Hormone Therapy and Combination Chemotherapy Before and After Surgery in Treating Patients With Stage I-IIIA Breast Cancer

PRIMARY OBJECTIVES: I. To assess the pathologic response rate in patients with operable breast cancer treated with a two part, neoadjuvant regimen consisting of complete hormonal blockade (CHB) for 2 weeks followed by four three-week cycles of Xeloda, Methotrexate and Navelbine with continuation of complete hormonal blockade. SECONDARY OBJECTIVES: I. To assess the clinical response rate in patients with surgically resectable breast cancer treated with complete hormonal blockade and four three-week cycles of Xeloda, Methotrexate and Navelbine. II. To assess the toxicity associated with these regimens. III. To assess the relapse rate, overall and disease-free survival in patients with operable breast cancer when treated with neoadjuvant CHB and XMN + CHB followed by adjuvant treatment using XMN or Taxol. IV. To assess whether the phenotype of breast cancer changes with treatment. V. To assess whether phenotypic changes in breast tumors predict outcome. OUTLINE: NEOADJUVANT CHB: Patients receive exemestane orally (PO) daily for 14 weeks. Premenopausal patients also receive triptorelin pamoate intramuscularly (IM) once monthly for 4 months beginning 2 weeks before the initiation of exemestane. NEOADJUVANT CHEMOTHERAPY: Patients receive capecitabine PO twice daily (BID) on days 1-14 and methotrexate intravenously (IV) and vinorelbine ditartrate IV over 6-10 minutes on days 1, 8, and 15. Treatment repeats every 21 days for 4 courses. SURGERY: Patients then undergo definitive surgical resection with or without radiation therapy. ADJUVANT CHEMOTHERAPY: Patients with microscopic complete response (pCR) or disease that has been down-staged to =\< 1 cm with no positive nodes receive capecitabine PO BID on days 1-14 and methotrexate IV and vinorelbine ditartrate IV over 6-10 minutes on days 1, 8, and 15. Treatment repeats every 21 days for 4 courses. Patients with down-staged T and 0 or 1 positive node receive paclitaxel IV over 1 hour once weekly for 12 weeks. ADJUVANT HORMONAL THERAPY: Patients receive hormonal therapy for 5 years. Treatment continues in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed every 3 months for 3 years, every 6 months for 2 years, and then annually thereafter.