Ultra-high combined positive score and high serum albumin are favorable prognostic biomarkers for immune checkpoint inhibitors in head and neck squamous cell carcinoma.

Abstract

Biomarkers that predict response to immune checkpoint inhibitor (ICI) in recurrent metastatic squamous cell carcinoma of the head and neck (RMHNSCC) are not well known. We prospectively measured the combined positive score (CPS) and administered ICI to patients with RMHNSCC. Of 51 patients, 23 patients had a CPS <20 and 12 patients (23.5%) had a CPS ≥90. CPS showed a negative correlation with serum albumin. Survival analysis showed a 2-year survival rate of 24.1%. In multivariate analysis, CPS ≥90 (HR 0.3026, p = 0.02614) and albumin >3.5 (HR 0.3463, p = 0.01354) were the significant factors and plus chemotherapy (HR 0.4648, p = 0.07632) was not significant. Seven patients (14%) with CPS ≥90 and albumin >3.5 showed a 2-year survival rate of 66. 7%. CPS ≥90 and albumin >3.5 cases are a subgroup of RMHNSCC that respond extremely well to ICI.