Colorectal Cancer, Precancerous Condition
Conditions
Keywords
colon cancer, rectal cancer, adenomatous polyp
Brief summary
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
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.
Interventions
DIETARY_SUPPLEMENTcholecalciferol
Given orally
OTHERplacebo
Given orally
Sponsors
National Cancer Institute (NCI)
Northwestern University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
ALL
Age
50 Years to No maximum
Healthy volunteers
No
Inclusion criteria
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
Design outcomes
Primary
| Measure | 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
| Measure | 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 |
Countries
United States
Outcome results
None listed