Prognostic analysis of CD5 expression in double-hit diffuse large B-cell lymphoma and effectiveness comparison in patients treated with dose-adjusted EPOCH plus rituximab/R-CHOP regimens

OBJECTIVES: To compare the efficacy of rituximab, dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide and doxorubicin (DA-EPOCH-R) with traditional rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) regimens in CD5+ double-hit lymphoma (DHL) and to evaluate prognostic factors. METHODS: We retrospectively studied 139 patients with newly diagnosed DHL/THL diffuse large B-cell lymphoma (including 20 cases CD5+ and 119 cases CD5−), 87 cases were MYC/BCL2 DHL, 30 cases were MYC/BCL6 DHL, 22 cases were THL. MYC, BCL2 and BCL6 rearrangements were examined by fluorescence in-situ hybridization. CD5 is detected by immunohistochemistry (IHC). RESULTS: The objective response rate (ORR) difference between CD5+ and CD5− was significant (80.0% vs 63.8%, P=0.003). The median follow-up time was 18 months (range: 4–39 months). Progression-free survival (PFS) of CD5+ group was significantly worse than that of CD5- (28.1% vs 59.0%, P=0.028), while no significant difference was observed in overall survival (OS) (32.1% vs 59.9%, P=0.057). Compared with the two regimens, the 2-year survival rate of DA-EPOCH-R group was significantly superior than that of R-CHOP (63.6% vs 45.4%, P=0.034 for PFS; 67.4% vs 47.8%, P=0.038 for OS). Besides, CD5+ patients receiving DA-EPOCH-R had survival benefits compared with R-CHOP in PFS (85.7% vs 23.0%, P=0.029), but there was no statistical difference in OS (87.7% vs 34.4.0%, P=0.064). However, in DA-EPOCH-R protocol, there was no significant difference between CD5+ DHL (MYC/BCl2 and MYC/BCL6) and triple-hit lymphoma (P=0.776 for PFS; P=0.728 for OS). Multivariate analysis showed that CD5+ treatment regimen and disease stage were independent prognostic factors. CONCLUSION: Our retrospective study shows that CD5+ has a poorer prognosis than CD5− patients. Based on its improved lifetime and good tolerance on CD5+ patients, which is expected to become the first-line treatment for high-risk DLBCL types based on more clinical research.