National survey of ovarian carcinoma VI: Critical assessment of Current International Federation of Gynecology and Obstetrics Staging System

Abstract

BACKGROUND: The Commission on Cancer of the American College of Surgeons recently completed a national survey of patients with ovarian cancer. From the large database, the prognostic value of current International Federation of Gynecology and Obstetrics (FIGO) staging system for ovarian carcinoma was re-examined. METHODS: Data was collected from 25 consecutive ovarian carcinomas diagnosed in 1983 and 1988 at 904 hospitals with cancer programs. Among a total of 12,316 cases, 5156 patients had long-term survival data. RESULTS: The overall 5-year survivals were 88.9 +/- 0.9%; 57.1 +/- 2.4%; 23.8 +/- 1.3%; and 11.6 +/- 0.9% for Stages I, II, III, and IV, respectively. Pairwise survival comparisons using Lee-Desu statistic confirmed the prognostic value of current staging system (P < 0.00001). When survival data was substratified further to substage division, the 5-year survivals were: IA, 92.1 +/- 0.9%; IB, 84.9 +/- 3.4%; IC, 82.4 +/- 2.0%; IIA, 69.0 +/- 4.3%; IIB, 56.4 +/- 3.6%; IIC, 51.4 +/- 4.5%; IIIA, 39.3 +/- 2.8%; IIIB, 25.5 +/- 2.6%; IIIC, 17.1 +/- 1.4%; and IV, 11.6 +/- 0.9%. As the disease process becomes more advanced, patients' survival reduces proportionally. However, the survival reduction is relatively small between IB-IC and IIB-IIC divisions. Survival comparisons revealed significant prognostic value for most substage divisions (P = 0.03-0.0002) except for IB-IC and IIB-IIC combinations (P > 0.33). Further analyses revealed no significant differences between IB-IC and IIB-IIC patients in several prognostic parameters such as age, histologic grade, cell type, and amount of residual disease. CONCLUSIONS: These data support the current FIGO staging system. However, Substages IB-IC and IIB-IIC should be combined to respective single substages.