cells Review Circulating Non-Coding RNAs in Head and Neck Cancer: Roles in Diagnosis, Prognosis, and Therapy Monitoring Araceli Diez-Fraile 1,†, Joke De Ceulaer 1,†, Charlotte Derpoorter 2,3,4, Christophe Spaas 1, Tom De Backer 1, Philippe Lamoral 1, Johan Abeloos 1,‡ and Tim Lammens 2,3,4,*,‡ 1 Division of Oral and Maxillofacial Surgery, Department of Surgery, AZ Sint-Jan Brugge-Oostende A.V., 8000 Bruges, Belgium;
[email protected] (A.D.-F.);
[email protected] (J.D.C.);
[email protected] (C.S.);
[email protected] (T.D.B.);
[email protected] (P.L.);
[email protected] (J.A.) 2 Department of Pediatric Hematology-Oncology and Stem Cell Transplantation, Ghent University Hospital, 9000 Ghent, Belgium;
[email protected] 3 Department of Internal Medicine and Pediatrics, Ghent University, 9000 Ghent, Belgium 4 Cancer Research Institute Ghent (C.R.I.G.), 9000 Ghent, Belgium * Correspondence:
[email protected]; Tel.: +32-9-332-2480 † Shared first authors. ‡ Shared senior authors. Abstract: Head and neck cancer (HNC), the seventh most common form of cancer worldwide, is a group of epithelial malignancies affecting sites in the upper aerodigestive tract. The 5-year overall survival for patients with HNC has stayed around 40–50% for decades, with mortality being attributable mainly to late diagnosis and recurrence. Recently, non-coding RNAs, including tRNA halves, YRNA fragments, microRNAs (miRNAs), and long non-coding RNAs (lncRNAs), have been identified in the blood and saliva of patients diagnosed with HNC. These observations have recently fueled the study of their potential use in early detection, diagnosis, and risk assessment.