CHANGING TRENDS IN THE INCIDENCE OF NON-HODGKINS-LYMPHOMA IN EUROPE

Non-Hodgkin's lymphoma (NHL) is not a uniform disease entity, and in o rder to investigate the reported changes in incidence we have set up a study in seven population-based cancer registries in Europe. The stud y is designed to look at changes in the incidence of total NHL and dis ease subgroups using standard definitions and methodology. The registr ies are based in Leeds, Dijon, Kuopio, Odense, Florence, Eindhoven, an d Ragussa. The classification system we have used is based on the REAL classification and has utility for epidemiological studies. We have u sed it to convert data sets which have utilized both local cases and t he ICD-O classification, In order to improve data reproducibility, CLL /LL, myeloma/MGUS, lymphoblastic disease, and Hodgkin's disease have b een excluded because of the difficulty in defining incident cases accu rately. The preliminary results of this study show that there is still an upward trend in incidence rate and that in Yorkshire this is 3% pe r annum in total NHL. The subgroups which are increasing are extranoda l and nodal peripheral T-cell lymphoma. Similar increases in incidence have been reported for the other registries, We conclude that there i s a continued upward trend in incidence of NHL, the causes of which ar e uncertain.