LAUSR

The recent inclusion of the classical myeloproliferative neoplasms (MPN) in the Australian Cancer Atlas, from state-based cancer registry data from 2007 to 2016, reveals marked variation in the reported incidence of MPN, not only between states but also between regions in close proximity that share similar demographics. In New South Wales (NSW), a striking difference is evident when one crosses the Hawkesbury River. The area south of the Hawkesbury River (greater Sydney) has an incidence that ranges from 33% below to 4% above the national average. The area north of the Hawkesbury River (Central Coast and Hunter), in contrast, records an incidence of 6% to 32% above the national average (Fig. 1). It is unlikely that this is