On the background of differences in survival of female breast cancer patients in the German Democratic Republic and the Estonian SSR.

The aim of this study was to describe the age-specific survival patterns and to analyse the differences between the survival rates of female breast cancer patients in the German Democratic Republic in 1976-1977 and the Estonian SSR in 1968-1981. The estimated 5-year relative survival rate (RSR) was 64.1% in the GDR and 55.9% in Estonia. Patients aged 55 years or older at diagnosis had higher survival in the GDR (5-year RSR 62.6%) than in Estonia (49.5%). That result was clearly connected with higher proportion of advanced tumors among older patients in Estonia. For patients younger than 55 years the difference of the 5-year RSR between the both countries was not statistically significant (GDR 65.3%, Estonia 63.4%). The standardization of overall 5-year RSR by stage and age, but also only by stage of the disease produced virtually equal results for the GDR and Estonia. It means that the main source of the differences in overall breast cancer survival rates between the GDR and Estonia are the discrepancies in stage distribution, particularly in older age groups.