The incidence and survival of acute de novo leukaemias in Estonia and in a well-defined region of western Sweden during 1982-1996: a survey of patients aged > or =65 years

OBJECTIVES: To compare the incidence and survival of acute de novo leukaemias with particular reference to political/socio-economic and environmental factors in two neighbouring countries over the three 5-year periods (1982-1996). PATIENTS: The present report covers only patients diagnosed when aged > or =65 years. SETTING: A well-defined area of Sweden, the so-called Western Swedish Health Care Region and Estonia. Population-wise, the western Swedish Region and Estonia are very similar; area-wise they are also well comparable. RESULTS: The number of acute de novo leukaemias was quite dissimilar in the two countries (Estonia, n = 137, Sweden, n = 354). The age standardized incidence rates regarding the total number of acute de novo leukaemias was 5.31 per 100,000 inhabitants/year for Estonia and 7.99 for Sweden, this difference being statistically significant. However, the difference was merely attributable to incidence rates as regards acute myeloblastic leukaemias (AML); on the contrary, differences as regards acute lymphoblastic leukaemias (ALL) and non-classifiable, undifferentiated or biphenotypic acute leukaemias (uAL) were negligible. The relative survival for the total material of patients was significantly higher for Swedish when compared with Estonian patients (P < 0.001). Thus, the relative survival for the total material of patients aged > or =65 years in Estonia at 1 year was 8.5% and at 3 years 3.5% respectively. The corresponding figures for the Swedish patients were considerably higher, 22.7 and 7.7% respectively. This difference, however, applied only for patients with AML (P < 0.001), whereas the results for patients with ALL and uAL were equally dismal. CONCLUSION: The results clearly reflect how political and socio-economic factors may influence the survival of acute leukemia patients in two neighbouring countries.