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

Summary

After definitive radiotherapy (RT) treatment (with or without chemotherapy), cervical and anal canal neoplasms frequently exhibit disease persistence or recurrence. Due to the local inflammatory process post-treatment, response assessment by imaging (current gold standard) is limited, often necessitating multiple follow-ups and repeated invasive biopsies. Conventional follow-up is complex and costly, requiring equipment from secondary and tertiary services, trained radiologists, and patient exposure to radiation and contrast. In this context of human papillomavirus(HPV)-related neoplasms, recent studies have demonstrated the role of ctDNA (circulating tumor DNA) in assessing the risk of recurrence or disease progression, providing a rationale for using the tool in two fronts: * Optimizing follow-up based on serial monitoring of ctDNA; * Selecting patients with positive ctDNA after RT, who are at high risk of recurrence, for treatment intensification. Monitoring with ctDNA as a standalone follow-up tool in cases evolving with negative ctDNA after RT has the potential to replace imaging exams, being a minimally invasive test performed on a peripheral blood sample. Currently, ctDNA testing has expensive methodologies not available in the Unified Health System (SUS). This project aims to develop a methodology for ctDNA evaluation focused on HPV ctDNA research that is low-cost and executable in SUS, as well to assess the accuracy of this test in the population with HPV-related tumors. Additionally, we will evaluate whether the early introduction of immunotherapy in patients with positive ctDNA after definitive treatment can increase cure rates. Immunotherapy already has a well-defined role in the treatment of metastatic HPV-related neoplasms. Recently, the use of anti-programmed death-1 (anti-PD1) has also shown benefits in patients with locally advanced cervical cancer with a high risk of recurrence who are candidates for chemoradiotherapy (CRT). Therefore, its use focused on HPV-related tumors, as well as a better understanding of which patients benefit from this strategy, warrants further investigation.

Eligibility

Inclusion Criteria:

1. Histological diagnosis of anal canal or cervical cancer.
2. Documented presence of HPV.
3. Locally confined or locally advanced disease, defined as:

   1. Anal canal carcinoma stage I to III, according to American Joint Committee on Cancer (AJCC) 8th edition;
   2. Cervical carcinoma stage I B2 to IV A, according to AJCC 8th edition.
4. Indication for definitive treatment with radiotherapy, with or without concomitant chemotherapy.
5. Eastern Cooperative Oncology Group (ECOG)-Performance Status (PS) 0 - 1.
6. Age ≥ 18 years.
7. Signing of the Informed Consent Form (ICF).
8. HIV-positive patients may be included if Cluster of Differentiation 4(CD4) count is greater than or equal to 200.
9. Patients may participate in other concurrent studies, as long as they do not involve interventions related to the treatment of the underlying cancer.

Exclusion Criteria:

1. Patients with unequivocal distant metastasis at diagnosis.
2. For participants with positive ctDNA after treatment, those candidates for participation in Phase II will be excluded if there is unequivocal radiological progression in the first imaging exam after the completion of radiotherapy (with or without chemotherapy) or routine indication for salvage surgery immediately after the conclusion of definitive treatment.
3. Need for recurrent blood transfusions, such as weekly frequency.
4. Another uncontrolled disease representing a life risk, as determined by medical judgment.
5. Personal history of another active invasive malignant neoplasm in the last 5 years, except for non-melanoma skin carcinomas and in situ carcinomas.
6. Pregnant individuals.
7. Active opportunistic infection or disease.
8. History of autoimmune diseases.

Conditions6

Browse More Trials