Format

Send to

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

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

Author information

1
Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.
2
Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden. Electronic address: patrick.micke@igp.uu.se.

Abstract

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

PMID:
30926355
DOI:
10.1016/j.cllc.2019.02.012

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center