PD-L1 protein expression in primary versus metastatic lesions in NSCLC

Retrospective analysis of the Foundation Medicine, Inc clinical database investigated discrepancy of PD-L1 protein expression between primary NSCLC tumors and unmatched metastatic lesions. Metastatic lesions werd more frequently high positive (tumor proportion score at least 50%) for PD-L1 expression than primary lesions among patients with non-squamous histology (OR 1.37; p<0.001) but not among patients with squamous histology (OR 0.89; p=0.197).