Related Experiment Video
Updated: Jan 1, 2026
Using 22C3 Anti-PD-L1 Antibody Concentrate on Biopsy and Cytology Samples from Non-small Cell Lung Cancer Patients
Published on: September 25, 2018
PD-L1 Testing for Lung Cancer in 2019: Perspective From the IASLC Pathology Committee
Sylvie Lantuejoul1, Ming Sound-Tsao2, Wendy A Cooper3
1Centre Léon Bérard Unicancer, Lyon, France; Université Grenoble Alpes, Grenoble, France.
Abstract:
The recent development of immune checkpoint inhibitors (ICIs) has led to promising advances in the treatment of patients with NSCLC and SCLC with advanced or metastatic disease. Most ICIs target programmed cell death protein 1 (PD-1) or programmed death ligand 1 (PD-L1) axis with the aim of restoring antitumor immunity. Multiple clinical trials for ICIs have evaluated a predictive value of PD-L1 protein expression in tumor cells and tumor-infiltrating immune cells (ICs) by immunohistochemistry (IHC), for which different assays with specific IHC platforms were applied. Of those, some PD-L1 IHC assays have been validated for the prescription of the corresponding agent for first- or second-line treatment. However, not all laboratories are equipped with the dedicated platforms, and many laboratories have set up in-house or laboratory-developed tests that are more affordable than the generally expensive clinical trial-validated assays. Although PD-L1 IHC test is now deployed in most pathology laboratories, its appropriate implementation and interpretation are critical as a predictive biomarker and can be challenging owing to the multiple antibody clones and platforms or assays available and given the typically small size of samples provided. Because many articles have been published since the issue of the IASLC Atlas of PD-L1 Immunohistochemistry Testing in Lung Cancer, this review by the IASLC Pathology Committee provides updates on the indications of ICIs for lung cancer in 2019 and discusses important considerations on preanalytical, analytical, and postanalytical aspects of PD-L1 IHC testing, including specimen type, validation of assays, external quality assurance, and training.
Insights
Immune checkpoint inhibitors (ICIs) show promise for advanced lung cancers. This review updates PD-L1 testing for ICIs, addressing challenges in assay validation, interpretation, and quality assurance for non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC).
Area of Science:
- Oncology
- Pathology
- Immunotherapy
Background:
- Immune checkpoint inhibitors (ICIs) targeting the programmed cell death protein 1 (PD-1) or programmed death ligand 1 (PD-L1) axis have advanced lung cancer treatment.
- PD-L1 expression, assessed by immunohistochemistry (IHC), is a key predictive biomarker for ICI efficacy in non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC).
- Challenges exist due to diverse IHC assays, platforms, and the need for affordable, reliable testing in routine pathology labs.
Purpose of the Study:
- To provide updated guidance on PD-L1 IHC testing for lung cancer patients receiving ICIs in 2019.
- To discuss critical preanalytical, analytical, and postanalytical considerations for PD-L1 IHC assays.
- To address the implementation and interpretation of PD-L1 testing in the context of multiple available assays and sample limitations.
Main Methods:
- Review of recent literature and guidelines published since the IASLC Atlas of PD-L1 Immunohistochemistry Testing in Lung Cancer.
- Discussion of preanalytical factors: specimen type and handling.
- Analysis of analytical factors: assay validation, antibody clones, platforms, and external quality assurance.
- Consideration of postanalytical factors: interpretation and training.
Main Results:
- Multiple PD-L1 IHC assays exist, with some validated for clinical use in first- or second-line lung cancer treatment.
- Laboratory-developed tests (LDTs) offer more affordable alternatives but require careful validation.
- Consistent implementation and interpretation of PD-L1 IHC are crucial for effective ICI therapy.
Conclusions:
- Standardized and validated PD-L1 IHC testing is essential for optimal patient selection for ICIs in NSCLC and SCLC.
- Addressing preanalytical, analytical, and postanalytical aspects, including quality assurance and training, is critical for reliable PD-L1 biomarker assessment.
- This review offers practical insights for pathology laboratories navigating the complexities of PD-L1 IHC testing in lung cancer.
More Related Videos
10:29Semi-automatic PD-L1 Characterization and Enumeration of Circulating Tumor Cells from Non-small Cell Lung Cancer Patients by Immunofluorescence
Published on: August 14, 2019
10:38DIPLOMA Approach for Standardized Pathology Assessment of Distal Pancreatectomy Specimens
Published on: February 1, 2020