Oncofertility outcomes after fertility-sparing treatment of bilateral serous borderline ovarian tumors: results of a large retrospective study

STUDY QUESTION: What are the oncofertility outcomes of young women (<= 40 years old) with bilateral serous borderline ovarian tumors (SBOTs) after fertility-sparing surgery? SUMMARY ANSWER: Fertility preservation with the bilateral ovarian cystectomy procedure is feasible for bilateral SBOTs, with an acceptable oncological outcome and worthwhile pregnancy rates. WHAT IS KNOWN ALREADY: Fertility-sparing approaches are becoming the standard management of young patients with unilateral SBOTs and other borderline histological subtypes. However, there is a paucity of evidence to dictate the best management in bilateral SBOTs. STUDY DESIGN, SIZE, DURATION: This was a retrospective observational study performed at the Peking Union Medical College Hospital in Beijing, China, between January 1999 and January 2019. PARTICIPANTS/MATERIALS, SETTING, METHODS: Ninety-four women (<= 40 years old) with pathologically confirmed bilateral SBOTs were included. Following preoperative counseling, patients self-selected into one of three treatment modalities: bilateral ovarian cystectomy (n = 48), unilateral adnexectomy plus contralateral cystectomy (UAC; n = 31), and radical surgery (n = 15). Univariate and multivariate analyses were used to determine the clinical and pathological features associated with disease-free survival and reproductive outcomes. MAIN RESULTS AND THE ROLE OF CHANCE: During the median follow-up of 64 months (range, 4-243 months), 61 patients (65%) developed relapse, including 3 (20%) in the radical group, 26 (84%) in the UAC group and 32 (67%) in the bilateral cystectomy group. In the multivariate analyses, preoperative CA-125>300 U/mL, fertility preservation and micropapillary pattern were independently associated with adverse disease-free survival (P = 0.001, 0.03 and 0.026, respectively). Fourteen patients (15%) experienced invasive recurrence, and three (3%) died of progressive disease. The micropapillary pattern was significantly associated with invasive evolution risk (P = 0.006). Of the 49 patients who attempted to conceive, 23 (47%) achieved 27 pregnancies (24 spontaneous and three after IVF-ET), resulting in 19 live births. There was no significant difference in disease-free survival (P = 0.13) or pregnancy rate (41 vs. 50%, P=0.56) between the UAC and bilateral procedures. LIMITATIONS, REASONS FOR CAUTION: As a retrospective study conducted in a referral center, inherent biases exist. The nonrandom allocation to treatment groups and relatively small number of patients attempt to conceive might limit the statistical power of our findings. Only 41 patients (43.6%) received complete staging during their initial surgeries, so an underestimation bias in terms of the FIGO stage and extraovarian implants might have occurred. WIDER IMPLICATIONS OF THE FINDINGS: The ultraconservative bilateral ovarian cystectomy procedure should be proposed in bilateral SBOTs when technically feasible. Invasive evolution occurs frequently in these women, and intense follow-up and oncofertility counseling are warranted, especially for those with micropapillary patterns.