Survival probability in ovarian clear cell adenocarcinoma

Objective: The aim of this study was to evaluate the 5-year survival probability (SP) of patients treated for ovarian clear cell adenocarcinoma (OCCA) at a single tertiary institution and to compare it to the 5-year SP of patients with other histologic subtypes of epithelial ovarian cancer.

Methods: Sixty-four patients with pure OCCA treated at the Cleveland Clinic Foundation from 1981 to 1996 were retrospectively identified and clinical information was abstracted. All histologic materials were reviewed by a single gynecologic pathologist. SP was calculated by the Kaplan-Meier method. SPs for OCCA patients were compared to that of other high-grade epithelial ovarian cancer patients in the gynecologic tumor registry. Cox proportional hazards modeling was used to identify varibles associated with decreased SP.

Results: The FIGO stages of OCCA study patients were Stage I, 31 (50%), Stage II, 6 (10%), Stage III, 17 (27%), and Stage IV, 8 (13%) (2 patients unstaged). Forty-four patients had no gross residual cancer at the completion of initial surgery while 9 patients had </=1 cm diameter residual and 10 had >1 cm residual. Forty-five (73%) received postoperative chemotherapy. The median follow-up for surviving patients is 97 months (range 38 to 209 months). The overall 5-year SP of OCCA patients is 50% with limited disease (Stages I and II) patients having a 5-year SP of 72% versus 17% 5-year SP in patients with advanced disease (P < 0.001). FIGO stage was most predictive of outcome. The overall 5-year SP of OCCA patients (50%) differed significantly (P < 0.05) from that of other ovarian cancer registry patients (30%). OCCA patients with limited cancer survived similarly to registry patients (72 vs 72%) as did patients with advanced OCCA compared with registry patients (17 vs 22%).

Conclusions: When controlled for grade and stage, the overall survival with OCCA is identical to that of other high-grade epithelial ovarian cancers. Factors that account for the better overall survival of OCCA patients are more favorable disease stage, younger age, and improved debulking status.