Clinical trial · Interventional
Antioxidant Supplement and Reduction of Metachronous Adenomas of the Large Bowel: a Double Blind Randomized Trial
Evaluation of the Efficacy of a Combination of Micronutrients (Vitamin A, C, E, Selenium and Zinc) in Reducing the Incidence of Colorectal Metachronous Adenomas. A Double Blind, Phase III, Randomized, Placebo-controlled Trial
- Source
- ClinicalTrials.gov
- Retrieved
- Sep 8, 2026
- Layer
- normalized (units and labels harmonized; values unchanged)
- Run
- ING-CLINICALTRIALS-20260908-000001
Why stopped (as posted): 50% of eligible patients refused to enter the study
Summary
Brief summary (as posted)
The trial was aimed at evaluating the efficacy of a multiagent antioxidant compound (vitamin A, C, E, selenium and zinc) in reducing the incidence of metachronous adenomas of the large bowel after endoscopic polypectomy. This is a randomized study: a 50% reduction in the incidence of metachronous adenomas was expected in patients allocated to the "active" compound (intervention) arm as compared to those assigned to a placebo.
Conditions
Conditions (1)
Free-text conditions as registered, with the CancerIndex entity they were reconciled to and the match type.
| Condition (as posted) | Mapped entity | Match | Confidence |
|---|---|---|---|
| Colorectal Adenomas | Colorectal Neoplasm | ONTOLOGY_EXACT | 0.90 |
Interventions
Interventions (2)
| Intervention | Type | Mapped drug | Match |
|---|---|---|---|
| antioxidants | Drug | — | UNRESOLVED |
| placebo | Drug | — | UNRESOLVED |
Design
Arms and outcomes
Arms (2)
- type
- EXPERIMENTAL
- label
- antioxidants
- description
- tablets composed of 200 mcg selenium \[as l-selenomethionine\], 30 mg zinc, 2 mg vitamin A \[retinol\], 180 mg vitamin C \[ascorbic acid\] and 30 mg vitamin E \[D-α-tocopherol acetate\]
- interventionNames
- Drug: antioxidants
- type
- PLACEBO_COMPARATOR
- label
- Sugar pill
- description
- placebo had an identical appearance as intervention
- interventionNames
- Drug: placebo
Primary outcomes (1)
- measure
- occurrence of metachronous adenomas or cancer detected during endoscopic follow up examinations
- timeFrame
Eligibility
Eligibility (as posted)
- Sex
- All
- Minimum age
- 25 Years
- Maximum age
- 75 Years
Show eligibility criteria text
Inclusion Criteria: * age 25-75 years * at least one histologically confirmed adenoma endoscopically removed from the large bowel resulting in a polyp-free colon-rectum (clean colon). Exclusion Criteria: * polypectomy performed more than 6 months before enrolment in the trial * history of Familial Adenomatous Polyposis * inflammatory bowel disease * adenoma with invasive carcinoma * ten or more adenomas * large sessile adenoma (3 cm or more * colorectal resection * invasive cancer at any site * life-threatening and/or chronic heart, liver or kidney diseases * current use of vitamin or calcium supplements * mental disability
References
Publications (0)
Data not yet available