Metformin for Reduction of Paclitaxel-Related Neuropathy in Patients With Breast Cancer

The goal of this clinical research study is to learn if metformin can help to control nerve damage (loss of motor or sensory function) that may be caused by treatment with paclitaxel in patients with breast cancer. In this study, metformin will be compared to a placebo. A placebo is not a drug. It looks like the study drug, but it is not designed to treat any disease or illness. It is designed to be compared with a study drug to learn if the study drug has any real effect.