An observational study in Cancer of the Rectum, sponsored by University of Colorado, Denver. Withdrawn. Open to participants aged 18 Years to 100 Years. Per ClinicalTrials.gov, last updated 2026-06-09.
Sponsored by University of Colorado, Denver · Observational
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.
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
1,762 studies on the registry are indexed under Rectal Neoplasms; 518 are open to participants now.
Browse Rectal Neoplasms studies →University of Colorado, Denver is the lead sponsor of 1,499 studies on the registry; 315 are open to participants now.
Of its 139 completed or terminated interventional studies of FDA-regulated products, 89 (64%) have results posted.
Counted across the registry records on this site, refreshed daily.
Rectal Cancer Stage II or III
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
Exclusion Criteria:
Patients who are less than 18 years old
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.
Time frame: 36 months
No study locations are listed for this record.
Plan to share: No — A plan has not been put in place at this time
No publications or documents are linked to this record.
This study is withdrawn, as verified in Jun 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
University of Colorado, Denver