Exercise and Metformin in Colorectal and Breast Cancer Survivors
Condition: Colorectal Cancer; Breast Cancer
MeSH terms: Breast Neoplasms
Intervention: Exercise training; Metformin; Educational information
Intervention description: Two supervised exercise sessions per week; Oral metformin QD for two weeks, then BID; educational information
Intervention MeSH terms: Metformin
Phase: Phase 2
Study type: Interventional
Primary purpose: Diagnostic
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Enrollment: 139.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: No
Keywords: Colorectal; Breast; Insulin; Exercise

Summary:

      Metformin is a medication that is commonly used in the treatment of diabetes. Recently small
      studies in cancer patients without diabetes suggest that metformin may benefit in lowering
      insulin levels. In those studies of patients with cancer but not diabetes, glucose (or sugar)
      levels in the blood are generally no lowered. Insulin and insulin-like growth factors affect
      the growth of cancer cells.

      This randomized study will compare different interventions; exercise, exercise and metformin,
      metformin alone, or a control arm. The investigators are not directly testing how either
      exercise or metformin affects your disease. The investigators are testing how they affect
      insulin levels in your body as well as other blood markers. The investigators believe that
      these blood tests may either be related to cancer recurrences or be an early sign of cancer
      recurrences and they are testing how both exercise and metformin may change those markers.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Histologically confirmed stage I-III colorectal or breast cancer

          -  Undergone curative-intent complete surgical resection and completed all adjuvant
             therapy (if indicated) at least 2 months prior to enrollment

          -  Note: Breast cancer subjects on hormonal therapy or trastuzumab only therapy and
             colorectal cancer subjects on adjunctive therapies not considered cytotoxic
             chemotherapy (including those participating in CALGB 80702 receiving only
             celecoxib/placebo) are eligible.

          -  Participants will be allowed to receive concomitant adjuvant endocrine therapy for
             breast cancer; however, all endocrine agents must be initiated at least 1 month prior
             to enrollment in the study and continued throughout the duration of study
             participation.

          -  Less than 120 minutes of exercise per week

          -  Approval by oncologist or surgeon

          -  English speaking and able to read English

          -  No planned surgery anticipated in the 3 month intervention period

          -  At least one month from any major surgery to start of intervention including colostomy
             reversal

        Exclusion Criteria:

          -  Concurrent other malignancy or history of other malignancy treated within the past 3
             years (other than non-melanoma skin cancer or in-situ cervical cancer)

          -  Metastatic disease

          -  Scheduled to receive any form of further adjuvant cancer therapy

          -  Currently on medication for diabetes treatment

          -  Pregnant or breast-feeding

          -  Any condition associated with increased risk of metformin-associated lactic acidosis
             (prior renal failure or liver failure, history of acidosis of any type; habitual
             intake of 3 or more alcoholic beverages per day)

          -  Known hypersensitivity or intolerance to metformin