Exemestane With Celecoxib as Neoadjuvant Treatment in Postmenopausal Women With Stage II, III, and IV Breast Cancer

Rationale: In postmenopausal women, the main source of estrogen is through the conversion of
androgens, or sex hormones produced by the adrenal glands. An enzyme called aromatase
carries out this process. Exemestane, an aromatase inhibitor, blocks production of
estrogens. Research indicates that the gene responsible for aromatase activity is CYPO19.
Therefore, exemestane helps to inhibit aromatese activity through CYP019. Along with CYP019,
another gene associated with breast cancer is an overexpression of COX-2 enzymes. Research
suggests that COX-2 overexpression can cause cancer cell division, increased blood flow to
tumors, and metastases. Celecoxib blocks COX-2 activity and produces fewer side effects
compared with other non-steroidal inflammatory drugs (NSAIDs). This study builds on previous
research to test the combination of exemestane and celecoxib for breast cancer.

Purpose: This study is evaluating the safety and efficacy of exemestane and celecoxib before
surgery for stage II, III, and IV breast cancer in postmenopausal women. Tests will analyze
the CYP019 gene after these treatments.

Treatment: Patients in this study will receive exemestane and celecoxib. Both drugs will be
given to patients as oral pills. Exemestane will be taken daily for sixteen weeks. Starting
in week 9, celecoxib will be taken twice daily for eight weeks. Therefore, during weeks
9-16, patients will be taking both exemestane and celecoxib. Several tests and exams will be
given throughout the study to closely monitor patients, including a biopsy performed after
the first 8 weeks on exemestane. After sixteen weeks on exemestane and celecoxib, patients
will have breast surgery.