Circulating Tumor Cells in Head and Neck Cancer

Head and neck cancer is a broad term that encompasses epithelial malignancies originating from the paranasal sinuses, nasal cavity, oral cavity, pharynx, and larynx. The percentage of metastases is very high in both locoregional and distant areas. Prognosis refers to several factors: stage of disease; locoregional relapses; distant metastasis. The majority of patients are diagnosed with locoregional advanced disease and are treated in a multidisciplinary approach. Despite this, however, around 50% of these patients will present disease recurrence. In this scenario, the utilization of circulating tumor cells (CTCs) yields a great perspective. Numerous marker-independent techniques have been developed for CTC isolation and detection from head and neck cancer. In general, the microfiltration assays show higher detection rates, probably related to the separation by size of the CTCs, independently of antibodies. This chapter is a review of studies involving CTCs of head and neck cancer and exposes the potential impact of CTCs on the prognosis of patients, the main clinical trials, and methodologies involving the topic.