Trends in therapy and survival of advanced stage epithelial ovarian cancer patients in the Netherlands

Abstract

Objective: The aim of this study was to describe trends in survival and therapy in advanced stage epithelial ovarian cancer (EOC) in the Netherlands and to determine if changes in therapy affected survival.

Methods: All EOC patients diagnosed in the Netherlands during 1989-2009 were selected from the Netherlands Cancer Registry. Differences in treatment over time were tested by the Cochran-Armitage trend test. Multivariable relative survival analyses were performed to test whether changes in treatment are associated with survival.

Results: 23,399 EOC patients were diagnosed, of whom 15,892 (67.9%) in advanced stage (stage ≥ 2b). In advanced stage patients, the proportion receiving (neo-)adjuvant chemotherapy and optimal debulking (residuals <1cm) increased over time in all age groups. In elderly patients (≥ 75 years) a stable proportion (approximately 28%) did not receive any treatment. Five-year relative survival in advanced stage patients increased from 18% in 1989-1993 to 28% in 2004-2009. In the multivariable model survival improved over time (relative excess risk (RER) of 2004-2009 was 0.71, 95% CI 0.67-0.75 compared to 1989-1993). This RER attenuated to 0.85 (95% CI 0.80-0.90) and 0.91 (95% CI 0.83-0.99) with inclusion of treatment variables in the model (surgery with chemotherapy or optimal surgery with chemotherapy, respectively). This suggests that the improvement was mainly, although not entirely, caused by changes in treatment.

Conclusion: Treatment in advanced stage EOC patients in the Netherlands improved over the last two decades; more patients received (neo)adjuvant chemotherapy and underwent optimal debulking surgery. Changes in treatment led to partial improvement of survival in EOC patients.