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