Value of cytogenetic abnormalities in post-polycythemia vera and post-essential thrombocythemia myelofibrosis: A study of the MYSEC project

we analyzed cytogenetic data available at the time of SMF (376 cases: 188 PET MF, 188 PPV MF) in order to study karyotype-genotype-clinical phenotype correlations and the impact on prognosis. G-banding with trypsin was the standard technique for chromosome analysis with at least 20 metaphases described. The study was approved by each Institutional Review Board and conducted in accordance with the principles of the Declaration of Helsinki. Continuous baseline values were compared via the Wilcoxon rank sum test and categorical feature counts via the Fisher’s exact tests. The Holm correction for multiple testing was used for post-hoc analysis. Time-to-event analyses were performed via Kaplan-Meier curves, using log-rank tests for comparisons and semi-parametric Cox models for regression. Tests for differences in normal (NK) versus abnormal karyotypes (AK) were conducted first; where a significant departure from the null was found, the individual abnormal karyotypes were compared with respect to the normal one.