CYTOGENETIC ABNORMALITIES AND THEIR PROGNOSTIC-SIGNIFICANCE IN IDIOPATHIC MYELOFIBROSIS - A STUDY OF 106 CASES

The prognostic significance of cytogenetic abnormalities was determine d in 106 patients with well-characterized idiopathic myelofibrosis who were successfully karyotyped at diagnosis. 35% of the cases exhibited a clonal abnormality (37/100), whereas 65% (69/106) had a normal kary otype. Three characteristic defects, namely del(13q) (nine cases), del (20q) (eight cases) and partial trisony 1q (seven cases), were present in 64.8% (24/37) of patients with clonal abnormalities. Kaplan-Meier plots and log rank analysis demonstrated an abnormal karyotype to be a n adverse prognostic variable (P< 0.001), Of the eight additional clin ical and haematological parameters recorded at diagnosis, age (P < 0.0 1), anaemia (haemoglobin less than or equal to 10 g/dl; P<0.001), plat elet (less than or equal to 100x10(9)/l. P<0.0001) and leucocyte count (>10.3x10(9)/l; P=0.06) were also associated with a shorter survival. In contrast, sex, spleen and liver size, and percentage blast cells w ere not found to he significant, Multivariate analysis, using Cox's re gression, revealed karyotype, haemoglobin concentration, platelet and leucocyte counts to retain their unfavourable prognostic significance, A simple and useful schema for predicting survival in idiopathic myel ofibrosis has been produced by combining age, haemoglobin concentratio n and karyotype with median survival times varying from 180 months (go od-risk group) to 16 months (poor-risk group).