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Flaxseed in Treating Postmenopausal Women With Hot Flashes Who Have a History of Breast Cancer or Other Cancer or Who Do Not Wish to Take Estrogen Therapy

This study has been completed.
National Cancer Institute (NCI)
Information provided by (Responsible Party):
Alliance for Clinical Trials in Oncology Identifier:
First received: August 8, 2009
Last updated: July 12, 2016
Last verified: July 2016

RATIONALE: Estrogen can relieve the symptoms of menopause, but can also cause the growth of breast cancer cells. Flaxseed may reduce the number of hot flashes and improve mood and quality of life in postmenopausal women not receiving estrogen therapy.

PURPOSE: This randomized phase III trial is studying flaxseed to see how well it works in treating postmenopausal women with hot flashes who have a history of breast cancer or other cancer or who do not wish to take estrogen therapy.

Condition Intervention Phase
Breast Cancer
Hot Flashes
Menopausal Symptoms
Unspecified Adult Solid Tumor, Protocol Specific
Dietary Supplement: flaxseed
Other: placebo
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Supportive Care
Official Title: Phase III, Randomized, Placebo-controlled, Double-Blind Trial of Flaxseed for the Treatment of Hot Flashes

Resource links provided by NLM:

Further study details as provided by Alliance for Clinical Trials in Oncology:

Primary Outcome Measures:
  • Hot flash score at week 7 [ Time Frame: Up to 7 weeks ]

Secondary Outcome Measures:
  • Toxicity as measured by CTCAE v3.0 [ Time Frame: Up to 7 weeks ]
  • Change of mood as measured by the POMS [ Time Frame: Up to 7 weeks ]
  • Change of menopause specific quality of life as measured by the MENQOL [ Time Frame: Up to 7 weeks ]
  • Change of daily interference as measured by the HFRDIS [ Time Frame: Up to 7 weeks ]

Enrollment: 210
Study Start Date: October 2009
Study Completion Date: May 2013
Primary Completion Date: October 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Arm I
Patients receive oral flaxseed in the form of a bar similar to a granola bar once daily.
Dietary Supplement: flaxseed
Given orally
Placebo Comparator: Arm II
Patients receive oral placebo bar once daily.
Other: placebo
Given orally

Detailed Description:


  • To evaluate the efficacy of flaxseed on hot flash scores in women with a history of breast cancer or other cancer or in women who do not wish to take estrogen therapy for fear of increased risk of breast cancer as measured by a daily prospective hot flash diary.
  • To evaluate the side effect profile of flaxseed in this population.
  • To evaluate the effects of flaxseed on mood (per the Profile of Mood States) and broader menopausal symptoms (per the MENQOL), daily interference from hot flashes (per the HFRDIS), and perception of benefit (per Global Impression of Change).

OUTLINE: Patients are stratified according to age (18-49 years vs ≥ 50 years); treatment with tamoxifen citrate, selective estrogen receptor modulators, or aromatase inhibitors (yes vs no); duration of hot flashes (≤ 9 months vs > 9 months); and daily frequency of hot flashes (4-9 vs ≥ 10). Patients are randomized to 1 of 2 treatment arms.

  • Arm I: Patients receive oral flaxseed in the form of a bar similar to a granola bar once daily.
  • Arm II: Patients receive oral placebo bar once daily. In both arms, treatment continues for 6-12 weeks. Patients in arm II may crossover to receive treatment as in arm I after 6 weeks.

Patients complete questionnaires (Hot Flash Diary, Side Effect Experience Questionnaire, Profile of Mood States, Hot Flash Related Daily Interference Scale, and Menopause Specific Quality of Life) at baseline and periodically during treatment. Patients are contacted by telephone at the end of weeks 2, 4, 5, and 7 to assess product tolerability, document compliance, encourage completion of questionnaires, and address problems.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No
  • Bothersome hot flashes, defined by their occurrence ≥ 28 times per week and of sufficient severity to make the patient desire therapeutic intervention

    • Presence of hot flashes for ≥ 1 month
  • Meets 1 of the following criteria:

    • History of breast cancer or other cancer (currently without malignant disease)
    • No history of breast cancer and wishes to avoid estrogen due to a perceived increased risk of breast cancer
  • Hormone receptor status not specified
  • Postmenopausal as defined by 1 of the following*:

NOTE: *Women with ≥ 1 ovary but without a uterus should be deemed postmenopausal by either age > 55 OR a combination of estrogen within a postmenopausal range (per local lab) and follicle-stimulating hormone > 40 mIU/mL

  • Absence of a period in the past 12 months
  • Bilateral oophorectomy

    • ECOG performance status 0-1
    • Life expectancy ≥ 6 months
    • Able to complete questionnaire(s) alone or with assistance
    • No diabetes requiring oral or injectable antihyperglycemics
    • No hypotension
    • No history of allergic or other adverse reaction to flaxseed
    • No irritable bowel syndrome, colitis, Crohn disease, or any gastrointestinal condition where the patient should not consume and/or has an intolerance/allergies to seeds or nuts
    • At least 4 weeks since prior and no concurrent or planned androgens, estrogens, or progestational agents
  • Tamoxifen, raloxifene, or aromatase inhibitors are allowed provided the patient has been on a constant dose for ≥ 4 weeks and is not expected to stop the medication during study treatment

    • At least 4 weeks since prior and no concurrent anti-cancer therapies of any kind

  • Trastuzumab allowed

    • No concurrent treatment with other anti-cancer therapies of any kind except for trastuzumab or endocrine therapies
    • No concurrent (≤ 7 days prior to registration) or planned use of other agents for treating hot flashes (i.e., gabapentin, clonidine, antidepressants, estrogen treatment, megestrol acetate, or Bellergal)
  • Stable dose of vitamin E (as a general vitamin supplement) allowed provided it is ≤ 800 IU/day, it was started > 30 days before study initiation, and is to be continued through study period
  • Patients who have been using antidepressants for mood and have been on a stable dose for over a month and meet the eligibility criteria for hot flash frequency and duration are eligible

    • No concurrent anticoagulants or anti-platelets (1 mg of Coumadin for central line patency allowed)

  • Aspirin allowed (≤ 81 mg)

    • No concurrent anti-hypertensives
    • No other concurrent herbal supplements for any reason, including soy and soy supplements (i.e., powders, pills, or milk)
  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: NCT00956813

  Show 107 Study Locations
Sponsors and Collaborators
Alliance for Clinical Trials in Oncology
National Cancer Institute (NCI)
Study Chair: Debra Barton, RN, PhD, AOCN, FAAN Mayo Clinic
  More Information

Responsible Party: Alliance for Clinical Trials in Oncology Identifier: NCT00956813     History of Changes
Other Study ID Numbers: N08C7  NCCTG-N08C7  CDR0000644811  NCI-2011-01928 
Study First Received: August 8, 2009
Last Updated: July 12, 2016

Keywords provided by Alliance for Clinical Trials in Oncology:
menopausal symptoms
hot flashes
breast cancer
unspecified adult solid tumor, protocol specific

Additional relevant MeSH terms:
Breast Neoplasms
Hot Flashes
Neoplasms by Site
Breast Diseases
Skin Diseases
Signs and Symptoms processed this record on February 23, 2017