Abstract 3672: Development of liquid biopsy HPV (Human Papilloma Virus) cell free DNA (cfDNA) based approach for prognosis of cervical cancer
Authors: Dagar Gunjan , Gupta Ashna , Chauhan Ravi , Shankar Abhishek , Sharma Daya Nand , Macha Muzafar A. , Bhat Ajaz A. , Goyal Rajeev , Suri Vaishali , Singh Mayank 
Published: March 2024

Abstract
Introduction: Recent progress in the analysis of blood samples for circulating tumor cells or cell-free circulating tumor DNA (ctDNA) has shown that liquid biopsies may have potential applications in the detection and monitoring of cancer. Human papillomavirus (HPV) circulating cell-free (ccf) DNA may act as a unique marker for the prognosis of high-risk HPV-related cancers. However, detection of circulating markers for cervical cancer (CC) requires extremely sensitive techniques that can measure circulating human papillomavirus DNA. Here, we used the sensitive droplet digital PCR (dd PCR) based approach for the detection and quantification of circulating human papillomavirus DNA in plasma from patients diagnosed with cervical cancer at baseline and subsequent follow up with intention of validating its utility as a prognostic marker in CC.
Method: Blood sera form 34 Patients diagnosed with cervical cancer (Stage 1-1V) at AIIMS Delhi was collected at baseline and after 3 months of the treatment. 10 healthy controls were also recruited in the study after due approval from AIIMS IEC. Plasma samples were stored at -80°C. ccf DNA was isolated from 1 ml of plasma and further processed to detect the presence of circulating high risk Human papilloma virus (HPV) i.e., HPV-16 and HPV18 cf DNA using dd PCR.
Result: The median cf DNA concentration was 9.3 ng/uL (range 3-26.6) for all patients while median cf DNA concentration was 7.2 ng/uL (Range 3-57.3) for healthy controls (n=10). Furthermore, the levels of cfDNA decreases post 3 months of treatment with average concentration of 8.07 ng/uL (Range 4.6-19.3). We further processed our samples for dd PCR based screening to detect low copy no HPV cf DNA and ddPCR detection yielded a positive rate of 51% (18/35) for circulating HPV18 DNA while a positivity of 88.5% (31/35) was seen for the circulating HPV16 DNA in the sera of CC patients. By comparing HPV16 and HPV18 genotypes, we observed detection of circulating HPV 16 DNA more frequently than circulating HPV18 DNA in CC patients coming at our center. Furthermore, we found that copies of circulating viral DNA (HPV18 and HPV16) decreased post induction therapy in CC patients indicating progression ability of thid marker.
Conclusion: In the current studies we provide evidence that cell free DNA concentration in CC patient can predict tumor burden and detection of low copy no of
circulating HPV DNA could be a promising indicator for prognosis in cervical cancer patients and can predict recurrence of the disease.
Citation Format: Gunjan Dagar, Ashna Gupta, Ravi Chauhan, Abhishek Shankar, Daya Nand Sharma, Muzafar A. Macha, Ajaz A. Bhat, Rajeev Goyal, Vaishali Suri, Mayank Singh. Development of liquid biopsy HPV (Human Papilloma Virus) cell free DNA (cfDNA) based approach for prognosis of cervical cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3672.