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Clinical and Biologic Effects of Metformin in Early Stage Breast Cancer

This study has been completed.
Princess Margaret Hospital, Canada
Information provided by:
Mount Sinai Hospital, Canada Identifier:
First received: May 8, 2009
Last updated: January 18, 2012
Last verified: January 2012
The study will be testing metformin in patients with breast cancer who are about to undergo surgery. Patients will take metformin 3 times daily for about 2-3 weeks prior to their surgery date. It is hypothesized that metformin will reduce cell proliferation rates in tumour tissue.

Condition Intervention
Breast Cancer Drug: Metformin

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Clinical and Biologic Effects of Metformin in Early Stage Breast Cancer

Resource links provided by NLM:

Further study details as provided by Mount Sinai Hospital, Canada:

Primary Outcome Measures:
  • To determine if taking metformin prior to surgery can reduce cell proliferation rates in tumour tissue. To be determined by tumour specimen analysis using pre- and post-operative biopsy sample. [ Time Frame: two to three weeks ]

Enrollment: 39
Study Start Date: October 2008
Study Completion Date: July 2011
Primary Completion Date: July 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Metformin
Patients will take metformin three times a day for two to three weeks prior surgery.
Drug: Metformin
500 mg tablet, taken 3 times a day for 2-3 weeks


Ages Eligible for Study:   18 Years to 70 Years   (Adult, Senior)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. invasive T1-4 (if T1, ≥ 1cm), NX operable breast cancer confirmed on core biopsy
  2. < 70 years of age
  3. breast surgery scheduled at least 2 weeks after study entry at one of the participating institutions (metformin will be started no more than 3 weeks prior to scheduled surgery) for the current breast cancer
  4. patient and physician consent

Exclusion Criteria:

  1. on metformin for any reason during the preceding 4 weeks
  2. recent (within 4 weeks) antiestrogen or estrogen therapy
  3. prior or concurrent systemic neoadjuvant BC therapy of any type (chemotherapy, hormone therapy, biologic therapy)
  4. known diabetes or baseline fasting glucose > or = 7.0 mmol/L (specific treatment is required)
  5. current or recent (within 4 weeks) use of drugs that may influence insulin or insulin sensitivity including oral corticosteroids, insulin sensitizers, exogenous insulin or oral hypoglycemic agents
  6. serum creatinine above upper limit of normal for the institution
  7. history of lactic or other metabolic acidosis
  8. consumption of > 3 alcoholic beverages per day (on average)
  9. AST > 1.5 times upper limit of normal for the institution
  10. known hypersensitivity or allergy to metformin
  11. current or past congestive heart failure
  12. coagulopathy (including use of anti-coagulants) precluding biopsy
  13. pregnancy or lactation within 3 months.
  14. Serious psychiatric illness

    • Note: Women with childbearing potential will be required to use an effective form of birth control (condom or other barrier method, tubal ligation or vasectomy - oral contraceptives are contra-indicated in breast cancer) and to have a negative pregnancy test prior to starting metformin.
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Please refer to this study by its identifier: NCT00897884

Canada, Ontario
Mount Sinai Hospital
Toronto, Ontario, Canada, M5G 1X5
Princess Margaret Hospital
Toronto, Ontario, Canada, M5G 2M9
Sponsors and Collaborators
Mount Sinai Hospital, Canada
Princess Margaret Hospital, Canada
Principal Investigator: Pamela J Goodwin, MD Mount Sinai Hospital, New York
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Dr. Pamela Goodwin, Mount Sinai Hospital Identifier: NCT00897884     History of Changes
Other Study ID Numbers: METFORMIN
Study First Received: May 8, 2009
Last Updated: January 18, 2012

Keywords provided by Mount Sinai Hospital, Canada:
breast cancer
breast surgery

Additional relevant MeSH terms:
Breast Neoplasms
Neoplasms by Site
Breast Diseases
Skin Diseases
Hypoglycemic Agents
Physiological Effects of Drugs processed this record on September 21, 2017