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