Metronomic administration of pegylated liposomal-doxorubicin in extensively pre-treated metastatic breast cancer patients: A mono-institutional case-series report

Background: Metronomic chemotherapy has shown efficacy in patients with metastatic breast cancer. Pegylated liposomal-doxorubicin (PLD) pharmacokinetic characteristics support the rationale for using the drug in a metronomic fashion, potentially able to combine anthracyclines efficacy to a low toxicity profile. Patients and methods: In a case-series report carried out in both anthracycline-naive and pre-treated metastatic breast cancer patients, we tested feasibility, clinical efficacy and tolerability of PLD administered with a novel metronomic schedule of 20mg/m2i.v. every two weeks. Results: 52 patients were enrolled and 45 were evaluated. Forty-four patients were assessed for either response or toxicity. Eight patients (18%) had partial responses (PR) and 17 (39%) stable disease (SD), with a clinical benefit (CB) of 45% (95% CI: 30.3%-59.7%). Nineteen patients (43%) had progressive disease (PD). Neither grade 3 nor grade 4 haematological or clinical side effects were recorded, except for 2 patients with grade 3 palmar-plantar erythrodysesthesia (PPE). No cardiac toxicity was recorded. Conclusion: Metronomic administration of PLD is a feasible and active treatment for extensively pre-treated metastatic breast cancer patients, alternative to classic anthracyclines, balancing clinical efficacy with a good quality of life in terms of reduced side effects and low personal costs for the patient.