Liquid Biopsies in Head and Neck Cancer: Current State and Future Challenges

SIMPLE SUMMARY: This review covers the most recent and up-to-date literature on liquid biopsy techniques in head and neck cancer. Head and neck cancer remains a common, difficult to treat and deadly type of disease. Part of the challenge in treating head and neck cancer lies in identifying disease at its early stages, determining responses to treatment and managing any recurrent disease. Liquid biopsies are the sampling of body fluids to determine markers that can indicate the presence of cancer. These technologies have immense potential in helping improve treatment for head and neck cancers. In this review, we discuss the current state of liquid biopsies for head and neck cancer, as well as limitations and challenges the field must overcome to advance our research in this area. ABSTRACT: Head and neck cancers are the seventh most frequent malignancy worldwide, consisting of a heterogeneous group of cancers that develop in the oral cavity, pharynx, and larynx, with head and neck squamous cell carcinoma (HNSCC) being the most common pathology. Due to limitations with screening and physical examination, HNSCC often presents in advanced disease states and is thus associated with poor survival. In this setting, liquid biopsies, or obtaining patient bodily fluid samples for cancer diagnosis and prognosis, may play a dramatic role in optimizing care for HNSCC patients. In recent years, there have been dramatic advancements in investigations focused on optimizing and implementing liquid biopsies in general, and specifically for HNSCC patients. Moving forward, there remain significant challenges in liquid biopsy technological development, as well as opportunities for the development of HNSCC liquid biopsy clinical trials and treatment paradigms. In this review, we discuss the current state of liquid biopsy technologies via circulating tumor cells, circulating tumor DNA and exosomes, approaches in head and neck cancer, challenges to optimization and application of liquid biopsies for clinical study, and future prospects for this field of research as it applies to head and neck cancer.