title: A retrospective cohort study of venous thromboembolism(VTE) in 1035 Japanese myeloma patients treated with thalidomide; lower incidence without statistically significant association between specific risk factors and development of VTE and effects of thromboprophylaxis with aspirin and warfarin.
abstract: BACKGROUND
  Rate of thalidomide-related VTE and risk factors in Japanese myeloma patients are not clear and effects of thromboprophylaxis remain controvertial.
  
  
  METHODS
  We retrospectively analyzed a cohort data of registered Japanese myeloma patients treated with thalidomide-based regimens between 2009 and 2010. Primary endpoint was rate of symptomatic VTE. Secondary endpoints were associations between VTE and clinical factors including age, gender, disease characteristics and duration, history of VTE, immobilization, comorbidities, treatment regimens, and laboratory parameters of Hb, leukocyte, platelet and FDP or D-dimer level, and effects of thromboprophylaxis with aspirin or warfarin. Statistical analysis was performed by Fischer's exact test and Cochran-Mantel-Haenszel test to control for confounders, and t test for dichotomous and continuous variables, respectively.
  
  
  RESULTS
  1035 refractory or relapsed myeloma patients were followed up for a median of 112days(range 2-311days), and 14 (1.4%) developed VTE with a median treatment of 31days (range 9-134days) with thalidomide. Treatments with or without other agents lead to similar rates of VTE, 1.7% and 1.1%, respectively (p=0.43) and no specific clinical factors influenced development of VTE. Thromboprophylaxis with aspirin or warfarin did not reduce risk of VTE; VTE with or without aspirin: 1.4% and 1.3% (p=1.00), and warfarin: 2.4% and 1.3% (0.31), respectively.
  
  
  CONCLUSIONS
  Rate of VTE is low in Japanese myeloma patients treated with thalidomide. Risk factors and effects of thromboprophylaxis with aspirin or warfarin are not apparent, however, controlled randomized studies of larger scale are needed for statistically valid conclusion.
authors.affiliation: Division of Hematology, Department of Medicine, Japanese Red Cross Society Hospital Musashino, Japan. akato@musashino.jrc.or.jp
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kato
authors.forename: Hina
authors.initials: H
authors.lastname: Takano
authors.forename: Ayako
authors.initials: A
authors.lastname: Ichikawa
authors.forename: Mayuko
authors.initials: M
authors.lastname: Koshino
authors.forename: Aiko
authors.initials: A
authors.lastname: Igarashi
authors.forename: Keiichiro
authors.initials: K
authors.lastname: Hattori
authors.forename: Kaoru
authors.initials: K
authors.lastname: Nagata
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001241:Aspirin / Q000627:therapeutic use*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000097:blood* / Q000188:drug therapy; D012189:Retrospective Studies; D012307:Risk Factors; D013792:Thalidomide / Q000009:adverse effects* / Q000627:therapeutic use; D054556:Venous Thromboembolism / Q000139:chemically induced* / Q000517:prevention & control*; D014859:Warfarin / Q000627:therapeutic use*
chemical_list: D013792:Thalidomide; D014859:Warfarin; D001241:Aspirin