Abstract P6-11-08: A Comparison of Chemotherapeutic Treatment Practice in Metastatic Breast Cancer (MBC) in Belgium (BE) and The Netherlands (NL)

Introduction: Current treatment recommendations provide limited guidance for chemotherapy (CT) of MBC, while physicians have many options to choose from. We undertook a retrospective survey to describe and compare actual CT approaches to MBC in clinical practice in two neighboring European countries, BE and NL. Methods: 20 BE and 18 NL hospitals collected data for 490 and 434 patients (pts), respectively, diagnosed with MBC in 2003-2009 and treated with ≥1 CT regimen. Demographic, disease and treatment data of the last 25 consecutively treated pts per hospital were included in each survey. The NL survey required age ≥70 yrs at MBC diagnosis, the BE survey had no upper age limit. We compared patient characteristics and treatment policies between both cohorts (BE vs. NL, for all comparisons). Results: BE patients were older at MBC diagnosis (median 60 vs. 56 yrs) and had M1 tumor status at primary diagnosis more frequently (26 vs. 20%). Average year of MBC diagnosis was 2005 for both countries. There were no striking differences in ER/PR positivity (61/50 vs. 64/47%), HER2/neu overexpression (27 vs. 31%), triple negative status (12 vs. 15%), or cardiac co-morbidity. Prior hormonal (22 vs. 12%), hormonal + adjuvant CT (32 vs. 26%), and total adjuvant CT (58 vs. 51%) had been given more frequently in the BE cohort. In pts receiving adjuvant CT, anthracyclines had been used more frequently in the NL cohort (61 vs. 78%). Pts in the BE and NL cohort received up to 10 and 6 lines of CT, respectively. 79 vs. 73% and 55 vs. 43% of pts received 2 and 3 lines of CT, respectively. BE pts received far more monotherapy in first line (46 vs. 25%), but not in second (66 vs. 65%) and third line (65 vs. 63%). Drugs used most frequently for monotherapy in lines 1-3 were the same in BE and NL: docetaxel (40 vs. 38%) and capecitabine (13 vs. 26%) in line 1; docetaxel (27 vs. 38%) and capecitabine (23 vs. 16%) in line 2; capecitabine (30 vs. 30%) and vinorelbine (16 vs. 19%) in line 3. The most frequently used CT combinations were very different: FEC (40%)vs. FAC (24%) in first line, FEC (7%) vs. CMF (14%) in second line, and non-pegylated liposomal doxorubicin/cyclophosphamide (6%) vs. CMF (15%) in third line. Many different CT regimens for MBC were used throughout all lines (e.g. > 20 regimens in first line) in both countries. Overall, 81 vs. 71% of pts received a taxane and/or an anthracycline in first line, 57 vs. 60% in second line, and 43 vs. 29% in third line. 33 vs. 36% were re-challenged with an anthracycline after having received anthracycline-based (neo) adjuvant CT. Physician-assessed response (52 vs. 53%) and stable disease rates (22 vs. 26%) to first-line CT were similar. Conclusions: Daily treatment practice of MBC differs considerably between BE and NL, in particular with respect to monotherapy vs. combination CT in first line, specific combination regimens used in lines 1-3, and the number of subsequent lines employed. More adjuvant treatment appeared to have been given to Belgian pts. Despite these differences, reported response rates were remarkably similar. Although a wide variety of CT regimens are used in MBC in BE and NL, anthracyclines and taxanes are the cornerstones in both countries. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-11-08.