OBJECTIVETo investigate the survival status and prognosis of patients with essential thrombocythemia(ET) and analyze the prognostic factors for the patients' survival, so as to provide a evidence for clinical treatment and prognosis evaluation.

METHODSA retrospective analysis of 118 patients with ET was conducted in the Fifth Affiliated Hospital of Sun Yat-Sen University and Zhongshan Municipale People's Hospital from December 2002 to December 2013. The clinical characteristics were summarized, such as the survival curve and multi-factor analysis, therefore looking for the disease characteristics and risk factors affecting the survival and prognosis.

RESULTSAmong 118 ET patients enrolled in this study, the survival rate of ET patients for 1, 3, 5 and 10 years were 95.5%,92.6%,89% and 81.6%, respectively. Kaplan-Meier survival curve showed that the age ≥60 years old at diagnosis, cardiovascular risk factors, anamnesis of thrombosis or hemorrhage, anemia(hemoglobin<120 g/L), thrombocythemia (≥1 000×10/L), risk stratification and hydroxyurea or HHT(hemoharringtonine) use in high-risk group were factors affecting the suvival rate, 7 out of those factors influencing survival rate were statistically significant (P<0.05). COX regression analysis showed that independent risk factors affecting survival have not yet been found.

CONCLUSIONET patients display a high survival rate and long survival time, and their conversion risk into the marrow fibrosis or leukemia has been found to be low. The age≥60 years old at diagnosis, cardiovascular risk factors, anamnesis of thrombosis or hemorrhage, anemia and therombocythemia are the risk factors affecting prognosis. The use of hydroxyurea or HHT in high-risk group can improve the prognosis.