Expression of Bax protein in normal tissue of premenopausal women treated with raloxifene - Revista Brasileira de Ginecologia e Obstetrícia

PURPOSE: to evaluate the expression of Bax antigen in the normal mammary epithelium of premenopausal women treated with raloxifene. METHODS: a randomized double-blind study was conducted in 33 ovulatory premenopausal women with fibroadenoma. Patients were divided into two groups: Placebo, (n=18) and Raloxifene 60 mg, (n=15). The medication was used for 22 days, beginning on the first day of the menstrual cycle. An excisional biopsy was carried out on the 23rd day of the menstrual cycle and a sample of normal breast tissue adjacent to the fibroadenoma was collected and submitted to immunohistochemical study using anti-Bax polyclonal antibody to evaluate the expression of Bax protein. Immunoreaction for Bax was evaluated taking into consideration intensity and fraction of stained cells, whose combination resulted in a final score ranging from 0 to 6. Cases with a final score >3 were classified as positive for Bax. The c2 test was used for statistical analysis (p<0.05). RESULTS: the percentage of positivity of Bax protein expression was 66.7 and 73.3% in Groups A and B, respectively. There was no significant difference in Bax expression between the two groups (p=0.678). CONCLUSIONS: raloxifene, administered for 22 days in the dose of 60 mg/day, did not alter the expression of Bax protein in the breast normal tissue of premenopausal women.