MYC rearrangements are useful for predicting outcomes following rituximab and chemotherapy: multicenter analysis of Japanese patients with diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma, and it has several morphologic and clinicopathologic variants. The prognosis of DLBCL can vary according to specific genetic and immunophenotypic abnormalities. The aim of this study was to investigate the prognostic impact of previously identified prognostic factors, such as activated B cell-like immunophenotype, CD5, BCL2 and MYC rearrangement (MYC-R), in patients treated with rituximab. We retrospectively analyzed the prognosis of 100 patients with DLBCL (median age, 66.5 years) treated with rituximab-containing chemotherapy. The 3-year overall survival (OS) and progression-free survival (PFS) were 66% and 62%. Outcomes were significantly worse in patients with MYC-R in 3-year OS (50% vs. 67.8%, p = 0.043) and PFS (30% vs. 57.8%, p = 0.003), and multivariate analysis showed that this finding was independent of the International Prognostic Index (IPI). Immunostaining by Muris algorithm had the highest predictive power among the three algorithms. However, other previously reported prognostic factors, such as BCL2 and CD5, were not good predictors of outcomes in these patients. In conclusion, our data suggest that fluorescence in situ hybridization (FISH) analysis for MYC-R can predict outcomes in response to rituximab-containing chemotherapy in Japanese patients with DLBCL.