Comparison of 22C3 PD-L1 Expression between Surgically Resected Specimens and Paired Tissue Microarrays in Non-Small Cell Lung Cancer
Publication in refereed journal



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%, p < 0.001). 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.
著者Chao Li, Cheng Huang, Tony S. Mok, Wu Zhuang, Haipeng Xu, Qian Miao, Xirong Fan, Weifeng Zhu, Yunjian Huang, Xiandong Lin, Kan Jiang, Dan Hu, Xiaohui Chen, Peisha Huang, Gen Lin
期刊名稱Journal of Thoracic Oncology
出版地United States
頁次1536 - 1543
關鍵詞PD-L1, Immunohistochemistry, Surgical resected specimen, Tissue microarray, Non–small cell lung cancer

上次更新時間 2021-19-01 於 01:24