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Comparison of 22C3 PD-L1 Expression between Surgically Resected Specimens and Paired Tissue Microarrays in Non–Small Cell Lung Cancer
- Source :
- Journal of Thoracic Oncology. 12:1536-1543
- Publication Year :
- 2017
- Publisher :
- Elsevier BV, 2017.
-
Abstract
- The extent to which intratumoral heterogeneity of programmed death ligand 1 (PD-L1) expression causes discordance of PD-L1 expression between paired samples remains unclear. Here, PD-L1 status was compared between whole sections from NSCLCs and the corresponding tissue microarrays (TMAs) serving as surrogate biopsy specimens.PD-L1 expression was evaluated by 22C3 immunohistochemistry assay on 190 archival surgical specimens and matched to the TMA results. PD-L1 expression was determined by the tumor proportion score (TPS) and classified as TPS lower than 1%, TPS of 1% to 49%, and TPS of 50% or higher. Agreement statistics were used.The percentage of PD-L1 expression on tumor cells differed greatly between individual TMAs and matched surgical specimens. When PD-L1 TPS was adopted, a total of 36 of 190 discordance cases (18.9%) were observed, with a κ-value of 0.630 between paired samples. The TMAs underestimated or overestimated PD-L1 status in 19 of 36 (52.8%) and 17 of 36 (47.2%) of the matched surgical specimens, respectively (p = 0.118). The discordance rate was much lower in cases with a PD-L1 TPS lower than 1% compared with in cases with a TPS of 1% to 49% and TPS of 50% or higher (18.4% versus 56.7% and 43.3%, p0.001). When a TPS of 50% or higher was used as the cutoff, the discordance rate of PD-L1 TPS less than 50% was further reduced to 7.5%. Such discrepancies were due mainly to intratumoral heterogeneity of PD-L1 expression and nonsignificant association with clinicopathological features.PD-L1 expression in TMAs correlates moderately well with that in the corresponding surgical specimens, indicating that evaluating PD-L1 expression in diagnostic biopsy specimens could be misleading in defining sensitivity to pembrolizumab treatment yet may be reliable as a way to exclude patients with a PD-L1 TPS less than 50% from first-line pembrolizumab treatment.
- Subjects :
- Adult
0301 basic medicine
Pulmonary and Respiratory Medicine
Pathology
medicine.medical_specialty
Lung Neoplasms
Pembrolizumab
B7-H1 Antigen
03 medical and health sciences
0302 clinical medicine
Paired samples
Carcinoma, Non-Small-Cell Lung
Biopsy
Biomarkers, Tumor
medicine
Humans
Lung cancer
Aged
Tissue microarray
medicine.diagnostic_test
business.industry
Middle Aged
medicine.disease
030104 developmental biology
Oncology
Tissue Array Analysis
030220 oncology & carcinogenesis
Immunohistochemistry
Pd l1 expression
Non small cell
business
Nuclear medicine
Subjects
Details
- ISSN :
- 15560864
- Volume :
- 12
- Database :
- OpenAIRE
- Journal :
- Journal of Thoracic Oncology
- Accession number :
- edsair.doi.dedup.....e0b9ffe62d8fa2e592517784582c1e15