NCT05081024 · OHSU Knight Cancer Institute
Establishing a ctDNA Biomarker to Improve Organ Preserving Strategies in Patients With Rectal Cancer
What this study is about
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.
View original scientific description
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.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Participant must provide written informed consent before any study-specific procedures or interventions are performed
- Participants aged \>= 18 years
- Pathologically-confirmed stage II or III primary adenocarcinoma of the rectum:
- T3N0M0 - T4bN2M0
Exclusion criteria
- Has radiologic evidence of distant metastases at the time of screening/enrollment
- Has received prior treatment for their rectal adenocarcinoma
- Requires or has received blood transfusion within 1 month of study enrollment
Where
- Portland, Oregon
- Seattle, Washington
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Sep 25, 2025 · Source of record for eligibility and locations