Contributions
Abstract: EP1105
Type: E-Poster Presentation
Session title: Myeloproliferative neoplasms - Clinical
Background
A nationwide survey of Japanese patients with Philadelphia-negative myeloproliferative neoplasms (MPNs) was reported in 2006, including 266 patients with polycythemia vera (PV) and 381 patients with essential thrombocythemia (ET). Since then,JAK2 and other driver gene mutations have been found in MPNs, and new diagnostic criteria such as the World Health Organization (WHO) 2008 and 2017 classifications have emerged, warranting a new survey to obtain novel insights regarding Japanese patients with MPNs.
Aims
To analyze the clinical characteristics of patients with PV in Japan, we conducted a retrospective study.
Methods
Patients who were diagnosed with PV according to either the WHO 2008 or 2017 classification between April 2005 and March 2018 were enrolled. This study was conducted by the Japanese Society of Hematology.
Results
In total, 1867 patients with PV or ET from 41 institutions in Japan were registered. Among them, 596 patients with PV were analyzed. The median age was 65 years, including 5.2% and 16.8% of patients <40 and <50 years of age, respectively. JAK2 V617F mutations were detected in 83.1% (456/549) of patients. Thrombotic and hemorrhagic events before or at the time of diagnosis occurred in 16.2% and 3.7%, respectively.
During a median follow-up of 47 months (range: 0–182 months), 49 deaths (8.2%) occurred. The median overall survival was not reached, likely due to the short follow-up time. The major causes of death were secondary malignancies (n=11; 1.8%), leukemic transformation (n=6; 1.0%), non-leukemic progressive disease (n=5; 0.8%), thrombotic complications (n=3; 0.5%), and hemorrhagic complications (n=3; 0.5%). Progression to secondary myelofibrosis was observed in 17 cases (2.9%), which subsequently progressed to acute leukemia in 1 case. Thrombotic and hemorrhagic events occurred in 24 (4.0%) and 20 (3.4%) cases, respectively. While extreme thrombocytosis (≥1000 × 109/L) was a risk factor for survival, leukocytosis (≥10 × 109/L) was a risk factor for survival and thrombosis-free survival. Age >60 years was a risk factor for leukemic transformation. Interestingly, splenomegaly was a predictor of hemorrhagic events in univariate analysis. The international PV prognostic score (age, venous thrombosis, and leukocytosis) clearly distinguished the Japanese PV population into three distinct risk groups.
Conclusion
This was the largest study of Japanese patients with PV, showing that leukocytosis is a risk factor for survival and thrombosis, and splenomegaly is a risk factor for hemorrhagic complications. Although splenomegaly has been reported as a risk factor for hemorrhage in patients with ET or whole MPN, to the best of our knowledge, it has not been specifically predicted in patients with PV. While few hemorrhagic events occurred before or at the time of diagnosis of PV, the number of thrombotic and hemorrhagic events after diagnosis showed only a slight difference (24 and 20, respectively). Among the 20 patients with hemorrhagic complications, 14 received an anti-thrombotic drug. These findings suggest that instead of preventing thrombotic complications during PV treatment, many hemorrhagic events may occur as iatrogenic events. Both thrombotic and hemorrhagic complications are significantly correlated with survival; thus, the risk of both thrombotic and hemorrhagic complications should be considered in the treatment algorithm.
Keyword(s): Bleeding, Polycythemia vera, Thrombosis
Abstract: EP1105
Type: E-Poster Presentation
Session title: Myeloproliferative neoplasms - Clinical
Background
A nationwide survey of Japanese patients with Philadelphia-negative myeloproliferative neoplasms (MPNs) was reported in 2006, including 266 patients with polycythemia vera (PV) and 381 patients with essential thrombocythemia (ET). Since then,JAK2 and other driver gene mutations have been found in MPNs, and new diagnostic criteria such as the World Health Organization (WHO) 2008 and 2017 classifications have emerged, warranting a new survey to obtain novel insights regarding Japanese patients with MPNs.
Aims
To analyze the clinical characteristics of patients with PV in Japan, we conducted a retrospective study.
Methods
Patients who were diagnosed with PV according to either the WHO 2008 or 2017 classification between April 2005 and March 2018 were enrolled. This study was conducted by the Japanese Society of Hematology.
Results
In total, 1867 patients with PV or ET from 41 institutions in Japan were registered. Among them, 596 patients with PV were analyzed. The median age was 65 years, including 5.2% and 16.8% of patients <40 and <50 years of age, respectively. JAK2 V617F mutations were detected in 83.1% (456/549) of patients. Thrombotic and hemorrhagic events before or at the time of diagnosis occurred in 16.2% and 3.7%, respectively.
During a median follow-up of 47 months (range: 0–182 months), 49 deaths (8.2%) occurred. The median overall survival was not reached, likely due to the short follow-up time. The major causes of death were secondary malignancies (n=11; 1.8%), leukemic transformation (n=6; 1.0%), non-leukemic progressive disease (n=5; 0.8%), thrombotic complications (n=3; 0.5%), and hemorrhagic complications (n=3; 0.5%). Progression to secondary myelofibrosis was observed in 17 cases (2.9%), which subsequently progressed to acute leukemia in 1 case. Thrombotic and hemorrhagic events occurred in 24 (4.0%) and 20 (3.4%) cases, respectively. While extreme thrombocytosis (≥1000 × 109/L) was a risk factor for survival, leukocytosis (≥10 × 109/L) was a risk factor for survival and thrombosis-free survival. Age >60 years was a risk factor for leukemic transformation. Interestingly, splenomegaly was a predictor of hemorrhagic events in univariate analysis. The international PV prognostic score (age, venous thrombosis, and leukocytosis) clearly distinguished the Japanese PV population into three distinct risk groups.
Conclusion
This was the largest study of Japanese patients with PV, showing that leukocytosis is a risk factor for survival and thrombosis, and splenomegaly is a risk factor for hemorrhagic complications. Although splenomegaly has been reported as a risk factor for hemorrhage in patients with ET or whole MPN, to the best of our knowledge, it has not been specifically predicted in patients with PV. While few hemorrhagic events occurred before or at the time of diagnosis of PV, the number of thrombotic and hemorrhagic events after diagnosis showed only a slight difference (24 and 20, respectively). Among the 20 patients with hemorrhagic complications, 14 received an anti-thrombotic drug. These findings suggest that instead of preventing thrombotic complications during PV treatment, many hemorrhagic events may occur as iatrogenic events. Both thrombotic and hemorrhagic complications are significantly correlated with survival; thus, the risk of both thrombotic and hemorrhagic complications should be considered in the treatment algorithm.
Keyword(s): Bleeding, Polycythemia vera, Thrombosis