when used according to manufacturers’ guidelines.
Keywords: gastric; cancer; PD-L1; biomarker; staining; interpretation gastric; cancer; PD-L1; biomarker; staining; interpretation

Share and Cite

MDPI and ACS Style

Ahn, S.; Hwang, I.; Kim, Y.; Lee, S.; Cho, Y.; Kang, S.Y.; Kim, D.G.; Lee, J.; Kim, K.-M. Best Practice PD-L1 Staining and Interpretation in Gastric Cancer Using PD-L1 IHC PharmDx 22C3 and PD-L1 IHC PharmDx 28-8 Assays, with Reference to Common Issues and Solutions. Biomedicines 2025, 13, 2824. https://doi.org/10.3390/biomedicines13112824

AMA Style

Ahn S, Hwang I, Kim Y, Lee S, Cho Y, Kang SY, Kim DG, Lee J, Kim K-M. Best Practice PD-L1 Staining and Interpretation in Gastric Cancer Using PD-L1 IHC PharmDx 22C3 and PD-L1 IHC PharmDx 28-8 Assays, with Reference to Common Issues and Solutions. Biomedicines. 2025; 13(11):2824. https://doi.org/10.3390/biomedicines13112824

Chicago/Turabian Style

Ahn, Soomin, Inwoo Hwang, Yuyeon Kim, Somin Lee, Yunjoo Cho, So Young Kang, Deok Geun Kim, Jeeyun Lee, and Kyoung-Mee Kim. 2025. "Best Practice PD-L1 Staining and Interpretation in Gastric Cancer Using PD-L1 IHC PharmDx 22C3 and PD-L1 IHC PharmDx 28-8 Assays, with Reference to Common Issues and Solutions" Biomedicines 13, no. 11: 2824. https://doi.org/10.3390/biomedicines13112824

APA Style

Ahn, S., Hwang, I., Kim, Y., Lee, S., Cho, Y., Kang, S. Y., Kim, D. G., Lee, J., & Kim, K.-M. (2025). Best Practice PD-L1 Staining and Interpretation in Gastric Cancer Using PD-L1 IHC PharmDx 22C3 and PD-L1 IHC PharmDx 28-8 Assays, with Reference to Common Issues and Solutions. Biomedicines, 13(11), 2824. https://doi.org/10.3390/biomedicines13112824

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop