Abstract
BACKGROUND: Previously, we proposed that the immune-modified Glasgow Prognostic Score (imGPS), which adds the lymphocyte count to the mGPS, is helpful as a prognostic marker for patients with head and neck squamous cell carcinoma. In this study, we investigated the imGPS as a marker for the therapeutic effect of pembrolizumab in treating recurrent and metastatic head and neck cancer (RMHNC). METHODS: This study included RMHNC patients who were treated with pembrolizumab from December 2019 to April 2024. ALB, CRP, lymphocyte counts, neutrophil-to-lymphocyte ratios (NLRs), mGPSs, and imGPSs were extracted as biomarkers, and the response rate and prognosis were analyzed for each. RESULTS: A total of 54 patients were enrolled. Lymphocyte counts were correlated with the overall response rates (ORRs) (p = 0.0082). Although the mGPS did not show significant differences in ORRs, imGPSs revealed a significant difference (p = 0.013). CRP, ALB, and lymphocyte counts were correlated with overall survival (OS) and/or progression-free survival (PFS). NLRs, mGPSs, and imGPSs were also correlated with OS and/or PFS, with imGPSs showing the greatest area under the curve (OS; AUC = 0.795, PFS; AUC = 0.754). CONCLUSIONS: This study demonstrates that the imGPS is an excellent predictive marker for the therapeutic effect and prognosis of pembrolizumab for RMHNC. The imGPS can be employed with daily blood tests, highlighting the potential to forecast the impact of the ICI with high reliability.