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 , , and have not been fully elucidated. We evaluated the EC and translocation statuses of , , and in 190 diffuse large B-cell lymphoma (DLBCL) cases using fluorescence hybridization. EC genotype was sub-classified according to copy number-gained tumor cell ratio (EC1, >20% but ≤50%; EC2, >50%). Only the -EC groups, not -EC or -EC groups, displayed significantly increased immunoreactivity of the corresponding protein. Moreover, the -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 , , concurrent , , or triple EC groups were observed. -EC may contribute to increased BCL-2 protein expression and serve as a predictor of treatment outcomes in DLBCL.