Deepali Jain1, Supraja Sukumar1, Anant Mohan2, Venkateswaran K Iyer1. 1. Department of Pathology, All India Institute of Medical Sciences, New Delhi, India. 2. Department of Pulmonary Medicine & Sleep Disorders, All India Institute of Medical Sciences, New Delhi, India.
Abstract
OBJECTIVE: Programmed death-ligand 1 (PD-L1) immunohistochemistry (IHC) is essential in patients of advanced non-small-cell lung cancer to determine eligibility for immunotherapy. PD-L1 IHC assays have been clinically validated only on formalin-fixed paraffin-embedded tissue; however, lung cancer is frequently diagnosed on cytology. PD-L1 immunocytochemistry (ICC) has shown high concordance of immunoexpression between cytology samples and paired small biopsies. Feasibility of liquid-based cytology (LBC) smears for PD-L1 ICC has not been analysed previously. METHODS: PD-L1 ICC and IHC (clone SP263) were performed on paired LBC smears and small biopsies, respectively, in patients with advanced non-small-cell lung cancer. Cases with fewer than 100 viable tumour cells on LBC smear/biopsy were excluded from analysis. PD-L1 was interpreted positive when 25% or more tumour cells showed membranous and/or cytoplasmic protein expression of any intensity greater than background staining. RESULTS: A total of 26 patients, harbouring adenocarcinomas (50%) and squamous cell carcinomas (50%), had available bronchial brushings/washings processed as LBC smears and concurrently obtained endobronchial biopsies. PD-L1 IHC was interpreted positive in 46% (12/26) biopsies. PD-L1 ICC was interpreted positive in 35% (9/26) LBC smears, all of which were IHC-positive. No IHC-negative case was positive on cytology. The overall concordance between LBC smears and small biopsies was 88.4%. CONCLUSION: PD-L1 ICC can be performed on LBC processed smears, with certain challenges in interpretation inherent to LBC smears and their processing methods. Nevertheless, they represent a potential resource for ICC, especially when alternate histology material is not available. Future studies are required to validate the predictive value of PD-L1 ICC on LBC smears.
OBJECTIVE:Programmed death-ligand 1 (PD-L1) immunohistochemistry (IHC) is essential in patients of advanced non-small-cell lung cancer to determine eligibility for immunotherapy. PD-L1 IHC assays have been clinically validated only on formalin-fixed paraffin-embedded tissue; however, lung cancer is frequently diagnosed on cytology. PD-L1 immunocytochemistry (ICC) has shown high concordance of immunoexpression between cytology samples and paired small biopsies. Feasibility of liquid-based cytology (LBC) smears for PD-L1 ICC has not been analysed previously. METHODS:PD-L1 ICC and IHC (clone SP263) were performed on paired LBC smears and small biopsies, respectively, in patients with advanced non-small-cell lung cancer. Cases with fewer than 100 viable tumour cells on LBC smear/biopsy were excluded from analysis. PD-L1 was interpreted positive when 25% or more tumour cells showed membranous and/or cytoplasmic protein expression of any intensity greater than background staining. RESULTS: A total of 26 patients, harbouring adenocarcinomas (50%) and squamous cell carcinomas (50%), had available bronchial brushings/washings processed as LBC smears and concurrently obtained endobronchial biopsies. PD-L1 IHC was interpreted positive in 46% (12/26) biopsies. PD-L1 ICC was interpreted positive in 35% (9/26) LBC smears, all of which were IHC-positive. No IHC-negative case was positive on cytology. The overall concordance between LBC smears and small biopsies was 88.4%. CONCLUSION:PD-L1 ICC can be performed on LBC processed smears, with certain challenges in interpretation inherent to LBC smears and their processing methods. Nevertheless, they represent a potential resource for ICC, especially when alternate histology material is not available. Future studies are required to validate the predictive value of PD-L1 ICC on LBC smears.
Authors: C Kuempers; L I S van der Linde; M Reischl; W Vogel; F Stellmacher; M Reck; D Heigener; K F Rabe; J Kirfel; S Perner; L Welker Journal: Virchows Arch Date: 2019-08-07 Impact factor: 4.064
Authors: Mohammed S I Mansour; Kajsa Ericson Lindquist; Tomas Seidal; Ulrich Mager; Rikard Mohlin; Lena Tran; Kim Hejny; Benjamin Holmgren; Despoina Violidaki; Katalin Dobra; Annika Dejmek; Maria Planck; Hans Brunnström Journal: Acta Cytol Date: 2021-07-07 Impact factor: 2.319
Authors: Bregje M Koomen; Willem Vreuls; Mirthe de Boer; Emma J de Ruiter; Juergen Hoelters; Aryan Vink; Stefan M Willems Journal: Histopathology Date: 2021-06-08 Impact factor: 5.087
Authors: Bo Franzén; Kristina Viktorsson; Caroline Kamali; Eva Darai-Ramqvist; Vitali Grozman; Vasiliki Arapi; Petra Hååg; Vitaliy O Kaminskyy; Per Hydbring; Lena Kanter; Sven Nyrén; Simon Ekman; Luigi De Petris; Rolf Lewensohn Journal: Mol Oncol Date: 2021-05-01 Impact factor: 6.603