Clinicopathologic features and prognostic indicators in Chinese patients with myelofibrosis

Objective: To define the clinicopathologic features, outcome, and prognostic indicators of myelofibrosis (MF) in Asian patients. Methods: Two hundred and seventy consecutive Chinese patients (primary MF, n = 207; post-polycythemia vera MF, n = 27; and post-essential thrombocythemia MF, n = 36) from seven regional referral hospitals were analyzed. Results: The median overall survival (OS) for primary MF was 66 months. Multivariate analysis showed that age >65 years (P = 0.02), platelet count < 100 x 10(9)/l (P = 0.001), and leukemic transformation (P = 0.001) negatively impacted on OS. The median OS of 63 patients with secondary MF was 44 months. In primary MF, the 10-year cumulative risk of leukemic transformation was 28%. On multivariate analysis, unfavorable karyotypes significantly predicted inferior leukemia-free survival (LFS) (P = 0.03). In secondary MF, the 10-year cumulative risk of leukemic transformation was 31%. Circulating blasts >= 1% significantly predicted inferior LFS (P = 0.04). The international prognostic scoring system (IPSS) and dynamic IPSS were not significant survival predictors in our cohort. Eighteen patients underwent allogeneic hematopoietic stem cell transplantation. The median OS post-transplantation was merely 19 months. Discussion: Platelet count < 100 x 10(9)/l, unfavorable karyotypes, and circulating blasts > 1% were negative prognostic indicators. Conclusion: Chinese MF patients were similar to Western patients in clinicopathologic features and outcome.