The role of liquid biopsy in management of the neck with indeterminate response on post-treatment imaging following non-surgical management of oropharyngeal cancer

• Published in: European journal of surgical oncology Vol. 49; no. 1; pp. 55 - 59
• Main Authors: Li, Lucy Q., Adamowicz, Martyna, Wescott, Robert A., Warlow, Sophie J., Thomson, John P., Robert, Christelle, Carey, Lara M., Thain, Helen, Cuschieri, Kate, Conn, Brendan, Hay, Ashley, Aitman, Timothy J., Nixon, Iain J.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.01.2023
• Subjects: Carcinoma, Squamous Cell - diagnostic imaging; Carcinoma, Squamous Cell - pathology; Carcinoma, Squamous Cell - therapy; Cell-free DNA; Cell-Free Nucleic Acids; Droplet digital PCR; Head and Neck Neoplasms - diagnostic imaging; Head and Neck Neoplasms - therapy; Human papillomavirus; Humans; Liquid Biopsy; Neoplasm Recurrence, Local - pathology; Oropharyngeal Neoplasms - diagnostic imaging; Oropharyngeal Neoplasms - pathology; Oropharyngeal Neoplasms - therapy; Oropharyngeal squamous cell carcinoma; Papillomavirus Infections - complications; Squamous Cell Carcinoma of Head and Neck - diagnostic imaging; Squamous Cell Carcinoma of Head and Neck - therapy; Oropharyngeal squamous cell carcinoma; Cell-free DNA; Liquid biopsy; Human papillomavirus; Droplet digital PCR
• ISSN: 0748-7983; 1532-2157
• DOI: 10.1016/j.ejso.2022.09.016

This study aimed to determine if post-treatment HPV cell-free DNA (cfDNA) can assist in the decision-making process for salvage neck dissection in patients following non-surgical treatment of oropharyngeal squamous cell carcinoma (OPSCC) with a partial response in the neck on imaging at 12 weeks post-treatment. 86 patients who completed treatment were prospectively recruited through the regional multidisciplinary team (MDT). Treatment response was categorised as complete response (CR), partial response (PR) or progressive disease on 12-week post-treatment imaging. Pre- and post-treatment blood samples were assessed for HPV cfDNA through droplet digital PCR (ddPCR). Eight patients had an isolated partial response in the neck. One (12.5%) had detectable HPV cfDNA (22.96 copies/ml) at ∼12 weeks post-treatment with positive disease on subsequent neck dissection (positive predictive value; PPV = 100%). Of the seven patients with undetectable HPV cfDNA, two patients had evidence of regional disease recurrence at 23.9 and 27.4 months respectively (negative predictive value; NPV = 71%). The detection of HPV cfDNA may help target salvage therapy in patients with a partial response in the neck. Follow-up studies in larger cohorts would be required to further validate the use of post-treatment HPV cfDNA in the management of OPSCC. •A partial response in the neck post OPSCC treatment represents a significant management challenge•HPV cell-free DNA (cfDNA) is a promising biomarker of disease recurrence in HPV + ve cancers•HPV cfDNA detection may help target salvage therapy in this group of patients