PROGNOSTIC VALUE OF CYTOGENETICS IN MULTIPLE-MYELOMA

Karyotypic studies of bone marrow were conducted in 79 previously untr eated patients with multiple myeloma who received a standard programme of chemotherapy. An abnormal karyotype was observed in 46% of patient s, virtually all showing multiple abnormalities consistent with a long period of preclinical clonal evolution. Patients with an abnormal pat tern showed various aberrations with hyperdiploidy in 64%, pseudodiplo idy in 5% and hypodiploidy in 31%. The number of chromosomes affected ranged from two to 19 (median 10), with at least one trisomy in 83%, o ne monosomy in 75%, and one translocation in 42% of patients, Lymphoma -like karyotypes were present in 17% of patients with an abnormality b ut were not associated with atypical clinical features, such as an ext ramedullary mass, leukaemia, or increased serum lactate dehydrogenase. Monosomy or deletion of chromosome 13 was present in 47% of patients with an abnormal pattern, who lived for a shorter duration (median 10 months) than patients with other abnormalities (median 34 months) or w ith diploidy (median 35 months). The cause of the short survival of pa tients with monosomy or deletion of chromosome 13 was not clear, but f urther studies on the relationship with specific oncogenes are indicat ed.