Myelodysplastic syndrome in New Zealand and Australia.
Myelodysplastic syndrome (MDS), a haematological disorder of the elderly, has been formally classified as a neoplastic disease for 10 years. Our aim was to collate national cancer registry incidence data to describe the epidemiology of MDS in New Zealand. The New Zealand Cancer Registry has now reported five complete years of incidence data, the last three of which were used for analysis. For the years 2005-2007, age-sex specific and age-standardised MDS incidence rates from New Zealand were compared with those from Australia. Age-standardised incidence rates were calculated by the direct standardisation method and standardised rate ratios were compared at the 5, 1 and 0.1% levels. Diagnoses of MDS represented 1.3% of total cancer registrations in New Zealand and 1.0% in Australia. In both New Zealand and Australia, 86-87% of MDS cases were diagnosed in individuals ≥60 years of age, the incidence increased significantly with age, and males had a significantly higher age-standardised incidence rate (P < 0.001) than females. The incidence rate for New Zealand males was significantly higher (P < 0.001) than Australian males. In both New Zealand males and females, the age-standardised incidence rate of MDS was significantly higher (P < 0.05) than most other haematological neoplasms. In New Zealand and Australia, MDS is a common haematological neoplasm. The marked difference between male and female incidence rates, especially with advancing age, may provide insights into the causes of this disease.