Fig. 9.

Median progression-free survival [PFS, months] (A) and median overall survival [OS, months] (B) of post-cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) treatments grouped by the therapy line in which subsequent therapy was received. Each subsequent treatment is presented along the X-axis with a unique reference number. The size of each bubble represents the sample size. Data were further grouped and color coded by the subsequent treatment received. Complete lists of included studies and reported PFS and OS are presented in Tables 5 and 6, respectively. #L number of lines of therapy, 2L second line, 3L third line, 4L fourth line, CT chemotherapy, ET endocrine therapy, NR not reported, Ref # reference number