title: Clinical features of polycythemia vera and essential thrombocythemia in Japan: retrospective analysis of a nationwide survey by the Japanese Elderly Leukemia and Lymphoma Study Group.
abstract: We conducted the first nationwide survey to clarify the clinical features, treatment methods, and prognoses for polycythemia vera (PV) and essential thrombocythemia (ET). A 1-page questionnaire was mailed to members of the Japanese Elderly Leukemia and Lymphoma Study Group (JELLSG). Surveys on 647 patients (PV, 266 patients; ET, 381 patients) were returned and analyzed. Thrombotic events at diagnosis and during follow-up occurred at rates of 15.4% and 8.5%, respectively, in PV cases and 17.6% and 8.7% in ET cases. Splenomegaly was observed in only 28.8% of PV patients and 10.8% of ET patients. The leukocyte alkaline phosphatase score was elevated in only 46.2% of PV patients. The incidences of abnormal karyotypes were less than 10% in both PV and ET cases. The rates of transformation to myelofibrosis were 2.6% in both PV and ET cases, and acute leukemia was noted in 1.1% of PV patients and 2.9% of ET patients. Prognostic factors were thrombotic history for PV and thrombotic history and age (>or=60 years) for ET. The present study clearly demonstrated clinical differences between Japanese and Western patients for PV and ET. Concerning the treatment of PV and ET, the study revealed considerable variation among Japanese hematologists. These results suggest the necessity of developing treatment guidelines according to risk stratification that are suitable for Japanese PV and ET patients.
authors.affiliation: Department of Hematology, Nippon Medical School, Tokyo, Japan. dan@nms.ac.jp
authors.forename: Kazuo
authors.initials: K
authors.lastname: Dan
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamada
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Kimura
authors.forename: Noriko
authors.initials: N
authors.lastname: Usui
authors.forename: Shinichirou
authors.initials: S
authors.lastname: Okamoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Sugihara
authors.forename: Kazue
authors.initials: K
authors.lastname: Takai
authors.forename: Michihiko
authors.initials: M
authors.lastname: Masuda
authors.forename: Mayumi
authors.initials: M
authors.lastname: Mori
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D017408:Guidelines as Topic; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D011087:Polycythemia Vera / Q000097:blood / Q000150:complications / Q000401:mortality*; D055728:Primary Myelofibrosis / Q000097:blood / Q000209:etiology / Q000401:mortality; D012189:Retrospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D015996:Survival Rate; D013920:Thrombocythemia, Essential / Q000097:blood / Q000150:complications / Q000401:mortality*; D013927:Thrombosis / Q000097:blood / Q000209:etiology / Q000401:mortality