PD-L1 testing using the clone 22C3 pharmDx kit for selection of patients with non-small cell lung cancer to receive immune checkpoint inhibitor therapy: are cytology cell blocks a viable option?

Conclusions In this cohort of advanced NSCLC patients with standard of care PD-L1 testing performed on either FFPE cytology cell blocks or FFPE surgical pathology specimens, similar patterns were observed in population tumor PD-L1 expression patterns, concomitant driver mutations, and clinical response to palliative pembrolizumab in selected patients with TPS ≥50%. Teaser For non-small cell lung carcinoma, formalin-fixed, paraffin embedded cytology cell blocks and surgical pathology specimens appear to be comparable testing substrates for PD-L1 using the 22C3 pharmDx kit in the selection of patients for immune checkpoint inhibitor therapy.
Source: Journal of the American Society of Cytopathology - Category: Cytology Source Type: research