Programmed Death Ligand-1 Combined Positive Score Concordance and Interrater Reliability in Primary Tumors and Synchronous Lymph Node Metastases in Resected Cases of p16+ Oropharyngeal Squamous Cell Carcinoma.

Given the high rates of interobserver and interspecimen variability, evaluation of additional material or by additional observers may be of value in performing CPS scoring in cases of p16+ OPSCC. This is particularly the case when a negative or low-positive result is being evaluated in a patient who is otherwise a good candidate for immunotherapy.