Survival outcomes and establishment of a novel risk stratification system in patients with ovarian yolk sac tumors

Objective: To evaluate the survival outcomes and establish a risk stratification system in patients with ovarian yolk sac tumors (OYST).Methods: The recurrence-free survival (RFS), disease-specific survival (DSS), and prognostic factors were retrospectively evaluated in 151 OYST patients treated in our hospital between 2006 and 2022. A risk stratification system based on the identified prognostic factors was established.Results: The median follow-up time was 5.1 years, with a 5-year RFS and DSS rate of 75.5% and 91.2%, respectively. FIGO stage III-IV and the interval between treatment and normalization of AFP were two prognostic predictors. Significant differences in RFS and DSS (both P < 0.001) were identified between patients who had normalized AFP <= 3 and >= 4 cycles of chemotherapy, or among patients who had normalized AFP after <= 2, 3-4, and >= 5 cycles of chemotherapy. FIGO stage I - II and stage III-IV were scored as 0 and 2, respectively. AFP normalization <= 2, 3, 4, and >= 5 cycles of chemotherapy were scored as 0, 1, 2, and 4, respectively. A total score of 0-1, 2-3, and >= 4 were stratified patients into low-risk (96 patients), intermediate-risk (35 patients), and high-risk groups (20 patients), respectively. Patients in three risk stratifications manifested significant differences in both RFS and DSS (P < 0.0001).Conclusion: This risk stratification system based on tumor stage and the interval between treatment and normalization of AFP may help to guide clinical management by dividing OYST patients into three risk groups.