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Comparing chemotherapy regimens for distal rectal cancer treatment

Chemoradiation and Consolidation Chemotherapy With or Without Oxaliplatin for Distal Rectal Cancer and Watch and Wait. A Multi-center Prospective Randomized Controlled Trial. (CCHOWW)

Not applicable Interventional Hospital Alemão Oswaldo Cruz · NCT05000697

This study is testing whether adding oxaliplatin to standard chemotherapy can help patients with distal rectal cancer respond better after initial treatment and possibly avoid surgery.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment216 (estimated)
Ages18 Years and up
SexAll
SponsorHospital Alemão Oswaldo Cruz Academic / other
Drugs / interventionschemotherapy, radiation
Locations24 sites (Buenos Aires and 23 other locations)
Trial IDNCT05000697 on ClinicalTrials.gov

What this trial studies

This clinical trial investigates the effectiveness of two different consolidation chemotherapy regimens following neoadjuvant chemoradiation in patients with distal rectal cancer. Participants will be randomized to receive either fluoropyrimidine alone or fluoropyrimidine with oxaliplatin after their initial treatment. The primary goal is to assess the rate of clinical complete response at 18 weeks, which may allow some patients to avoid surgery through a Watch and Wait approach. Secondary endpoints include various survival metrics over three years, such as surgery-free and colostomy-free survival.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 and older with biopsy-confirmed primary rectal adenocarcinoma and no evidence of metastatic disease.

Not a fit: Patients with metastatic rectal cancer or those unable to undergo the required imaging and assessments may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance treatment options for distal rectal cancer patients, potentially allowing for organ preservation and improved survival rates.

How similar studies have performed: Previous studies have shown promising results with similar chemotherapy regimens, but the specific combination of fluoropyrimidine and oxaliplatin in this context is being evaluated for the first time.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria:

1. Age ≥18 years;
2. ECOG 0-2 or KPS≥70;
3. Primary rectal adenocarcinoma (biopsy confirmed) within the reach of digital rectal examination (at least lower tip/border) by the attending colorectal surgeon;
4. Endoscopic documentation;
5. Abdominal and chest CT scans showing no evidence of metastatic disease;
6. High-resolution magnetic resonance images performed at either 1.5T or 3.0T system using a phased array surface coil with: sagittal T2 images including the anal verge and the sacrum; axial oblique T2 weighted images acquired in a plane perpendicular to the long axis of the rectal wall guided by the sagittal images; coronal images acquired in parallel to the anal canal plane. Small field of view (16-18cm), 3mm section thickness, increased matrix size and increased number of signal averages are required;
7. Radiological defining criteria (centralized):

   1. Lower edge of tumor at the level (max. 1cm distance) or below the anorectal ring defined at sagittal or coronal views;
   2. mrT2, mrT3 (any subclassification)
   3. mrN0-1 (≤3 radiologically positive lymph nodes)
   4. mrEMVI: any status
   5. mrMRF: any status

Exclusion Criteria:

1. Pregnancy
2. ECOG ≥3 or KPS\<70
3. Unwilling to consent
4. Metastatic disease (any kind; internal iliac and obturator nodes are considered local disease and not metastatic disease and therefore will not be considered as exclusion criteria)
5. mrT4 or mrN2
6. Previous pelvic irradiation
7. Baseline neuropathy
8. Receiving treatment of other anti-cancer drug or methods
9. Presence of uncontrolled life threatening diseases

Where this trial is running

Buenos Aires and 23 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
View on ClinicalTrials.gov → Find more trials like this →
Conditions Rectal CancerConsolidationRectal cancerConsolidation ChemotherapyComplete ResponseWatch and Wait
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.