Abstract
BACKGROUND: Ovarian clear cell carcinoma (OCCC) is a rare histological subtype of ovarian cancer, often associated with endometrial lesions, and characterized by poor prognosis and a high propensity for recurrence and metastasis. This study aimed to investigate the clinical characteristics of patients with OCCC and identify prognostic factors. METHODS: A retrospective analysis was conducted on patients diagnosed with OCCC at Fujian Cancer Hospital from January 2007 to December 2018. Inclusion criteria were as follows: (I) histologically confirmed pure OCCC; (II) surgical intervention; (III) standardized and completed postoperative follow-up. Exclusion criteria were as follows: (I) patients with recurrence or metastasis; (II) patients who did not receive treatment. Kaplan-Meier survival curves were used to estimate progression-free survival (PFS) and overall survival (OS). Clinical outcomes were further analyzed using Cox proportional hazards regression. RESULTS: The median follow-up duration for 102 patients was 89.62 months. At the time of the final follow-up, 44 patients had died, and 43 had experienced recurrence or metastasis. The 5-year OS and PFS rates were 59.2% and 50.0%, respectively. Univariate Cox regression analysis indicated that stage, concurrent endometriosis, chemotherapy, carbohydrate antigen 125 (CA-125) normalization, and CA-125 ≤20 U/mL were associated with both OS and PFS (P<0.05). Lymph node metastasis, platinum resistance, and venous thrombosis were only associated with OS (P<0.05). Multivariate analysis revealed that stage [hazard ratio (HR) =2.780, 95% confidence interval (CI): 1.265-6.110, P=0.01], chemotherapy (HR =0.211, 95% CI: 0.075-0.593, P=0.003), and platinum resistance (HR =8.233, 95% CI: 3.617-18.743, P<0.001) were independent prognostic factors for OS. Concurrent endometriosis (HR =0.385, 95% CI: 0.189-0.784, P=0.009) and stage (HR =4.507, 95% CI: 2.346-8.660, P<0.001) were independent prognostic factors for PFS. CONCLUSIONS: Stage, endometriosis, platinum resistance, and platinum-based chemotherapy are significant prognostic factors in OCCC. CA-125 levels, positive lymph nodes, and venous thrombosis are also associated with survival outcomes.