12P Exploring the prognostic value of circulating tumor HPV DNA in cervical cancer

Persistent infection with high-risk HPV is a known cause of cervical cancer. Minimal residual disease (MRD) is increasingly well recognized in guiding adjuvant therapy for colorectal and lung cancer, and exploring its role in cervical cancer is essential for improving patient outcomes. This study investigates the prognostic potential of circulating tumor HPV DNA (ctHPV-DNA) in monitoring treatment response and predicting recurrence in cervical cancer. The prospective, observational clinical study (NCT05602831) enrolled patients undergoing radical radiotherapy or surgery. Blood samples were collected for HPV digital droplet PCR (ddPCR) testing, targeting HPV16/18/33/52/58, at baseline, post-surgery, and the day after radical radiotherapy, at 1 and 3 months to assess HPV clearance in relation to treatment efficacy and prognosis. From August 2022 to March 2024, 43 patients were enrolled, with 27 completing sequential blood collections and 23 undergoing baseline tissue and ctHPV-DNA testing. Among the 23 patients, all are squamous cervical cancer, with a mean age of 55 years and 82.6% (19/23) at stage III. The majority (95.7%) received radical radiotherapy, with a 73.9% complete remission rate. Concordance between baseline ctHPV-DNA and tissue HPV testing was 100%. The 18 tissue-confirmed HPV-positive patients were analyzed for ctHPV-DNA dynamic surveillance: 13 HPV16+, 3 HPV58+, 1 HPV52+, and 1 HPV18+. A positive correlation existed between baseline tissue HPV copy number and ctHPV-DNA copy number (r=0.4718, p=0.0615). Notably, patients with stage IIIC had higher ctHPV-DNA copy numbers than those with IIIB. Post-radiation, 4 patients (22.22%) tested positive for ctHPV-DNA, with two experiencing relapse. Detailed case studies highlighted the prognostic value of ctHPV-DNA, with early detection of recurrence possible 105 days ahead of imaging and 90 days ahead of tumor marker SCC-Ag elevation. The study demonstrates a strong correlation between ctHPV-DNA and tissue HPV testing, positioning ctHPV-DNA as a valuable prognostic tool for cervical cancer. Future research with increased enrollment and extended follow-up period will further validate these promising results.