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Using 22C3 Anti-PD-L1 Antibody Concentrate on Biopsy and Cytology Samples from Non-small Cell Lung Cancer Patients
Published on: September 25, 2018
Accuracy of Cytologic vs Histologic Specimens for Assessment of Programmed Cell Death Ligand-1 Expression in
Pattraporn Tajarernmuang1, Felipe Aliaga2, Amr J Alwakeel3
1Respiratory Epidemiology and Clinical Research Unit, Montreal Chest Institute, McGill University Health Centre, Montreal, QC, Canada; Respiratory, Critical Care and Allergy Division, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
Background:
Programmed cell death ligand-1 (PD-L1) expression on tumor cells, evaluated by immunohistochemistry, guides the use of immunotherapy in advanced non-small cell lung cancer (NSCLC).
Research Question:
What is the sensitivity and specificity of PD-L1 testing performed in cytologic vs paired histologic specimens in patients with NSCLC?
Study Design And Methods:
The MEDLINE, Embase, Web of Science, and Cochrane Library databases were searched through June 1, 2021. The primary outcome was pooled sensitivity and specificity of PD-L1 testing performed on cytologic specimens compared with the reference standard of histologic specimens, analyzed at the PD-L1 expression cutoffs (tumor proportion score) ≥ 1% and ≥ 50%. Pooled sensitivity and specificity, and associated 95% CIs, were estimated using bivariate generalized linear mixed models.
Results:
Twenty-six articles were included, encompassing a total of 1,064 pairs of histology specimens and cytology cell blocks, and 267 pairs of histology specimens and direct smears. Among these, 946 paired specimens were acquired without interval treatment between the collection of histology and cytology samples. The pooled sensitivity and specificity of cytology specimens compared with paired histology specimens at the PD-L1 expression cutoff ≥ 1% were 0.84 (95% CI, 0.77-0.89) and 0.88 (95% CI, 0.82-0.93), respectively, whereas the pooled sensitivity and specificity at cutoff ≥ 50% were 0.78 (95% CI, 0.69-0.86) and 0.94 (95% CI, 0.91-0.96), respectively. When only paired specimens acquired without interval treatment were considered, the pooled sensitivity and specificity of cytology specimens at PD-L1 expression cutoff ≥ 1% were 0.84 (95% CI, 0.76-0.90) and 0.89 (95% CI, 0.82-0.94), respectively, whereas the pooled sensitivity and specificity at cutoff ≥ 50% were 0.80 (95% CI, 0.71-0.89) and 0.94 (95% CI, 0.91-0.96), respectively.
Interpretation:
Cytologic specimens provide an accurate assessment of PD-L1 expression in most patients with NSCLC, at both ≥ 1% and ≥ 50% cutoffs, when compared with histologic specimens.
Trial Registration:
PROSPERO; No.: CRD42020153279; URL: https://www.crd.york.ac.uk/prospero/.
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