Short Cycle of Immunochemotherapy Followed by Radiation Therapy Compared with Prolonged Cycles of Immunochemotherapy for Localized DLBCL: The Osaka Lymphoma Study Group (OLSG) Retrospective Analysis

Abstract

1628 Introduction: Standard treatment for localized diffuse large B cell lymphoma (DLBCL) has been rather a short cycle of immunochemotherapy followed by involved field radiotherapy or prolonged cycles of immunochemotherapy. There is no convincing evidence in favor of either strategy. This retrospective analysis is an attempt to compare these treatment options. Methods: Patients were eligible if they had histologicaly newly diagnosed localized DLBCL by the Osaka Lymphoma Study Group (OLSG) central review panel and registered between 2003 and 2011, and received rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisolone (R-CHOP) like immunochemotherapy with more than three consecutive courses as initial therapy. In this study, we defined a localized DLBCL as DLBCL with Ann Arbor stage I or non-bulky (<10cm) stage II. One hundred thirty-seven localized DLBCL patients were analyzed retrospectively. Of 137 patients, 83 had 6 to 8 cycles of R-CHOP like immunochemotherapy (Chemo group), and 28 had 3 to 4 cycles of R-CHOP like immunochemotherapy followed by radiotherapy (Chemo+RT group). In this study, the efficacy and tolerability of the 2 treatment groups, Chemo group and Chemo+RT group, in localized DLBCL patients were compared. Treatment outcomes were evaluated, overall survival (OS), progression free survival (PFS) and toxicity were compared according to each treatment option and risk factor. Results: With a median follow-up time of 34 months, neither OS nor PFS differ between these treatment groups. The 3-year OS were 85.5% in Chemo group and 96.2% in Chemo+RT group, respectively (P=0.225). The 3-year PFS were 74.3% in Chemo group and 89.7% in Chemo+RT group, respectively (P=0.185). A multivariate Cox regression model showed that Chemo+RT group have a tendency to improve PFS [hazard ratio =0.33; 95% confidence interval 0.10–1.07; P =0.066] of localized DLBCL compared with Chemo group. Grade 3 to 4 neutropenia and neutopenic fever were more frequent in patients with Chemo group (P<0.01, P<0.01, respectively). Conclusion: For the treatment of localized DLBCL, although the difference between two treatment options was not significant in efficacy, short cycle of immunochemotherapy followed by radiation therapy seems to be superior to prolonged cycles of immunochemotherapy in terms of safety. Further studies are needed to define the optimal treatment option for localized DLBCL in the rituximab era. Disclosures: No relevant conflicts of interest to declare.

Excellent outcomes and lack of prognostic impact of cell of origin for localized diffuse large B-cell lymphoma in the rituximab era

“…A matched pair analysis was performed to control for potential confounders and showed an improvement in OS and PFS with combined modality therapy versus chemotherapy alone, however, this matched pair analysis was limited by a small sample size and probably wide confidence intervals for hazard ratio estimates (44 matched pairs), selection bias inherent in subset analysis and matching on only three factors [disease bulk (>5 cm), response to therapy (defined as resolution of original tumours) and IPI score]. In contrast, other retrospective analyses reported no significant differences in outcome for 6-8 cycles of R-CHOP chemotherapy alone versus 3-4 cycles of R-CHOP followed by IFRT (Terada et al, 2012;Odejide et al, 2015). One study was a large retrospective Surveillance, Epidemiology, and End Results Program database analysis comparing treatment with 3-4 cycles of R-CHOP plus RT to 6-8 cycles of R-CHOP in 874 elderly (>65 years) patients with DLBCL, and showed no difference in OS using propensity-score weighted Cox regression models (Odejide et al, 2015).…”

“…This study was risk-adapted based on a stage-modified IPI and interim positron emission tomography (PET) after 4 cycles and found that, overall, combined modality therapy was not significantly superior to R-CHOP alone in patients achieving early PET negativity (Lamy et al, 2014). Several retrospective analyses have reported conflicting results of the comparative effectiveness of short-course immunochemotherapy or extended-course immunochemotherapy with or without IFRT in patients treated with R-CHOP (Phan et al, 2010;Terada et al, 2012;Tomita et al, 2013;Odejide et al, 2015).…”

COO and MYC/BCL2 status do not predict outcome among patients with stage I/II DLBCL: a retrospective multicenter study

“…The decision to include patients treated with combined modality therapy and chemoimmunotherapy was based on the weight of published evidence showing no difference in outcomes in the rituximab era. 43,44 Although these studies are mostly retrospective, Lamy et al demonstrated, in a prospective randomized study of nonbulky stage I/II DLBCL, that patients who achieved a negative interim positron emission tomography could be managed with no RT without compromising disease control. 45 Second, in this study we used the Hans algorithm to assign COO.…”