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

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00512850
Recruitment Status : Completed
First Posted : August 8, 2007
Last Update Posted : March 3, 2017
National Cancer Institute (NCI)
Dana-Farber/Brigham and Women's Cancer Center
Information provided by (Responsible Party):
Edward Giovannucci, Brigham and Women's Hospital

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.

Condition or disease Intervention/treatment Phase
Adenoma of Large Intestine Dietary Supplement: Folic acid Other: Placebo Not Applicable

Detailed Description:



  • 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.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 672 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Prevention
Official Title: The Nurses' Health Study (NHS) and Health Professionals Follow-Up Study (HPFS) Folic Acid Prevention Trial
Study Start Date : May 1996
Actual Primary Completion Date : March 2004
Actual Study Completion Date : February 1, 2017

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Folic acid
Folic acid supplement 1g/day
Dietary Supplement: Folic acid
Intervention group 1g folic acid per day

Placebo pill once per day
Other: Placebo
One placebo pill per day

Primary Outcome Measures :
  1. Recurrent colorectal adenoma [ Time Frame: May 1996-March 2004 ]

Secondary Outcome Measures :
  1. recurrent adenoma by location, size, stage, number, [ Time Frame: May1996-March 2004 ]

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   up to 75 Years   (Child, Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No


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


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


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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00512850

Sponsors and Collaborators
Brigham and Women's Hospital
National Cancer Institute (NCI)
Dana-Farber/Brigham and Women's Cancer Center
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Principal Investigator: Edward L. Giovannucci, MD, ScD Dana-Farber/Brigham and Women's Cancer Center

Publications of Results:
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Responsible Party: Edward Giovannucci, Edward Giovannucci, MD, Brigham and Women's Hospital Identifier: NCT00512850    
Other Study ID Numbers: BWH-1999-P-001674/10
CDR0000559650 ( Registry Identifier: PDQ (Physician Data Query) )
BWH-94-06819 ( Other Identifier: Brigham and Women's Hospital Legacy # )
R01CA067883 ( U.S. NIH Grant/Contract )
First Posted: August 8, 2007    Key Record Dates
Last Update Posted: March 3, 2017
Last Verified: March 2017
Keywords provided by Edward Giovannucci, Brigham and Women's Hospital:
Folic acid
Adenoma of Large Intestine
Additional relevant MeSH terms:
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Neoplasms, Glandular and Epithelial
Neoplasms by Histologic Type
Folic Acid
Vitamin B Complex
Growth Substances
Physiological Effects of Drugs