Carboplatin/pegylated liposomal doxorubicin/bevacizumab (CD-BEV) vs. carboplatin/gemcitabine/bevacizumab (CG-BEV) in patients with recurrent ovarian cancer: A prospective randomized phase III ENGOT/GCIG-Intergroup study (AGO study group, AGO-Austria, ANZGOG, GINECO, SGCTG).