Clinical features and prognostic analysis of diffuse large B-cell lymphoma coexisting with follicular lymphoma at initial diagnosis

Abstract The clinicopathological information of patients with diffuse large B-cell lymphoma (DLBCL) along with concurrent follicular lymphoma (FL) at initial diagnosis (FL/DLBCL) is scarce. In this retrospective study, we aimed to elucidate the clinical characteristics and outcomes of patients with FL/DLBCL. The study involved all patients consecutively diagnosed with FL/DLBCL (n = 46) and those with pure FL (n = 131), de novo DLBCL (n = 365), or transformed FL (t-FL, n = 17) as controls. In patients with FL/DLBCL, 63.0% of the tumors were of GCB origin, 32.6% were non-GCB, and 4.4% were unclassified. The median proportion of DLBCL components was 50% (range: 15%–99%). The cell of origin and the proportion of DLBCL component did not affect the outcomes of FL/DLBCL. Seventy-one percent of patients with FL/DLBCL received immunochemotherapy, such as the R-CHOP regimen, and none received further intensive treatment. Complete and overall response rates were 60% and 87.5%, respectively, similar to those for DLBCL. Progression-free and overall survival of patients with FL/DLBCL were between those of patients with FL and DLBCL and significantly better than those of patients with t-FL. None of the independent risk factors affected FL/DLBCL prognosis in the multivariate analyses. In conclusion, patients with FL/DLBCL had the GCB subtype with outcomes similar to those of patients with DLBCL, and the treatments for these patients should be similar to those for patients with DLBCL. The outcome of patients with FL/DLBCL was significantly better than that of patients with t-FL, and these patients should not be considered to have “transformed lymphoma.”