A population-based study of childhood myelodysplastic syndrome in British Columbia, Canada

Myelodysplastic syndrome (MDS) is considered to be very rare in children. H owever, the only true published population-based studies reported widely di vergent incidence figures. To further explore the epidemiology of childhood MDS and to evaluate the accuracy of cancer registry and treatment trial da ta, we conducted a population-based study of children aged 0-14 years in Br itish Columbia (BC), Canada, between 1982 and 1996. MDS was diagnosed in 31 cases corresponding to an annual incidence of 3.2 per million children or 6% of all leukaemias, compared with an incidence of 6.0/million for acute m yeloid leukaemia (AML), and of 0.5 million for chronic myeloid leukaemia. T here was a non-significant (P=0.19) trend toward an increase in MDS inciden ce with time, the increase was partly explained by an increasing number of patients with Down syndrome. Associated abnormalities were found in 48% of the MDS cases with Down syndrome as the most common (seven cases). Only one third of the MDS cases were correctly registered in the Cancer Registry an d less than half of the eligible MDS patients were enrolled on a cooperativ e group study, Data on MDS from treatment-based studies and cancer registri es were inaccurate and seemed to significantly underestimate the incidence of MDS in children.