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Low-Fiber Diet or High-Fiber Diet in Preventing Bowel Side Effects in Patients Undergoing Radiation Therapy for Gynecological Cancer, Bladder Cancer, Colorectal Cancer, or Anal Cancer

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: NCT01170299
Recruitment Status : Completed
First Posted : July 27, 2010
Last Update Posted : November 1, 2016
Information provided by:
National Cancer Institute (NCI)

Brief Summary:

RATIONALE: Fiber may lessen bowel side effects caused by radiation therapy. It is not yet known whether a high-fiber diet is more effective than a low-fiber diet in preventing bowel side effects caused by radiation therapy.

PURPOSE: This randomized clinical trial is studying a high-fiber diet to see how well it works compared with a low-fiber diet in preventing bowel side effects in patients undergoing radiation therapy for gynecological cancer, bladder cancer, colorectal cancer, or anal cancer.

Condition or disease Intervention/treatment Phase
Anal Cancer Bladder Cancer Cervical Cancer Colorectal Cancer Fallopian Tube Cancer Gastrointestinal Complications Ovarian Cancer Radiation Toxicity Sarcoma Dietary Supplement: dietary intervention Other: laboratory biomarker analysis Procedure: gastrointestinal complications management/prevention Procedure: management of therapy complications Radiation: selective external radiation therapy Not Applicable

Detailed Description:



  • To compare the efficacy of a high- vs low-fiber intervention in preventing bowel toxicity in patients receiving radical pelvic radiotherapy treatment for gynecological, urological (bladder), colorectal, or anal malignancy.
  • To compare whether a high- or low-fiber intervention has any beneficial effect over no intervention (i.e., ad-libitum fiber consumption).
  • To examine the effect of a low- or high-fiber diet on gastrointestinal symptoms, measured using the IBDQ-B and Bristol Stool Chart, in patients receiving radical radiotherapy for pelvic malignancies.
  • To minimize any potential risk associated with change in fiber intake by using a controlled and gradual dietary-based intervention combined with dietetic advice.


  • To examine the relationship between volume of irradiated bowel and onset of gastrointestinal symptoms as measured by the Bristol Stool Chart.
  • To measure percentage compliance with fiber prescription through validated dietetic techniques including the 7-day Food Diary using household measures and the 24-hour recall.

OUTLINE: Patients are stratified according to disease (gynecological vs gastrointestinal) and concomitant therapy (received vs not received). Patients are randomized to 1 of 3 treatment arms.

  • Arm I (low-fiber diet): Patients are assessed by a qualified dietitian, receive written guidance, and are counseled as to how best to meet their study fiber prescription of a low-fiber diet, comprising 'not more than' 10 g of fiber per day for up to 7 weeks.
  • Arm II (high-fiber diet): Patients are assessed by a qualified dietitian, receive written guidance, and are counseled as to how best to meet their study fiber prescription of a high-fiber diet, comprising a target of between 18 and 22 g of fiber per day for up to 7 weeks.
  • Arm III (no intervention): Patients receive advice designed to ensure they maintain their normal habitual diet for up to 7 weeks.

All patients undergo radiotherapy once daily comprising approximately 25 (or more) fractions in total to be delivered for 5-7 weeks in the absence of unacceptable toxicity.

All patients are asked to complete two 7-day Food Diaries at baseline and end of radiotherapy treatment. All patients keep a daily record of stool characteristics and frequency using the Bristol Stool Chart. Patients also complete a short 1-page weekly-cost questionnaire to assess the economic impact of symptom management. Patients in arms I and II complete several additional questions regarding the costs (if any) of adhering to their fiber prescription and the palatability of the diet.

Blood and stool samples may be collected at baseline and during study therapy for biomarker analysis.

After completion of study treatment, patients are followed up for up to 1 year.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 177 participants
Allocation: Randomized
Masking: None (Open Label)
Primary Purpose: Supportive Care
Official Title: A Randomized Controlled Trial to Investigate the Role of Low or High 'Fibre' Diets in Patients Undergoing Pelvic Radiotherapy - The Fibre Study
Study Start Date : October 2009
Actual Primary Completion Date : December 2012
Actual Study Completion Date : January 2014

Primary Outcome Measures :
  1. Change in IBDQ-B (Inflammatory Bowel Disease Questionnaire - Bowel Subset) score between baseline (i.e., Day 1 of radiotherapy treatment) and the nadir score during treatment

Secondary Outcome Measures :
  1. Incidence of toxicity, defined using the Bristol Stool Chart
  2. Costs for symptom management

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 120 Years   (Child, Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No


  • Diagnosis of gynecological, urological (bladder), colorectal, or anal malignant cancer
  • Scheduled to undergo a course of radical or adjuvant pelvic radiotherapy (≥ 45 Gy)

    • Radiotherapy regimen will be delivered in daily fractions comprising approximately ≥ 25 fractions over 5-7 weeks


  • No prior prescribed low-residue diet for a clear medical reason
  • No established wheat intolerance or celiac disease
  • No concurrent condition precluding oral nutritional intake


  • No gastrointestinal stent
  • No jejunostomy, ileostomy, or colostomy
  • No concurrent participation in a study with toxicity as an endpoint

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): NCT01170299

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United Kingdom
Royal Marsden - London
London, England, United Kingdom, SW3 6JJ
Sponsors and Collaborators
Royal Marsden NHS Foundation Trust
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Study Chair: Peter R. Blake, MD Royal Marsden NHS Foundation Trust
OverallOfficial: Jervoise Andreyev, MD Royal Marsden NHS Foundation Trust
Layout table for additonal information Identifier: NCT01170299    
Other Study ID Numbers: RM-FIBRE-STUDY
CDR0000681693 ( Registry Identifier: PDQ (Physician Data Query) )
First Posted: July 27, 2010    Key Record Dates
Last Update Posted: November 1, 2016
Last Verified: July 2010
Keywords provided by National Cancer Institute (NCI):
radiation toxicity
gastrointestinal complications
cervical cancer
fallopian tube cancer
ovarian epithelial cancer
ovarian germ cell tumor
ovarian sarcoma
ovarian stromal cancer
uterine sarcoma
bladder cancer
colon cancer
rectal cancer
anal cancer
Additional relevant MeSH terms:
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Colorectal Neoplasms
Uterine Cervical Neoplasms
Urinary Bladder Neoplasms
Fallopian Tube Neoplasms
Anus Neoplasms
Intestinal Neoplasms
Gastrointestinal Neoplasms
Digestive System Neoplasms
Neoplasms by Site
Digestive System Diseases
Gastrointestinal Diseases
Colonic Diseases
Intestinal Diseases
Rectal Diseases
Neoplasms, Connective and Soft Tissue
Neoplasms by Histologic Type
Adnexal Diseases
Genital Neoplasms, Female
Urogenital Neoplasms
Uterine Neoplasms
Uterine Cervical Diseases
Uterine Diseases
Urologic Neoplasms
Urinary Bladder Diseases
Urologic Diseases
Fallopian Tube Diseases
Rectal Neoplasms
Anus Diseases