# Resolving Clinically Indeterminate Findings During Anal Cancer Surveillance with TTMV-HPV DNA

## TL;DR

TTMV-HPV DNA testing helps resolve unclear results in anal cancer follow-up, accurately identifying cancer recurrence and reducing the need for additional procedures.

## Contribution

TTMV-HPV DNA testing is shown to resolve 92% of clinically indeterminate findings with high accuracy and earlier detection of recurrence.

## Key findings

- TTMV-HPV DNA testing resolved 92% of clinically indeterminate findings during anal cancer surveillance.
- Positive TTMV-HPV DNA tests were the first indicator of recurrence in 73% of cases, with a median lead-time of 29 days.
- Negative TTMV-HPV DNA tests predicted cancer-free status in 90% of cases with indeterminate findings.

## Abstract

During post-treatment surveillance for anal squamous cell carcinoma (ASCC), clinical examination, anoscopy, and imaging frequently yield inconclusive findings that cannot be confidently classified as the presence or absence of disease. These clinically indeterminate findings (CIFs) delay care decisions and lead to additional procedures that carry financial, physical, and psychological burden. Circulating tumor tissue-modified viral (TTMV)-HPV DNA measured from plasma is accessible, repeatable, and independent of local post-treatment anatomic changes. In this multi-center retrospective cohort, TTMV-HPV DNA testing accurately resolved 92% of CIFs and positive tests often served as the earliest indicator of recurrence. These findings support the clinical utility of TTMV-HPV DNA to clarify indeterminate assessments post-treatment and help guide next steps in care.

Background/Objectives: Surveillance for anal squamous cell carcinoma (ASCC) recurrence relies on clinical examination and imaging. Post-treatment edema, fibrosis, and inflammation can result in clinically indeterminate findings (CIFs) that delay diagnosis and increase patient and system burden. Circulating tumor tissue-modified viral (TTMV)-HPV DNA offers a biologically specific, noninvasive biomarker that may clarify equivocal assessments. Methods: In this multi-center retrospective study, 233 patients with HPV-associated ASCC were evaluated, including 185 with ≥1 post-treatment TTMV-HPV DNA test. CIFs were defined as exams or imaging results not definitively positive or negative for disease, and were paired with subsequent TTMV-HPV DNA tests. Concordance was defined by prespecified follow-up windows comparing TTMV-HPV DNA results with subsequent clinical outcomes. Results: Ninety patients (39%) experienced 214 CIFs, arising from exams (46%, 98) or imaging (54%, 116). Indeterminate rates by assessment were 7% for exams, 17% for imaging, and 1.3% for TTMV-HPV DNA testing. Overall, 52 CIF/TTMV-HPV DNA pairs were eligible for analysis, and TTMV-HPV DNA resolved disease status accurately for 48/52 (92%, 95% CI: 81.5–97.9). Negative tests predicted cancer-free status for 37/41 CIFs (90%), while 100% of positive tests (11/11) were concordant with clinically confirmed recurrence. In 73% of positive cases (8/11), TTMV-HPV DNA was the first indication of recurrence (median lead-time 29 days; IQR 25–147). Conclusions: TTMV-HPV DNA testing reliably clarifies clinically indeterminate findings during ASCC surveillance, demonstrating high accuracy (92%) and earlier detection of recurrence. These data support integration into post-treatment management to reduce diagnostic uncertainty and guide timely care.