Patients with Stage I-III breast cancer who will receive paclitaxel or docetaxel treatments as part of their standard of care adjuvant or neoadjuvant therapy are eligible for this study.

Quantitative measures that include additional aspects of peripheral neuropathy, such as pain, thermal allodynia, numbness and tingling are needed. We propose to evaluate several pharmacodynamics biomarkers in patients before and during chemotherapy: changes in nerve conduction velocity and amplitude, quantitative sensory testing (QST), computer based cognitive assessment, and rate of drop-out from treatment. The tests from this list that best correlate with decreased CIPN would be added to EORTC QLQ-CIPN20 scores and will provide an early indication of CIPN and/or CICI.

The phrase "Shopping List Learning" is displayed on screen. The pre-task on-screen instructions tell the test supervisor to start this task with the screen facing the supervisor so that the subject cannot see the screen. There are 3 initial rounds of this test. In the first round, the subject is told by the test supervisor: "In this task, I am going to read you a shopping list. I would like you to remember as many items from this list as possible.Total number of correct responses made in remembering the 16 word list on three consecutive learning trials. (Higher score = better performance)

The pre-task on-screen instructions ask: "Has the card turned over?" The test supervisor reads the full instructions to the subject from the test supervisor script. To begin the task, a playing card is presented in the center of the screen. The card will flip over so it is face up. As soon as it does, the subject must press the "Yes" key. The card will go to the back of the pack and the subject must press the "Yes" key as soon as the next card flips over and so on. The subject will practice until they reach the required number of responses, or until the practice period expires. Then, on screen instructions for the real test are presented. The test supervisor or subject must press the "Enter" key to begin the real test.

Speed of performance; mean of the log10 transformed reaction times for correct responses. Lower score = better performance

To begin the task, the test supervisor or subject must press the "Enter" key. A playing card is presented in the center of the screen. The card will flip over so it is face up. As soon as it does this the subject must decide whether the card is red or not. If it is red they should press "Yes", if it is not red they should press "No". The subject will practice until they reach the required number of responses, or until the practice period expires. Then, on screen instructions for the real test are presented. The subject should be encouraged to work as quickly as they can and be as accurate as they can.

Low score = better performance.

Blood samples will be collected in heparinized tubes before the first paclitaxel/docetaxel treatment (baseline). We will collect approximately 20 mL of blood from each subject. White blood cells will be isolated using standard procedures. NCS1 levels will be assessed by Western blot analysis and by qPCR. Additional parameters will be monitored, especially if the variability in NCS1 levels is large. Parameters will be chosen from our understanding of the biochemical pathways identified in the Ehrlich laboratory as part of a separate on-going basic project. The prospective NCS1 values will be correlated with the assessment of CIPN and CICI in each patient obtained in Aim 1.