Stereotactic body radiotherapy for lung-only oligometastatic head and neck squamous cell carcinoma: Long-term clinical outcome and favorable predictive factors

Abstract

Background

Oligometastatic disease in head and neck squamous cell carcinoma (HNSCC) is a rare setting. Local ablative therapies are the most adopted strategies although no evidence-based recommendations are currently published. We report on long-term clinical outcomes of a cohort of HNSCC patients treated with stereotactic body radiotherapy (SBRT) for lung-only oligometastatic disease. Material and Methods: Eligible patients had 1–5 lung metastases. The oligometastatic pattern was classified as “de novo” or “induced oligoprogressive”. We evaluated time to progression (TTP) as the time from the last day of SBRT to disease progression or death from any cause. Predictive factors of better clinical outcome and survival analysis were performed. Results: A cohort of 50 patients (52 metastases) was retrospectively evaluated. The median age was 68 years and 45 patients had an ECOG PS 0–1. Oropharynx cancer was the primary tumor subsite in 20 patients and HPV positive status was reported in 13 patients. “De novo” oligometastatic pattern was observed for the majority of patients. After a median follow up of 24,5 months, median TTP and overall survival (OS) from the end of SBRT were 17 months and 46 months, respectively. The 2-years LC rates was 86 %. At univariate analysis, patients aged > 70 years reported a better TTP (0.03). Conclusion: Our findings suggested that SBRT may improve clinical outcome prolonging time to progression in a properly selected cohort of HNSCC patients with lung-only oligometastatic disease. Distant metastases from HPV-related primary HNSCC should be tested for p16/HPV status.