Characteristics of long-term survival in advanced stage ovarian cancer: a nationwide cohort in the Netherlands

Objective: Despite optimal treatment with debulking surgery and chemotherapy, the majority of patients with advanced stage epithelial ovarian cancer (EOC) die within five years. Survival beyond eight years is rare and the mechanisms that lead to such favorable outcomes are incompletely understood. We aimed to identify characteristics associated with long-term survival (LTS) in a population-based cohort of patients with advanced stage EOC. Methods: Patients with advanced stage (FIGO IIB-IV) EOC diagnosed between 2008 and 2012 were identified from the Netherlands Cancer Registry. LTS was defined as survival for more than eight years after diagnosis, based on 20% survival within this cohort. Patient, tumor, and treatment characteristics were analyzed using multivariable logistic regression to find predictors for LTS. Results: We identified 2744 eligible patients of whom 571 were long-term survivors (survival longer than eight years). Younger age, lower tumor stage, low-grade histology, FIGO IV based on extra-abdominal lymph node compared to pleural metastasis, primary debulking surgery vs neo-adjuvant chemotherapy followed by interval debulking surgery, residual disease less than one cm or no macroscopic disease, and ascites less than 100 mL were associated with LTS. Furthermore, less than six chemotherapy cycles compared to six, and carboplatin plus paclitaxel combined with other chemotherapy agents compared to carboplatin plus paclitaxel, were associated with a lower odds of LTS. Conclusion: Characteristics of the tumor, patient and treatment play a substantial role in respect to the prognosis of advanced stage EOC, and can assist in the prediction of LTS