Spatial distribution of acute myeloid leukaemia in Denmark

Although various occupational and environmental exposures are suspected risk factors for acute myeloid leukaemia (AML), the aetiology of AML is largely unknown. We present an analysis of the spatial distribution of AML in Denmark on an unprecedented, detailed scale. Such investigations have the potential to uncover geographical areas of increased risk, which may in turn be tied to environmental or occupational exposures.

Individuals diagnosed with AML during 2000-2020 were obtained from the Danish National Acute Leukaemia Registry and assigned to a parish based on their residence six months prior to diagnosis. The incidence rate ratio (IRR) by parish was calculated as the ratio between the age- and sex-standardised incidence rate and the national incidence rate. The IRRs were smoothed using a spatial Poisson distributed generalised linear mixed model with a conditional autoregressive correlation structure. Parishes with a smoothed IRR > 1.10 with a posterior probability > 75% were considered to have an increased risk of AML.

The study included 5,177 AML cases. The spatial model showed a homogeneous distribution of AML in Denmark with no parishes having an increased risk.

The study indicates that the risk of developing AML in Denmark is not affected by place of residence, suggesting that if an unknown environmental or occupational risk factor is present, it does not seem to be associated with specific areas.