In:
Clinical Medicine Insights: Oncology, SAGE Publications, Vol. 13 ( 2019-01), p. 117955491882131-
Abstract:
In recent years, the anti-programmed cell death 1 (PD-1) drug pembrolizumab (Keytruda) was approved for treatment of unresectable advanced non-small cell lung cancer (NSCLC) as first- or second-line therapy depending on the clone 22C3-programmed death-ligand 1 (PD-L1) immunohistochemical expression score by the companion diagnostic assay. We herein evaluated 22C3-PD-L1 expression of NSCLC in a single institution experience and compared it with clinicopathologic features. Materials and methods: We assessed 22C3-PD-L1 expressions of 411 patients with NSCLC from our institution, including in past specimens. Programmed death-ligand 1 immunohistochemistry (IHC) testing was performed using the PD-L1 clone 22C3 pharmDx kit (Agilent Technologies/Dako, Carpinteria, CA, USA). Patients were separated into 3 groups with 〈 1% (no expression), 1% to 49% (low expression), or ⩾50% (high expression) positive tumor cells. Results: In all, 137 patients (33%) did not express PD-L1, 155 (38%) showed low expression, and 119 (29%) demonstrated high expression. Archival samples showed lower PD-L1 expression than that of recent samples, and the ratios of no expression case significantly increased by using paraffin blocks embedded particularly in more than 4 years ago. Programmed death-ligand 1 positivity was significantly associated with male sex, smoking, higher tumor grade, squamous cell carcinoma in histologic type, wild-type EGFR, and ALK rearrangement positive. Conclusions: The rate of 22C3-PD-L1 expression of NSCLC detected in this study was similar to the frequencies of the previous reports, although the ratio of expression case decreased when using old paraffin blocks.
Type of Medium:
Online Resource
ISSN:
1179-5549
,
1179-5549
DOI:
10.1177/1179554918821314
Language:
English
Publisher:
SAGE Publications
Publication Date:
2019
detail.hit.zdb_id:
2577877-8
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