Letrozole and Celecoxib in Treating Postmenopausal Women With Locally Advanced or Metastatic Breast Cancer

DISEASE CHARACTERISTICS: Histologically or cytologically confirmed adenocarcinoma of the breast Locally advanced or metastatic disease Measurable disease No bone disease only No history of brain metastases unless controlled with radiotherapy or surgical resection for ≥ 6 months before study entry Hormone receptor status: Estrogen receptor- OR progesterone receptor-positive PATIENT CHARACTERISTICS: Age 18 and over Sex Female Menopausal status Postmenopausal, as defined by 1 of the following: Prior bilateral oophorectomy Prior bilateral ovarian irradiation No spontaneous menstrual bleeding within the past 12 months Age 55 and over AND prior hysterectomy without oophorectomy Age 54 and under AND prior hysterectomy without oophorectomy (or status of ovaries is unknown) AND documented follicle-stimulating hormone level in postmenopausal range Performance status ECOG 0-2 Life expectancy At least 3 months Hematopoietic Granulocyte count ≥ 1,000/mm^3 Platelet count ≥ 100,000/mm^3 Hepatic Bilirubin ≤ 1.5 times upper limit of normal (ULN) AST and ALT ≤ 2.5 times ULN Renal Creatinine ≤ 1.5 times ULN Other No prior allergic reaction attributed to compounds of similar chemical or biologic composition to study drugs No prior allergic reaction to sulfonamides No active peptic ulcer disease No active infection No other medical condition that would preclude study participation Able to swallow oral medication PRIOR CONCURRENT THERAPY: Biologic therapy Not specified Chemotherapy No prior chemotherapy for metastatic or recurrent disease Endocrine therapy No prior endocrine therapy for metastatic disease Prior adjuvant tamoxifen allowed No prior aromatase inhibitors No prior hormonal therapy for recurrent disease No other concurrent hormonal therapy Radiotherapy See Disease Characteristics See Menopausal status No concurrent radiotherapy Surgery See Disease Characteristics See Menopausal status Other No concurrent fluconazole or lithium No concurrent aspirin, non-steroidal anti-inflammatory drugs, or other cyclooxygenase-2 inhibitors Concurrent chronic cardioprotective low-dose aspirin allowed No other concurrent investigational agents