Fig. 2

Disease-free interval (DFI) of stage I–II–III assessed using AJCC 2018 anatomical stage (log-rank test p < 0.001) (a), prognostic stage (log-rank test p < 0.001) (b) and Ki67-PS (log-rank test p < 0.001) (c) (Kaplan–Meier analysis). DFI of stage IA and IB assessed using prognostic stage and of stage IA obtained from downstaging of IB using Ki67-integrated prognostic score (Ki67-PS) (log-rank test p < 0.001) (Kaplan–Meier analysis) (d).