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

This study has been completed.
National Cancer Institute (NCI)
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: March 2, 2017
Last verified: March 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 Intervention
Adenoma of Large Intestine
Dietary Supplement: Folic acid
Other: Placebo

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Participant, 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 ]

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

Enrollment: 672
Study Start Date: May 1996
Study Completion Date: February 1, 2017
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   (Child, Adult, Senior)
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
  Contacts and Locations
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, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00512850

Sponsors and Collaborators
Brigham and Women's Hospital
National Cancer Institute (NCI)
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 ( Registry Identifier: PDQ (Physician Data Query) )
BWH-94-06819 ( Other Identifier: Brigham and Women's Hospital Legacy # )
R01CA067883 ( US NIH Grant/Contract Award Number )
Study First Received: August 6, 2007
Last Updated: March 2, 2017

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 processed this record on April 28, 2017