Time Trends in Ovarian Cancer Survival in Estonia by Age and Stage

The objective of the study was to examine temporal trends in ovarian cancer (OC) survival in Estonia during 1995 to 2009 in relation to age and stage.

Estonian Cancer Registry data on all adult cases of primary OC diagnosed during 1995 to 2009 and followed up for vital status until 2014 were used to estimate relative survival ratios (RSRs). Cohort analysis was used to estimate 1-, 2-, and 5-year RSRs for patients diagnosed in 1995 to 1999, 2000 to 2004, and 2005 to 2009. Analysis was performed by age at diagnosis (<50; 50-59; 60-69; 70+ years) and stage (International Federation of Gynecology and Obstetrics 1988).

Among 2296 women included in the study, the age-adjusted 5-year RSR improved from 27% in 1995 to 1999 to 38% in 2005 to 2009. Survival increase of 10% units from 1995 to 1999 to 2005 to 2009 was seen for women aged 50 to 59 and 60 to 69 years. Among younger and older women, the respective changes were smaller. In 1995 to 1999, the difference in survival between the youngest and oldest age groups was 41% units. This decreased over the study period to 37% units. From 1995 to 1999 to 2005 to 2009, the 5-year RSR increased from 82% to 91% for stage I patients; from 48% to 67% for stage II patients; from 25% to 35% for stage III patients; and from 11% to 16% for stage IV patients.

The study showed an improvement of OC survival in Estonia in all age and stage groups, but particularly among younger women and those with early stage disease. Slower progress among older women is of great concern.