Prognostic Factors and a Polymetastasis-Free Survival Nomogram in Oligometastatic Head and Neck Squamous Cell Carcinoma Treated with Local Ablative Therapy

Abstract

Evidence supporting metastasis-directed local ablative therapy (LAT) in head and neck squamous cell carcinoma (HNSCC) with oligometastatic disease (OMD) is limited. We retrospectively reviewed 93 patients with HNSCC who developed OMD and received LAT to all metastatic sites between 2006 and 2025. Clinical variables, sarcopenia, nutritional status, and inflammatory indices were evaluated as potential predictors of overall survival (OS), progression-free survival (PFS), polymetastasis-free survival (PMFS), and polymetastatic conversion (PC). An exploratory prognostic nomogram for PMFS was developed to inform treatment decision-making. After a median follow-up of 28.2 months, the 3-year OS and PMFS rates were 67.2% and 51.7%, respectively. Local failure occurred in 9 patients, while disease progression was predominantly distant. An HPV-positive oropharyngeal primary tumor was associated with improved OS and PMFS, whereas non-lung metastatic sites were adverse prognostic factors for PFS, and having two or more metastases was adverse for PC. Lower serum albumin levels correlated with worse OS and PFS, and an increasing systemic immune-inflammation index (SII) showed borderline significance for OS and PMFS. A PMFS nomogram based on four clinical parameters achieved an optimism-corrected concordance index of 0.66. Long-term survival and high local control were observed in this selected cohort of HNSCC patients with OMD treated with LAT. Tumor type, metastatic site, tumor burden, and host nutritional and inflammatory indices were associated with survival and progression to PC.