Recurrence and Malignant Transformation After Borderline Ovarian Tumors: A Systematic Review and Meta-analysis

BACKGROUND/AIM: Borderline ovarian tumours (BOTs) frequently affect women of reproductive age. Fertility-sparing surgery (FSS) is commonly offered, but recurrence risk varies by surgical approach and histological subtype, while malignant transformation remains incompletely defined. This systematic review and meta-analysis aimed to quantify recurrence and malignant transformation risks following different surgical strategies for BOTs. MATERIALS AND METHODS: . Methodological quality was evaluated using MINORS. RESULTS: =26.42%). In serous BOTs, recurrence after cystectomy was 0.29 (0.23-0.56) and after USO 0.15 (0.09-0.24). In mucinous BOTs, corresponding estimates were 0.26 (0.14-0.38) and 0.08 (0.02-0.13). Overall malignant transformation occurred in 1% of women (0.01; 0.01-0.02) but increased substantially following recurrence (0.22). CONCLUSION: Cystectomy-based FSS is associated with significantly higher recurrence than oophorectomy-based approaches or radical surgery. Although malignant transformation is rare overall, its marked increase following recurrence highlights the need for histology-informed counselling and long-term, risk-adapted surveillance.