Monitoring Circulating Cell-free HPV DNA in Metastatic and Recurrent Cervical Cancer: Clinical Importance and Implications for Treatment - A Pilot Study

Abstract Purpose Monitoring of circulating human papillomavirus (HPV) cell-free DNA (cfDNA) is a minimally invasive approach for surveillance in HPV-associated cancers, particularly cervical cancer. The aim of this study was to monitor circulating HPV cfDNA levels in patients with recurrent or metastatic cervical cancer during treatment and follow-up, assessing the utility of HPV cfDNA as a tumor marker for disease surveillance and in guiding clinical treatment decisions. Experimental Design In this prospective pilot observational study, levels of HPV cfDNA in serum samples from 28 patients with recurrent or metastatic HPV-positive cervical cancer were measured via digital droplet polymerase chain reaction. Results for HPV cfDNA levels were matched to clinical outcomes and to serum levels of squamous cell carcinoma antigen (SCC-Ag) to assess the clinical potential of HPV cfDNA as a tumor marker. Results HPV cfDNA was detected in all 28 patients (100% detection rate). Notably, median baseline HPV cfDNA levels varied according to the metastatic pattern observed in individual patients (P=0.019). Patients with a combined multi-metastatic pattern (lymph node + hematogenous ± diffuse serosal metastasis) exhibited a higher median baseline HPV cfDNA level compared to those with a single-metastasis pattern (local recurrence, lymph node metastasis, or hematogenous metastasis) (P = 0.003). All participants exhibited changes in HPV cfDNA levels over a median monitoring period of 2 months (range 0.3 to 16.9 months) prior to evaluations for treatment response or disease progression. Among 26 patients initially diagnosed with squamous cell cervical cancer, the positivity rate was 100% for HPV cfDNA and 69.2% for SCC-Ag (P = 0.004, 95% confidence interval, 0-0.391). Among 20 patients longitudinally monitored for squamous cell cervical cancer, the concordance with changes in disease status was 90% for HPV cfDNA and 50% for SCC-Ag (P = 0.014, 95% confidence interval, 0.022-0.621). Conclusions HPV cfDNA is a promising tumor marker for HPV-positive cervical cancer. In the context of precision medicine, HPV cfDNA is poised to play an increasingly pivotal role in monitoring treatment efficacy, providing valuable insights into disease progression, and guiding clinical decisions.