No increase in age-specific incidence of myelodysplastic syndromes

Epidemiological data on myelodysplastic syndromes (MDS) are sparse. However, the available evidence indicates that MDS is among the most common hematologic diseases.

In a previous study, we showed that incidence rates rose from 1 to 4.1 in the period 1976-1990, with no increase between 1986 and 1990. We extended our study, covering the years 1991 through 2001. Diagnostic criteria and cytomorphology remained the same, consistently applying the criteria of the FAB classification.

Three-hundred and eight new cases of MDS were identified in the town district of Düsseldorf, which provides the reference population for calculating incidences. There was no further rise in MDS incidence. The crude incidence in the period 1991-2001 was 4.9 (5.52 in males, 4.36 in females), which is similar to that in the 1986-1990 period. Age specific incidences were 8.7, 24.5, and 31.3 for the age groups 60-70, 71-80, and 80-90, respectively. The incidence of MDS in the age group >70 years was significantly higher among males (42.3) than among females (19.0). The preponderance of males was found among patients with refractory anemia with excess blasts (16 vs 3), refractory anemia with excess blasts in transformation (7 vs 2), refractory anemia (15 vs 6) and chronic myelomonocytic leukemia (7 vs 2), whereas, somewhat surprisingly, the age-related incidences refractory anemia with ringed sideroblasts was similar for males and females (4 vs 5). The data on MDS incidence in the town district of Düsseldorf showed a plateau since 1986.

Interpreting our data covering a 26-year period, we feel that the increase in the early years primarily reflected improved case ascertainment, whereas our new data may provide a good approximation of the true incidence of MDS. There is no evidence that the age-adjusted incidence of MDS is rising.