Abstract
BACKGROUND/AIM: The prognosis of recurrent/metastatic squamous cell carcinoma of the head and neck (R/M SCCHN) is poor, although immune checkpoint inhibitors (ICIs), such as nivolumab, have been shown to prolong survival. We investigated the factors that predict the efficacy of nivolumab when selecting an appropriate treatment strategy for patients with R/M SCCHN. PATIENTS AND METHODS: Forty-four Japanese patients with R/M SCCHN treated with nivolumab between May 2017 and October 2021 were analyzed. The primary endpoint of the study was overall survival (OS). We defined pre-treatment tumor size (PTS) as the sum of the size of all measurable lesions, and tumor growth rate (TGR) as the total growth rate of the largest tumor diameter on CT scans taken to determine treatment response, divided by the interval between CT scans. Receiver operating characteristic (ROC) curves were used to identify the cutoff points of PTS and TGR for OS. Cox proportional hazards regression analysis was performed to examine the relationships between various factors, including patient characteristics, PTS, and TGR, as well as treatment outcomes. RESULTS: In multivariate analysis, Eastern Cooperative Oncology Group (ECOG) performance status (PS) score ≥1, progressive disease (PD) as best overall response (BOR), and TGR >0.60%/day were independent risk factors for poor OS in patients with R/M-SCCHN. CONCLUSION: Higher TGR, poor PS, and PD as BOR may be prognostic factors in patients with R/M SCCHN.