Static disease on anastrozole provides similar benefit as objective response in patients with advanced breast cancer.

Abstract

BACKGROUND: This paper reports on the clinical relevance of durable static disease (SD) (> or = 24 weeks) in breast cancer patients treated with the aromatase inhibitor anastrozole. PATIENTS AND METHODS: All patients were part of two prospective, randomised, multicentre studies in postmenopausal women with advanced disease in which megestrol acetate was compared with anastrozole 1 mg. Survival from initiation of treatment was analysed by the response type, i.e., complete response (CR)/partial response (PR), static disease (SD) (> or = 24 weeks), or progressive disease (PD), achieved on therapy. RESULTS: Median survival with anastrozole 1 mg was similar between patients who obtained CR/PR and SD (> or = 24 weeks). Similarly, no difference in survival was observed in patients treated with megestrol acetate who achieved CR/PR and SD. With both treatments patients with CR/PR and SD had improved survival over those patients with PD within 24 weeks. There was no difference between treatment arms for patients showing PD within 24 weeks. CONCLUSIONS: These data confirm that durable SD (> or = 24 weeks) is a clinically useful remission criterion in postmenopausal women with advanced breast cancer with predictive value for overall survival. It also confirms the value of this endpoint with anastrozole, a new generation aromatase inhibitor.