Abstract 4272The incidence of Philadelphia positive (Ph+) chronic myeloid leukemia (CML) in Europe is still difficult to estimate, due to insufficient information. Currently, it is believed to range between 8 and 22 cases per million people per year, age adjusted. Prior to the introduction of the tyrosine kinase inhibitor (TKI) imatinib the annual death rate was about 10% for the first 2 to 3 years, and about 20% from the 4th year on, with less than 10% of patients alive after 10 years. Interferon-alfa treatment and allogeneic hematopoietic stem cell transplantation were very effective treatments but only in a minority of patients. Following the introduction of IM, and of the second generation TKI nilotinib and dasatinib the annual death rate has decreased to less than 5%, and more than 75% of patients are projected to be alive 10 years after diagnosis. Based on these figures, the prevalence of the disease is expected to double every 5 years and the management of the disease will rapidly become an important social and pharmacoeconomic issue. To govern this progress it is necessary to improve the level of information on the epidemiology of CML, on the treatment of CML in clinical practice, and on the outcome of treatment outside prospective, controlled clinical trials on which current outcome estimates are based. With that purpose, the European Leukemia Network (ELN) has established a registry of all new cases of Ph+ CML. In a public private partnership with Novartis Oncology Europe this registry has been expanded to also include treatment and quality controlled outcome (European Treatment and Outcome Study [EUTOS] for CML). The infrastructure of the registry is based on a EUTOS Central Scientific Headquarter (Dpt. Hematology-Oncology “L. and A. Seràgnoli”, University of Bologna, S.Orsola-Malpighi Hospital, Bologna, Italy) and a EUTOS Central Data Center (Dpt. For Medical Informatics, Biometric and Epidemiology, University of Munich, Munich, Germany), interacting with each national hub. Registry is population-based, covers completely most European countries with less than 12 millions inhabitants (Portugal, Belgium, Sweden, Finland, Lithuania, Latvia, Estonia, Czech Republic, Slovakia, Slovenia, Croatia, Serbia, Hungary, Austria, Greece, Cyprus), and covers partially (for larger countries, only sub-regions with roughly 10 millions inhabitants have been selected) most of the countries with more than 12 millions inhabitants, including Spain, the United Kingdom, The Netherlands, Germany, Poland, France, Romania, Russia and Italy. About 2500 newly diagnosed cases are planned to be registered over one year and to be followed for treatment and outcome including cytogenetic response, molecular response, and BCR-ABL KD mutations. Moreover, flanking projects have been implemented in the EUTOS frame: a network of standardized laboratories across Europe, to provide a molecular monitoring with quality controlled data, a central facility for imatinib blood level testing, soon in many European countries, and an educational effort (symposia, training workshops, internet platform). The EUTOS registry joins epidemiological and outcome data: its implementation requires considerable efforts and resources, but in the long run CML could become a model for epidemiologi and management of other cancers. Disclosures:Hasford:Novartis Pharma: Research Funding.