Cytogenetic studies and their prognostic contribution in 565 Chinese patients with primary myelofibrosis.

To study the feature and prognostic contribution of cytogenetic information in Chinese patients with primary myelofibrosis (PMF), we analyzed cytogenetic data from 565 patients with PMF. One hundred and sixty-two subjects (29%) had abnormal karyotypes, including trisomy 8 (45; 28%), deletion of 20q (25; 15%), deletion of 13q (13; 8%), deletion of 11q (12; 7%), and abnormal chromosome 1 (21; 13%); balanced translocations (14; 9%); a complex karyotype (CK; 30; 19%), and a monosomal karyotype (MK; 19; 12%). Using these data, we showed that the Dynamic International Prognostic Scoring System (DIPSS)-plus, which includes cytogenetic information, is a better survival predictor than the DIPSS. We next used our data to construct the following two cytogenetic-based cohorts: (1) favorable karyotype-subjects with a normal karyotype, a CK that is not a MK, +8 only or a balanced translocation only and (2) unfavorable karyotype-all others. The median survival times were not reached and were 52 month (95% CI, 32-72 months; P = 0.01) in patients with favorable and unfavorable karyotypes, respectively. These data provided the detailed cytogenetic information in Chinese patients with PMF and confirmed the impact of cytogenetic abnormalities on survival in Chinese patients.