Vitamin D Supplement in Preventing Colon Cancer in African Americans With Colon Polyps

Study Overview
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Brief Summary
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RATIONALE: Chemoprevention is the use of certain drugs to keep cancer from forming. The use of vitamin D may keep colorectal cancer from forming in patients with colon polyps. PURPOSE: This randomized phase I trial is studying a vitamin D supplement to see how well it works compared with a placebo in preventing colorectal cancer in African Americans with colon polyps.

Detailed Description
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OBJECTIVES: Primary To determine the accrual rate of African Americans with adenomatous polyps to a 6-month randomized intervention trial comprising supplementation with either cholecalciferol (vitamin D3) or placebo. To determine the compliance rates in patients treated with these regimens. Secondary To compare changes in pre- and post-treatment vitamin D levels in patients treated with these regimens. To correlate vitamin D levels with vitamin D modifiers, such as levels of skin pigmentation, dietary vitamin D intake, and sun exposure in this patient population. OUTLINE: Patients are randomized to 1 of 2 arms. Arm I: Patients receive oral cholecalciferol (vitamin D3) supplementation daily for up to 6 months in the absence of disease progression or unacceptable toxicity. Arm II: Patients receive oral placebo supplementation daily for up to 6 months in the absence of disease progression or unacceptable toxicity. Patients complete questionnaires about demographics, dietary vitamin D intake, personal history (e.g., ancestry, alcohol and tobacco intake, occupation, height, and weight), medical history (e.g., personal and family history of colorectal cancer and polyps), and ultraviolet radiation exposure. Blood samples are collected at baseline and at 6 months for correlative laboratory studies. Blood samples are analyzed for vitamin D levels by enzyme immunoassay. Patients also undergo assessment of skin pigmentation in sunprotected and sunexposed areas of skin by reflectance spectrometry at baseline.

Official Title
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Vitamin D Intervention For Colon Cancer Prevention In African-Americans-A Pilot Study

Conditions
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Colorectal Cancer, Precancerous Condition

Intervention / Treatment
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* Dietary Supplement: cholecalciferol
* Other: placebo


Participation Criteria
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Eligibility Criteria
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DISEASE CHARACTERISTICS: Histologically confirmed adenomatous polyp At least 1 adenoma Self-identified as an African American AND undergoing screening or diagnostic colonoscopy at the University of Chicago No history of colon or rectal cancer or hereditary or familial colon cancer (e.g., hereditary non-polyposis colon cancer or familial adenomatous polyposis) PATIENT CHARACTERISTICS: Total bilirubin normal AST and ALT ≤ 2.5 times upper limit of normal Creatinine normal Albumin ≥ 3.0 mg/dL Baseline serum calcium level normal Not pregnant No history of thyroid disease No history of renal stones PRIOR CONCURRENT THERAPY: See Disease Characteristics No other concurrent vitamin D intake

Ages Eligible for Study
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Minimum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Arm I<br>Patients receive oral cholecalciferol (vitamin D3) supplementation daily for up to 6 months in the absence of disease progression or unacceptable toxicity. | Dietary Supplement: cholecalciferol<br>* Given orally<br>|
| Placebo Comparator: Arm II<br>Patients receive oral placebo supplementation daily for up to 6 months in the absence of disease progression or unacceptable toxicity. | Other: placebo<br>* Given orally<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of compliance as assessed at 6 months |  | Following 6 months of study treatment | 
| Rate of accrual |  | After accrual goal is reached | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in pre- and post-treatment vitamin D levels |  | At baseline and following completion of study treatment | 
| Correlation of vitamin D levels with vitamin D modifiers (e.g., levels of skin pigmentation, dietary vitamin D intake, and sun exposure) |  | After completion of study treatment & final colonic biopsy | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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colon cancer, rectal cancer, adenomatous polyp