A population-based 5-year cohort study including all cases of epithelial ovarian cancer in western Sweden: 10-year survival and prognostic factors

Abstract

Epithelial ovarian cancer (EOC) is the major gynecologic cancer mortality cause in Sweden. The aim of the present study was to investigate the long-term survival and prognostic factors of a complete population-based 5-year cohort of 682 patients with invasive EOC in western Sweden (population around 1.6 million). Data relating to residual tumor after surgery, FIGO stage, grade, histopathologic subtype, ploidy status, adjuvant chemotherapy (the prepaclitaxel period), and disease state (recurrence and death) were reported to a quality register in a prospectively kept database and were controlled against the Swedish National Cancer Registry for completeness. The median follow-up durations for the prospectively collected data in the Cox analysis and for the survival analysis that was made for all patients were 81 months (range, 52-109 months) and 11.7 years (range, 8.7-14.1 years), respectively. No patient was lost to follow-up. The relative 10-year survival rate was 38.4% (95% confidence interval, 34.5%-42.8%). The median relative survival time was 4.3 years (95% confidence interval, 3.6%-5.2%). In the univariate Cox regression analysis, prognostic significances for age, stage, residual tumor, histopathologic subtype of serous cystadenocarcinoma, grade, CA-125, and ploidy status were seen. In the multivariate analysis, age, stage, residual tumor after surgery, and postoperative CA-125 were of prognostic significance. In conclusion, 4 major prognostic factors were found for EOC in this population-based cohort study that also presents nearly accurate long-term survival owing to the nonselective nature and completeness regarding patients and follow-up of the study.