Folic Acid in Preventing Colorectal Polyps in Patients With Previous Colorectal Polyps

Mass General Brigham

Status

Completed

Conditions

Adenoma of Large Intestine

Treatments

Other: Placebo

Dietary Supplement: Folic acid

Study type

Interventional

Funder types

Other

NIH

Identifiers

NCT00512850

CDR0000559650 (Registry Identifier)

BWH-94-06819 (Other Identifier)

R01CA067883 (U.S. NIH Grant/Contract)

BWH-1999-P-001674/10

Details and patient eligibility

About

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.

Full 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.

Enrollment

672 patients

Sex

All

Ages

Under 75 years old

Volunteers

No Healthy Volunteers

Inclusion and exclusion 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