Folate-Depleted Diet Compared With Folate-Supplemented Diet in Preventing Colorectal Cancer in Patients at High Risk for Colorectal Cancer

You may be eligible if

• DISEASE CHARACTERISTICS:
• Healthy persons at increased risk for colorectal neoplasia due to 1 of the following reasons:
• * Personal history of colorectal adenomatous polyps
• * Family history of colorectal adenoma or adenocarcinoma
• No history of multiple family members with colorectal neoplasia that is suggestive of dominant hereditary neoplasia
• PATIENT CHARACTERISTICS:
• Age
• 40 to 72
• Performance status
• Ambulatory
• Life expectancy
• At least 6 months
• Hematopoietic
• No excessive bleeding or coagulation disorder
• Hepatic
• ALT or AST ≤ 2 times upper limit of normal
• No unexplained elevated alkaline phosphatase
• Renal
• Creatinine ≤ 2.0 mg/dL
• Cardiovascular
• Homocysteine concentration ≤ 17um/L
• No sustained blood pressure \> 150/95 mm Hg for 3 consecutive readings
• Other
• Vitamin B\_12 ≥ 250 pg/mL
• Folate level ≤ 20 mg/dL
• HIV negative
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for 4 weeks after study participation
• No intestinal malabsorption or inflammatory bowel disease
• No prior malignancy except nonmelanoma skin cancer
• No calcium metabolism abnormalities or predisposing conditions, such as hyperparathyroidism
• No untreated hyperthyroidism
• No untreated insulin-requiring diabetes mellitus
• No daily alcohol intake \> 2 ½ shot glasses of whiskey or three 8 ounce glasses of beer or wine
• No other serious illness that might limit life expectancy to \< 6 months
• PRIOR CONCURRENT THERAPY:
• Biologic therapy
• None
• Chemotherapy
• None
• Endocrine therapy
• No concurrent hormone replacement therapy, including oral, transplanted, or injected contraceptives
• Concurrent thyroid hormone replacement is allowed as long as the patient is euthyroid for 3 months
• Radiotherapy
• None
• Surgery
• No prior gastrointestinal surgery, including gastrectomy or small or large bowel resections
• * Prior appendectomy or surgery of the esophagus allowed
• Other
• More than 3 months since regular ingestion of ≥ 650 mg per day of aspirin (≥ 2 tablets of 325 mg regular strength OR \> 1 tablet of 500 mg extra strength aspirin)
• More than 3 months since regular daily ingestion of nonsteroidal anti-inflammatory drugs
• At least 1 month since vitamin, mineral, or herbal supplementation
• No other concurrent vitamin, mineral, or herbal supplementation
• No concurrent anticoagulants
• No concurrent sterol-binding resins (i.e., cholestyramine)
• No other concurrent investigational drugs or medications that might alter rectal mucosal proliferation, folate metabolism, or renal/hepatic impairment
• No concurrent weight control medications
• No concurrent supplemental folate preparations containing \> 400 mcg of folic acid per day
• No concurrent lipid-lowering medications
• * The following concurrent statin drugs are allowed provided patient has been taking a stable dose for ≥ 1 month:
• * Atorvastatin 10 or 20 mg/day
• * Fluvastatin 20 or 40 mg/day
• * Lovastatin 10 or 20 mg/day
• * Pravastatin 10 or 20 mg/day
• * Simvastatin 5 or 10 mg/day