Metformin and Locally Advanced Cervix Cancer

Cervical cancer remains an important health problem worldwide. Poor tumor oxygenation (hypoxia) is associated with inferior survival in cervical cancer and resistance to radiation treatment. Hypoxia-modifying therapies improve survival, but existing therapies are impractical and/or toxic. Metformin, a non-toxic drug for diabetes, has been shown to decrease tumor hypoxia in animal studies and its use is associated with better survival in diabetic cancer patients. It is hypothesized that metformin may decrease cervical tumor hypoxia and thereby improve tumor response to radiation and survival in patients with locally advanced cervix cancer. This is a randomized, multicenter phase II study of standard chemoradiation in combination with metformin versus standard chemoradiation alone in women with locally advanced cervix cancer. Women randomized to the metformin group will take metformin starting 1 week prior to standard chemoradiation and throughout the duration of external radiation treatment. Tumor hypoxia will be measured by a special X-ray test called positron emission test (PET) performed with a hypoxia dye called FAZA. The main purpose of this study is to see if metformin decreases tumor hypoxia measured on FAZA-PET; information about response and side effects will also be collected.