Safety and fertility outcomes after the conservative treatment of endometrioid borderline ovarian tumours

BACKGROUND: Because of the rarity of endometrioid borderline ovarian tumours (EBOTs), there is a paucity of data concerning the natural history and prognosis of this condition. Thus, the objective of our study was to establish the feasibility of fertility preservation in young women with EBOTs, as well as their oncological and reproductive outcomes. METHODS: Consecutive patients with EBOTs, treated at a tertiary referral centre during a span of 22 years, were retrospectively analysed. Recurrence-free interval, as well as its association with the type of surgery and with other clinical and pathological features, was assessed using the Kaplan-Meier and Cox proportional hazards methods. RESULTS: Of the 59 patients studied, the median follow-up time was 30 months (range, 6–177 months). Nine (15.3%) patients developed 13 recurrences 6–137 months after the initial surgeries, including three patients (5.1%; n = 3/59) who developed six invasive recurrences 8, 18 and 68 months after their initial surgeries. Conservative surgery showed a tendency towards a high recurrence rate (17.2% versus 13.3%); however, this difference was not significant (p = 0.45). The 5-year recurrence-free survival rate was significantly higher in the oophorectomy group than in the cystectomy group (p = 0.001). Cox regression analysis showed that none of the variables assessed were associated with an increased hazard ratio for recurrence, except for a younger age at diagnosis (p = 0.021). Of 20 patients who attempted to conceive, three pregnancies among two patients (10.0%) resulted in two live births. CONCLUSIONS: Conservative surgery with unilateral adnexectomy can be proposed for young women with EBOTs with fertility desire; however, the reproductive result is not satisfactory. In addition, careful evaluations of the endometria should be offered during the initial surgery and follow-up period. TRIAL REGISTRATION: Retrospectively registered.