Centralization of ovarian cancer in the Netherlands: Hospital of diagnosis no longer determines patients' probability of undergoing surgery.

ABSTRACT

OBJECTIVE: Surgical care for advanced stage epithelial ovarian cancer (EOC) patients has been centralized in the Netherlands since 2012. We evaluated whether the likelihood for patients to undergo surgery depends on the hospital of initial diagnosis before and after centralization of surgical care. METHODS: Patients with EOC FIGO stage IIB-IV, diagnosed in the Netherlands between 2000 and 2015, were identified from the Netherlands Cancer Registry. Multilevel multivariate logistic regression was used to study the association between hospital of diagnosis and patients' likelihood of undergoing surgery in subsequent time periods. Furthermore, changes in overall survival were analyzed by multivariable Cox regression models. RESULTS: 15,314 EOC patients were selected from the NCR. Hospital of diagnosis was identified as a significant level for patients' likelihood of undergoing surgery in 2000-2005 (LR test p<0.001), as well as in 2006-2011 (LR test p=0.002) but not in 2012-2015 (LR test p=0.127). Patients who underwent surgery in 2012-2015 had a better survival when compared to 2006-2011 (HR 0.90(0.84-0.96)). CONCLUSION: This study shows that centralization of surgical care resolved the variation between hospitals in the probability to undergo cytoreductive surgery for patients with advanced EOC. Since centralization was established in 2012, the decision to operate patients seems solely attributable to patient and tumor characteristics. This supports the growing evidence in favor of centralizing (surgical) treatment for complex and heterogeneous diseases such as EOC.