[Analysis of prognostic factors in Chinese patients with post-polycythemia vera myelofibrosis and post-essential thrombocythemia myelofibrosis].

Objective: To evaluate the performances of the prognostic scoring systems devised for primary myelofibrosis(PMF)and the new developed MYSEC- PM(Mysec Prognostic Model)and investigate the risk factors in Chinese patients with post-polycythemia vera myelofibrosis and post-essential thrombocythemia myelofibrosis(post- PV/ET MF). The most widely used prognostic scoring systems in PMF included the International Prognostic Scoring System(IPSS), dynamic International Prognostic Scoring System(DIPSS), refined DIPSS(DIPSS plus), modified IPSS for Chinese(IPSS-Chinese), and modified DIPSS for Chinese(DIPSS- Chinese). Methods: The clinical and hematologic information of 55 consecutive patients diagnosed with post- PV/ET MF from March 1984 to December 2013 were retrospectively collected. All post-PV/ET MF patients were categorized according to IPSS, DIPSS, DIPSS plus, IPSS-Chinese, DIPSS-Chinese and MYSEC-PM, and the possible prognostic factors were statistically analyzed. Results: Fifty five patients diagnosed with post-PV MF(n=32)or post-ET MF(n=23)were analyzed with a median age of 59(range: 20- 88)years old, including 20 males and 35 females. Median time from original diagnosis to myelofibrosis was 7.8(range: 1.1- 23.4)years. With a median follow up from post-PV/ET MF diagnosis of 37(range: 1-156)months, 44(80.0%)patients were censored alive, 11(20.0%)patients died. Median survival was 110(95% CI 87.5-132.8)months. Using IPSS, DIPSS, DIPSS plus, IPSS- Chinese and MYSEC- PM criteria, there were no statistically significances in survival among different risk groups(P>0.05). In univariate analyses HGB<100 g/L(P=0.003)was the only factor associated with poorer overall survival. The prognosis in subjects with HGB≥100 g/L was significantly better than that with HGB<100 g/L(median OS: not reached vs 47 months, P=0.003). Conclusion: IPSS, DIPSS, DIPSS plus, IPSS- Chinese and MYSEC- PM did not accurately discriminate different risk categories in post PV/ET MF patients. HGB< 100 g/L was associated with poor outcome in post-PV/ET MF patients.