Biomarkers in Chemotherapy-Induced Peripheral Neurotoxicity

This pilot study will attempt to establish the feasibility of using tissue oxygen measurements and the protein, neurofilament light chain (NF-L), as potential biomarkers for chemotherapy-induced peripheral neuropathy (CIPN). Thirty (30) subjects scheduled to begin taxane-based chemotherapy for breast tumor will be assigned to receive an India ink injection under the skin of the foot. The ink will be used to make up to five (5) 45-minute "electron paramagnetic resonance" (EPR) oximetry readings prior to the start of chemotherapy. Subjects will undergo electrophysiologic assessments including nerve conduction studies, in addition to a neurological examination prior to the start of chemotherapy. Subjects will have the EPR oximetry readings, electrophysiologic tests, and neurological examination two more times: at the halfway point of their chemotherapy treatment -- or at the onset of CIPN symptoms -- and again after chemotherapy has been completed. Subjects will also have blood drawn prior to beginning taxane-based chemotherapy, prior to every scheduled chemotherapy treatment, and after completion of chemotherapy in order to test for neurofilament light chain (NF-L).