Clinical Trial: Folic Acid in Preventing Colorectal Polyps in Patients With Previous Colorectal Polyps
Study Status: Completed
Recruit Status: Completed
Study Type: Interventional
Official Title: The Nurses' Health Study (NHS) and Health Professionals Follow-Up Study (HPFS) Folic Acid Prevention Trial
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 Summary:
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.
Sponsor: Brigham and Women's Hospital
Current Primary Outcome: Recurrent colorectal adenoma [ Time Frame: May 1996-March 2004 ]
Original Primary Outcome: Diagnosis of a recurrent adenomatous polyp(s) of the colorectum on subsequent colonoscopy
Current Secondary Outcome: recurrent adenoma by location, size, stage, number, [ Time Frame: May1996-March 2004 ]
Original Secondary Outcome:
- Number of adenomas per patient and the size of these adenomas
- Interaction between folic acid intake and alcohol, methionine, and aspirin intake
Information By: Brigham and Women's Hospital
Dates:
Date Received: August 6, 2007
Date Started: May 1996
Date Completion:
Last Updated: March 2, 2017
Last Verified: March 2017