Folic Acid in Preventing Colorectal Polyps in Patients With Previous Colorectal Polyps
|ClinicalTrials.gov Identifier: NCT00512850|
Recruitment Status : Completed
First Posted : August 8, 2007
Last Update Posted : March 3, 2017
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.
|Condition or disease||Intervention/treatment|
|Adenoma of Large Intestine||Dietary Supplement: Folic acid Other: Placebo|
- Determine if folic acid supplementation lowers the adenoma recurrence rate.
- 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.
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||672 participants|
|Intervention Model:||Parallel Assignment|
|Masking:||Double (Participant, Investigator)|
|Official Title:||The Nurses' Health Study (NHS) and Health Professionals Follow-Up Study (HPFS) Folic Acid Prevention Trial|
|Study Start Date :||May 1996|
|Primary Completion Date :||March 2004|
|Study Completion Date :||February 1, 2017|
Folic acid supplement 1g/day
Dietary Supplement: Folic acid
Intervention group 1g folic acid per day
Placebo pill once per day
One placebo pill per day
- Recurrent colorectal adenoma [ Time Frame: May 1996-March 2004 ]
- recurrent adenoma by location, size, stage, number, [ Time Frame: May1996-March 2004 ]
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00512850
|Principal Investigator:||Edward L. Giovannucci, MD, ScD||Dana-Farber/Brigham and Women's Cancer Center|