Additional rituximab-CHOP (R-CHOP) versus involved-field radiotherapy after a brief course of R-CHOP in limited, non-bulky diffuse large B-cell lymphoma: a retrospective analysis

BACKGROUND: Standard treatment for stage I or non-bulky stage II diffuse large B-cell lymphoma (DLBCL) has been either a brief course of chemotherapy plus involved-field radiotherapy (IFRT) or prolonged cycles of chemotherapy. The introduction of rituximab has necessitated re-evaluation of the treatment for limited disease (LD) DLBCL. METHODS: Thirty-nine LD DLBCL patients (median age, 52 years; range, 24-85) treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) were retrospectively analyzed. Treatment outcomes were evaluated, and toxicity, event-free survival (EFS), and overall survival (OS) were compared according to the treatment and risk factors. RESULTS: The median follow-up duration was 34.6 months (range, 9.1-65.4). The 3-year EFS and OS were 76.0% and 86.0%, respectively. Among the 36 patients who underwent either 3-4 cycles of R-CHOP followed by IFRT (N=22) or 6-8 cycles of R-CHOP (N=14), there was no difference in the 3-year EFS (79.4% vs. 71.6%, P=0.638) and 3-year OS (85.7% vs. 92.9%, P=0.732). Severe neutropenia and neutropenic fever were more frequent in patients treated with R-CHOP alone, with 1 treatment-related mortality. Among the IFRT patients, 1 required hospital admission for IFRT-related complications. No events or deaths were reported among patients without adverse risk factors. CONCLUSION: The difference in outcomes between the 2 treatment options was not significant. Analysis of treatment outcomes suggested that baseline characteristics and expected toxicities should be considered in LD DLBCL treatment. Further studies are needed to define the optimal treatment in the rituximab era.