Survival of ovarian cancer patients in Denmark: Results from the Danish gynaecological cancer group (DGCG) database, 1995-2012

Background: Ovarian cancer has a high mortality rate, especially in Denmark where mortality rates have been reported higher than in adjacent countries with similar demographics. This study therefore examined recent survival and mortality among Danish ovarian cancer patients over an 18-year study period.Methods: This nationwide registry-based observational study used data from the Danish Gynecology Cancer Database, Danish Pathology Registry, and Danish National Patient Registry. All patients with ovarian cancer diagnosed between 1995 and 2012 were included in the study. The data sources were linked via the patients' personal identification number and the analyses included data on cancer stage, age, survival, surgery status and comorbidity. The computed outcome measures were age-adjusted mortality rates and age-adjusted overall and relative survival rates for one and five years.Results: We identified 9972 patients diagnosed with ovarian cancer in the period 1995-2012. The absolute one-year mortality rate decreased from 42.8 (CI 40.3-45.6) in 1995-1999 to 28.3 (CI 25.9-30.9) in 2010-2012, and the five-year mortality rate decreased from 28.2 (CI 27.0-29.5) in 1995-1999 to 23.9 (CI 22.9-25.0) in 2005-2009. After stratification by age, comorbidity and cancer stage, the decrease in one-year mortality was most substantial in the 65-74 year old age group 41.1 (CI 38.8-43.5) to 26.5 (CI 24.4-28.7) and for stage III 39.1 (CI 35.1-43.6) to 22.9 (CI 19.9-26.5) and stage IV 91.3 (CI 80.8-103.2) to 41.9 (CI 35.5-49.5). For overall survival, we showed an increase in one-year survival from 68% (CI 66-69%) in 1995-1999 to 76% (CI 74-78%) in 2010-2012 and an increase in five-year survival from 33% (CI 32-35%) in 1995-1999 to 36% (CI 34-38%) in 2005-2009. Relative survival showed similar increases through the period.Conclusions: Ovarian cancer survival in Denmark has improved substantially from 1995 to 2012, bringing Denmark closer to the standards set by adjacent countries.