Postoperative ctHPVDNA Kinetics in Patients With HPV-Related Oropharyngeal Cancer.

Importance: Circulating tumor human papillomavirus DNA (ctHPVDNA) is an important biomarker for the presence of HPV-associated oropharyngeal squamous cell carcinoma (OPSCC), but little is known about early postoperative kinetics of ctHPVDNA clearance.

Objective: To investigate early postoperative kinetics of ctHPVDNA in patients with HPV-associated OPSCC.

Design, setting, and participants: This prospective cohort study was conducted at a single tertiary care center from January 4, 2020, to January 26, 2023. Patients with newly diagnosed HPV-associated OPSCC undergoing surgical management were enrolled. HPV status was defined as positive if findings of p16 immunohistochemistry and/or HPV DNA in situ hybridization and/or E6/E7 RNA in situ hybridization were positive. Exclusion criteria included history of prior head and neck cancer and metastatic disease at presentation. Data were analyzed from September 1, 2024, to April 25, 2025.

Exposures: Transoral robotic surgery with concurrent neck dissection.

Main outcomes and measures: Blood was drawn prior to surgery (pretreatment), 1 to 2 days after surgery (postoperative days 1 to 2), and approximately 2 weeks after surgery (postoperative week 2; range, 8 to 20 days). ctHPVDNA was quantified by a tumor tissue-modified viral (TTMV) HPV DNA test. Correlations were tested between the pretreatment and postoperative day 1 to 2 TTMV HPV DNA levels using Gaussian regression. Concordance between detectability at postoperative day 1 to 2 and postoperative week 2 was explored using negative predictive value and positive predictive value.

Results: Of 57 included patients with detectable pretreatment TTMV HPV DNA, 51 (89%) were male, and the median (IQR) age was 59 (54-66) years. A total of 35 patients (61%) had blood draws at all 3 time points; 16 (28%) had detectable TTMV HPV DNA on postoperative day 1 to 2. Pretreatment and postoperative day 1 to 2 TTMV HPV DNA levels had a medium positive linear correlation (r = 0.31; 95% CI, 0.04-0.54). Undetectable TTMV HPV DNA on postoperative day 1 to 2 blood draw had a negative predictive value of 0.95 (95% CI, 0.74-1.00) for an undetectable level on postoperative week 2 blood draw, but a detectable level on postoperative day 1 to 2 blood draw only had a positive predictive value of 0.19 (95% CI, 0.04-0.46). Of the 16 patients with detectable TTMV HPV DNA pretreatment and at postoperative day 1 to 2, only 3 (19%) continued to have detectable TTMV HPV DNA at postoperative week 2. One patient had undetectable levels at postoperative day 1 to 2 and detectable levels at postoperative week 2.

Conclusions and relevance: In this study, ctHPVDNA detectability early after surgery did not predict detectability at 2 weeks after surgery. ctHPVDNA clearance early after surgery could predict a negative test at 2 weeks. A negative blood draw finding on postoperative day 1 may be used to omit a postoperative blood draw at 2 weeks for minimal residual disease detection in future clinical trials.