Investigation of Genetic Determinants of Capecitabine Toxicity

Inclusion Criteria:

- women with breast cancer in whom single agent capecitabine therapy is being considered

- aged 18 years and older

Exclusion Criteria:

- patients who have previously received capecitabine are excluded

- patients cannot be receiving capecitabine in combination with another cancer
chemotherapy; concurrent use of trastuzumab is not permitted; concurrent use of
zoledronic acid is allowed

- serum albumin less than 3.0 g/dL within the last 30 days

- creatinine clearance (CrCL) or glomerular filtration rate (GFR) less than 60 mL/min
[/body surface area (BSA)] (within the last 30 days)

- inability to understand and give informed consent to participate

- patients with a history of inflammatory bowel disease requiring therapy or patients
with chronic diarrhea syndromes or paralytic ileus

- patients with prior or concurrent pelvic irradiation

- patients who use an ostomy for fecal excretion

- there is no limit on the number of prior chemotherapies; the decision to use
capecitabine is determined solely by the treating physician