The difficult “childhood era” of the liquid biopsy as a diagnostic method in head and neck cancer patients

<br><b<Aim:</b> Liquid biopsy (LB) is a method that detects circulating tumor cells or circulating tumor DNA or RNA in the body fluids of patients with cancer. Despite the developments in LB, it is still not used in clinical practice in head and neck cancers (HNC). The aim of our study was to analyze the epidemiological data of HNC patients and controls who were enrolled in an LB study based on circulating free DNA (cfDNA) detection.</br> <br><b>Material and methods:</b> A group of 152 patients diagnosed with HNC (128 men and 24 women) and 56 healthy volunteers (48 men and 8 women) were enrolled into the study. Peripheral blood samples were collected before treatment from HNC patients and controls. Plasma was isolated and cfDNA concentration was assessed in the range of 35–10,380 bp.</br> <br><b>Results:</b> The comparison of cfDNA concentration by gender between the HNC patients and the control group, and by comorbidities in the control group, showed no significant differences (p values: 0.13–0.69, 0.15–0.50 and 0.13–0.80, respectively).</br> <br><b>Conclusions:</b> Patients’ gender and general status were found to have no effect on cfDNA concentration. Further analysis is necessary to define other correlations and the possible application of LB in HNC diagnosis, follow-up, and treatment.</br>