Ovarian clear-cell carcinoma is a subtype of epithelial ovarian cancer with unique characteristics, including resistance to chemotherapy. In addition, ovarian clear-cell carcinoma does not have specific tumor markers. Researchers sought to investigate the clinical characteristics and outcomes of patients with ovarian clear-cell carcinoma and to provide evidence that may aid in clinical diagnosis and management.
In a retrospective study, the clinical characteristics and survival outcomes of 87 patients with ovarian clear-cell carcinoma diagnosed at a single institution were analyzed. Patients were treated between January 2010 and March 2020. Survival analysis was also performed on 179 patients with ovarian clear-cell carcinoma diagnosed between 1975 and 2017 from data obtained from a cancer registry database.
Study participants had a median age of 49.28 years, and 74.71% were diagnosed with ovarian clear-cell carcinoma at an early stage. The median CA 125 level was 607.26 IU/mL, and 23.94% of patients had a normal CA 125 level. Coexisting endometriosis was present in 16 (18.39%) patients, and 8 (9.2%) patients had a history of venous thromboembolism preoperatively or as a postoperative complication. Surgical staging procedures were performed on 65 patients. Cytoreduction was performed on 22 patients, of whom 17 received optimal cytoreduction. Lymphadenectomy was performed in 67 (77.01%) patients, and of these, 3 (4.48%) were found to have positive lymph nodes.
Patients diagnosed at an early stage had a higher 3-year overall survival rate compared with those with advanced-stage ovarian clear-cell carcinoma at diagnosis (89.47% and 44.44%, respectively). The rate of progression-free survival was 78.95% for patients with early-stage ovarian clear-cell carcinoma at diagnosis and 22.22% for those with advanced-stage ovarian clear-cell carcinoma at diagnosis. Elevated CA 19-9 level and presence of ascites were significantly associated with overall survival, while HE4 expression and the presence of ascites were significantly associated with progression-free survival. Based on analysis of data from the cancer registry database, the presence of positive lymph nodes was also an independent prognostic factor for overall survival.
According to the researchers, ovarian clear-cell carcinoma often presents at an early stage and young age with only mild elevation in CA 125 levels. Level of CA 19-9, expression of HE4, and the presence of massive ascites and positive lymph nodes are important prognostic factors for overall survival in patients with ovarian clear-cell carcinoma.
Abstract 314. ESGO 2020.