Selenium for Prevention of Adenomatous Colorectal Polyps
Condition: Colorectal Cancer; Adenomatous Colorectal Polyps; Precancerous Condition
MeSH terms: Colorectal Neoplasms; Precancerous Conditions; Adenomatous Polyps; Polyps
Intervention: Selenium
Intervention description: Participants will be randomized either to selenium or placebo, taking the randomized intervention for 3 to 5 years, depending on when their recommended follow up colonoscopy is scheduled.
Intervention MeSH terms: Selenium
Phase: Phase 3
Study type: Interventional
Primary purpose: Prevention
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Enrollment: 1621.0
Sex: All
Minimum age: 40 Years
Maximum age: 80 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: colon cancer; rectal cancer; colorectal cancer; adenomatous polyp

Summary:

      RATIONALE: Chemoprevention therapy is the use of certain drugs to try to prevent the
      development or recurrence of cancer. Selenium may be effective in preventing the recurrence
      of adenomatous colorectal polyps.

      PURPOSE: This randomized phase III trial is studying selenium to see how well it works in
      preventing the recurrence of polyps in patients with adenomatous colorectal polyps.
    

Eligibility 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