Clinical characteristics and prognosis of ovarian clear cell carcinoma: a 10-year retrospective study

Abstract Background Ovarian clear cell carcinoma (OCCC) is a special pathological type of epithelial ovarian carcinoma (EOC). We conducted this research to investigate the clinical characteristics and outcomes of OCCC and to provide additional supporting evidence to aid in the clinical diagnosis and management. Methods This was a retrospective study investigating the clinical characteristics and survival outcomes of 86 patients with OCCC treated at our center between January 2010 and March 2020. Survival analysis was also performed on 179 patients with OCCC obtained from the Surveillance, Epidemiology and End Results (SEER) cancer registry database. Results The median age of participants was 49.21 ± 9.91 years old, and 74.42% of them were diagnosed at early stage. The median CA125 level was 601.48 IU/mL, while 19.77% of the patients had normal CA125 levels. Sixteen patients (18.60%) had co-existing endometriosis and 8 patients (9.3%) developed venous thromboembolism (VTE). There were 5 patients received suboptimal cytoreduction. Sixty-six patients (76.74%) underwent lymphadenectomy, and only 3 (4.55%) patients had positive lymph nodes. Patients diagnosed at an early stage had higher 3-year overall survival (OS) and progression-free survival (PFS) rates than those with advanced stage OCCC. CA19–9 (P = 0.025) and ascites (P = 0.001) were significantly associated with OS, while HE4 (P = 0.027) and ascites (P = 0.001) were significantly associated with PFS. Analysis of data from the SEER database showed that positive lymph nodes is also an independent prognostic factor for OS (P = 0.001). Conclusions OCCC often presents at an early stage and young age with a mildly elevated CA125. CA19–9, HE4, massive ascites, and positive lymph node are independent prognostic factors.