Pretreatment Liquid Biopsy and Clinicopathologic Features in HPV-Associated Oropharyngeal Squamous Cell Carcinoma

Abstract

Importance: Despite the favorable prognosis for HPV-positive oropharyngeal squamous cell carcinoma (HPV+ OPSCC), efforts to de-escalate treatment intensity, while maintaining low recurrence and mortality rates, have proven challenging. Identifying appropriate prognostic factors remains elusive; however, the association of pretreatment circulating tumor tissue viral-modified HPV (TTMV-HPV) DNA level with known characteristics of disease burden-clinical staging, characteristics of pretreatment imaging, and aggressive histopathologic features of surgical specimen-may offer insights that could shift treatment paradigms for HPV+ OPSCC.

Objective: To investigate the association of pretreatment TTMV-HPV DNA levels with clinical, radiologic, histopathologic, and outcome metrics in patients with HPV+ OPSCC.

Design, setting, and participants: This cohort study of patients with HPV+ OPSCC and positive test results for pretreatment TTMV-HPV DNA fragment levels used data from a single tertiary center from April 2020 to September 2023. TTMV-HPV DNA fragments levels were categorized into 3 cohorts: low (≤99 fragments/mL), moderate (100-999/mL), and high (≥1000/mL).

Main outcomes and measures: Association of clinical tumor (cT) and nodal (cN) staging with TTMV-HPV DNA fragment level. Secondary outcomes included the association between TTMV-HPV DNA fragment level and positive emission tomography-computed tomography (PET-CT) characteristics as well as histopathologic features of surgical specimen. The association of pretreatment fragment level with receiving adjuvant therapy for surgical patients was also analyzed. Recurrence-free survival and disease-specific survival were also assessed.

Results: The study population included 203 patients (mean [SD] age, 62 [10] years; 24 [12%] females and 179 males [88%]), 58 (29%) of whom were in the low, 73 (36%) in the moderate, and 72 (35%) in the high TTMV-HPV DNA fragment-level cohort. Compared to patients with cT0/1 stage, those with cT2 stage and cT3/4 stage had increased odds of higher TTMV-HPV DNA levels, with adjusted odds ratios (aORs) of 2.33 (95% CI, 1.24-4.46) and 2.51 (95% CI, 1.17-5.46), respectively. Compared to patients with cN0 stage, those with cN1 stage and cN2/3 stage also had increased odds of higher TTMV-HPV DNA levels, with aORs of 4.26 (95% CI, 1.82-10.34) and 3.64 (95% CI, 1.46-9.36), respectively. In adjusted analysis of pretreatment PET-CT characteristics, total primary tumor plus nodal volume was associated with higher TTMV-HPV DNA levels, with an aOR of 1.04 (95% CI, 1.02-1.07). Among 94 surgical patients, no significant association was found between pretreatment fragment level and lymphovascular invasion, perineural invasion, pathologic T stage, number of positive nodes, or extranodal extension on pathological analysis of surgical specimen. No significant differences in recurrence-free survival or disease-specific survival were found.

Conclusion and relevance: This cohort study found that higher pretreatment TTMV-HPV DNA fragment levels were associated with more advanced clinical staging and higher aggregate primary and cervical nodal volume on PET-CT results. Future studies are needed to explore how pretreatment fragment level may influence treatment decisions.