Cytogenetic Analysis Of Multiple Myeloma

Objective:To investigate the cytogenetic characteristics of multiple myeloma(MM) and its relationship with clinical prognosis.Method:Retrospective analysis of cytogenetic results of MM patients diagnosed from 2000 to 2008 who visited the Department of Hematology and Institute of Hematology of 1^st affiliated hospital of Zhejiang University,College of medicine.Chromosome specimens of bone marrow cells were prepared by 24-hour culture,R-banding karyotyping and fluorescence in situ hybridization(FISH) were conducted.Results:Chromosome aberrations were detected in 36 of 183 patients(19.7%) by conventional cytogenetics analysis.The chimeric existence of abnormal and normal clones were detected in 31 of 36 patients(86.1%).Numerical aberrations were detected in 29 of 36 patients(80.6%),majority of which were aneuploid,especially hypodiploid. Structural aberrations mainly involved chromosome1,chromosome13,chromosome14, chromosome17and various kinds of marker chromosomes.The detection rates were 25%(9/36),25%(9/36),19.4%(7/36)and11.1%(4/36)respectively.Complex aberrations were detected in 19 of 36 patients(52.7%).The detection rates ofadd(1q21),del(13q14), 14q32 rearrangements and del(17p13.1) were 15.4%(2/13),28.1%(9/32),6.25%(1/16) and 9.4%(3/32) by FISH.The plasmacytes in bone marrow from MM patients with chromosome aberrations were higher than those with normal karyotypes,and the patients who with chromosome aberrations demonstrated poor responses to the conventional chemotherapy and had poor prognosis.The median overall survival of those patients was only 12 months(range 4-35months),while the patients with del(13q14) had poorer responses to the conventional chemotherapy than those without such aberration(P＜0.01).Conclusion:Chromosome complex aberration is the mainly cytogenetic characteristics of multiple myeloma,where multiple numerical or structural aberrations are involved. Compared to the cytogenetic characteristics of MM patients in western countries, aberrations involving chromosomes1,13 and17,nonhyperdiploidy,hyperdiploidy and translocations involving immunoglobulin heavy chain locus(IgH) are recurrent in our cohort.Both conventional cytogennetic analysis and FISH are suggested for patients at diagnosis and during the disease progression so as to evaluate the prognosis.The patients with chromosome complex aberration may have poor prognosis,especially those with del(13q14).