Abstract Abstract #6132 Material and Methods: Fulvestrant is an estrogen receptor (ER) antagonist with a distinct mode of action used in the treatment of postmenopausal women with advanced breast cancer progressing or recurring on an antiestrogen. 848 postmenopausal women with ER+ advanced mamma carcinoma, relapsed during or after adjuvant anti-estrogene treatment, or with a disease progression under an anti-estrogene therapy, were enrolled in this Fulvestrant In Practice Evaluation Programme (IPEP). Under daily routine conditions and without intervention by the sponsor regarding selection of subjects, diagnostic procedures or therapeutic decisions relevant data of the fulvestrant therapy was documented over a period of 9 months. Results: The median patient age was 64 years, 52 % of patients had a co-morbidity, 78 % one or more prior palliative therapies. Efficacy: Clinical benefit was observed in 627/848 patients, including 62 complete and 177 partial remissions. Best response was delayed in 115 patients (not seen at 3 months but at 6 months). Estimated 9-month overall survival (OS) was 89%; 9-month event-free survival (EFS) was 71%. Safety: 244 non-serious adverse events by patient were recorded, most commonly General disorders and administration site conditions, gastrointestinal and musculo-sceletal symptoms. Excluding deaths, 7 serious adverse events were recorded (none attributed to fulvestrant); no new or unexpected safety issues arose. 20 patients died during observation. Tolerability: Tolerability was judged as good to very good by the majority of both specialists and patients with stable values at 3, 6 and 9 months. Acceptance of injection: The vast majority of both doctors and patients found the application via injection to be acceptable or very acceptable, the handling was judged by the doctors as mostly good to very good. Conclusion: Fulvestrant treatment was well tolerated and well accepted in this palliative patient collective, no new safety findings occurred. The treatment showed good efficacy with any patient, who had achieved disease stabilization or better after three months being likely to gain survival benefit from prolonged Fulvestrant therapy. Best response often occured delayed. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6132.