Long-term follow-up of patients with metastatic breast cancer treated by trastuzumab: impact of institutions.

ABSTRACT

PURPOSE: Trastuzumab in Human Epidermal growth Receptor 2-positive (HER2+) metastatic breast cancer (MBC) was established as standard therapy since 2001. The objective of this study was to search for significant prognostic factors in patients with HER2+ MBC treated by trastuzumab taking into account the institution where the treatment was given. PATIENTS & METHODS: All patients with HER2+ MBC treated by trastuzumab between 2001 and 2010 in the 8 hospitals of Franche Comte region were analysed. Univariate and multivariate analysis were conducted to search for factors related to overall survival (OS). RESULTS: Among 1234 patients with MBC treated by chemotherapy between 2001 and 2010, 217 patients received trastuzumab. In this subset, the median age was 60 years, 8% and 38% had brain and liver metastases at first occurrence of MBC, 36% of, tumours were hormonal receptors positive. Patients were treated in 48% and 52% of cases in specialized and in general hospitals, respectively. The median OS length was 45.2 months (IQR 23.2-89.3 months). In univariate analysis the following factors were significantly related to favourable OS inclusion in clinical trials, treatment in a specialized hospital, positive hormonal receptors status, age <50. In multivariate analysis remained significant treatment in specialized hospital (aHR 0.78; 95%CI 0.64-0.94; p = 0.03) and age <50 (aHR 0.76; 95%CI 0.59-0.95; p = 0.02). CONCLUSION: Exposure to trastuzumab erases all established prognostic factors at the metastatic setting. The fact that patients treated in specialized hospitals presented a longer survival emphasizes the dramatic impact of this therapy and the relevance to optimize its use.