Dr. Burtness on the Use of Biomarkers in Metastatic HNSCC

Barbara Burtness, MD, professor of Medicine (Medical Oncology); Disease Aligned Research Team Leader, Head and Neck Cancers Program; co-director, Developmental Therapeutics Research Program; of Yale Cancer Center, discusses the use of biomarkers in metastatic head and neck squamous cell carcinoma (HNSCC).

A PD-L1 combined positive score (CPS) ≥20 is likely to become a biomarker that will drive treatment decisions for patients with metastatic HNSCC in the near future, says Burtness. With the promise of immunotherapy in this setting, many institutions are now doing PD-L1 testing, says Burtness. PD-L1 expression can either be reported in terms of the proportion of tumor cells stained for PD-L1 or the proportion of stromal cells that stain for PD-L1. Looking at the proportion of positive cells on either tumor cells or immune cells is a novel way for the pathologist to test for the biomarker, says Burtness.

Though, assessing CPS ≥20 is going to require a different reporting algorithm, Burtness notes. If it is going to go forward as a companion biomarker with PD-L1, that will add some complexity to the landscape. Currently, looking at PD-L1 seems to be the standard of care as response rates with pembrolizumab (Keytruda) and nivolumab (Opdivo) are low in the unselected population.