Comparison of programmed death ligand-1 expression in preoperative transbronchial lung biopsy and resected specimens in non-small cell lung cancer.

The concordance according to Cohen's kappa was κ = 0.410 (95% confidence interval: 0.243-0.577).

In the group with > 400 tumor cells, agreement rate was 100%.

The least absolute shrinkage and selection operator model identified never smoker, small tumor size, clinical stage II-IV and ≤ 200 tumor cells in biopsy specimens as predictors of underestimation.

The area under the receiver operating characteristic curve using those four factors was 0.773 (0.663-0.884).