INCIDENCE TRENDS OF HEMATOLOGICAL MALIGNANCIES IN BELGIUM OVER 2004-2015: IMPACT OF THE RESIDENCE ON CHRONIC MYELOID DISORDERS Hu00e9lu00e8ne A. Poirel, Tamara Vandendael, Fru00e9du00e9ric Calay, Ju00e9ru00f4me Xicluna, Gilles Macq, Evelien Vaes, Kris Henau, Liesbet Van EyckenBelgian Cancer Registry, Brussels, BelgiumThe Belgian Cancer Registry collects information about all new cancer diagnoses in Belgium since 2004 to map out the nature and extent of cancers in Belgium. In 2015, hematological malignancies (HM) represent 10.7% of all cancers in Belgium and are the 3rd cause of death by cancer. We aim to describe the incidence trends of the main categories of HM in Belgium over a 17yr-period taking into account 2 criteria of residence at time of diagnosis (the 3 Belgian regions, rural vs. non-rural areas) and their impact on the relative survival.A total of 71,783 HM (lymphoid: 49,204; myeloid: 22,579) were registered over 2004-2015. The increased crude incidence rate is mainly explained by an aging and growing Belgian population and by an increased incidence rate of chronic disorders (myelodysplastic syndromes (MDS), myeloproliferative neoplasms (MPN), MDS/MPN, and to a lesser extent, chronic lymphocytic leukemia/lymphoma (SLL/CLL)). The increased incidence rate seems to be more important in the Walloon and Brussels-Capital regions than in the Flemish region for MDS while similar between the 3 regions for MPN & MDS/MPN and SLL/CLL. Regarding the rurality level, the most obvious observation is the higher incidence of MPN in urban populations compared to rural populations. No major incidence trends are observed for the main categories of lymphoid disorders.In conclusion, the increased WSR incidence over 2004-2015 of chronic HM (MDS, MPN, MDS/MPN, SLL/CLL) may be at least partly explained by an earlier detection at an asymptomatic stage and/or a better registry of the hospitals. However, the disparity of the WSR trend between the 3 Belgian regions for MDS and the rural vs. non-rural housing for MPN suggest a ...