Extra copy number of BCL2 is correlated with increased BCL-2 protein expression and poor survival in diffuse large B-cell lymphoma treated with chemoimmunotherapy.

The clinical significance of extra copy (EC) genotypes of BCL2 , MYC , and BCL6 have not been fully elucidated. We evaluated the EC and translocation statuses of BCL2 , MYC , and BCL6 in 190 diffuse large B-cell lymphoma (DLBCL) cases using fluorescence in situ hybridization. EC genotype was sub-classified according to copy number-gained tumor cell ratio (EC1, >20% but ≤50%; EC2, >50%). Only the BCL2 -EC groups, not MYC -EC or BCL6 -EC groups, displayed significantly increased immunoreactivity of the corresponding protein. Moreover, the BCL2 -EC2 group was significantly associated with poor overall survival (OS) and progression-free survival (PFS) in a 147 R-CHOP-treated patient subset, which was also statistically significant as per the multivariate survival analysis for PFS. No significant differences in the survival of MYC , BCL6 , concurrent BCL2/MYC , BCL6/MYC , BCL2/BCL6, or triple EC groups were observed. BCL2 -EC may contribute to increased BCL-2 protein expression and serve as a predictor of treatment outcomes in DLBCL.