Preoperative CA 125: An Independent Prognostic Factor in Patients With Stage I Epithelial Ovarian Cancer

OBJECTIVE: To evaluate the prognostic importance of preoperative CA 125 levels in patients with International Federation of Gynecology and Obstetrics (FIGO) stage I epithelial ovarian cancer in comparison with the established prognostic factors: degree of differentiation, FIGO substage, and age. METHODS: In a retrospective analysis, the traditional prognostic factors and CA125 levels (cutoff value 65 U/mL) were studied in 201 patients who were treated in five centers during 1984-1993. Patients with borderline tumors or non-epithelial ovarian carcinomas were excluded, as were women in whom CA 125 had not been determined preoperatively. RESULTS: In univariate analysis (Mantel test), overall survival decreased significantly in patients positive for CA 125 (P < .001). Substage (P = .004) and histologic grade (P = .01) also significantly influenced survival prognosis. When the effects of preoperative CA 125 levels were correlated with histologic grade, all three subgroups with CA 125 levels equal to or greater than 65 U/mL were associated with a decreased survival probability (grade 1, P = .04; grade 2, P = .003; grade 3, P = .01). Multivariate analysis (Cox model) identified preoperative CA 125 as the most powerful prognostic factor for survival (P < .001), the risk of dying of disease being 6.37 times higher (95% confidence interval 2.39-16.97) in CA 125-positive patients. Although FIGO substage retained its significant influence on survival (P = .03), histologic grade and age were not prognostically important. CONCLUSION: Randomized trials investigating the efficacy of adjuvant treatment in patients with FIGO stage I epithelial ovarian cancer should also include stratification by preoperative CA 125 levels.