[Cytogenetic characteristics of patients with multiple myeloma in China: analysis of 100 case].

OBJECTIVE

To summarize the cytogenetic characteristics of patients with multiple myeloma (MM) in China and clinical significance thereof.

METHODS

Specimens of bone marrow were collected from 100 patients with MM who visited the Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences in Tianjin, China. Chromosome banding analysis and fluorescence in situ hybridization (FISH) were conducted.

RESULTS

(1) Clonal chromosome aberrations (CA) were detected in 16 of 93 patients (17.2%) by conventional cytogenetics (CC), and when subclonal CA was included CA were detected in 37.0% of the patients. Numerical aberration analysis showed that the most common trisomies were 11, 21, 3, 6, and 12, and the most common monosomies were 16, 13, 8, 22, and 11. Structural aberration analysis showed that the most frequently involved arms were 14q, 8q, 1q, 6q, 11q, 12p, and 1p, and the most frequently involved breakpoints were 14q32, 8q22 - 24, 11q13 - 14, 6p21, 1q10 - 11, and 12p12 - 13. Ploidy level was arranged in decreasing order as: hypodiploidy (46.1%), pseudodiploid (38.5%), hyperdiploidy (18.8%), and tri-/tetraploidy (15.4%). Chromosome 13 abnormality (C13A) was detected in 7 of the 100 patients (7%). The C13A prevalence rates by CC and interphase FISH were 6.0% and 33.3% respectively. Translocations involving chromosome 14 and/or 14q32 aberrations were detected in 6 patients (6.0%). (2) Univariate analysis showed that C13A, nonhyperdiploidy, and clonal CA were associated with significantly shorter overall survival (OS) and time to progression (TTP). Multivariate analysis showed that C13A was the only independent unfavorable factor.

CONCLUSION

The concrete CA of the patients with MM in China are comparable to those from Western countries, among which C13A, nonhyperdiploidy, hyperdiploidy, and translocations involving immunoglobulin heavy chain locus (IgH) are recurrent. C13A, nonhyperdiploidy, and clonal CA are associated with shorter OS and time-to-progression, and C13A is the only independent adverse prognostic factor.