Advanced-stage (FIGO III-IV) epithelial ovarian cancer: Multivariate analysis of prognostic factors in an area without a tertiary referral oncology center. A population-based study

Background: Most of the time, prognostic factors of patients with epithelial ovarian cancer (EOC) have been evaluated in hospital-based populations, mostly in secondary or tertiary referral centers. The aim of the study was to analyze these factors in a well-defined and nonselected population with complete follow-up from a cantonal cancer registry and to assess the adequacy of treatment in an area which has no central institution for oncological treatment. Patients and Methods: From 1989 to 1995, the cantonal cancer registry of the Valais has registered 73 patients with ovarian epithelial cancers of stages III and IV; 72 patients have been evaluable. We have calculated survival rates and analyzed variables such as age (<55/55-70/>70 years), stage (III/IV), DNA ploidy (diploid/aneuploid), residual tumor after surgery (tumor ≤2 cm/>2 cm), histologic grading (G1/G2/G3) and chemotherapy treatment (curative/palliative). The median follow-up was 25 (range 18-101) months. Multivariate analyses (Cox's proportional hazard) were used to identify an independent effect of each variable on survival time. Survival rates were calculated according to the Kaplan and Meier method. Results: The Canton Valais has no tertiary center and no trained gynecological (surgical) oncologist. The patients have been operated in 7 regional hospitals and one private clinic by 16 different gynecologists and 8 general surgeons, chemotherapy regimens have been given by 5 medical oncologists. Both treatments were very heterogeneous. The median age was 63 years. The estimated 5-year survival rate was 30%. Multivariate analyses identified age and stage as the only significant prognostic factors associated with survival. DNA ploidy, size of residual disease after primary surgery, histologic grading and chemotherapy had no significant impact on survival. Conclusions: Variables such as primary treatment (surgical and chemotherapy) do not improve survival time, probably because patients had too heterogeneous surgical and chemotherapy treatments, the choice of which was influenced by the many treating physicians. Patients with ovarian cancer should be referred to central institutions where they are more likely to have standardized and optimal surgery and chemotherapy treatment.