The purpose of this study is to find out what effects (good and bad) taking capecitabine for 12 weeks before surgery will have on women with breast cancer.

• Prior to the start of treatment, patients will have a small metal clip inserted into the tumor bed to identify the tumor site to the surgeon. At that time, a needle biopsy of the breast tumor or a sentinel (underarm) lymph node biopsy will also be performed.
• Patients will take capecitabine orally twice daily for 14 days. This treatment will repeat every 21 days (1 cycle). Patients will receive 4 cycles of this treatment.
• A physical exam and blood work will be done every three weeks after starting therapy to monitor side effects.
• After two weeks of capecitabine a biopsy from the tumor will be done to generate information about the characteristics of the tumor that may respond to capecitabine.
• After completing 4 cycles (12 weeks) of capecitabine, patients will then undergo surgery to remove any remaining breast cancer (lumpectomy or mastectomy). Post-surgical treatment (radiation, chemotherapy, and hormonal therapy) is at the discretion of the patients physician.

• Invasive Breast Carcinoma
• Primary Invasive Breast Cancer
• Stage I Breast Cancer
• Stage II Breast Cancer
• Stage III Breast Cancer

Inclusion Criteria:

• Histological confirmation of primary invasive breast cancer
• Stage I-III operable breast cancer.
• Primary tumor must be greater than or equal to 2cm by radiographic imaging or palpitation
• Women greater than 18 years of age
• ECOG performance status 0-1
• WBC > 4000/mm3
• Platelet count > 100,000/mm3
• SGOT < 2x ULN
• Calculated creatinine clearance > 50ml/min

Exclusion Criteria:

• Evidence of metastatic (stage IV) cancer on physical exam or any diagnostic study.
• Pregnant or breast-feeding women
• Inflammatory breast cancer
• HER2 positive disease
• History of hypersensitivity to a 5-FU or known dihydropyrimidine dehydrogenase (DPD) deficiency
• Uncontrolled intercurrent illness
• Prior history of breast cancer are ineligible except: diagnosed at least 2 years ago; present cancer is not in previously irradiated breast; no prior chemotherapy in the past 5 years; no prior high-dose chemotherapy with stem cell or bone marrow transplant.
• Excisional biopsy performed prior to enrollment
• Uncontrolled coagulopathy
• Lack of physical integrity of the upper gastrointestinal tract or malabsorption syndrome.

• Hoffmann-La Roche
• Beth Israel Deaconess Medical Center
• Brigham and Women's Hospital
• Faulkner Hospital