Impact on survival of addition of etoposide to primary chemotherapy in diffuse large B-cell lymphoma: a Swedish Lymphoma Registry study.

No randomised study in the rituximab era has been performed specifically to evaluate addition of etoposide to treatment of diffuse large B-cell lymphoma (DLBCL). The aim of this study was to compare the outcome with three chemotherapy regimens (R-CHOP-21, R-CHOP-14 and R-CHOEP-14) in a population-based cohort in terms of overall survival, adjusted for clinical prognostic factors. Through the Swedish Lymphoma Registry, 3443 patients with DLBCL were identified 2007-2012. Among all patients, there was no evidence of a difference between the regimens, after adjustment for prognostic factors. However, when restricted to patients aged up to 65, R-CHOEP-14 was associated with superior outcome compared to both R-CHOP-21 (hazard ratio: 0.49, 95% confidence interval: 0.3-0.9, p = 0.028) and R-CHOP-14 (hazard ratio: 0.64, 95% confidence interval: 0.4-1.0, p = 0.06), when adjusted for prognostic factors. Results were consistent in an additional stratified analysis with patients grouped according to age and IPI-score. In conclusion, we could show that R-CHOEP-14 was associated with superior overall survival in patients with DLBCL aged up to 65 years, indicating that this may be a valid treatment option for this patient population. To further investigate which patient groups that may benefit the most from treatment intensification, R-CHOEP-14 should be compared to R-CHOP-21 in a randomised setting.