Clinical significance of cytogenetics and interphase fluorescence in situ hybridization analysis in newly diagnosed multiple myeloma in Taiwan.

BACKGROUND The incidence of multiple myeloma (MM) is lower in Asia than in Western countries. However, it is not known whether cytogenetic abnormalities (CA) characteristic of MM in Asia differ from those documented in the West. PATIENTS AND METHODS We analyzed CA by conventional cytogenetics (CG) and/or fluorescence in situ hybridization (FISH), assessed their clinical significance in 150 Chinese MM patients and compared our data with that derived from Western countries. RESULTS CA were detected by CG (CG_CA) in 44 (29.3%) of the 150 patients and by FISH (FISH_CA) in 59 (67%) of the 88 patients studied. Presence of either CG_CA or FISH_CA was associated with a poor prognosis. Patients with CG_CA and hyperdiploid chromosomes, always associated with several trisomies, had a longer survival (median 25 months versus 12 months; P=0.025) in comparison with those with non-hyperdiploid chromosomes, usually associated with a monosomy 13/partial deletion of 13q (Delta13) and a rearrangement of 14q32. A novel recurrent CG_CA, add(19)(p13), was found in four patients: all males with immunoglobulin G/lambda isotypes, extramedullary myeloma at diagnosis and a poor prognosis. Three groups of patients with significantly different survival, CG_Delta13, FISH_Delta13 but without CG_Delta13, and neither CG_Delta13 nor FISH_Delta13 (median 9 versus 15 versus 32 months; P=0.013) were identified. CONCLUSIONS We conclude that MM CA in our patients are similar to those noted in Western countries, and that combined CG and FISH analysis can predict prognosis. The clinical significance of add(19)(p13) needs to be further investigated.