Introduction/Background Cervical cancer (CC) is the 4th most commonly diagnosed cancer among women, leading to approximately 528,000 new cases annually. Current screening approaches for this disease have certain limitations; Pap tests require dedicated cytopathology infrastructure, while human papillomavirus (HPV) DNA testing may lead to invasive procedures in patients with transient infection. Liquid biopsy has emerged as a minimally invasive approach to detect and monitor disease. We and others have previously demonstrated the clinical utility of circulating tumor (ct)DNA to monitor HPV+ cancers. However, little is known about the presence of ctDNA from different liquid biopsy analytes in CC patients.

Methodology The aim of this study was to compare the presence of HPV-ctDNA isolated from different liquid biopsy analytes in patients with CC and cervical dysplasia (CD). Blood, urine, and vaginal swabs were collected from 23 patients with CC (adenocarcinoma or squamous cell carcinoma) and 22 patients with CD at the McGill University Health Centre. Of these patients, longitudinal samples pre- and post-treatment were collected in 7 patients. DNA was extracted using a commercial kit and tested for ctDNA by digital droplet PCR for HPV16, 18 and 33.

Results HPV16, 18 or 33 ctDNA was found to be detectable 14/23 (60%) CC samples and 2/22 (9%) CD patients in plasma, urine, and/or vaginal swab. Concordance in ctDNA positivity across sample types was seen in 90% of cases. Major reductions (97.7–100%) were seen in ctDNA concentrations in all analytes in CC patients following treatment.

Conclusion HPV-DNA was detectable in all liquid biopsy analytes sampled in patients with CC and CD, with a higher frequency of detection in CC samples. Treatment led to reductions in ctDNA across analytes in cancer patients. Globally, this data points to HPV ctDNA analysis as a promising method for detecting and monitoring HPV-related CC and CD.

Disclosures The authors have no disclosures