Minimally Invasive Surgery and Recurrence Risk in Borderline Ovarian Tumours: A 10-Year Cohort Analysis

Background and Objectives: Borderline ovarian tumours (BOTs) predominantly affect women of reproductive age. Following concerns about minimally invasive surgery (MIS) in cervical cancer, the oncological safety of the surgical approach in BOTs requires evaluation, particularly in fertility-sparing procedures where clinical implications are greatest. This study aimed to assess whether MIS is associated with increased recurrence risk in BOTs, with stratified analysis by fertility-sparing status based on a pre-specified hypothesis of differential effects. Materials and Methods: Single-centre cohort study of 91 BOT patients treated at Nottingham City Hospital Cancer Centre between 2014-2023. The primary outcome was progression-free survival comparing MIS versus open surgical approaches. Results: Minimally invasive surgery was associated with higher observed recurrence compared to open surgery (5/25 [20.0%, 95% CI: 6.8-40.7%] vs. 3/66 [4.5%, 95% CI: 0.9-12.7%], absolute risk difference 15.5% [95% CI: 2.1-28.9%]; unadjusted HR 5.29, 95% CI: 1.26-22.17; p = 0.022). Conclusions: This study identifies an association between minimally invasive surgery and higher recurrence in borderline ovarian tumours, particularly in fertility-sparing procedures. While based on small numbers necessitating cautious interpretation, the consistency across analytical approaches, substantial magnitude of observed differences, and biological plausibility warrant validation in larger cohorts to inform surgical counselling.