[Evaluation of the prognostic value of MIPSS70-plus in Chinese patients with primary myelofibrosis].

Objective: To evaluate the prognostic value of MIPSS70-plus in Chinese patients with primary myelofibrosis (PMF) . Methods: A total of 113 Chinese patients with PMF were retrospectively analyzed. The Kaplan-Meier method, Log-rank test, and Cox proportional hazard regression model were performed to evaluate the prognostic factors. The likelihood ratio test was used to evaluate the predictive power between MIPSS70-plus and DIPSS systems. Results: The median age of the Chinese patients was 55 (range: 20-70) years, including 71 males and 42 females. According to the standard of MIPSS70-plus system, 99 patients (79.6% ) had a favorable karyotype and 23 patients (20.4% ) had an unfavorable karyotype. JAK2V617F in 55.8% (n=63) , CALR exon9 in 17.7% (including 15 CALR type 1 and 5 CALR type 2, n=20) , MPLW515 in 4.4% (n=5) , and triple negative (no detectable JAK2, MPL, and CALR mutations) in 22.1% of patients in our cohort were found by target-specific next-generation sequencing approach. At least one high-molecular risk mutations were presented in 45.1% (n=51) of patients, with ASXL1 in 38.9% (n=44) , SRSF2 in 7.1% (n=8) , IDH1/2 in 4.4% (n=5) , and EZH2 in 3.5% (n=4) of patients. A total of 28 patients (26.7% ) were in low risk, 20 (19.0% ) in intermediate risk, 41 (39.0% ) in high risk, and 16 (15.3% ) in very-high risk categories, which were delineated for the MIPSS70-plus model. A 2-year OS was 100% in low risk, 89.7% (95% CI 76.2% -100.0% ) in intermediate risk, 64.8% (95% CI 47.0% -82.6% ) in high risk, and 35.0% (95% CI 10.3% -59.7% ) in very-high risk categories, which had a significant difference (P<0.001) . A significantly higher predictive power for survival of the MIPSS70-plus group was observed compared with the DIPSS group (P=0.001, -2 log-likelihood ratios of 86.355 vs 95.990 for the MIPSS70-plus and DIPSS systems, respectively) . Conclusion: The MIPSS70-plus had significantly higher predictive power than the DIPSS.