Try the modernized beta website. Learn more about the modernization effort.
Working… Menu

Flaxseed, Aromatase Inhibitors and Breast Tumor Characteristics (FABrC)

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: NCT00612560
Recruitment Status : Completed
First Posted : February 11, 2008
Results First Posted : August 16, 2017
Last Update Posted : October 12, 2017
National Center for Complementary and Integrative Health (NCCIH)
Information provided by (Responsible Party):
Roswell Park Cancer Institute

Brief Summary:
The proposed study plans to examine the effect of flaxseed consumption, a phytoestrogen rich food, compared to aromatase inhibitors as a complementary approach to treating estrogen receptor positive breast cancer, as well as the effect of combined flaxseed and aromatase inhibitor therapy on breast cancer treatment. Because of the increasing use of both complementary and alternative approaches to treatment, and the use of aromatase inhibitors in the treatment of breast cancer, the proposed study has potential to provide important clinical information about the effect of foods high in phytoestrogens on a common endocrine therapy used in breast cancer.

Condition or disease Intervention/treatment Phase
Breast Cancer Drug: Anastrozole Dietary Supplement: flaxseed Drug: Placebo Not Applicable

Detailed Description:
Although the 10 year survival rate for women with early stage breast cancer is very good, distant recurrence is still a serious concern, especially for estrogen receptor positive women. Consequently, breast cancer survivors are interested in therapies that might improve their recurrence free survival (RFS). Used in postmenopausal women, aromatase inhibitors (AI) block the peripheral conversion of androgens to estrogen, effectively lowering the estradiol available to promote breast tumor proliferation. However, use of AIs is associated with hot flashes, joint pain, bone loss, and an increase in cardiac events. Furthermore, many breast tumors eventually develop resistance to hormonal treatments. Complementary and alternative medicines (CAMs) are widely used by cancer survivors in an attempt to reduce disease recurrence with fewer side effects and potential health benefits, and use is particularly prevalent among breast cancer survivors. Flaxseed (FS) is a commonly available food often consumed as a dietary supplement and is the richest food source of lignans, a phytoestrogen. In experimental models, flaxseed consumption has been shown to exhibit a number of activities that suggest a potential benefit of flaxseed in the adjuvant setting. However, the majority of human studies investigating the biologic effects of flaxseed have involved healthy women. There is a paucity of clinical data regarding the efficacy and safety of use of flaxseed among women with breast cancer, especially among those receiving AIs. Because the phytoestrogens in flaxseed can influence many of the same biologic pathways affected by hormonal agents, diet-drug interactions are possible. Additionally, it is possible flaxseed could act through growth and signaling pathways, modifying the development of endocrine resistance. Potential synergistic or antagonistic effects between flaxseed and antiestrogens are of particular interest given the increasing use of AIs to treat postmenopausal women with hormone responsive disease. We propose to conduct a pilot 2x2 factorial randomized intervention study between tumor biopsy and resection, in postmenopausal women diagnosed with ER positive breast cancer, to assess the effects of flaxseed and AI on a number of steroid hormone and tumor-related characteristics associated with long-term survival, and to investigate the potential interaction between flaxseed and AI on tumor expression of Ki-67, caspase, ERα, ERβ, PgR, HER2, IGF1, IGFIR. The pre-surgical setting offers a unique opportunity to rapidly obtain information on intervention related effects on growth factor and signaling pathways related to tumor characteristics in a short time period without the interference of other treatments. We hypothesize that both flaxseed and AI interventions will independently favorably affect growth factor and signaling pathway protein expression resulting in reduced tumor proliferation and increased apoptosis. We further hypothesize that these improvements will be reflected in improved recurrence scores as estimated by the Mammostrat antibody panel (Applied Genomics Incorporated). The proposed study will provide important clinical data for future dietary intervention studies involving phytoestrogen lignans from flaxseed.

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 28 participants
Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
Official Title: Flaxseed vs. Aromatase Inhibitors: Breast Tumor Characteristics and Prognosis
Study Start Date : November 2007
Actual Primary Completion Date : January 2011
Actual Study Completion Date : April 2014

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Breast Cancer
Drug Information available for: Anastrozole

Arm Intervention/treatment
Experimental: 2
Flaxseed 25 mg per day and 1 placebo pill per day
Dietary Supplement: flaxseed
25 g per day ground

Experimental: 3
25 mg flaxseed per day and 1 mg anastrozole pill per day
Drug: Anastrozole
1 mg per day
Other Name: Arimidex

Dietary Supplement: flaxseed
25 g per day ground

Placebo Comparator: 4
Placebo pill 1 per day
Drug: Placebo
Placebo pill 1 per day

Experimental: 1
Anastrozole 1 mg pill per day
Drug: Anastrozole
1 mg per day
Other Name: Arimidex

Primary Outcome Measures :
  1. Expression of Estrogen Receptor (ER-beta) [ Time Frame: Biopsy/Week 1 and Surgical Resection/Week 2 ]
    Mean percentage of cells expressing estrogen receptor (ER-beta)

  2. Progesterone Receptor (PR) Expression [ Time Frame: Biopsy/Week 1 and Surgical Resection/Week 2 ]
    Mean percentage of cells expressing PR

  3. Human Epidermal Growth Factor Receptor 2 (Her2) Expression [ Time Frame: Biopsy/Week 1 and Surgical Resection/Week 2 ]
    Mean percentage of cells expressing human epidermal growth factor receptor 2 (Her2)

Secondary Outcome Measures :
  1. Growth Hormone Serum Levels IGF-1 [ Time Frame: Biopsy/Week 1 and Surgical Resection/Week 2 ]
    Mean serum level IGF-1(pg/ml)

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.

Layout table for eligibility information
Ages Eligible for Study:   18 Years to 85 Years   (Adult, Older Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Age ≥ 18 and ≤ 85 years
  • Postmenopausal status defined as: no menstrual cycle in the past 12 months hysterectomy with bilateral oophorectomy hysterectomy with intact ovaries if age > 55 years
  • Newly diagnosed with incident, primary, invasive, estrogen receptor positive clinical stage II or lower breast cancer
  • ECOG performance status of 1 or less
  • Willingness to comply with study guidelines and procedures
  • Willingness and ability to provide informed consent
  • Usual consumption of soy no more than 1 time per week and willingness to avoid whole soy foods or concentrated soy sources (soy milk, tofu, substitute meat products, meal replacement bars) during the intervention period
  • Willingness to avoid herbal and dietary supplements (not including vitamins), aspirin, and ibuprofen during the intervention period
  • No competing neoadjuvant or chemotherapy treatment
  • Time between pre-surgical visit and surgery must be at least 2 weeks
  • No chemotherapy in the past 12 months

Exclusion Criteria:

  • Inability to read and write English
  • Previous invasive breast cancer
  • Insulin dependent Type I or II diabetes diagnosed by physician
  • History of coagulopathy, thrombocytopenia, or bleeding disorder
  • Current (past 30 days) regular (at least once per week) use of reproductive hormone therapy, Tamoxifen, aromatase inhibitors, or other estrogen inhibitors, flaxseed, or antibiotics
  • Current chemotherapy or neoadjuvant chemotherapy
  • Allergies to flaxseed, nuts, or other seeds
  • Renal dysfunction defined as creatinine > 1.5 mg/dl
  • History of Crohns' disease, ulcerative colitis, irritable bowel syndrome, celiac sprue, or other malabsorption syndrome, diverticulitis, diverticulosis, or other bowel diagnosis which, in the opinion of the breast surgeon, would contraindicate large doses of dietary fiber or would impair nutrient absorption
  • Current, regular (more than once weekly) use of prescription blood-thinning agents including coumadin, heparin and heparin related drugs, clopidogrel bisulfate

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): NCT00612560

Layout table for location information
United States, New York
Roswell Park Cancer Institute
Buffalo, New York, United States, 14263
Sponsors and Collaborators
Roswell Park Cancer Institute
National Center for Complementary and Integrative Health (NCCIH)
Layout table for investigator information
Principal Investigator: Tracey L O'Connor, MD Roswell Park Cancer Institute
Publications automatically indexed to this study by Identifier (NCT Number):
Layout table for additonal information
Responsible Party: Roswell Park Cancer Institute Identifier: NCT00612560    
Obsolete Identifiers: NCT00635908
Other Study ID Numbers: I 99507
R21AT004024-01 ( U.S. NIH Grant/Contract )
First Posted: February 11, 2008    Key Record Dates
Results First Posted: August 16, 2017
Last Update Posted: October 12, 2017
Last Verified: September 2017
Keywords provided by Roswell Park Cancer Institute:
breast neoplasms
tumor characteristics
estrogen receptor
Additional relevant MeSH terms:
Layout table for MeSH terms
Breast Neoplasms
Neoplasms by Site
Breast Diseases
Skin Diseases
Antineoplastic Agents, Hormonal
Antineoplastic Agents
Aromatase Inhibitors
Steroid Synthesis Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Estrogen Antagonists
Hormone Antagonists
Hormones, Hormone Substitutes, and Hormone Antagonists
Physiological Effects of Drugs