The incidence and survival of acute de novo leukemias in Estonia and in a well-defined region of western Sweden during 1997–2001: A survey of patients aged ≥65 years

Abstract 

Background: In a recently published retrospective population-based study over three 5-year periods (1982–1996) we investigated the outcome for de novo acute leukemia (AL) patients aged ≥65 years at diagnosis in Estonia (a country that had been occupied by the Soviet Union over 5 decades) and in the so-called Western Swedish Health Care Region. The age-standardized yearly incidence rates regarding the total number of de novo AL was 5.3/100000 inhabitant for Estonia and 8.0 for Sweden, this difference being statistically significant merely as regards acute myeloid leukemia (AML). The relative survival for the total cohort of de novo AL as well as for de novo AML was significantly longer (p<0.001) for Swedish as compared to Estonian patients. Methods: In view of the miserable outcome for the Estonian patients we decided to prospectively compare the results for incidence and outcome of de novo AL between the two countries. Results: The present report covers the first 5-year period comprising 1997–2001 and deals only with patients aged ≥65 years at diagnosis. The age-adjusted annual incidence rates for de novo AML were lower in Estonia (6.4/100000) than in Sweden (9.2/100000) but not significantly so. The present results also show that the outcome for the Estonian AML patients had improved considerably over the study period; thus, at no time point, i.e., at 1, 3 and 5 years did relative survival between the two countries differ significantly. Conclusion: Yet, as compared to the Swedish cohort relative survival for the Estonian patients did still not reach an acceptable level.

Keywords: Acute de novo leukemia, Incidence, Survival, Estonia, Sweden