Oncological outcomes and risk factors for recurrence of mucinous borderline ovarian tumors: A 15-year experience at a tertiary center

Background: The most common subtype of borderline ovarian tumors in Asia is mucinous borderline ovarian tumors (mBOTs). Intraoperative distinction from mucinous carcinoma can be difficult. Despite the indolent behavior of mBOTs, recurrence or metastases may occur. The objectives of this study were to determine the oncological outcomes of mBOTs and the risk factors for their recurrence. Results: This retrospective study enrolled patients with mBOTs treated or referred to our institution between January 2005 and December 2019. Histological reviews of the recurrent cases (primary and recurrent or metastatic tumors) were performed. Patients with other tumor subtypes, pseudomyxoma peritonei, or no in-house operation were excluded. Two hundred thirty-two patients were diagnosed with mBOTs. The median follow-up was 52 months. Six patients (2.58%) had tumor recurrence or metastasis. The risk factors for recurrence were a ruptured tumor, residual tumor after an operation, high serum CA19-9 level, and stage of the disease. The recurrence rates of fertility-sparing and radical surgery were not significantly different. Detailed surgical staging, intraepithelial carcinoma, and microinvasion were also not associated with disease recurrence. Conclusions: mBOTs have an excellent prognosis. Currently, fertility-sparing surgery is the standard treatment, showing no significant difference in oncological outcomes compared to radical surgery. Patients with risk factors should be closely monitored.