NCT05081024

Establishing a ctDNA Biomarker to Improve Organ Preserving Strategies in Patients With Rectal Cancer

• Status: Recruiting
• Phase: —
• Study type: Observational
• Enrollment: 50 (estimated)
• Sponsor: OHSU Knight Cancer Institute · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

This study measures the levels of circulating tumor DNA (ctDNA) in patients with stage II-III rectal cancer before, during, and after treatment to find out if the presence or absence of ctDNA in patient's blood using the Signatera test can be used to gauge how different treatments may affect rectal cancer. ctDNA is DNA from the rectal cancer that is circulating in the blood. The purpose of this study is to understand if the way rectal tumors respond to standard treatment can be associated with varying levels of ctDNA.

Detailed description

PRIMARY OBJECTIVE: I. To estimate the percentage of participants that achieve complete clinical response. SECONDARY OBJECTIVES: I. To assess circulating tumor deoxyribonucleic acid (ctDNA) status among participants receiving total neoadjuvant therapy (TNT). II. To assess molecular residual disease (MRD i.e., ctDNA status). III. To assess the rate of transabdominal surgery. IV. To assess the rate pathological complete response after surgery. V. To assess the rate of watch and -wait (W\&W) after TNT. VI. To assess disease-free survival (DFS). VII. To assess overall survival (OS). EXPLORATORY OBJECTIVES: I. To characterize ctDNA clearance or non-clearance patterns during TNT. II. To correlate ctDNA levels with a participant's pathological features. III. To preliminary assess the prognostic performance of ctDNA levels in relation to participant's clinical outcome. OUTLINE: Patients undergo collection of blood samples at baseline (before any neoadjuvant therapy), every 2 months while undergoing TNT, and then every 3 months for up to 3 years after completion of TNT. Patients' medical records are also reviewed. Patients may undergo collection of tissue sample if an archival tissue sample is not available.

Conditions

• Rectal Adenocarcinoma
• Stage II Rectal Cancer AJCC v8
• Stage IIA Rectal Cancer AJCC v8
• Stage IIB Rectal Cancer AJCC v8
• Stage IIC Rectal Cancer AJCC v8
• Stage III Rectal Cancer AJCC v8
• Stage IIIA Rectal Cancer AJCC v8
• Stage IIIB Rectal Cancer AJCC v8
• Stage IIIC Rectal Cancer AJCC v8

Interventions

Type	Name	Description
PROCEDURE	Biopsy	Undergo biopsy
PROCEDURE	Biospecimen Collection	Undergo collection of blood and/or tissue samples
OTHER	Electronic Health Record Review	Medical records are reviewed

Timeline

• Start date: 2021-09-03
• Primary completion: 2026-09-03
• Completion: 2026-09-03
• First posted: 2021-10-18
• Last updated: 2025-09-25

Locations

2 sites across 1 country: United States