Cancer of the RectumSNOWWNCT07292285
The Surveillance Nonoperative Watch & Wait (SNOWW) Rectal Cancer Trial.
An observational study of Cancer of the Rectum, run by University of Colorado, Denver.
Trial summary
The primary objectives of this study are to determine if the inclusion of ctDNA testing in the evaluation and management of stages 2 and 3 rectal cancers will allow clinicians to improve their selection of patients for wait and watch (WW) management and to facilitate the detection of cancer regrowth during WW… Read more about this study
- Who is it for?
- Ages 18 to 100 years
- Conditions the study is for
- Cancer of the Rectum
- How many people
- 0 participants
- Where
- No sites listed yet
- Study dates
- 1 Oct 2026to 30 Jun 2030
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 100 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Rectal Cancer Stage II or III
Who may be able to join
- Provision to sign and date the consent form.
- Stated willingness to comply with all study procedures and be available for the duration of the study.
- Additional Inclusion Criteria:
- Pre-TNT phase Adult male and female patients (>18 years old) Clinical stage 2 or 3 rectal cancer, within or beyond the reach of digital rectal exam (DRE), who are evaluated in a multidisciplinary setting and who will receive induction or consolidation total neoadjuvant therapy (TNT) and are candidates for watch and wait management (WW) with curative intent.
- Post-TNT phase complete or near complete clinical response to TNT High-definition flexible endoscopy: Pale smooth scar with or without telangiectasia No ulceration, nodularity, or mucosal irregularities No stricture DRE: Smooth, flat scar No nodularity Diffusion-weighted MRI2 Fibrotic, linear scar with low signal intensity on T2-weighted images No diffusion restriction No suspicious lymph nodes
- Near Complete Clinical Response:
- Endoscopic appearance with irregular small mucosal nodules, superficial ulceration, or mild persistent erythema DRE: Smooth induration or superficial minor mucosal irregularity MRI: T2-weighted MRI with downstaging with or without residual fibrosis, small area of residual signal, and complete or partial regression of lymph nodes. Diffusion-weighted MRI with small area of residual high signal intensity
Who cannot join
- • Patients who are less than 18 years old
- Patients who are pregnant during the study period
- Patients with stage I or IV rectal cancer
- Patients who receive neoadjuvant therapy other than TNT.
- Patients who receive short-course neoadjuvant radiotherapy.
- Patients who are actively enrolled in other clinical trials that prohibit inclusion in this study.
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- Patients who refuse or are unable to undergo ctDNA testing and subsequent follow ups
- Patients who refuse or are unable to undergo WW management of rectal cancer.
- Patients who are undergoing "WW" management of rectal cancer due to refusal of recommended surgical resection. (For example, the hypothetical patient with an incomplete clinical response to TNT who refuses surgery).
- Patients who undergo WW for palliation only.
- Patients with prior history of rectal cancer with or without chemoradiation treatment or surgical resection
- Patients who have a different cancer, in addition to rectal cancer, in whom the study ctDNA testing would be uninterpretable.
About this study
Official title: The Surveillance Nonoperative Watch & Wait (SNOWW) Rectal Cancer Trial
The primary objectives of this study are to determine if the inclusion of ctDNA testing in the evaluation and management of stages 2 and 3 rectal cancers will allow clinicians to improve their selection of patients for wait and watch (WW) management and to facilitate the detection of cancer regrowth during WW surveillance.
Read the detailed description
This will be a prospective multi-center observational study for adult patients with stage 2 or 3 rectal adenocarcinoma who will be treated with TNT and are potential candidates for WW management. Study eligibility will be determined prior to the initiation of TNT by individual site investigators with the expectation that both the patient and investigator will be involved in multidisciplinary cancer decision-making. The rectal cancer tissue samples that were used to make the cancer diagnosis will also be used by our collaborative sponsor (Natera, Inc) to develop a tissue-informed and patient-specific ctDNA profile for each study patient. Patient blood samples will then be collected before the start of TNT, during TNT, after the completion of TNT, and for WW patients, at the time of every scheduled endoscopic surveillance exam, as recommended by the NCCN, and when non-scheduled endoscopic exams are performed. Figure 1. The patients will be prospectively followed for 2 years after the initiation of W\&W or until cancer regrowth is suspected or confirmed and treatments other than WW are implemented. Patients who have cancer regrowth and then salvage surgery will be followed until their first postoperative cancer re-staging examination. Patients who have cancer regrowth and do not have salvage surgery will be followed. until this decision to not pursue salvage surgery is made.
The study surgeons and their patients will have access to their ctDNA test results. The study surgeon and other members of the patients' cancer care team will be advised to consider these results in their patient care decision-making and to document how each ctDNA effected decision making, if at all. The study surgeon will be responsible for ensuring that their patients are aware of the limitations of ctDNA testing and the NCCN recommendations for its use in WW management of rectal cancer.
To evaluate the impact of ctDNA on the shared decision-making process, the validated 9 Item Shared Decision-Making Questionnaire (SDM-Q-9) and the Control Preference Sale (CPS) will be administered to patients at the re-staging visit following TNT, when the decision to pursue WW or surgery is being considered. For patients managed with WW, the SDM-Q-9 will also be re-administered every time ctDNA is used in surveillance and whether a treatment decision is being actively reconsidered based on ctDNA results.
Additionally, the Shared Decision-Making Questionnaire- Physician Version (SDM-Q-Doc) will be completed by study surgeons at the re-staging visit following TNT, when the decision to pursue WW or surgery is being considered. For patients managed with WW, the SDM-Q-Doc will also be re-administered every time ctDNA is used in surveillance and whether a treatment decision is being actively reconsidered based on ctDNA results. This will allow assessment of surgeon perspectives on the decision-making process and how ctDNA influences clinical recommendations
- Conditions
- Cancer of the Rectum
- Keywords
- Management of Stage 2 or 3 Rectal Cancer
- Medical subject headings
- Rectal Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Rectal Cancer Clinical Stage II or III | Not described |
What is being measured
The primary outcome is the main question the study is designed to answer.
Improve selection of patients for WW management
determine if the inclusion of ctDNA testing in the evaluation and management of stages 2 and 3 rectal cancers will allow clinicians to improve their selection of patients for WW management and to facilitate the detection of cancer regrowth during WW surveillance.
Measured: 36 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Dec 2025
- Study start1 Oct 2026 (estimated)
- Primary completion31 Dec 2029 (estimated)
- Study completion30 Jun 2030 (estimated)
Why it stopped: Sponsor decided not to move forward with the site.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cancer of the RectumStudies of the same condition, open and under way.
- More trials run by University of Colorado, DenverThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Other
- Time perspective
- Prospective
- Enrolment
- 0 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Colorado, Denver
- Sponsor type
- University, hospital or other
- Collaborators
- Natera, Inc.
- Responsible party
- Sponsor
- Investigators
- Jon MT Vogel, MD, Principal investigator, University of Colorado Denver Anschutz Medical Campus
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07292285
- Sponsor's protocol ID
- 25-1647.cc
- Acronym
- SNOWW
- Status last verified
- Jun 2026
- First submitted
- 5 Dec 2025
- Last updated
- 9 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: A plan has not been put in place at this time
Study at a glance
From the registry record, last updated by the sponsor on 9 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Surveillance Nonoperative Watch & Wait (SNOWW) Rectal Cancer Trial
- ClinicalTrials.gov ID
- NCT07292285
- Acronym / sponsor ID
- SNOWW / 25-1647.cc
- Conditions
- Cancer of the Rectum
- Keywords
- Management of Stage 2 or 3 Rectal Cancer
- Study type
- Observational
- Recruitment status
- WithdrawnReason stopped: Sponsor decided not to move forward with the site.
- Enrolment
- 0 participants (actual)
- Lead sponsor
- University of Colorado, DenverUniversity, hospital or other
- Collaborators
- Natera, Inc.
- Study start
- 1 Oct 2026 (estimated)
- Primary completion
- 31 Dec 2029 (estimated)
- Study completion
- 30 Jun 2030 (estimated)
- First posted
- 18 Dec 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The primary objectives of this study are to determine if the inclusion of ctDNA testing in the evaluation and management of stages 2 and 3 rectal cancers will allow clinicians to improve their selection of patients for wait and watch (WW) management and to facilitate the detection of cancer regrowth during WW surveillance.
Detailed description
This will be a prospective multi-center observational study for adult patients with stage 2 or 3 rectal adenocarcinoma who will be treated with TNT and are potential candidates for WW management. Study eligibility will be determined prior to the initiation of TNT by individual site investigators with the expectation that both the patient and investigator will be involved in multidisciplinary cancer decision-making. The rectal cancer tissue samples that were used to make the cancer diagnosis will also be used by our collaborative sponsor (Natera, Inc) to develop a tissue-informed and patient-specific ctDNA profile for each study patient. Patient blood samples will then be collected before the start of TNT, during TNT, after the completion of TNT, and for WW patients, at the time of every scheduled endoscopic surveillance exam, as recommended by the NCCN, and when non-scheduled endoscopic exams are performed. Figure 1. The patients will be prospectively followed for 2 years after the initiation of W\&W or until cancer regrowth is suspected or confirmed and treatments other than WW are implemented. Patients who have cancer regrowth and then salvage surgery will be followed until their first postoperative cancer re-staging examination. Patients who have cancer regrowth and do not have salvage surgery will be followed. until this decision to not pursue salvage surgery is made.
The study surgeons and their patients will have access to their ctDNA test results. The study surgeon and other members of the patients' cancer care team will be advised to consider these results in their patient care decision-making and to document how each ctDNA effected decision making, if at all. The study surgeon will be responsible for ensuring that their patients are aware of the limitations of ctDNA testing and the NCCN recommendations for its use in WW management of rectal cancer.
To evaluate the impact of ctDNA on the shared decision-making process, the validated 9 Item Shared Decision-Making Questionnaire (SDM-Q-9) and the Control Preference Sale (CPS) will be administered to patients at the re-staging visit following TNT, when the decision to pursue WW or surgery is being considered. For patients managed with WW, the SDM-Q-9 will also be re-administered every time ctDNA is used in surveillance and whether a treatment decision is being actively reconsidered based on ctDNA results.
Additionally, the Shared Decision-Making Questionnaire- Physician Version (SDM-Q-Doc) will be completed by study surgeons at the re-staging visit following TNT, when the decision to pursue WW or surgery is being considered. For patients managed with WW, the SDM-Q-Doc will also be re-administered every time ctDNA is used in surveillance and whether a treatment decision is being actively reconsidered based on ctDNA results. This will allow assessment of surgeon perspectives on the decision-making process and how ctDNA influences clinical recommendations
Study design
- Observational model
- Other
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Rectal Cancer Clinical Stage II or III | – | – |
Who may qualify
- Ages
- 18 to 100 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Rectal Cancer Stage II or III
Key inclusion criteria (7 listed)
- Provision to sign and date the consent form.
- Stated willingness to comply with all study procedures and be available for the duration of the study.
- Pre-TNT phase Adult male and female patients (>18 years old) Clinical stage 2 or 3 rectal cancer, within or beyond the reach of digital rectal exam (DRE), who are evaluated in a multidisciplinary setting and who will receive induction or consolidation total neoadjuvant therapy (TNT) and are candidates for watch and wait management (WW) with curative intent.
- Post-TNT phase complete or near complete clinical response to TNT High-definition flexible endoscopy: Pale smooth scar with or without telangiectasia No ulceration, nodularity, or mucosal irregularities No stricture DRE: Smooth, flat scar No nodularity Diffusion-weighted MRI2 Fibrotic, linear scar with low signal intensity on T2-weighted images No diffusion restriction No suspicious lymph nodes
- Endoscopic appearance with irregular small mucosal nodules, superficial ulceration, or mild persistent erythema DRE: Smooth induration or superficial minor mucosal irregularity MRI: T2-weighted MRI with downstaging with or without residual fibrosis, small area of residual signal, and complete or partial regression of lymph nodes. Diffusion-weighted MRI with small area of residual high signal intensity
Key exclusion criteria (12 listed)
- • Patients who are less than 18 years old
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Improve selection of patients for WW management
Time frame: 36 months
determine if the inclusion of ctDNA testing in the evaluation and management of stages 2 and 3 rectal cancers will allow clinicians to improve their selection of patients for WW management and to facilitate the detection of cancer regrowth during WW surveillance.
Results and safety
The study was withdrawn before enrolling participants, so there are no results.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Jun 2026.
- Individual participant dataSharing planned: No. A plan has not been put in place at this time
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Jon MT Vogel, MD principal investigator
University of Colorado Denver Anschutz Medical Campus
Questions about this trial
What is this clinical trial studying?
An observational study of Cancer of the Rectum, run by University of Colorado, Denver.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: withdrawn, as of the sponsor's last update on 9 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study was withdrawn before enrolling participants, so there are no results.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Improve selection of patients for WW management (time frame: 36 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Jun 2026.