Detecting HPV-Driven Oropharyngeal Carcinoma Recurrence Using Circulating Tumor HPV DNA

Monday, October 2, 2023

8:00 AM - 8:06 AM East Coast USA Time

Location: 201AB

Presenting Author(s)

Leyn B. Shakhtour, BS

Medical Student
George Washington University School of Medicine and Health Sciences
Washington, District of Columbia, United States

Co-Author(s)

Leyn B. Shakhtour, BS

Medical Student
George Washington University School of Medicine and Health Sciences
Washington, District of Columbia, United States
Timothy Brandon Shaver, MD

Resident
Department of Otolaryngology-Head and Neck Surgery, The George Washington University School of Medicine and Health Sciences
Capitol Heights, MD, United States
AP

Alisha R. Pershad, BS

Student
Department of Otolaryngology-Head and Neck Surgery, The George Washington University School of Medicine and Health Sciences
Silver Spring, MD, United States
Maxwell S. Madani, BA

Student Researcher
Department of Otolaryngology-Head and Neck Surgery, The George Washington University School of Medicine and Health Sciences
Clifton, VA, United States
fH

faysal Haroun, MD

Fellowship Program Director
Division of Hematology & Oncology, George Washington University Hospital
washington DC, DC, United States

Senior Author(s)

PT

Punam Thakkar, MD

Associate Professor
The George Washington University Medical Faculty Associates, Department of Otolaryngology
Washington, District of Columbia, USA

Disclosure(s):

Leyn B. Shakhtour, BS: No relevant relationships to disclose.

Introduction: Our institution utilizes neoadjuvant chemotherapy followed by transoral robotic surgery and neck dissection (NAC+S) as a novel de-escalated treatment strategy for selected patients with HPV-driven oropharyngeal squamous cell carcinoma (HPV OPC). As our approach has been shown to have non-inferior DFS and reduced treatment related morbidities, we aim to describe trends in persistent disease or recurrence using circulating tumor tissue modified viral (TTMV)-HPV DNA (ctHPVDNA) obtained during routine surveillance in this group of patients.

Methods: A retrospective review was performed to identify patients who were ≥ 3 months posttreatment with NAC+S for HPV OPC between May 1, 2008 and January 1, 2023. Included patients had a ctHPVDNA test (NavDx) obtained during posttreatment surveillance. Further analysis will be performed to quantify treatment response using ctHPVDNA collected during treatment.

Results: Eleven HPV OPC patients with a mean age of 62.2 years were included. All patients had stage III or IV disease per AJCC 7th Edition criteria; none had T4 or N3 disease. Posttreatment pathologic stages ranged from ypT0N0 (63.6%, n=7) to ypT1N1. Seven patients were tested for ctHPVDNA by 13 months posttreatment and three patients were tested at >6 years postreatment (all negative). ctHPVDNA was detected in three patients (all within 24 months of treatment), confirming PET/CT findings of recurrence in the first patient and prompting further evaluation in the rest. In the third patient, the positive ctHPVDNA detected a strain of HPV that was different from the original tumor sample strain. To date, 9 of the 11 patients are disease-free from HPV OPC, and those with persistent disease confirmed were salvaged with chemoradiation.

Conclusions: With the emergence of de-escalation treatment protocols for HPV OPC, ctHPVDNA tests have shown excellent correlation with pathologic downstaging achieved after NAC+S. While this subset of patients was clinically deemed to be free of disease based on favorable pathology, posttreatment PET/CT, and physical exam, the ctHPVDNA test is a useful tool in guiding therapy and surveillance.