Similar prognosis of transformed and de novo diffuse large B-cell lymphomas in patients treated with immunochemotherapy.

BACKGROUND: The prognosis of diffuse large B-cell lymphomas (DLBCL) transformed from indolent lymphoma (TL) has been considered poorer than that of de novo DLBCL. However, it seems to have improved since the introduction of rituximab.

PATIENTS AND METHODS: We compared the characteristics (including the cell-of-origin), and the prognosis of 29 patients with TL and 101 with de novo DLBCL treated with immunochemotherapy.

RESULTS: Patients with TL and de novo DLBCL had similar characteristics. All TL cases evolving from follicular lymphoma were germinal-center B-cell-like, while those TL from marginal zone lymphoma or chronic lymphocytic leukemia were non-germinal-center B-cell-like. The complete response rate was similar in TL and de novo DLBCL (62 vs. 66%, P=.825). The 5-year overall and progression-free survival probabilities (95% CI) were 59% (40-78) and 41% (22-60) for TL and 63% (53-73) and 60% (50-70) for de novo DLBCL, respectively (P=.732 for overall survival and P=.169 for progression-free survival).

CONCLUSION: In this study, the prognosis of TL and de novo DLBCL treated with immunochemotherapy was similar. The role of intensification with stem cell transplantation in the management of TL may be questionable in the rituximab era.