Fig. 1

Profile of the study, the selection of optimal cut-off points, and Kaplan–Meier (KM) curves of DFS and OS between ovarian preservation (OP) and bilateral salpingo-oophorectomy (BSO) groups. A Flowchart of the study analysis process. B-D The optimal cut-off points to dichotomize age, tumor maximal diameter, and LNM ratio into different groups are 46 years old, 2.4 cm, and 24% (determined by survminer R package using logrank test). E-F Comparison of OP and BSO in all patients. G-H Comparison of OP and BSO in patients ≤ 46 years old. I Landmark analysis of follow-up 30 months in patients ≤ 46 years old