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Exemestane in Reducing Breast Density in Postmenopausal Women at Risk for Breast 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: NCT00066586
Recruitment Status : Completed
First Posted : August 7, 2003
Last Update Posted : April 2, 2020
Information provided by (Responsible Party):
Canadian Cancer Trials Group ( NCIC Clinical Trials Group )

Brief Summary:

RATIONALE: High estrogen levels may be associated with dense breast tissue and an increased risk of developing breast cancer. Exemestane may be effective in preventing the development of breast cancer by decreasing estrogen levels and reducing breast density.

PURPOSE: Randomized clinical trial to study the effectiveness of exemestane in preventing the development of breast cancer by decreasing estrogen levels and reducing breast density in postmenopausal women who are at increased risk for breast cancer.

Condition or disease Intervention/treatment Phase
Breast Cancer Drug: exemestane Drug: Placebo Not Applicable

Detailed Description:


  • Determine the efficacy of exemestane in decreasing breast density at least 1 grade in postmenopausal women with increased radiological breast density at increased risk for breast cancer.
  • Determine whether the decrease in breast density is sustained 1 year after the cessation of this drug in these participants.
  • Correlate the grade of breast density with bone density at baseline and at 1 year in participants treated with this drug.
  • Determine the overall safety of this drug, in terms of bone and lipid metabolism and toxicity, in these participants.
  • Determine the menopause-specific quality of life of participants treated with this drug.

OUTLINE: This is a randomized, double-blind, placebo-controlled, multicenter study. Participants are stratified according to baseline mammographic density grade (2 vs 3 vs 4 vs 5 vs 6). Participants are randomized to 1 of 2 treatment arms.

  • Arm I: Participants receive oral exemestane once daily for 1 year.
  • Arm II: Participants receive oral placebo once daily for 1 year. In both arms, treatment continues in the absence of disease or unacceptable toxicity.

Quality of life is assessed at baseline and then at 3, 6, 9, 12, 18, and 24 months.

Participants are followed at 18 and 24 months.

PROJECTED ACCRUAL: A total of 120 participants (60 per treatment arm) will be accrued for this study.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 98 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary Purpose: Prevention
Official Title: A Randomized Study Of The Effect Of Exemestane (Aromasin) Versus Placebo On Breast Density In Postmenopausal Women At Increased Risk For Development Of Breast Cancer
Actual Study Start Date : August 1, 2001
Actual Primary Completion Date : November 16, 2007
Actual Study Completion Date : February 10, 2009

Resource links provided by the National Library of Medicine

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

Arm Intervention/treatment
Active Comparator: Exemestane Drug: exemestane
exemestane 25 mg once daily x 1 year

Placebo Comparator: Placebo Drug: Placebo
placebo once daily x 1 year

Primary Outcome Measures :
  1. Change in breast density as measured by Boyd Scale at 1 year [ Time Frame: 6 years ]

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:   Female
Accepts Healthy Volunteers:   No


  • Radiologically confirmed density occupying at least 25% of the breast tissue on baseline mammogram*

    • Grade 2, 3, 4, 5, or 6 (Boyd classification)

      • Participants with different grades between the 2 breasts should be classified according to a higher grade NOTE: *Performed within 6 months before study entry
  • Bone mineral density T-score of either posterior-anterior spine or hip (femoral neck) must be no greater than 2.0 standard deviations below the mean value of peak bone mass in young normal women as determined by DEXA scan within the past 6 months
  • No concurrent breast cancer
  • No prior invasive breast cancer or ductal carcinoma in situ
  • No breast implants
  • Hormone receptor status:

    • Not specified



  • Postmenopausal


  • Female

Menopausal status

  • Postmenopausal, defined as 1 of the following:

    • Over 50 years of age with no spontaneous menses for at least 1 year
    • 50 years of age and under with no menses (e.g., spontaneous or secondary to hysterectomy) within the past year AND a follicle-stimulating hormone level within institution postmenopausal range
    • Bilateral oophorectomy

Performance status

  • Not specified

Life expectancy

  • Not specified


  • Not specified


  • Not specified


  • Not specified


  • No cardiovascular disease
  • No history of myocardial infarction
  • No history of stroke
  • No uncontrolled high blood pressure


  • No uncontrolled metabolic or endocrine disease
  • No malabsorption syndrome
  • No known hypersensitivity to exemestane or its excipients
  • No other malignancy within the past 5 years except curatively treated squamous cell or basal cell skin cancer or carcinoma in situ of the cervix


Biologic therapy

  • No prior immunotherapy
  • No concurrent immunotherapy


  • No prior chemotherapy
  • No concurrent chemotherapy

Endocrine therapy

  • More than 3 months since prior exogenous estrogen and/or progesterone/progestin therapy
  • More than 6 months since prior selective estrogen-receptor modulators (e.g., tamoxifen, toremifene, or raloxifene)
  • No concurrent selective estrogen-receptor modulators (e.g., tamoxifen, toremifene, or raloxifene)
  • No concurrent steroids
  • Vaginal estrogens allowed (e.g., Estring® or Vagifem®)

    • No concurrent compounded creams


  • Not specified


  • Not specified


  • More than 4 weeks since prior investigational agents
  • No other concurrent medications that would preclude study endpoints
  • No concurrent over-the-counter products or supplements considered to have an estrogenic effect, including any of the following:

    • Ginseng
    • Ginkgo biloba
    • Black cohosh
    • Dong quai
    • Fortified soy supplements (e.g., phytoestrogen preparations)

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): NCT00066586

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United States, Florida
Mayo Clinic - Jacksonville
Jacksonville, Florida, United States, 32224
United States, Massachusetts
Massachusetts General Hospital Cancer Center
Boston, Massachusetts, United States, 02114
Dana-Farber/Harvard Cancer Center at Dana Farber Cancer Institute
Boston, Massachusetts, United States, 02115
Beth Israel Deaconess Medical Center
Boston, Massachusetts, United States, 02215
Brigham and Women's Hospital
Boston, Massachusetts, United States, 02215
United States, Minnesota
Mayo Clinic Cancer Center
Rochester, Minnesota, United States, 55905
United States, Ohio
Arthur G. James Cancer Hospital and Solove Research Institute at Ohio State University
Columbus, Ohio, United States, 43210-1240
United States, Rhode Island
Memorial Hospital of Rhode Island
Pawtucket, Rhode Island, United States, 02860
Canada, Ontario
Margaret and Charles Juravinski Cancer Centre
Hamilton, Ontario, Canada, L8V 5C2
Northwestern Ontario Regional Cancer Care at Thunder Bay Regional Health Sciences Centre
Thunder Bay, Ontario, Canada, P7B 6V4
Princess Margaret Hospital
Toronto, Ontario, Canada, M5G 2M9
Canada, Quebec
Centre Hospitalier de l'Universite de Montreal
Montreal, Quebec, Canada, H2L-4M1
Sponsors and Collaborators
NCIC Clinical Trials Group
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Study Chair: Paul E. Goss, MD, PhD Massachusetts General Hospital
Publications of Results:
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Responsible Party: NCIC Clinical Trials Group Identifier: NCT00066586    
Obsolete Identifiers: NCT00258648
Other Study ID Numbers: MAP2
CAN-NCIC-MAP2 ( Other Identifier: PDQ Identifier )
PFIZER-971-ONC-0028-088 ( Other Identifier: Pfizer )
CDR0000316328 ( Other Identifier: PDQ )
First Posted: August 7, 2003    Key Record Dates
Last Update Posted: April 2, 2020
Last Verified: March 2020
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Canadian Cancer Trials Group ( NCIC Clinical Trials Group ):
breast cancer
Additional relevant MeSH terms:
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Breast Neoplasms
Neoplasms by Site
Breast Diseases
Skin Diseases
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