Cytogenetic findings and their clinical relevance in myelofibrosis with myeloid metaplasia

The prognostic significance of bone marrow cytogenetic lesions in myelofibr osis with myeloid metaplasia (MMM) was investigated in a retrospective seri es of 165 patients. An abnormal karyotype was demonstrated in 57% of patien ts. At diagnosis (n = 92), 48% of the patients had detectable cytogenetic a bnormalities, and clonal evolution was frequently demonstrated in sequentia l studies. More than 90% of the anomalies were represented by 20q-, 13q-, 8, +9, 12p-, and abnormalities of chromosomes 1 and 7. Of these, 20q-, 13q- and +8 were the most frequent sole abnormalities, each occurring in 15-25% of the abnormal cases. Trisomy 9 and abnormalities of chromosomes 1 and 7 were equally prevalent but were usually associated with additional cytogene tic lesions. Chromosome 5 abnormalities were infrequent but were over-repre sented in the group of patients exposed to genotoxic therapy, In a multivar iate analysis that incorporated other clinical and laboratory variables, th e presence of an abnormal karyotype did not carry an adverse prognosis. Ins tead, +8, 12p-, advanced age and anaemia were independent prognostic determ inants of inferior survival. In particular, survival was not adversely affe cted by the presence of either 20q- or 13q-.