OBJECTIVE: To evaluate the prognosis and fertility of patients with stage II to IV borderline ovarian tumors who underwent fertility-sparing surgery. METHODS: This retrospective single-institution study included patients aged <
40 years with stage II to IV borderline ovarian tumors at the First Affiliated Hospital of Zhengzhou University between January 2007 and March 2023. The primary outcome was disease-free survival. The association of disease-free survival was assessed using the Kaplan-Meier and Cox proportional hazards methods. RESULTS: A total of 144 patients were included in this study. Based on whether fertility-sparing surgery was performed, the patients were categorized into 2 groups: a fertility-sparing surgery group with 96 patients (66.67%) and a radical surgery group with 48 patients (33.3%). There were differences between the 2 groups in terms of age (27.36 ± 6.42 vs 34.67 ± 5.43, p <
.001), pregnancy history (53.1%
51/96) vs 81.2% (39/48), p = .001), maximum tumor diameter (103.00 [76.25, 148.25] vs 88.50 [60.25, 124.75], p = .011), involvement of bilateral ovaries (45.83%
[44/96] vs 66.67% [32/48], p = .018), and whether postoperative adjuvant chemotherapy (15.6% [15/96] vs 31.2% [15/48], p = .030). The median follow-up time after primary cytoreduction was 67.0 months (interquartile range
44.0-101.75). At the end of the observation period, 32 (22.2%) patients experienced recurrence. There were 3 (2.1%) deaths and 2 cases (1.4%) of survival with tumors. Multivariate Cox proportional hazards regression analysis showed that fertility-sparing surgery, incomplete cytoreduction, micropapillary subtype, International Federation of Gynecology and Obstetrics stage III, and invasive implants were independent risk factors for poor disease-free survival. Among the patients with fertility intentions (41 cases), 34 (82.9%) had successful pregnancies. Twenty-nine patients (70.7%) had successful births, and 3 patients were pregnant at the time of study completion. CONCLUSIONS: Fertility-sparing surgery may be feasible and considered for patients lacking other significant risk factors for disease-free survival, including incomplete cytoreduction, micropapillary subtype, International Federation of Gynecology and Obstetrics stage III, and invasive implants.