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

September 24, 2025 updated by: Adel Kardosh M.D., Ph.D., OHSU Knight Cancer Institute
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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
50

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Oregon
      • Portland, Oregon, United States, 97239
        • Recruiting
        • OHSU Knight Cancer Institute
        • Contact:
        • Principal Investigator:
          • Adel Kardosh, M.D.,Ph.D.
    • Washington
      • Seattle, Washington, United States, 98109
        • Recruiting
        • Fred Hutch
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Patients with stage II-III rectal adenocarcinoma at Oregon Health & Science University (OHSU), its affiliated community oncology (CHO) site, or collaborating research site

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Observational (biospecimen collection, medical record review)
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.
Procedure: Biopsy
Undergo biopsy
Other Names:
  • Bx
  • BIOPSY_TYPE
Other: Electronic Health Record Review
Medical records are reviewed
Procedure: Biospecimen Collection
Undergo collection of blood and/or tissue samples
Other Names:
  • Biological Sample Collection

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Complete clinical response (cCR)
Time Frame: 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.
From time of treatment start up to date of completing total neoadjuvant therapy (TNT), up to 3 months.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Positive circulating tumor deoxyribonucleic acid (ctDNA)
Time Frame: From date of baseline measure of ctDNA (i.e., number of mutant molecules per mL) to date of until the date of first documented progression, up to 3 years.
The proportion of ctDNA positive participants (at baseline, throughout TNT, and follow-up) and its exact 95% CI will be evaluated using the ctDNA analysis set. Where appropriate, sub-analyses will be conducted using populations that underwent surgery or were monitored using a watch and wait (W&W) strategy.
From date of baseline measure of ctDNA (i.e., number of mutant molecules per mL) to date of until the date of first documented progression, up to 3 years.
Positive ctDNA after completing TNT
Time Frame: From date of baseline measure of ctDNA (i.e., number of mutant molecules per mL) to date of until the date of first documented progression, up to 3 years
The proportion of ctDNA positive participants (at baseline, throughout TNT, and follow-up) and its exact 95% CI will be evaluated using the ctDNA analysis set. Where appropriate, sub-analyses will be conducted using populations that underwent surgery or were monitored using a W&W strategy.
From date of baseline measure of ctDNA (i.e., number of mutant molecules per mL) to date of until the date of first documented progression, up to 3 years
Rate of transabdominal surgery
Time Frame: Up to 3 years following completion of TNT
Will be evaluated using the TNT analysis set. The corresponding exact 95% CI will also be presented.
Up to 3 years following completion of TNT
Rate of pathological complete response (pCR)
Time Frame: From start of treatment until completion of surgery, up to 3 years.
Will be evaluated using the TNT analysis set. The corresponding exact 95% CI will also be presented.
From start of treatment until completion of surgery, up to 3 years.
Rate of watch and wait strategy
Time Frame: Up to 3 years following completion of TNT
Will be evaluated using the TNT analysis set. The corresponding exact 95% CI will also be presented.
Up to 3 years following completion of TNT
Disease-free survival
Time Frame: Time between the date of surgery (or W&W population, the date of completing TNT) and the date of local or metastatic recurrence or death from any cause, assessed up to 3 years following completion of TNT
Will be estimated using the Kaplan-Meier method.
Time between the date of surgery (or W&W population, the date of completing TNT) and the date of local or metastatic recurrence or death from any cause, assessed up to 3 years following completion of TNT
Overall survival
Time Frame: Time between the date of signed consent to the date of death from any cause, assessed up to 3 years following completion of TNT
Will be estimated using the Kaplan-Meier method.
Time between the date of signed consent to the date of death from any cause, assessed up to 3 years following completion of TNT

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
ctDNA status
Time Frame: From date of baseline measure of ctDNA (i.e., number of mutant molecules per mL) to date of until the date of first documented progression, up to 3 years
positive versus negative results per test results
From date of baseline measure of ctDNA (i.e., number of mutant molecules per mL) to date of until the date of first documented progression, up to 3 years
Positive ctDNA by clinical characteristics
Time Frame: From date of baseline measure of ctDNA to date of recurrence or death from any cause, assessed up to 3 years following completion of TNT
association or recurrence on ctDNA test and standard imaging
From date of baseline measure of ctDNA to date of recurrence or death from any cause, assessed up to 3 years following completion of TNT
Sensitivity
Time Frame: From date of baseline measure of ctDNA to date of recurrence or death from any cause, assessed up to 3 years following completion of TNT
Sensitivity and specificity will be calculated using complete clinical response (yes versus [vs.] no), or tumor recurrence (yes vs. no) as reference standard.
From date of baseline measure of ctDNA to date of recurrence or death from any cause, assessed up to 3 years following completion of TNT
Specificity
Time Frame: From date of baseline measure of ctDNA to date of recurrence or death from any cause, assessed up to 3 years following completion of TNT
Sensitivity and specificity will be calculated using complete clinical response (yes vs. no), or tumor recurrence (yes vs. no) as reference standard.
From date of baseline measure of ctDNA to date of recurrence or death from any cause, assessed up to 3 years following completion of TNT

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
OHSU Knight Cancer Institute

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Natera, Inc.

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Adel Kardosh, M.D.,Ph.D., OHSU Knight Cancer Institute

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 3, 2021

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 3, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 3, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 7, 2021

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 4, 2021

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 18, 2021

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 25, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 24, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • STUDY00022247 (Other Identifier: OHSU Knight Cancer Institute)
  • NCI-2021-08733 (Registry Identifier: CTRP (Clinical Trial Reporting Program))

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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Drug Interventions

Conditions

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