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

This study is ongoing, but not recruiting participants.
Dana-Farber/Brigham and Women's Cancer Center
Information provided by (Responsible Party):
Edward Giovannucci, Brigham and Women's Hospital Identifier:
First received: August 6, 2007
Last updated: July 29, 2013
Last verified: July 2013

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 Intervention
Adenoma of Large Intestine
Dietary Supplement: Folic acid
Other: Placebo

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Prevention
Official Title: The Nurses' Health Study (NHS) and Health Professionals Follow-Up Study (HPFS) Folic Acid Prevention Trial

Resource links provided by NLM:

Further study details as provided by Brigham and Women's Hospital:

Primary Outcome Measures:
  • Recurrent colorectal adenoma [ Time Frame: May 1996-March 2004 ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • recurrent adenoma by location, size, stage, number, [ Time Frame: May1996-March 2004 ] [ Designated as safety issue: No ]

Enrollment: 672
Study Start Date: May 1996
Estimated Study Completion Date: January 2016
Primary Completion Date: March 2004 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
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

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.

Ages Eligible for Study:   up to 75 Years
Genders Eligible for Study:   Both
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
  Contacts and Locations
Please refer to this study by its identifier: NCT00512850

Sponsors and Collaborators
Brigham and Women's Hospital
Dana-Farber/Brigham and Women's Cancer Center
Principal Investigator: Edward L. Giovannucci, MD, ScD Dana-Farber/Brigham and Women's Cancer Center
  More Information

Responsible Party: Edward Giovannucci, Edward Giovannucci, MD, Brigham and Women's Hospital Identifier: NCT00512850     History of Changes
Other Study ID Numbers: BWH-1999-P-001674/10, CDR0000559650, BWH-94-06819, R01CA067883
Study First Received: August 6, 2007
Last Updated: July 29, 2013
Health Authority: United States: Institutional Review Board

Keywords provided by Brigham and Women's Hospital:
Folic acid
Adenoma of Large Intestine

Additional relevant MeSH terms:
Neoplasms, Glandular and Epithelial
Neoplasms by Histologic Type
Folic Acid
Vitamin B Complex
Growth Substances
Physiological Effects of Drugs
Pharmacologic Actions
Hematologic Agents
Therapeutic Uses processed this record on April 16, 2014