Contributions
Abstract: EP1101
Type: E-Poster Presentation
Session title: Myeloproliferative neoplasms - Clinical
Background
The treatment goals for essential thrombocythemia (ET) are to prevent thrombotic and hemorrhagic events, genetic transformation, and secondary malignancies. In recent years, the risk factors (including epigenetic mutations) of thrombosis and genetic transformation have been intensively investigated. However, the risk factors of hemorrhagic events have not been sufficiently investigated because the incidence of hemorrhagic events after diagnosis of ET is lower than that of thrombosis. Serious hemorrhagic events can lead to impaired activities of daily life and poor survival, and thus, prevention is of extreme importance.
Aims
We conducted a large-scale, nationwide retrospective study on Japanese patients with ET to investigate the clinical characteristics, survival rate, and incidence of thrombotic and hemorrhagic events and identify the risk factors of these events.
Methods
We included patients aged ≥20 years who were newly diagnosed with ET according to the World Health Organization’s 2008 or 2017 criteria between April 2005 and March 2018. We reviewed data on patient characteristics including driver gene mutations, treatment, thrombotic and hemorrhagic events after diagnosis, genetic transformation, incidence of secondary malignancies, overall mortality, and the cause of death collected from patient medical records. This study was conducted by the Japanese Society of Hematology.
Results
In total, 1232 patients with ET were enrolled. Of these patients, 80 patients were excluded according to the selection criteria. The remaining 1152 patients were included in the analysis. At the time of diagnosis, the median patient age was 65 years old, the median platelet count was 832 × 109/L, and the positive mutation rates of JAK2V617F, CALR, and MPL were 62.8%, 25.1%, and 4.1%, respectively. The median follow-up period was 45 months (range: 0-188 months). During the study period, fifty-nine (5.1%) patients experienced hemorrhagic events. The hemorrhagic event-free survival rate was 94.2% and 89.4% at 5 and 10 years, respectively. There was no significant difference in hemorrhagic event-free survival among patients with different driver gene mutations (JAK2V617F, CALR, MPL, and triple-negative). In multivariate analysis, platelet count ≥1000 × 109/L (hazard ratio, 2.007), previous history of hemorrhage (hazard ratio, 3.793), and splenomegaly (hazard ratio, 2.888) were identified as risk factors for of hemorrhagic events. Furthermore, multivariate analysis with hemorrhagic events (hazard ratio, 7.180) as a time-dependent variable showed that hemorrhagic events were a life-threatening risk factor, and the same results were seen for landmark analysis.
Conclusion
In this large-scale retrospective study of Japanese ET patients, platelet count ≥1000 × 109/L, previous history of hemorrhage, and splenomegaly were risk factors of hemorrhagic events, and hemorrhagic events after diagnosis of ET was a risk factor of mortality. Since an increased platelet count is not a risk factor for thrombosis but for hemorrhagic events, appropriate cytoreductive therapy is required to prevent hemorrhagic events.
Keyword(s): Essential Thrombocytemia, Hemorrhage, Risk factor
Abstract: EP1101
Type: E-Poster Presentation
Session title: Myeloproliferative neoplasms - Clinical
Background
The treatment goals for essential thrombocythemia (ET) are to prevent thrombotic and hemorrhagic events, genetic transformation, and secondary malignancies. In recent years, the risk factors (including epigenetic mutations) of thrombosis and genetic transformation have been intensively investigated. However, the risk factors of hemorrhagic events have not been sufficiently investigated because the incidence of hemorrhagic events after diagnosis of ET is lower than that of thrombosis. Serious hemorrhagic events can lead to impaired activities of daily life and poor survival, and thus, prevention is of extreme importance.
Aims
We conducted a large-scale, nationwide retrospective study on Japanese patients with ET to investigate the clinical characteristics, survival rate, and incidence of thrombotic and hemorrhagic events and identify the risk factors of these events.
Methods
We included patients aged ≥20 years who were newly diagnosed with ET according to the World Health Organization’s 2008 or 2017 criteria between April 2005 and March 2018. We reviewed data on patient characteristics including driver gene mutations, treatment, thrombotic and hemorrhagic events after diagnosis, genetic transformation, incidence of secondary malignancies, overall mortality, and the cause of death collected from patient medical records. This study was conducted by the Japanese Society of Hematology.
Results
In total, 1232 patients with ET were enrolled. Of these patients, 80 patients were excluded according to the selection criteria. The remaining 1152 patients were included in the analysis. At the time of diagnosis, the median patient age was 65 years old, the median platelet count was 832 × 109/L, and the positive mutation rates of JAK2V617F, CALR, and MPL were 62.8%, 25.1%, and 4.1%, respectively. The median follow-up period was 45 months (range: 0-188 months). During the study period, fifty-nine (5.1%) patients experienced hemorrhagic events. The hemorrhagic event-free survival rate was 94.2% and 89.4% at 5 and 10 years, respectively. There was no significant difference in hemorrhagic event-free survival among patients with different driver gene mutations (JAK2V617F, CALR, MPL, and triple-negative). In multivariate analysis, platelet count ≥1000 × 109/L (hazard ratio, 2.007), previous history of hemorrhage (hazard ratio, 3.793), and splenomegaly (hazard ratio, 2.888) were identified as risk factors for of hemorrhagic events. Furthermore, multivariate analysis with hemorrhagic events (hazard ratio, 7.180) as a time-dependent variable showed that hemorrhagic events were a life-threatening risk factor, and the same results were seen for landmark analysis.
Conclusion
In this large-scale retrospective study of Japanese ET patients, platelet count ≥1000 × 109/L, previous history of hemorrhage, and splenomegaly were risk factors of hemorrhagic events, and hemorrhagic events after diagnosis of ET was a risk factor of mortality. Since an increased platelet count is not a risk factor for thrombosis but for hemorrhagic events, appropriate cytoreductive therapy is required to prevent hemorrhagic events.
Keyword(s): Essential Thrombocytemia, Hemorrhage, Risk factor