The impact of lymphadenectomy on the survival outcomes of ovarian clear cell carcinoma: A retrospective study of the SEER database and Chinese registry

Background: Ovarian clear cell carcinoma (OCCC) is a rare pathological type of ovarian cancer with a poor prognosis, and lymphadenectomy is controversial in patients with OCCC. The objective of this study was to evaluate the impact of lymphadenectomy on the prognosis of patients with OCCC. Methods: In this retrospective study, we collected data from the Surveillance, Epidemiology and End Results (SEER) database and institutional registries in China. The SEER cohort included 1777 women diagnosed with OCCC between 2010 and 2019, while the Chinese cohort included 199 women diagnosed between April 2004 and April 2021. Recurrence-free survival (RFS) and overall survival (OS) were studied using Kaplan-Meier curve and Cox regression analysis. We also employed propensity score matching (PSM) to adjust for baseline imbalances between the lymphadenectomy group and the no-lymphadenectomy group. Results: Multivariate cox regression analysis showed that lymphadenectomy was not associated with better overall survival (OS) in either early (hazard ratio [HR] 0.84[0.50-1.43], p = 0.528) or advanced (HR 0.78 [0.50-1.21], p = 0.270) patients in the SEER cohort after PSM. Additionally, in the Kaplan-Meier curve analysis, lymphadenectomy did not significantly improve OS in both early (p = 0.28) and advanced (p = 0.49) patients in the SEER cohort after PSM. Similarly, in the Chinese cohort, lymphadenectomy had no significant effect on OS (early p = 0.22; advanced p = 0.61) or RFS (early p = 0.18; advanced p = 0.83) in both early and advanced patients. Conclusion: In completely homogeneous groups, lymphadenectomy in women diagnosed with OCCC had no effect on either recurrence-free survival or overall survival compared to patients without lymphadenectomy.