Discussion
Our data indicate that sDNA could aid in the monitoring of patients' follow-up as low-frequency somatic mutations could be assessed from the saliva of HNSCC patients. Prospectively, these results suggest that salivary-based liquid biopsy might pave the way for personalized molecular therapies based on mutational data.
Methods
Our cohort included 17 patients diagnosed with HNSCC over 4 years. The first saliva sample was collected before surgery while the rest were collected during the subsequent visits, according to the follow-up schedule. Salivary DNA (sDNA) was extracted, and a 52-gene next generation sequencing (NGS)-based panel was used for somatic variants detection.
Results
41.2% of samples collected before surgery bore a deleterious variant (n=7/17). Overall, 29.2% of samples harbored at least a pathogenic variant (n=21/72). The most frequently mutated genes were TP53 (80%), FBXW7 (8%), PDGFRA (4%) and PTEN (4%). Finally, three patients experienced a loco-regional relapse by clinical evaluations, anticipated in 67% of cases by the molecular one (n=2/3).