Prognostic factors for high-risk early-stage epithelial ovarian cancer: a Gynecologic Oncology Group study

BACKGROUND: The purpose was to identify the factors predictive of recurrence and survival in patients with high-risk (stage I, grade 3; stage IC, stage II, or clear cell) epithelial ovarian cancer after adjuvant therapy. METHODS: Data was extracted from patients who underwent primary surgery followed by adjuvant therapy in 2 randomized trials by the Gynecologic Oncology Group (Protocols 95 and 157). Kaplan-Meier survival estimates and Cox proportional hazards model adjusted for covariates were used for analyses. RESULTS: Of 506 patients (median age = 56.2 years), 347 (68.6%) had stage I and 159 (31.4%) had stage II cancers. The 5-year recurrence-free (RFS) and overall survivals (OS) were 75.5% and 81.7%, respectively. On multivariate analysis, older age, higher stage, higher grade, and malignant cytology were independent prognostic factors predictive for recurrence and poorer survival. The risk of recurrence was higher for those >/=60 versus < 60 years (hazards ratio [HR] = 1.57, 95% confidence interval [CI], 1.12-2.19), stage II (stage II: HR = 2.70, 95% CI, 1.41-5.16) versus stage IA or IB, grade 2 (HR = 1.84, 95% CI, 1.04-3.27) and grade 3 (HR = 2.47, 95% CI, 1.39-4.37) versus grade 1, and positive versus negative cytology (HR = 1.72, 95% CI, 1.21-2.45). By using these factors in a prognostic index, those with low-risk (no or 1 risk factor), intermediate-risk (2 factors), and high-risk (3-4 risk factors) disease had survivals of 88%, 82%, and 75%, respectively (P < .05). CONCLUSIONS: Age, stage, grade, and cytology are important prognostic factors in high-risk early-stage epithelial ovarian cancer. This information may be used in the design of future clinical trials.