Polyp Prevention Trial
N/A
75 Years
Both
Colorectal Cancer
Trial Information
Polyp Prevention Trial
OBJECTIVES:
Primary
- Determine if folic acid supplementation lowers the adenoma recurrence rate.
Secondary
- Determine the number of adenomas per patient and the size and histology of the adenoma.
- Assess the interaction between folic acid and alcohol, methionine, and aspirin intake.
- Assess the interaction between folic acid and pretrial and midtrial folate levels.
- Assess other complementary biomarkers such as DNA methylation and blood folate level as
risk factors for polyp recurrence.
OUTLINE: Patients are randomized to 1 of 2 treatment arms.
- Arm I: Patients receive oral folic acid once daily.
- Arm II: Patients receive oral placebo once daily. At least 1 year after beginning
treatment, patients are sent a blood collection kit in order to measure plasma vitamin
B12 levels, to measure folate to assess compliance.
Inclusion Criteria
DISEASE CHARACTERISTICS:
Inclusion criteria:
- Participated in the Nurses' Health Study (NHS I) or the Health Professionals
Follow-Up Study (HPFS) and have had a previous confirmed diagnosis of adenomatous
polyp of the colon or rectum
- Plan on having an endoscopy within 4 years after initiation of the trial
- Must release medical records regarding past and any future endoscopies
PATIENT CHARACTERISTICS:
Inclusion criteria:
- Plasma vitamin B12 concentration of ≥ 300 pg/mL or have a vitamin B12 concentration
between 200 and 299 pg/mL and a methylmalonic acid (MMA) level ≤ 32 µg/L
Exclusion criteria:
- Diagnosis of cancer other than non-melanoma skin cancer, or early stage breast or
prostate cancer
- Diagnosis of homocystinemia
- Diagnosis of pernicious anemia
- Any gastrointestinal disorder that could lead to a vitamin B12 deficiency
- Diagnosis of cirrhosis or pancreatitis
- Diagnosis of epilepsy, Alzheimer's disease, Parkinsonism, and psychiatric disorders
that may interfere with normal functioning
PRIOR CONCURRENT THERAPY:
Exclusion criteria:
- No prior gastrectomy, total colectomy, or pancreatectomy
- Other concurrent multivitamins or supplements that contain folic acid (they may take
specific supplements, such as A, C, E, calcium, and iron, or antioxidant formula
vitamins)
- No concurrent methotrexate or anticonvulsant
Type of Study:
Interventional
Study Design:
Allocation: Randomized, Primary Purpose: Prevention
Outcome Measure:
Diagnosis of a recurrent adenomatous polyp(s) of the colorectum on subsequent colonoscopy
Safety Issue:
No
Principal Investigator
Edward L. Giovannucci, MD, ScD
Investigator Role:
Principal Investigator
Investigator Affiliation:
Dana-Farber/Brigham and Women's Cancer Center
Authority:
United States: Federal Government
Study ID:
CDR0000559650
NCT ID:
NCT00512850
Start Date:
Completion Date:
Related Keywords:
- Colorectal Cancer
- colon cancer
- rectal cancer
- Colorectal Neoplasms
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