Incidence of myelodysplastic syndromes in a Swedish population.

The myelodysplastic syndromes (MDS) have attracted great interest during the last decade. Unfortunately there is not much material published concerning the incidence of these conditions. We present epidemiologic data on MDS based on case registration of patients in a well-defined population and as a comparison similar data on acute myeloid leukaemia (AML). Between the years 1978-1992 we registered 120 cases of MDS and 146 cases of AML. The median age for all the MDS cases was 74.1 years for men and 78.2 years for women. Among haematologists there is a suspicion that the incidence of MDS is rising. Our study does not support this opinion. We have divided the study period into 5-year periods and the crude incidence has been 3.2, 4.1 and 3.5/100,000/year for each period. In the age group over 70 years MDS was more frequent than AML and in the last 5-year period the incidence was 15.0/100,000/year for MDS compared to 10.2/100,000/year for AML. In conclusion MDS is quite common among elderly people and there is no evidence for a rising incidence during the last 15 years.