Objective: The objective was to identify demographic, clinical, and provider characteristics that might influence cancer survival in a cohort of Northern California women using a population-based cancer registry.
Methods: We used California Cancer Registry data to evaluate survival in 1051 Northern California women who were diagnosed with epithelial ovarian cancer between 1994 and 1996 and underwent a surgical procedure for their cancer. Chemotherapy data from the cancer registry were supplemented with a physician survey and medical record review. Database linkages with census and hospital discharge data provided socioeconomic and comorbidity measures. Kaplan-Meier method was used to generate survival curves and multivariate Cox proportional hazard models were used to evaluate the effect of different factors on survival.
Results: Crude 5-year survival was 82, 57, 28, and 10% for women with FIGO stage IC, II, III, and IV disease, respectively. Adverse survival was most strongly influenced by advanced stages III and IV with a hazards ratio ranging from 8 to 11.8 compared to stage IC disease. Multivariate analysis also identified other adverse factors including high grade and other adverse histologies, age over 45, and rural location. Chemotherapy decreased the risk of death by 50% if the patient had advanced-stage disease. Medical comorbidity increased the risk of death by 40%. Survival was not influenced by race/ethnicity, socioeconomic status, physician specialty, or hospital characteristics.
Conclusion: Advanced age remains an adverse prognostic factor even after adjustment for treatment and comorbidity factors. These results also suggest that there may be important regional differences in ovarian cancer survival.