The study hypothesis is that changes in serially obtained nerve conduction study data obtained every 3-4 weeks in cancer patients receiving chemotherapy can be used to predict the development of a clinically significant / disabling drug induced neuropathy six and twelve months following the start of treatment. Patients with breast cancer, colon cancer, gastroesophageal cancer, and non-Hodgkins lymphoma will be enrolled. Six lower extremity nerves--three in each leg--will be electrically stimulated and their responses recorded at three to four week intervals coinciding with patient's scheduled chemotherapy.

Inclusion Criteria:

• Clinical diagnosis of untreated breast cancer, treated (advance stage) or untreated colon cancer, untreated non-Hodgkins lymphoma, or advanced gastroesophageal cancer scheduled to begin chemotherapy with either Taxol, oxaliplatin, or vincristine

Exclusion Criteria:

• Individuals with an implanted electronic medical devices (cardiac pacemaker or defibrillator, vagus nerve stimulator, deep brain stimulator, intrathecal pump, others)
• Individuals whose chemotherapy regimen will include nerve toxic drugs other than Taxol, oxaliplatin, or vincristine, or includes more than one of these three drugs in combination
• Individuals whose screening nerve conduction studies show peroneal motor amplitude < 1 mV bilaterally or sural sensory amplitude < 3 uV bilaterally or no result obtainable

Patients presenting to an oncology clinic for treatment of breast cancer, colon cancer, or non-Hodgkins lymphoma, or treatment of advanced gastroesophageal cancer