Considerable interlaboratory variation in PD-L1 positivity for head and neck squamous cell carcinoma in the Netherlands— A nationwide evaluation study

Aims: Patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) are eligible for first-line immune checkpoint inhibition if their tumour is positive for programmed death ligand 1 (PD-L1) determined by the combined positive score (CPS). This nationwide study, using real-world data, investigated the developing PD-L1 testing landscape in the first 3 years after introduction of the test in HNSCC and examined interlaboratory variation in PD-L1 positivity rates. Methods: Pathology reports of HNSCC patients mentioning PD-L1 were extracted from the Dutch Pathology Registry (P... Mehr ...