Objective: To investigate the cytogenetic abnormalitis in patients with diffuse large B-cell lymphoma(DLBCL) patients with bone marrow involvement and their influence on prognosis.
Methods: Conventional karyotyping was performed on bone marrow specimens in 47 DLBCL patients with histologically confirmed bone marrow involvement(BMI). The karyotyping results of bone marrow, the characteristics and clinical effect of chromosomal abnormalities were analysed.
Results: In 47 DLBCL cases with BMI, the chromosomal abnormalities were detected in 25(53%) cases. Among them, complex karyotype was more frequent, being noted in 19(40%) patients. The most frequently involved chromosomes were chromosome 1 and 18(both 26%), others were chromosome 3(23%), 6(19%), 7, 8 and 14(13%). Among all karyotype changes, the most common numerical aberrations, in decreasing order of incidence, were trisomy 3(13%), trisomy 5, trisomy 7, trisomy 12, trisomy 18 and loss of 21(6%,each), and the most predominant structural aberrations, in decreasing order of incidence, were 1q+(17%), 1p+, 6q-, 8q+, 14q+, 18p+, 18q+ and aberrations involving band 2p21-p23 (6%,each). The prognostic impact analysis of both clinical features and cytogenetic aberrations revealed that IPI≥3 (P=0.03) or the presence of chromosomal abnormalities (P=0.005) were significantly related with poor progression free survival(PFS), and IPI≥3 (P=0.024), lactate dehydrogenase(LDH)≥ three times of the upper limit of normal (P=0.027) and the presence of chromosomal abnormalities (P=0.001) predominantly related with poor overall survival(OS). In multivariate analysis, the presence of chromosomal abnormalities was the only independently adverse factor for PFS(P=0.037, HR 2.323) and OS(P=0.015, HR 2.833). The analysis of prognostic effects of specific chromosomal aberrations showed that patients with specific cytogenetic abnormalities of 1q+, 8q+, +12, 12q+, 18p+ and aberrations involving band 2p21-23 had significantly poor PFS, and patients with specific cytogenetic abnormalities of 1q+, +3, +5, +7, 8q+, +12, 12q+ and aberrations involving band 2p21-23 had significantly poor OS. When the above mentioned specific chromosomal aberrations were analyzed with clinical covariate, the presence of chromosomal aberration of 8q+ (P=0.022, HR 2.701) and IPI≥3 (P=0.043, HR 2.949) were independently poor prognostic factors for PFS, and 1q+ (P=0.032, HR 2.973) was the independently poor prognostic factor for OS.
Conclusion: In DLBCL patients with BMI, the presence of chromosomal abnormalities is the only independently poor factor for PFS and OS, and among them, the specific cytogenetic aberrations of 8q+ or 1q+ have an independently poor prognostic impact on PFS or OS, respectively, which need to be further studied.