Prognostic Value and Clinical Implication of Lymph Node-to-Primary Tumor SUV Ratio in Node-Positive Hypopharyngeal Squamous Cell Carcinoma Treated With Radiotherapy With or Without Chemotherapy.

Purpose: The aim of this was to evaluate the prognostic significance of the nodal-to-primary tumor SUV max ratio (NTR) in patients with node-positive hypopharyngeal squamous cell carcinoma (HPSCC) treated with radiotherapy with or without concurrent chemotherapy. The study aims to enhance prognostic accuracy by incorporating NTR into the American Joint Committee on Cancer (AJCC) staging system.

Patients and methods: This retrospective study included 191 patients with biopsy-proven node-positive HPSCC treated from 2005 to 2013. NTR was calculated as the ratio of SUV max of metastatic lymph nodes to the primary tumor's SUV max . Survival analyses were conducted using Cox regression models and Kaplan-Meier analysis. Receiver operating characteristic analysis compared the prognostic performance of the modified and AJCC staging systems.

Results: The median follow-up was 8.27 years, with 135 deaths (70.7%). High NTR (≥0.63) was significantly associated with worse overall survival (OS) and was an independent prognostic factor in multivariable analysis (adjusted hazards ratio [HR] = 1.63, P = 0.007). Median OS for high NTR was 17.4 months, compared with 75.2 months for low NTR. High NTR significantly predicted worse OS within AJCC stage IVA patients (HR = 6.09, P = 0.014). Patients in modified stage IVA (AJCC stage IVA with low NTR) had significantly longer OS than those in modified stage IVB (AJCC stage IVA with high NTR and AJCC stage IVB) (HR = 8.62, P = 0.003). The modified staging system incorporating NTR showed superior prognostic performance compared with the AJCC staging system.

Conclusions: NTR is a significant independent prognostic factor for OS in node-positive HPSCC patients. Integrating NTR into the AJCC staging system improves prognostic accuracy.