Determinants of Circulating Tumor HPV DNA in Surgically Treated Oropharyngeal Cancer

Abstract

Importance Circulating tumor DNA (ctDNA) is a biomarker of disease status in patients with human papillomavirus (HPV)–mediated oropharyngeal squamous cell carcinoma (OPSCC). Objective To assess clinicopathologic variables associated with circulating tumor human papillomavirus DNA (ctHPVDNA) before and after surgery. Design, Setting, and Participants The retrospective review and cohort study was conducted at a tertiary academic medical center and included patients with HPV-mediated OPSCC who were treated with upfront surgery between September 2021 and April 2025. Data were analyzed between September 2025 and December 2025. Exposures Clinicopathologic variables, including demographic characteristics, pathologic T and N stage, American Joint Committee on Cancer Staging Manual, 8th edition stage, tumor size, margin status, pathologic extranodal extension (pENE), and lymphovascular and perineural invasion. Main Outcomes and Measures Multivariable negative binomial regression was used to identify clinicopathologic factors associated with preoperative ctHPVDNA, which was measured using tumor tissue–modified viral HPV DNA. Factors associated with detectable postoperative ctHPVDNA were evaluated using logistic regression. Results A total of 104 patients (mean [SD] age, 59 [10] years; 20 female individuals [19%] and 84 male individuals [81%]; 3 Black individuals [3%] and 101 White individuals [97%]) with HPV-associated OPSCC who were treated with upfront surgery had preoperative ctHPVDNA measurements, and 74 patients had preoperative and postoperative assessments. The mean (SD) preoperative ctHPVDNA level was 2786 (9714) copies/mL. On multivariable negative binomial regression, higher estimated glomerular filtration rate (eGFR; rate ratio [RR], 1.05; 95% CI, 1.01-1.09) and higher pathologic N stage (RR, 12.30; 95% CI, 2.65-57.5) were independently associated with higher preoperative ctHPVDNA levels, whereas perineural invasion (PNI; RR, 0.23; 95% CI, 0.07-0.83) and pathologic extranodal extension (pENE; RR, 0.11; 95% CI, 0.04-0.28) were associated with lower levels. Detectable postoperative ctHPVDNA was observed in 15 of 74 patients (20.2%) and was associated with more than 4 positive lymph nodes (odds ratio [OR], 4.86; 95% CI, 1.39-19.49) higher preoperative ctHPVDNA levels (OR, 1.17; 95% CI, 1.04-1.36), PNI (OR, 2.95; 95% CI, 0.51- 15.51), and pENE (OR, 3.38; 95% CI, 0.84-13.29). Recurrence occurred for 3 of 15 patients (20.0%) with detectable postoperative ctHPVDNA compared with 8 of 59 patients (13.6%) with undetectable ctHPVDNA. Among patients with undetectable postoperative ctHPVDNA, 4 locoregional recurrences occurred in individuals who declined guideline-concordant adjuvant therapy. Conclusions and Relevance The results of this cohort study illuminate the biological and clinical factors associated with ctHPVDNA shedding and clearance, potentially offering guidance for integrating ctHPVDNA into biomarker-driven clinical trials.