Adenoma of Large Intestine
Conditions
Keywords
Folic acid, Adenoma of Large Intestine
Brief summary
RATIONALE: Chemoprevention is the use of certain substances to keep cancer from forming. The use of folic acid may prevent colorectal cancer. PURPOSE: This randomized clinical trial is studying how well folic acid works compared with a placebo in preventing colorectal polyps in patients who have had previous colorectal polyps.
Detailed description
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.
Interventions
DIETARY_SUPPLEMENTFolic acid
Intervention group 1g folic acid per day
OTHERPlacebo
One placebo pill per day
Sponsors
National Cancer Institute (NCI)
Dana-Farber/Brigham and Women's Cancer Center
Brigham and Women's Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
ALL
Age
No minimum to 75 Years
Healthy volunteers
No
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:
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Recurrent colorectal adenoma | May 1996-March 2004 |
Secondary
| Measure | Time frame |
|---|---|
| recurrent adenoma by location, size, stage, number, | May1996-March 2004 |
Outcome results
None listed