Suspended

Phase III Study of the Effects of Selenium on Adenomatous Polyp Recurrence

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What is being tested

Selenium

Drug
Who is being recruted

Adenoma+15

+ Colonic Diseases

+ Digestive System Diseases

From 40 to 80 Years
See all eligibility criteria
How is the trial designed

Prevention Study

Placebo-ControlledPhase 3
Interventional
Study Start: January 2005
See protocol details

Summary

Principal SponsorUniversity of Arizona
Last updated: January 13, 2026
Sourced from a government-validated database.Claim as a partner

Study start date: January 20, 2005

Actual date on which the first participant was enrolled.

OBJECTIVES: Primary * Compare the effects of selenium vs placebo on the recurrence of adenomatous colorectal polyps, in terms of histologic type, degree of dysplasia, number, size, and location, in patients with adenomatous colorectal polyps. * Compare the type, incidence, and outcome of side effects in patients treated with these regimens. * Determine patient adherence to long-term treatment with these regimens. Secondary * Determine the effects of regimen modification by baseline blood selenium level, low-dose aspirin, selenoprotein genetic marker polymorphisms (e.g., GPx-1, GPx-2, and SEP15) * Determine the effects of low-dose aspirin (81 mg/day) modification by ornithine decarboxylase promoter genotype, and toxicity by slow-metabolizer genotypes of the cytochrome p450 2C9 and UT1A6 loci in these patients. OUTLINE: This is a randomized, double-blind, placebo-controlled, multicenter study. Patients are stratified according to use of low-dose (≤ 81 mg/day) aspirin (yes vs no). Patients are randomized to 1 of 2 treatment arms. * Arm I: Patients receive oral selenium once daily. * Arm II: Patients receive oral placebo once daily. In both arms, treatment continues for up to 5 years\* in the absence of disease progression or unacceptable toxicity. Patients undergo follow-up colonoscopy approximately 5 years\* after baseline colonoscopy. NOTE: Some patients will continue participation for up to 7 and a half years PROJECTED ACCRUAL: A total of 1,600 patients with an adenoma will be randomized to this study, followed by a second group of randomization of 200 patients with at least one advanced adenoma (at baseline) for a substudy. Total planned randomizations = 1,800 participants.

Official TitlePhase III Study of the Effects of Selenium on Adenomatous Polyp Recurrence 
NCT00078897
Principal SponsorUniversity of Arizona
Last updated: January 13, 2026
Sourced from a government-validated database.Claim as a partner

Protocol

This section provides details of the study plan, including how the study is designed and what the study is measuring.
Design Details

1621 patients to be enrolled

Total number of participants that the clinical trial aims to recruit.

Prevention Study

Prevention studies aim to stop a disease from developing. They often involve people at risk and test things like vaccines, lifestyle changes, or preventive medications.



Eligibility

Researchers look for people who fit a certain description, called eligibility criteria: person's general health condition or prior treatments.
Conditions
Criteria

Any sex

Biological sex of participants that are eligible to enroll.

From 40 to 80 Years

Range of ages for which participants are eligible to join.

Healthy volunteers allowed

If individuals who are healthy and do not have the condition being studied can participate.

Conditions

Pathology

AdenomaColonic DiseasesDigestive System DiseasesDigestive System NeoplasmsGastrointestinal DiseasesGastrointestinal NeoplasmsIntestinal DiseasesIntestinal NeoplasmsNeoplasmsNeoplasms by Histologic TypeNeoplasms by SiteNeoplasms, Glandular and EpithelialPolypsPrecancerous ConditionsRectal DiseasesColorectal NeoplasmsAdenomatous PolypsPathological Conditions, Anatomical

Criteria

DISEASE CHARACTERISTICS: * Histologically confirmed colorectal adenomatous polyps * Meets the following criteria by colonoscopy (performed within the past 6 months): * Cecum was totally visualized or reached * At least 90% visualization of colon surface area * Removed at least 1 adenomatous polyp of at least 3 mm in size during procedure (For the Advanced Adenoma Sub-study: Removal of at least 1 advanced colorectal adenomatous polyp during procedure. An adenoma is considered advanced if it is 10 mm or greater in size, and/or has villous histology and/or shows high grade dysplasia) * Removed no more than 10 adenomatous polyps of any size by endoscopy * All other neoplastic and non-neoplastic colon polyps must have been completely removed (except for diminutive \[less than 3 mm\] sessile rectal polyps) * For the sub-study, at least 1 advanced adenomatous polyp defined as 10 mm or greater in size and/or has villous histology and/or shows high grade dysplasia * No prior diagnosis of any of the following: * Colorectal cancer * Familial adenomatous polyposis * Ulcerative colitis * Crohn's disease * Hereditary non-polyposis colon cancer (HNPCC), defined as: * Histologically confirmed colorectal cancer in at least 3 relatives, 1 of whom is a first-degree relative of the other 2 * Disease occurrence in at least 2 consecutive generations * Colorectal cancer diagnosis in at least 1 family member who is less than 50 years of age * Patients with a family history of colorectal cancer but who are not diagnosed with HNPCC are allowed * No more than 1 prior segmental colon resection PATIENT CHARACTERISTICS: Age * 40 to 80 Performance status * SWOG 0-1 Life expectancy * Not specified Hematopoietic * Hemoglobin \> 11 g/dL * WBC 3,000 - 11,000/mm\^3 Hepatic * AST and ALT \< 2 times upper limit of normal * Bilirubin \< 2.0 mg/dL Renal * Creatinine \< 1.9 mg/dL Cardiovascular * No unstable\* cardiac disease despite medication (e.g., diuretics or digitalis) * No uncontrolled hypertension (i.e., systolic blood pressure ≥ 170 mm Hg and/or diastolic blood pressure ≥ 110 mm Hg) despite medication NOTE: \*Unstable defined as unable to walk across the room without chest pain or shortness of breath Other * Not pregnant or nursing * Fertile patients must use effective contraception for at least 2 months before and during study treatment * Resident of a clinical center metropolitan area or obtaining regular health care in a clinical metropolitan area for at least 6 months out of the year * Must be able to swallow pills * No unexpected weight loss of 10% or more within the past 6 months * No prior rheumatoid arthritis * No poorly controlled diabetes mellitus despite medication, defined as: * Blood sugar level ≥ 200 mg/dL on more than half of the readings taken within the past month * No invasive malignancy within the past 5 years that required medical excision, radiotherapy, or chemotherapy except basal cell or squamous cell carcinoma PRIOR CONCURRENT THERAPY: Biologic therapy * No concurrent drugs that regulate the immune system Chemotherapy * No concurrent chemotherapy Endocrine therapy * Not specified Radiotherapy * No concurrent radiotherapy Surgery * See Disease Characteristics Other * Prior enrollment in another adenoma prevention study allowed * Concurrent routine aspirin (≤ 81 mg/day) allowed * No regular use of non-steroidal anti-inflammatory drugs (NSAIDs) * No concurrent enrollment in another research study using pharmacological cancer drugs, a cyclo-oxygenase-2 inhibitor, or selenium * No other concurrent selenium unless dosage is ≤ 50 µg/day

Study Plan

Find out more about all the medication administered in this study, their detailed description and what they involve.
Treatment Groups
Study Objectives

2 intervention groups are designated in this study

50% chance of being blinded to the placebo group

Treatment Groups

Group I

Placebo
Participants receive oral placebo once daily.

Group II

Active Comparator
Participants receive oral selenium 200 mcg once daily.

Study Objectives

Primary Objectives

Study Centers

These are the hospitals, clinics, or research facilities where the trial is being conducted. You can find the location closest to you and its status.

This study has 7 locations

Suspended

Veterans Affairs Medical Center - Phoenix

Phoenix, United StatesSee the location
Suspended

Virginia G. Piper Cancer Center at Scottsdale Healthcare - Shea

Scottsdale, United States
Suspended

Mayo Clinic Scottsdale

Scottsdale, United States
Suspended

Arizona Cancer Center - Tucson Clinic

Tucson, United States
Suspended7 Study Centers