Oligometastasis in Head and Neck Squamous Cell Carcinoma.

Up to 40% of patients who present with, or later develop, metastatic disease from head and neck squamous cell carcinoma have oligometastatic disease, defined as 5 or fewer sites of metastasis. Patients with limited number of metastases clearly have improved overall survival compared with those with more disseminated metastases, but the risk of, and factors associated with, true oligometastatic state in head and neck cancer are not yet known. Current standard of care for patients with metastatic disease is single agent or combination systemic therapy, but the data are accumulating on the role of both metastasis-directed local ablative therapy and locoregional radiation therapy to improve outcomes. Although surgical resection has been the treatment of choice to address oligometastasis historically, stereotactic ablative radiotherapy has become a viable and less invasive alternative option with encouraging retrospective data in head and neck cancers. Biomarkers to help identify the oligometastatic state and prospective studies to better elucidate the role of local therapies are urgently needed.