The Surveillance Nonoperative Watch & Wait (SNOWW) Rectal Cancer Trial.

NCT07292285 | Not Yet Recruiting

• 1 other identifier: 25-1647.cc
• Study Type: observational
• Target: 200
• Locations: 0 countries
• Sites: N/A

Brief 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 surveillance.

Conditions

Cancer of the Rectum

Keywords

Management of Stage 2 or 3 Rectal Cancer

Outcome Measures

Primary Outcomes (1)

• 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.

  36 months

Study Arms (1)

Rectal Cancer Clinical Stage II or III

Eligibility Criteria

• Age: 18 Years - 100 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

Rectal Cancer Stage II or III

You may qualify if:

• 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
• 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

You may not qualify if:

• 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 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.

Sponsors & Collaborators

• University of Colorado, Denver: lead
• Natera, Inc.: collaborator

Biospecimen

Retention: SAMPLES WITH DNA

ctDNA testing

MeSH Terms

Conditions

Rectal Neoplasms

Condition Hierarchy (Ancestors)

Colorectal Neoplasms; Intestinal Neoplasms; Gastrointestinal Neoplasms; Digestive System Neoplasms; Neoplasms by Site; Neoplasms; Digestive System Diseases; Gastrointestinal Diseases; Intestinal Diseases; Rectal Diseases

Study Officials

• Jon MT Vogel, MD

  University of Colorado Denver Anschutz Medical Campus

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Tracey Mac, BA BS CCRC

CONTACT

3037242757; tracey.macdermott@cuanschutz.edu

Nargis Kalia, MPH

CONTACT

303-724-0333; nargis.kalia@cuanshcutz.edu

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: December 5, 2025
• First Posted: December 18, 2025
• Study Start (Estimated): October 1, 2026
• Primary Completion (Estimated): December 31, 2029
• Study Completion (Estimated): June 30, 2030
• Last Updated: February 17, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will not share