Low incidence of BCL-6 gene alterations for diffuse large B-cell lymphomas in Taiwan Chinese.
BACKGROUND
In Western populations, rearrangement of the BCL-6 gene can be identified in 20-40% of patients with diffuse large B-cell lymphoma (DLBCL). Analysis of the BCL-6 gene has revealed the presence of point mutations or small deletions in 70% of DLBCL tumors; however, few studies have investigated BCL-6 gene alteration in patients with non-Hodgkins lymphoma (NHL) of Chinese descent.


METHODS
Samples from 135 Taiwanese patients with NHL were examined (28 samples of T-cell NHL and 107 samples of B-cell NHL; 59 samples from patients with DLBCL) for gene rearrangement and mutation of the BCL-6 proto-oncogene using Southern blot analysis and single-strand conformation polymorphism (SSCP) followed by sequence analysis.


RESULTS
BCL-6 rearrangement and point mutations were found in 14.8% of patients (n = 20) and in 7.4% of patients (n = 10), respectively. All BCL-6 gene alterations occurred in patients with B-cell NHL, and none occurred in patients with T-cell NHL. Among the 59 patients with DLBCL, BCL-6 gene rearrangements were identified in 10 patients (16.9%), and mutations were identified in 8 patients (13.6%), with the BCL-6 mutation occurring independent of the BCL-6 rearrangement. The incidence of BCL-6 gene rearrangement and mutations in patients with extranodal DLBCL was 9.5% (2 of 21 patients) and 23.8% (5 of 21 patients), respectively. Univariate analysis and multivariate logistic regression found no association between BCL-6 gene alternations and clinical characteristics, including extranodal tumors in patients with DLBCL, and no association between the BCL-6 alterations and prognosis was found.


CONCLUSIONS
The incidence of BCL-6 alterations was lower in Taiwanese patients with DLBCL compared with Western populations, and BCL-6 gene alterations showed no prognostic significance in patients with DLBCL.
Chen
Po-Min
PM
Division of Medical Oncology, Department of Medicine, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei 112, Taiwan, Republic of China. pmchen@vghtpe.gov.tw
Yang
Muh-Hwa
MH
Yu
I-Ting
IT
Lin
Jen-Tsun
JT
Lin
Yu-Chen
YC
Fan
Frank S
FS
Wang
Wei-Shu
WS
Yen
Chueh-Chuan
CC
Chiou
Tzeon-Jye
TJ
Liu
Jin-Hwang
JH
D000368:Aged; D044466:Asian People; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D015321:Gene Rearrangement; D006801:Humans; D016393:Lymphoma, B-Cell / Q000453:epidemiology / Q000235:genetics*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000453:epidemiology / Q000235:genetics*; D008297:Male; D009154:Mutation; D017354:Point Mutation; D018807:Polymorphism, Single-Stranded Conformational; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D051560:Proto-Oncogene Proteins c-bcl-6; D013624:Taiwan / Q000453:epidemiology; D014157:Transcription Factors / Q000235:genetics*
D004268:DNA-Binding Proteins; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D051560:Proto-Oncogene Proteins c-bcl-6; D014157:Transcription Factors