The role of lymphadenectomy in surgical management of malignant ovarian germ cell tumors: a multi-center retrospective cohort study with inverse propensity of treatment weighting.

OBJECTIVE: To evaluate the association between lymphadenectomy (LND) and survival outcomes in malignant ovarian germ cell tumors. METHODS: In this multi-center, retrospective cohort study, patients surgically treated for malignant ovarian germ cell tumors at three tertiary hospitals in China between 2016 and 2023 were included. Progression-free survival (PFS), surgical performance and perioperative complications were analyzed. An inverse propensity of treatment weighting model was performed to minimize selection bias. RESULTS: A total of 213 patients were eligible for analysis, of whom 57 (26.8%) underwent LND and 156 (73.2%) did not. The overall rate of lymph-node metastasis was 17.5% (immature teratoma 0%, yolk sac tumor 9.5%, dysgerminoma 27.8%). LND was associated with increased operative time (p<0.001), hospital stay (p=0.019) and estimated blood loss (p=0.007). No significant difference was identified in the 5-year PFS between the 2 groups before and after inverse propensity of treatment weighting adjustment. Multivariate analysis showed the delayed post-operative chemotherapy and unfavorable pathological types (yolk sac tumor and mixed malignant germ cell tumors) were independent predictors of survival (hazard ratio [HR]=2.86, 95% confidence interval [CI]=1.27-6.44, p=0.011; HR=2.88, 95% CI=1.03-8.08, p=0.044; and HR=3.90, 95% CI=1.37-11.08, p=0.011, respectively). CONCLUSION: Our study indicated that LND was not associated with a survival benefit but increased surgical morbidity in patients with malignant ovarian germ cell tumors, underscoring the critical importance of timely chemotherapy. However, it may still be considered in select cases, such as for imaging-suspected dysgerminoma.