Risk Factors for Progressive Disease After Immune Checkpoint Inhibitor Therapy in Head and Neck Squamous Cell Carcinoma

Background: This study analyzed the clinical features of patients with recurrent or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC), who developed progressive disease (PD) after immune checkpoint inhibitor (ICI) therapy. Methods: We retrospectively analyzed 256 patients with R/M HNSCC treated with ICIs at 11 medical centers. Associations between the treatment outcomes―best response, overall survival, and progression-free survival―and various clinical factors were analyzed. Results: The objective response rate was 19.5% and PD was observed in 50.4% of the patients. A high neutrophil-to-lymphocyte ratio (NLR > 4; HR, 2.20 [1.28–3.78]) and large tumor size (sum of the target lesions > 40 mm; HR, 1.74 [1.03–2.94]) were significant risk factors for PD. High NLR (HR, 2.00 [1.42–2.82]), poor performance status (ECOG PS 2–3; HR, 3.51 [2.04–6.05]), and large tumor size (HR. 1.63 [1.19–2.24]) were independently associated with poor overall survival. Conclusions: Patients with high NLR and large tumor size are at higher risk of PD during ICI therapy.