Liquid Biopsy of Head and Neck Cancer Patients in Blood and Saliva

Clinical examination including imaging and - if necessary - tissue biopsy sampling - is the current clinical standard in therapy monitoring of metastatic head and neck tumors. This includes both the initial diagnosis, the assessment of the therapeutic response during ongoing chemotherapy / radiochemotherapy and follow-up care with the aim of detecting recurrences at an early stage. The detection of circulating nucleic acids as well as proteins in the peripheral blood and saliva could represent a minimally invasive and exact method for the assessment of the tumor burden, for the early detection of recurrences and for the individual assessment of the therapy response in patients with head and neck cancer. The present study aims to evaluate the value of tumor-specific nucleic acids and proteins in peripheral blood and saliva as possible biomarkers for minimally invasive therapy monitoring of head and neck tumors. For this purpose, Next Generation Sequencing (NGS), ELISA and quantitative polymerase chain reaction (PCR) methods are used as diagnostic methods. NGS initially enables the creation of a genetic profile of the primary tumor with targeted massive parallel sequencing of frequently mutated genes in head and neck tumors. The amount of nucleic acids in the peripheral blood and saliva is then quantified by means of digital PCR with the aid of specifically designed digital PCR assays. In addition, tumor-associated nucleic acids and proteins in the primary tumor, blood and saliva are examined. The aim is to examine if the amount of tumor specific circulating nucleic acids and the concentration of protein biomarkers found in the blood and saliva are associated with the response to treatment, early detection of recurrence, and the overall prognosis.