Clinical and Biologic Effects of Metformin in Early Stage Breast Cancer

Study Overview
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Brief Summary
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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.

Official Title
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Clinical and Biologic Effects of Metformin in Early Stage Breast Cancer

Conditions
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Breast Cancer

Intervention / Treatment
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* Drug: Metformin


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: invasive T1-4 (if T1, ≥ 1cm), NX operable breast cancer confirmed on core biopsy < 70 years of age 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 patient and physician consent Exclusion Criteria: on metformin for any reason during the preceding 4 weeks recent (within 4 weeks) antiestrogen or estrogen therapy prior or concurrent systemic neoadjuvant BC therapy of any type (chemotherapy, hormone therapy, biologic therapy) known diabetes or baseline fasting glucose > or = 7.0 mmol/L (specific treatment is required) 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 serum creatinine above upper limit of normal for the institution history of lactic or other metabolic acidosis consumption of > 3 alcoholic beverages per day (on average) AST > 1.5 times upper limit of normal for the institution known hypersensitivity or allergy to metformin current or past congestive heart failure coagulopathy (including use of anti-coagulants) precluding biopsy pregnancy or lactation within 3 months. 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.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Metformin<br>Patients will take metformin three times a day for two to three weeks prior surgery. | Drug: Metformin<br>* 500 mg tablet, taken 3 times a day for 2-3 weeks<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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. |  | two to three weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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breast cancer, metformin, breast surgery