Dynamic Assessment of ctDNA in Patients With Cervical and Anal Canal Tumors to Optimize Follow-up and Clinical Outcomes in the Brazilian Unified Health System (SUS)

What this Trial Is About

Researchers are investigating the use of a blood test called circulating tumor DNA (ctDNA) to improve follow-up and treatment for patients with cervical and anal canal cancers related to human papillomavirus (HPV). These cancers often show persistent or recurring disease after radiotherapy, making current imaging methods for monitoring less effective, costly, and invasive. This study aims to develop a low-cost ctDNA test suitable for Brazil's public health system and assess its accuracy in detecting residual or recurrent disease. The study includes several phases: selecting patients diagnosed with cervical or anal canal cancer who will undergo radiotherapy with or without chemotherapy; developing and validating the ctDNA HPV test; monitoring ctDNA levels through blood samples over time; and offering additional immunotherapy with pembrolizumab to patients who have positive ctDNA after standard treatment. Immunotherapy will be given intravenously for up to 12 months or until disease progression or unacceptable side effects occur. Participants will have blood samples collected during treatment and follow-up to track ctDNA levels and compare results with traditional imaging. Those with positive ctDNA after treatment will be closely monitored and may receive immunotherapy. The study will also evaluate long-term outcomes such as survival and quality of life. All patients will be followed for at least two years to assess the effectiveness of ctDNA monitoring and treatment strategies.

Dynamic ctDNA Assessment in Cervical and Anal Canal Tumors: Optimizing Follow-up and Clinical Outcomes