Programmed Cell Death Ligand 1 Immunohistochemistry: A Concordance Study Between Surgical Specimen, Biopsy, and Tissue Microarray

Clin Lung Cancer. 2019 Jul;20(4):258-262.e1. doi: 10.1016/j.cllc.2019.02.012. Epub 2019 Feb 27.


Background: The immunohistochemical analysis of programmed cell death ligand 1 (PD-L1) expression in tumor tissue of non-small-cell lung cancer patients has now been integrated in the diagnostic workup. Analysis is commonly done on small tissue biopsy samples representing a minimal fraction of the whole tumor. The aim of the study was to evaluate the correlation of PD-L1 expression on biopsy specimens with corresponding resection specimens.

Materials and methods: In total, 58 consecutive cases with preoperative biopsy and resected tumor specimens were selected. From each resection specimen 2 tumor cores were compiled into a tissue microarray (TMA). Immunohistochemical staining with the antibody SP263 was performed on biopsy specimens, resection specimens (whole sections), as well as on the TMA.

Results: The proportion of PD-L1-positive stainings were comparable between the resection specimens (48% and 19%), the biopsies (43% and 17%), and the TMAs (47% and 14%), using cutoffs of 1% and 50%, respectively (P > .39 all comparisons). When the resection specimens were considered as reference, PD-L1 status differed in 16%/5% for biopsies and in 9%/9% for TMAs (1%/50% cutoff). The sensitivity of the biopsy analysis was 79%/82% and the specificity was 90%/98% at the 1%/50% cutoff. The Cohens κ value for the agreement between biopsy and tumor. was 0.70 at the 1% cutoff and 0.83 at the 50% cutoff.

Conclusion: The results indicate a moderate concordance between the analysis of biopsy and whole tumor tissue, resulting in misclassification of samples in particular when the lower 1% cutoff was used. Clinicians should be aware of this uncertainty when interpreting PD-L1 reports for treatment decisions.

Keywords: Checkpoint inhibitors; Nivolumab; PD-1; PD-L1; Pembrolizumab.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers, Tumor / metabolism*
  • Biopsy / methods*
  • Carcinoma, Non-Small-Cell Lung / diagnosis*
  • Female
  • Humans
  • Immunohistochemistry / methods*
  • Lung Neoplasms / diagnosis*
  • Male
  • Middle Aged
  • Pneumonectomy
  • Programmed Cell Death 1 Receptor / genetics
  • Programmed Cell Death 1 Receptor / metabolism*
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Tissue Array Analysis / methods*


  • Biomarkers, Tumor
  • PDCD1 protein, human
  • Programmed Cell Death 1 Receptor