Circulating tumour DNA as a complementary tool for treatment evaluation
in HPV-associated Head and neck squamous cell carcinoma: An
observational cohort study
Abstract
Objectives HPV-positive Oropharyngeal squamous cell carcinoma (OPSCC)
and Head and neck carcinoma of unknown primary (HNCUP) is increasing.
Despite good prognosis, recurrence rates range from 10- to 25%.
Surveillance with clinical controls and imaging are not always reliable.
Circulating tumour human papillomavirus DNA (ctHPV-DNA) has emerged as a
potential biomarker for treatment evaluation and detection of
recurrence. We aimed to investigate the correlation between ctHPV-DNA in
HPV+ OPSCC/HNCUP and radiologic tumour burden. Additionally, we sought
to assess whether ctHPV-DNA could serve as a tool in treatment
evaluation. Design A prospective observational cohort study. Setting
This multicenter study involved three otolaryngology units located in
central Sweden. We utilised HPV genotype-specific assays for droplet
digital PCR (ddPCR) to detect ctHPV-DNA in plasma at diagnosis and
follow-up. ctHPV-DNA levels were correlated to radiological tumour
burden and radiological response using Kendall Rank correlation
coefficient and Kruskal Wallis test. Participants Patients with HPV+
OPSCC/HNCUP undergoing definitive (chemo)radiotherapy. Results Out of 54
patients, 51 were eligible for analyses. At baseline, ctHPV-DNA was
detectable in 88%. The majority of patients with a favourable
radiological evaluation according to RECIST, had a corresponding
undetectable ctHPV-DNA at follow-up. The levels of ctHPV-DNA at baseline
correlated with Total Tumour Volume and Nodal Volume (r τ = 0.39,
p<0.01, respectively r τ =0.26, p<0.01).
Conclusion ctHPV-DNA shows correlation with tumour burden. This study
strengthens the role of ctHPV-DNA as a promising biomarker for
diagnosing and monitoring HPV-related OPC/HNCUP. With further research
on serial plasma sampling, ctHPV-DNA could complement radiological
treatment evaluation in HPV+ OPSCC/HNCUP.