Progression-Free Survival and line of palliative therapy. Kaplan-Meier plot illustrating progression-free survival (PFS) in patients with metastasized breast cancer who received liposomal pegylated doxorubicin (PLD) monotherapy. Plotted according to line of palliative treatment in which PLD was applied, median PFS was 7.8 months for patients treated with PLD in first line, 7.1 months in second line, 7.4 months in third line, and 5.0 months in fourth or higher line, which was significantly different when pooled over strata (P = 0.010). Interestingly, pairwise comparisons showed no PFS difference between patients with PLD in first, second or third line. However, PFS was shorter for patients in fourth or higher line of PLD (when compared with first line: P = 0.012; second line: P = 0.004; third line: P = 0.095).