Safety and efficacy of metronomic non-pegylated liposomal encapsulated doxorubicin in heavily pretreated advanced breast cancer patients.

Purpose: Metronomic administration of the same chemotherapy agents (lower doses with closer intervals) may optimize their antiangiogenic properties. The aim of our study was to determine the efficacy and safety of a metronomic regimen based in non-pegylated liposomal doxorubicin (NPLD) in advanced breast cancer patients.

Methods: Clinical records of patients with pretreated advanced breast cancer and who were treated with the Metronomic-Cooper-type regimen consisting of weekly fixed doses of NPLD (30 mg IV) plus 5-Fluorouracil (5-FU) (500 mg IV) plus vincristine (0.25 mg IV) and daily oral cyclophosphamide (50 mg) plus prednisone (20 mg) were reviewed.

Results: In 84 pretreated patients, a tumor response was observed in 38 patients (45 %); stable disease was observed in 23 patients (27 %). Median progression-free survival (PFS) time to progression was 8.4 months and median overall survival (OS) was 21 months. The most common grade 2-3 hematologic adverse event was neutropenia, which was observed in 47 patients (56 %). Febrile neutropenia was observed in 10 patients (12 %). The most common non-hematologic adverse events were asthenia and mucositis which were observed in 60 patients (71 %) and 26 patients (31 %), respectively. Three patients (4 %) experienced an asymptomatic decline of the left ventricular ejection fraction.

Conclusions: NPLD-based metronomic regimen was effective and safe in pretreated advanced breast cancer patients. It could be considered as an appealing option to treat patients previously exposed to anthracyclines.