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.
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.
Patnaik
Mrinal M
MM
Division of Hematology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
Caramazza
Domenica
D
Gangat
Naseema
N
Hanson
Curtis A
CA
Pardanani
Animesh
A
Tefferi
Ayalew
A
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