Increased disease-free and relative survival in advanced ovarian cancer after centralized primary treatment

Abstract

Objective: To analyze 5-year disease-free survival (DFS) and relative survival (RS) before and after the 2011 implementation of centralized primary treatment of patients with advanced ovarian cancer.

Methods: A population-based cohort study using the Swedish Quality Registry for Gynecological Cancer (SQRGC). Women with FIGO stage III and IV epithelial ovarian and Fallopian tube cancers were divided into two cohorts: before and after centralization. We estimated RS using the Ederer II method, analyzed the difference in the excess mortality rate ratio (EMRR) and estimated 5-year DFS in a Cox proportional hazard regression model with centralization, age, primary treatment and complete cytoreduction as variables.

Results: A total of 495 women were identified with 244 women before (2008-2010) and 251 after (2011-2013) centralization. An increased 5-year RS from 24% (95%CI:19-31) to 37% (95%CI:31-44) and an increased median RS from 27 months (95%CI:23-34) to 44 months (95%CI:40-52), p < 0.001 (log-rank), were observed in the total cohort regardless of primary treatment. EMRR was found to be 0.62 (95%CI:0.51-0.76) in 2011-2013 compared to 2008-2010 for all patients. After centralization, 5-year DFS was significantly longer, hazard ratio of 0.77 (95%CI:0.64-0.93) and centralization was found to be an independent significant factor for both survival and DFS. Complete cytoreduction was found to be a significant independent factor associated with increased RS and DFS.

Conclusion: Centralization of primary treatment of advanced ovarian cancer was associated with significantly increased complete cytoreduction, 5-year RS and DFS, and was found to be a significant independent factor for both RS and DFS.

Keywords: Epidemiology; Fallopian tube Cancer; Ovarian cancer; Surgery.