Intratumoral heterogeneity in programmed death-ligand 1 immunoreactivity is associated with variation in non-small cell lung carcinoma histotype.

Intratumoral heterogeneity in PD-L1 is associated with variation in histotype. Over-representation of solid areas may increase the PD-L1 score assigned to a tumour, whereas over-representation of lepidic areas may decrease the PD-L1 score. Evaluation of how histotype representation impacts on the predictive value of PD-L1 testing is warranted.