1. PD-L1 assessment in cytology samples predicts treatment response to checkpoint inhibitors in NSCLC
- Author
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Sally C.M. Lau, Madhumitha Rabindranath, Jessica Weiss, Janice J.N. Li, Andrea S. Fung, Dorinda Mullen, Najd Alshamlan, Heather M. Ruff, Leung Chu B. Tong, Prodipto Pal, Michael R. Cabanero, Ying-Han R. Hsu, Adrian G. Sacher, Frances A. Shepherd, Geoffrey Liu, Penelope A. Bradbury, Kazuhiro Yasufuku, Katarzyna Czarnecka-Kujawa, Hyang Mi Ko, Ming-Sound Tsao, Natasha B. Leighl, and Joerg Schwock
- Subjects
Pulmonary and Respiratory Medicine ,Cancer Research ,Lung Neoplasms ,Oncology ,Carcinoma, Non-Small-Cell Lung ,Biomarkers, Tumor ,Humans ,B7-H1 Antigen - Abstract
Testing for tumor programmed death ligand-1 (PD-L1) expression was initially developed with histology specimens in non-small cell lung cancer (NSCLC). However, cytology specimens are widely used for primary diagnosis and biomarker studies in clinical practice. Limited clinical data exist on the predictiveness of cytology-derived PD-L1 scores for response to immune checkpoint inhibitor (ICI) therapy.We reviewed all NSCLC specimens clinically tested at the University Health Network (UHN) for PD-L1 with 22C3pharmDx, from 01/2013 to 04/2021. Treatment outcomes in patients treated with single agent ICI therapy were reviewed and compared according to cytology- and histology-derived PD-L1 scores.We identified 494 and 1942 unique patients with cytology- and histology-derived tumor proportion scores, respectively, during the study period. Informative testing rates were 95 % vs 98 % for cytology and histology, respectively. Clinical data were available for 152 patients treated with single agent ICI: 61 cytology and 91 histology. Overall response rates (ORR) were similar for cytology and histology (36 % vs 34 %; p = 0.23), as well as median progression free survival (PFS) (4.9 vs 4.2 months; p = 0.99) and overall survival (23.4 vs 19.7 months; p = 0.99). The results remained similar even after adjusting for PD-L1 expression levels and line of ICI treatment (PFS HR 1.15; 95 %CI 0.78-1.70; p = 0.47).Treatment outcomes to single agent ICI based on cytology-derived PD-L1 scores were comparable to histology controls. Our results support PD-L1 biomarker testing on both cytology and histology specimens.
- Published
- 2022