Adding Etoposide to R-CHOP (R-CHOEP) Does Not Significantly Increase the Risk of Secondary Neoplasms in Patients with Aggressive B-Cell Lymphoma - Results from Randomized Phase 3 Trials of the German Lymphoma Alliance (GLA)

Introduction:Considering the increasing numbers of lymphoma patients (pts) surviving long-term, late effects of current treatment strategies such as secondary (sec) malignancies gain increasing importance. Many treatment regimens used in pts with lymphoma (R-CHOEP, DA-EPOCH-R, BEACOPP) include etoposide, a cytotoxic agent reported to increase sec leukemias. In order to further investigate the role of etoposide in inducing sec malignancies in pts with aggressive lymphoma we analyzed the R-MegaCHOEP trial (Schmitz et al., Lancet Oncology 2012) where young, high-risk pts with aggressive B-cell lymphomas had received R-CHOEP or R-MegaCHOEP, a regimen containing very high doses of etoposide (4g/m²). We compared rates of secondary tumors to incidences found in young patients treated with R-CHOP only.

Methods:We analyzed 1536 pts aged 18-60 years with aggressive B-cell lymphoma treated in the prospective phase 3 trials FLYER (NCT00278421; n=588, median observation time (OT)=66 months), UNFOLDER (NCT00278408; n=695, median OT=72 months) and MegaCHOEP (NCT00129090; n=253, median OT=112 months) to compare the cumulative incidences of sec neoplasms. We performed a competing risk analysis for time from randomization to occurrence of sec malignancy (myelodysplastic syndrome/acute myeloid leukemia (MDS/AML) or other) according to first-line therapy with R-CHOP (n=1283) vs. R-CHOEP (n=127) vs. R-MegaCHOEP (n=126). We used a cause-specific hazard model adjusted for gender, age (>50 vs. <= 50 years) and radiotherapy.

Results:Adjusting for competing events, we found sec MDS/AML in 0.3% of pts treated with R-CHOP, in 1% of pts treated with R-CHOEP and in 2% of pts following treatment with R-MegaCHOEP. Cause-specific hazard ratios showed a trend for increased risk for sec AML following R-MegaCHOEP in comparison to R-CHOP (HR 5.2, 95%CI (1.0; 27.5), p=0.052) while R-CHOEP did not significantly increase the incidence of sec AML (HR 1.4, 95%CI (0.1; 14.0), p=0.777). Male gender and age >50 years showed a trend for increasing sec AML. We found very similar incidences of sec solid tumors (not MDS/AML) affecting 4% of pts treated with R-CHOP or R-MegaCHOEP and 6% of pts following R-CHOEP regimen. The only factor significantly increasing the risk of sec solid tumors was age >50 years (HR 2.6, 95%CI (1.5; 4.3), p<0.001).

Conclusions:This analysis shows that sec malignancies represent rare events in younger patients with aggressive B-cell lymphoma, even after extreme dose-escalation of etoposide. Compared to standard R-CHOP, 8 cycles of R-CHOEP were not associated with increased risk of sec AML or solid tumors thus remaining an attractive first-line treatment for young high-risk pts with DLBCL.