Clinical Trial of Letrozole （femara） versus Aminoglutethimide in Postmenopausal Women with Advanced Breast Cancer

Objective: To compare the response and adverse reactions of aminoglutethimide with that of femara, an oral aromatase inhibitor, in postmenopausal women with advanced breast cancer. Methods: Fifty patients were randomly assigned to femara 2.5 mg once daily (n=26) or aminoglutethimide (n=24) 125 mg twice daily in the first week, 250 mg twice daily in the second week, 250 mg three times daily in the third week and 250 mg four times daily in the fourth week, 30 days for one cycle for both groups. Results: Overall objective response rate (complete+partial) of 26.9% for femara was 12.5% higher than that of aminoglutethimide, but there was no significant difference (P=0.294). The percentages of stable disease were 53.8% and 50.0% respectively in both treatment groups and that of progressive disease of two groups were 19.2% and 37.5%. There was no significant difference between two arms in the receptor status, disease-free intervals, sites of disease and stages of treatment. Femara-related adverse events were fatigue (15.4%), anorexia (11.5%), dizziness (7.7%), nausea (3.8%) and somnolence (3.8%). However, incidence of nausea (25.0%) and vomiting (16.7%) in aminoglutethimide group was obviously higher and severer than that in femara group (P=0.045 and P=0.046). Compared to femara group, frequency in dizziness (25.0%), fatigue (20.8%), anorexia (16.7%), somnolence (12.5%) and cutaneous pruritus (12.5%) was higher in aminoglutethimide group. Allergic rash occurred in aminoglutethimide group. Conclusion: Femara was more effective and well tolerated than aminoglutethimide with respect to side effects in the treatment of postmenopausal women with advanced breast cancer.