Survival and prognostic factors after pulmonary metastasectomy of head and neck cancer: what are the clinically informative prognostic indicators?

OBJECTIVES: The purpose of this study was to elucidate the surgical outcomes and identify the prognostic factors after pulmonary metastasectomy for head and neck cancer (HNC) using a recent, large, single-institutional cohort. METHODS: We retrospectively reviewed the clinicopathological profiles of 77 consecutive patients who underwent metastasectomy for pulmonary metastases (PMs) arising due to HNC from 1992 to 2013. The prognostic factors associated with overall survival (OS) after pulmonary metastasectomy were evaluated using the univariable and multivariable Cox proportional hazard models. The cut-off value of continuous variables was determined by a receiver operating characteristic analysis. RESULTS: The most predominant histology was squamous cell carcinoma (75%). The median disease-free interval between the treatment of primary HNC and the diagnosis of PMs was 17 months. Recurrence before lung metastasectomy was observed in 32% of patients. The median size of the PM was 2.2 cm. The median survival time after lung metastasectomy was 66 months, and the 5-year OS was 54%. In the multivariable analysis, squamous cell histology [hazard ratio (HR) 2.92, 95% confidence interval (Cl) 1.00-8.57], disease-free interval (<18 months, HR 3.23, 95% CI 1.49-7.02) recurrence before lung metastasis (HR 2.39, 95% CI 1.19-4.80) and size of the PM (>2.5 cm, HR 2.75, 95% CI 1.33-5.69) were independent predictors of a poor prognosis. The OS of patients with 3 or more factors was significantly worse than that of patients with 2 or less factors (3-year OS 20% vs 83%, P < 0.01). CONCLUSIONS: Surgical resection of PMs from HNC can achieve favourable survival in a selected population. The number of prognostic factors may be useful information for determining the surgical indications and for predicting survival for PMs from HNC.