Evaluation of Metformin, Targeting Cancer Stem Cells for Prevention of Relapse in Gynecologic Patients

Inclusion Criteria:

1. Patients with potential diagnosis of ovarian, fallopian, or primary peritoneal cancer.
2. Care plan including surgical debulking and traditional adjuvant or neo-adjuvant chemotherapy (6-9 cycles of platinum and taxane based therapy).
3. Eastern Cooperative Oncology Group performance status 0-2.
4. Age \> 18 years or \< 80 years.
5. Adequate renal function (serum creatinine \<1.4mg/dL).
6. Adequate liver function (bilirubin \< 1.5 times ULN).

   * Alanine Aminotransferase (ALT) or Aspartate Aminotransferase (AST) \< 5 times the upper limit of normal in case of liver metastases.
   * ALT or AST \< 2.5 times the ULN in absence of liver metastases.
7. Ability to understand and complete written informed consent.
8. Mentally, physically, and geographically able to undergo treatment and follow up.

Exclusion Criteria:

1. Patients diabetes mellitus. (Patients with only a history of gestational diabetes will be allowed to be included in the study.)
2. Metformin use in the last 6 months.
3. A known hypersensitivity to metformin.
4. A history of metabolic acidosis, including ketoacidosis or increased risk of lactic acidosis.
5. Pregnancy or Lactation.
6. Patients who have any severe and/or uncontrolled medical conditions.
7. Patients with a history of renal disease.
8. Patients with other known active malignancy (excluding adequately treated basal cell / squamous cell skin cancer, in situ cancer, or other cancer for which the patient has been disease free for 2 years).
9. Patients receiving any other investigational agents.