Liquid biopsy in head neck cancer: ready for clinical routine diagnostics?

Abstract

Purpose of reviewThe bodily fluids of patients with solid cancers representing a minimally-invasive source of clinically exploitable biomarkers have attracted an increasing amount of attention in recent years. In patients with head and neck squamous cell carcinoma (HNSCC), cell-free tumour DNA (ctDNA) belongs to the most promising liquid biomarkers for monitoring disease burden and identifying patients at high risk of recurrence. In this review, we highlight recent studies, evaluating the analytical validity and clinical utility of ctDNA as a dynamic biomarker in HNSCC, especially as it relates to risk stratification and contrasting human papilloma virus (HPV+ and HPV-) and carcinomas.Recent findingsThe clinical potential of minimal residual disease monitoring through viral ctDNA in identifying HPV+ oropharyngeal carcinoma patients at higher risk of recurrence has recently been demonstrated. Furthermore, accumulating evidence supports a potential diagnostic value of ctDNA dynamics in HPV-negative HNSCC. Altogether, recent data suggest that ctDNA analysis may be a valuable tool in guiding (de)escalation of surgical interventions as well as adaptation in radiotherapy dosage, both in the definitive and adjuvant settings.SummaryRigorous clinical trials with patient-relevant endpoints are critical in order to demonstrate that treatment decisions based on ctDNA dynamics result in better outcomes in HNSCC.

Squamous Cell Carcinoma Antigen in the Follow‐up of Patients With Head and Neck Cancer

“…However, the precise clinical implications and accuracy of these several liquid tumor markers as well as for SCC-Ag in the context of HPV tumors remain unclear and warrant further investigation. 26,27 In the 9 patients with a false-negative SCC-Ag during follow-up, the SCC-Ag value was just beneath the cut-off value and was therefore considered not elevated. Besides, some of these patients did have an elevated SCC-Ag compared to the latest measurement but remained beneath the cutoff value and therefore considered as low SCC-Ag.…”

“…Multiple liquid markers have been identified for HPV‐associated tumors, such as circulating tumorDNA. However, the precise clinical implications and accuracy of these several liquid tumor markers as well as for SCC‐Ag in the context of HPV tumors remain unclear and warrant further investigation 26,27 …”