A liquid biopsy for head and neck cancers

ABSTRACT

Head and neck cancer patients often present with advanced metastatic disease resulting in a poor 5-year survival. Therefore, there is a need for non-invasive diagnostic tools that could complement conventional imaging to inform clinicians of patient outcomes and treatment responses. A liquid biopsy addresses this unmet clinical need; a simple peripheral blood draw could provide information about the disseminated disease in terms of circulating tumor cells and circulating tumor DNA. Moreover, detectable tumor DNA in the saliva of head and neck cancer patients could signify the early signs of the disease and present an opportunity for clinical intervention. This review provides an overview of the current literature with regard to the feasibility of such a test in the head and neck cancer field and highlights the need for such a test.

Keywords:

• Circulating tumor cells (CTCs)
• circulating tumor DNA (ctDNA)
• head and neck cancer (HNC)
• head and neck squamous cell carcinoma (HNSCC)
• human papillomavirus (HPV)

Key issues

• Head and neck cancers account for the sixth most common cancer globally.

• Early detection of head and neck cancer events allows for clinical interventions leading to better clinical outcomes and overall survival.

• Non-invasive biopsies through mediums such as saliva and peripheral blood are preferred to invasive tissue biopsies.

• Circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) are biomolecules which can be non-invasively sampled from head and neck cancer patients.

• CTCs can inform of patients at risk of developing metastasis before clinically/radiographically detectable metastasis form.

• ctDNA can be detected in early-stage patients in saliva and in the plasma of more advanced stage head and neck cancer patients.

• CTCs and ctDNA as biomarkers have the potential to complement conventional imaging platforms in head and neck cancer patients.

• Clinically, CTC detection allows for determining patients at risk of developing metastasis whereas ctDNA allows for determining minimal residual disease.

Acknowledgements

We thank Professor William B. Coman (School of Medicine, University of Queensland, Queensland, Australia) for his clinical input in this review and Dr Sarah-Jane Dawson (Molecular Biomarkers and Translational Genomics Laboratory and Department of Medical Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia) for editorial assistance.

Financial & competing interests disclosure

This study was supported by the Queensland Centre for Head and Neck Cancer funded by Atlantic Philanthropies, the Queensland Government, and the Princess Alexandra Hospital. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.