Hidroxiurea en neoplasias mieloproliferativas Ph negativas: experiencia en la Argentina.

Ph negative myeloproliferative neoplasms (NMP), polycythemia vera (PV), essential thrombocythemia(ET) and primary myelofibrosis (MF), are clonal hematopoietic disorders characterized in their chronicphase by an overproduction of differentiated hematopoietic cells. Hydroxyurea (HU) is an antineoplasticagent belonging to the family of antimetabolites.  (According to ELN guidelines, it is recommended as first-line cytoreductive therapy). It is the cytoreductive agent recommended in the first line by the European Leukemia Net (ELN). The aim of this work was to describe the criteria for the initiation of cytoreductive treatment, vascular complications and response rates, intolerance, resistance and progression to myelofibrosis or AML in a population of patients with NMP treated with hydroxyurea in Argentina. 419 patients referred by 63 members of the SAH, belonging to 37 institutions, diagnosed between 1986 and 2017 were included, of which 417 were available for analysis. We observed that the main reason for starting treatment was age (51%), followed by the presence of vascular risk factors (26.6%), thrombocytosis (24.7%) with an average platelet count 1.052 x 109/L (DS 360.32) and previous thrombosis (16.8%). Complete hematological responses lasting at least three months were obtained in PV and TE (61 and 66%). The presence of arterial and venous thrombosis had a similar frequency (14%). The use of HU significantly reduced the risk of thrombosis in the higher risk group. The clinical course and complications of the patients studied with PV JAK2 and positive JAK2 TE were similar and adverse events due to the use of HU were mild but frequent (32.6%).