Non Pegylated Liposomal Doxorubicin Beyond the First Line Treatment of Metastatic Breast Cancer Patients: A Retrospective Analysis

ABSTRACT Background The aim of this retrospective study was to access the benefit of a non-pegylated liposomal doxorubicin (NPLD) treatment beyond the first line therapy in patients with metastatic breast cancer (MBC) after previous exposure to an anthracycline containing regimen. Patients and methods A pharmacy prospectively collected database in the Franche-Comte region, was used to identify a cohort of patients with MBC treated by NPLD regimen between 2003 and 2010.In total, 140 patients were included in the analysis. Progression-free survival (PFS) was chosen as the primary efficacy endpoint. Cox proportional hazard models were fitted to identify factors that could influence both PFS and overall survival (OS) lenght. Survival data were computed according to Kaplan Meier method. Results Primary tumours characteristics were oestrogen receptor-positive, progesterone receptor positive and HER2 positive in 77%, 63% and 20% respectively. Median PFS length was 4 months [95% CI: 2-5] and 33% of patients experienced a PFS longer than 6 months. Overall response (OR) was observed in 27 patients (19.3%, 95%CI [10.2-28.4]). Median OS after NPLD was 13 months [95% CI: 10-14]. In multivariate analysis, prognostic factors significantly related to longer OS from NPLD first exposure were age younger than 50 years old (HR = 0.57 [0.35-0.93], p = 0.02) and HER2 positive tumour (HR = 0.53 [0.30-0.95], p = 0.03). 17 patients (12.1%) discontinued NPLD treatment due to toxicity. In those, 9 (6.4%) patients experienced cardiac toxicity (grade 2 or 3). There were 2 (1.4%) deaths related to cardiac toxicity. Conclusion Re-challenge by an anthracycline-containing regimen should been considered in patients with MBC taking into account this encouraging ORR and the length of PFS and response duration. However cardiac safety of patients must be carefully investigated during the treatment taking into account the number of treatment cessation due to cardiac damage. Of interest the subset of patients with HER2 positive tumour seemed to highly benefit from the NLPD. This finding emphasizes the sensitivity to anthracycline in this subset of HER2 positive tumours and oncologist should not forgot anthracycline containing regimen as a possible option in MBC after failure to numerous lines including chemotherapy and HER2 targeted agents. Disclosure All authors have declared no conflicts of interest.