Jabalee, James

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.

Background: The incidence and mortality of anal squamous cell carcinoma (ASCC) are rising, with greater than 80% of cases linked to human papillomavirus (HPV), primarily HPV16. Post-treatment surveillance can be challenging due to the limitations of anoscopy, digital anal rectal exam (DARE), and imaging. Plasma tumor tissue modified viral (TTMV)-HPV DNA has shown strong sensitivity, specificity, and predictive value in detecting the recurrence of HPV-driven oropharyngeal cancer. Here, we investigate the ability of TTMV-HPV DNA for the early recurrence detection of ASCC. Methods: This retrospective clinical case series included 117 patients with HPV-driven ASCC across 7 U.S. centers, monitored with TTMV-HPV DNA during routine clinical care between March 2020 and June 2024. Physician-reported clinical data and biomarker testing data were combined to create a comprehensive, longitudinal dataset for evaluating test performance metrics. Results: Patients had a median age of 63 years and median post-diagnosis follow-up of 19 months. HPV status was primarily confirmed by TTMV-HPV DNA (52%) or p16 immunohistochemistry (39%). Of those tested for TTMV-HPV DNA pretreatment, 85% had a positive result. TTMV-HPV DNA clearance during or within three months post-treatment was associated with significantly better recurrence-free survival. The per-patient surveillance sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 82.8%, 98.4%, 96.0%, and 92.5%. Of 24 patients with a documented recurrence and a positive TTMV-HPV DNA test, the test was the first evidence of recurrence in 14 patients (58.3%), with a median lead time of 59 days (range: 10–536). TTMV-HPV DNA accurately resolved 94.3% of cases with indeterminate clinical findings. Conclusions: TTMV-HPV DNA testing provides a sensitive and specific approach for detecting patients with recurrent ASCC and resolving the status of patients with indeterminate clinical findings.

Abstract Purpose: Squamous cell carcinoma of the anus (SCCA) is primarily driven by human papillomavirus (HPV) infection. Up to 30% of patients experience recurrence, necessitating improved surveillance strategies. Liquid biopsies have shown promise as a tool in oncology. This study investigates the clinical performance of circulating tumor tissue modified viral (TTMV)- HPV DNA in the post-treatment surveillance of SCCA. Patients and methods: This central IRB-approved retrospective cohort study included 117 patients diagnosed with HPV-driven SCCA from seven U.S. centers who had ≥1 TTMV-HPV DNA tests (NavDx®, Naveris, Inc., Waltham, MA) performed between March 2020 and June 2024. TTMV-HPV DNA for HPV subtypes 16, 18, 31, 33, and 35 were analyzed using droplet digital PCR. The diagnostic accuracy of TTMV-HPV DNA was evaluated by comparing test results with clinical evidence of SCCA recurrence determined through anoscopy, radiology, and/or tissue biopsy. Recurrence is defined as either a positive biopsy or subsequent salvage therapy. Results: Patients were primarily female (73%) with a median age 63 years. Median follow-up after initial treatment was 19 months. Forty-seven patients (40%) had pretreatment TTMV-HPV DNA testing, with a baseline detectability of 85.1% (40/47, 95% CI: 74.9–95.3). Of these, 24 were re-tested within 3 months post-treatment and 18 had undetectable TTMV-HPV DNA (75%). Those patients whose scores became undetectable had significantly longer recurrence-free survival than those whose scores remained detectable (log-rank test, p=0.01). One hundred and four patients (89%) underwent post-treatment testing, of which 91 provided relevant data for the analysis. Of these 91 patients, 27 (29.7%) experienced recurrence. Post-treatment testing demonstrated a per- patient sensitivity of 85.7% (24/28, 95% CI: 72.8-98.7). Of four patients with a false negative test, only one had biopsy-confirmed recurrence, whereas the remaining recurrences were not biopsied prior to starting salvage treatment. The positive predictive value of a single positive test was 97.6% (40/41; 95% CI: 92.8–100.0). One patient remains in active follow-up. Of the true positive post-treatment tests, 58% (14/24) predicted recurrence before clinical detection, with a median lead time of 59 days (range: 10–536). There were 141 negative post-treatment tests across 66 patients. This yielded a per-test specificity and negative predictive value of 99.3% (136/137, 95% CI: 97.8-100.0) and 97.2% (136/140, 95% CI: 94.9-99.9), respectively. Indeterminate TTMV-HPV DNA tests were rare (5/268,1.9%). However, clinically indeterminate findings (CIFs) were common, with 141 post-treatment CIFs identified across 52/117 patients (44.4%). TTMV-HPV DNA testing was able to correctly predict recurrence status in 94.3% of CIF cases. Conclusion: TTMV-HPV DNA testing is a sensitive and specific surveillance method for detecting early recurrence of HPV-driven SCCA. Citation Format: Shane Lloyd, Rafi Kabarriti, James Jabalee, Tyler Slater, Corbin Jacobs, Sean Inocencio, Michael Rutenberg, Chance Matthiesen, Kasha Neff, Gene-Fu F Liu, Tiffany M Juarez, Catherine DV Fitz, Stanley Liauw. Plasma-based circulating tumor tissue modified viral (TTMV)-HPV DNA for detection of recurrent HPV-driven anal cancer [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr B018.