PD-L1 expression is a favorable prognostic factor in early stage non-small cell carcinoma

PD-L1 is expressed at high levels in a significant proportion of NSCLC and appears to be a favorable prognostic factor in early stage disease. As there are potential sampling limitations using tissue microarrays to assess heterogeneously expressed biomarkers, and as the results may differ in advanced stage disease, further studies are recommended.