title: Age and platelet count are IPSS-independent prognostic factors in young patients with primary myelofibrosis and complement IPSS in predicting very long or very short survival.
abstract: OBJECTIVE
  The current study was designed to identify International Prognostic Scoring System (IPSS)-independent prognostic factors in young patients with primary myelofibrosis (PMF). The study also examined the overall risk profile of long-term (>15 yr) and short-term (<5 yr) survivors.
  
  
  METHODS
  Study patients were selected from the Mayo Clinic database for PMF, and study eligibility included age <60 yr, minimum follow-up of 5 yr and availability of IPSS-relevant variables at time of diagnosis.
  
  
  RESULTS
  A total of 148 consecutive patients met the above-stipulated criteria. To date, 89 (60%) patients have died; 48 (32%) died within 5 yr of their diagnosis (short-term survivors). Median follow-up of patients who are alive was 9 yr (range 5-28) with a >15-yr survival documented in 16 patients (long-term survivors). Multivariable analysis identified unfavorable IPSS category (intermediate-2/high risk), age >50 yr and platelet count <100 x 10(9)/L as independent predictors of inferior survival (P < 0.01). Median survival in the absence of all three risk factors was approximately 18 yr and was shortened to 7 and 1.6 yr in the presence of 1 or > or = 2 risk factors, respectively (P < 0.01). Among long-term survivors, 69% were age < or = 50 yr, 100% had favorable IPSS profile and 100% displayed platelet count > or = 100 x 10(9)/L; the corresponding figures for short-term survivors were 29%, 50% and 65% (P < 0.01).
  
  
  CONCLUSIONS
  Age and platelet count are IPSS-independent predictors of survival in young patients with PMF, and they complement the IPSS in identifying patients with very long or very short survival.
authors.affiliation: Division of Hematology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
authors.forename: Mrinal M
authors.initials: MM
authors.lastname: Patnaik
authors.forename: Domenica
authors.initials: D
authors.lastname: Caramazza
authors.forename: Naseema
authors.initials: N
authors.lastname: Gangat
authors.forename: Curtis A
authors.initials: CA
authors.lastname: Hanson
authors.forename: Animesh
authors.initials: A
authors.lastname: Pardanani
authors.forename: Ayalew
authors.initials: A
authors.lastname: Tefferi
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D055728:Primary Myelofibrosis / Q000097:blood* / Q000175:diagnosis / Q000401:mortality*; D012307:Risk Factors; D015996:Survival Rate