| Abstract: |
Background:Tamoxifen, for many years the ‘gold standard’ in the adjuvant setting of endocrine sensitive early breast cancer, is associated with an increased risk of endometrial cancer and other life-threatening events. Moreover, many women relapse during or after tamoxifen therapy due to development of resistance. This provided the rationale for a switching trial with anastrozole. Aim of the work: to evaluate the efficacy and safety associated with switching to anastrazole after three years of tamoxifen therapy, in post menopausal women with estrogen receptors positive early breast cancer. Patient and Methods: After receiving tamoxifen treatment for 3 years, eligible patients (n=100) were randomly assigned to switch to anastrazole(1mg/d)or continue tamoxifen(20 mg/d)for an additional 2 years. Patients were monitored every 3 months for local recurrences,and distant mets. Mammography of the contra lateral breast, chest X-ray, ultrasound of the liver, skeletal sintigraphy performed every 12 months For 3 years follow up period ,the primary objective was to compare the disease free survival, Secondary objectives were to compare the overall survival, safety and tolerability between the two treatment groups..Results: early results at 36 months follow up period: the mean 3 year disease free survival time was 34 month in group (A) versus 33 months in group (B). This difference is statistically insignificant (p value 0.294). Fewer patients who switched to anastrazole experienced first recurrence events compared with those who continued on tamoxifen 6 patients (12%) in group A and 9 patients (18%) in group B. The mean overall survival time was 36 months in group (A) versus 34 months in group (B). This difference is statistically insignificant (P value 0.1429).Generally, there is improved disease free survival and overall survival in patients of group (A) than patients of group (B), though statistically insignificant, and this can be explained by the small number of the patients and short follow up period.The toxicity pattern was generally tolerable, endometrial events and thromboembdic events were higher in tamoxifen group. Lipid metabolism disorders, arthralgia, bone pain and osteoporosis were higher in anastrazole group. Conclusion: switching to anastrazol in postmenopausal women with estrogen receptor positive early breast cancer may improve the disease free survival, overall survival and improving the toxicity profile rather than continuing on tamoxifen but to confirm this results larger number of patients and longer period of follow up is required. Key words: Anastrazole, tamoxifen,breast cancer,postmenopausal.
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