Conservative surgery in stage I adult type granulosa cells tumors of the ovary: Results from the MITO-9 study

Objective: About 30% of Adult type granulosa cell tumors of the ovary (AGCTs) are diagnosed in fertile age. In stage I, conservative surgery (fertility-sparing surgery, FSS), either unilateral salpingo-oophorectomy (USO) or cystectomy are possible options. The aim of this study is to compare oncological outcomes of FSS and radical surgery (RS) in apparently stage I AGCTs treated within the MITO group (Multicenter Italian Trials in Ovarian cancer). Methods: Survival curves were calculated using the Kaplan-Meier method and compared with log-rank test. The role of clinicopathological variables as prognostic factors for survival was assessed using Cox's regression. Results: Two-hundred and twenty-nine patients were included; 32.6% received FSS, 67.4% RS. In the FSS group, 62.8% underwent USO, 16.7% cystectomy, 20.5% cystectomy followed by USO. After a median follow up of 84 months, median DFS was significantly worse in the FSS-group (10 yr DFS 50% vs 74%, in FSS and RS group, p = 0.006). No significant difference was detected between RS and USO (10 yr DFS 75% vs 70%, p = 0.5).Cystectomy-group showed a significantly worse DFS compared to USO (10 yr DFS 16% vs 70%, p < 0.001). Patients receiving cystectomy and subsequent USO showed a better prognosis, even though significantly worse compared to USO (10 yr DFS 41% vs 70%, p = 0.05). Between FSS and RS, no difference in OS was detected. At multivariate analysis, FIGO stage IC and cystectomy retained significant predictive value for worse survival. Conclusions: This study supports the oncological safety of FSS in stage I AGCTs, provided that cystectomy is avoided; USO should be the preferred approach.