RESUMO
BACKGROUND: The aim of this study was to evaluate the effect of raloxifene on CD34 and Ki-67 antigen expression in breast cancer specimens from postmenopausal women. METHODS: Sixteen postmenopausal patients with operable, stage II (>or=3 cm), estrogen receptor-positive breast cancer, who took 60 mg of raloxifene daily for 28 days, participated in this study. Immunohistochemistry was carried out in tumor samples prior to and following raloxifene treatment to evaluate CD34 and Ki-67 protein expression. Angiogenesis was quantified in 10 randomly selected fields per slide, and Ki-67-stained nuclei were counted in 1,000 cells per slide using an image capture and analysis system with 400x magnification. Student's t test for paired samples was used for the statistical analysis of data. Statistical significance was established at p < 0.05. RESULTS: The mean number of microvessels was 44.44 +/- 3.54 prior to raloxifene therapy and 22.63 +/- 1.61 following therapy (p < 0.001), and the mean percentage of Ki-67-stained nuclei was 19.28 +/- 1.61 and 12.13 +/- 1.48 prior to and following raloxifene treatment, respectively (p < 0.001). CONCLUSION: Raloxifene significantly reduces CD34 and Ki-67 protein expression in breast carcinoma in postmenopausal women.
