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Observational Study for ctDNA in Rectal Cancer

This study is looking at how levels of circulating tumor DNA (ctDNA) in your blood might help doctors understand how well rectal cancer treatments are working. ctDNA is DNA from the cancer that circulates in your bloodstream. If you have stage II or III rectal adenocarcinoma, you might be able to join. Researchers will collect blood and tissue samples before, during, and after your standard treatment. They want to see if changes in ctDNA levels, measured by the Signatera test, can predict how your tumor responds to treatment and if it can help guide decisions about organ-preserving strategies. The main goal is to see what percentage of participants achieve a complete clinical response (when the cancer completely disappears). This is an observational study, meaning you will receive standard care, and researchers will collect information about your treatment and outcomes.

Study design
This is an observational study with a planned enrollment of 50 participants. It is not specified if it is randomized or blinded.
What's involved
You would provide written consent, have blood samples collected at baseline, every 2 months during treatment, and every 3 months for up to 3 years after treatment. Your medical records will also be reviewed, and a tissue sample may be collected if not already available.
Compensation
Not stated in the trial record.
Follow-up
Participants will have blood samples collected for up to 3 years after completing total neoadjuvant therapy (TNT).

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT05081024

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

Recruiting
Not specifiedAges 18+Observational
OHSU Knight Cancer Institute
~50 participants
Updated 2026-09-16 on ClinicalTrials.gov
What's tested:BiopsyBiospecimen CollectionElectronic Health Record Review

At a glance

Recruiting sites
2 of 2 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Complete clinical response (cCR)
Measured over From time of treatment start up to date of completing total neoadjuvant therapy (TNT), up to 3 months.

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

Explore related trials

Rectal Adenocarcinoma

NCT05081024

Where you'd take part

This study runs at 2 sites. They're the same protocol — you choose where, and that choice sets who your contact draft is addressed to.

  • Fred Hutch

    Seattle, Washingtonstudy coordinator listed

    Recruiting

  • OHSU Knight Cancer Institute

    Portland, Oregonstudy coordinator listed

    Recruiting

Sites open and close at different times, so the status above is per site — it can differ from the study's overall status.

Study leadership

  • Adel Kardosh, M.D.,Ph.D. · PRINCIPAL_INVESTIGATOR · OHSU Knight Cancer Institute

Who to contact

Adel Kardosh, M.D.,Ph.D.
[email protected]
503-494-5207
Email the study team

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Eligibility criteria

Inclusion

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

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

What this trial measures

  • Complete clinical response (cCR)From time of treatment start up to date of completing total neoadjuvant therapy (TNT), up to 3 months.

    cCR following TNT will be analyzed using the TNT analysis set. Proportions of participants that achieved cCR will be calculated and the exact 95% confidence interval (CI) will be presented.