Oncological Outcomes after Pulmonary Metastasectomy for Head and Neck Squamous-Cell Carcinoma and Adenoid Cystic Carcinoma

Introduction: Pulmonary metastatic head and neck cancer has a poor prognosis. Pulmonary metastasectomy has been performed but only in carefully selected patients. The aim of this study was to examine the clinical characteristics and oncological follow-up of patients who underwent pulmonary metastasectomy. Methods: Data of 54 patients with squamous-cell carcinoma (SCC) or adenoid cystic carcinoma (ACC) who underwent metastasectomy between 2003 and 2019 at two tertiary referral centers were retrospectively reviewed. Results: The 3-year and 5-year disease-free survival rates after metastasectomy were 49.9% and 39.9% for SCC and 38.9% and 32.4% for ACC, respectively. Univariate analysis revealed that a disease-free interval (DFI) less than 14 months and R1 resection (hazard ratio [HR] [95% confidence interval]: 2.95 [0.77-5.62], 4.64 [0.99-21.65], respectively) were risk factors for recurrence in SCC and that a high T stage (HR: 5.24 [1.22-22.58]) was a risk factor in ACC. In SCC, a DFI less than 14 months and R1 resection (hazard ratio: 6.35 [1.36-29.54], 12.79 [1.53-106.95], respectively) were risk factors in a multivariate analysis. Conclusion: Pulmonary metastasectomy had a fair effect on head and neck SCC and ACC, and the prognosis was better in SCC patients with a DFI greater than 14 months.