Clinical Characteristics, Surgical Management, and Outcomes of Borderline Ovarian Tumours: A Retrospective Observational Study from North East London

<b>Background:</b> Borderline ovarian tumours (BOTs) are a unique subset of epithelial ovarian neoplasms characterised by atypical epithelial proliferation without stromal invasion. BOTs are typically diagnosed at an early stage, primarily affect women of reproductive age, and have a favourable prognosis. This study aims to evaluate the clinical characteristics, surgical management, and outcomes of BOTs in a North East London cohort. <b>Methods:</b> A retrospective, multicentric analysis was conducted on 69 patients with histologically confirmed BOTs managed between January 2018 and December 2022 across the Barts Health NHS Trust hospitals. Clinical and demographic data, surgical details, histopathological findings, and recurrence rates were analysed. We used descriptive and exploratory statistical methods. <b>Results:</b> The mean age at diagnosis was 44 years, with 46.37% under 40, including 18 nulliparous women. Most tumours (91.3%) were FIGO stage I, with mucinous histology predominating (56.52%), followed by serous BOTs (27.53%). Ultrasound and MRI demonstrated 65.45% and 81.5% sensitivities for borderline or malignant features, respectively. Surgical approaches included open surgery (75.4%), laparoscopy (17.4%), and robotic-assisted procedures (2.9%). Fertility-sparing surgery (FSS) was performed in all nulliparous women under 40 years of age. Recurrence occurred in 2 cases, both in patients with prior FSS performed over a decade earlier. <b>Conclusions:</b> FSS is a viable option for young women, especially if nulliparous and under the age of 40, with recurrence rates comparable to radical procedures. Most patients were diagnosed early (FIGO I) with excellent prognoses. MRI proved most sensitive for diagnosis, while long-term follow-up with transvaginal ultrasound and CA-125 monitoring is crucial for detecting recurrences.