Outcomes in patients with primary gastric diffuse large B-cell lymphoma after rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) chemotherapy

Abstract

e19543 Background: The optimal therapy for primary gastric diffuse large B- cell lymphoma (DLBCL) still needs to be defined. The aim of this study was to investigate the patient's outcomes after rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) treatment in primary gastric DLBCL in a single institution. Methods: We searched AMC Registry for Non-Hodgkin's Lymphoma and found 26 patients with primary gastric DLBCL, who received R-CHOP as first-line chemotherapy. Ten of 26 patients had localized disease. Remaining patients had disseminated disease. R-CHOP was repeated every 21 days in all patients. Results: Overall, complete response (CR) was observed in 20 of 26 patients (76.9%). Three-year event free survival (EFS) and overall survival (OS) was 76.5% and 75.0%, respectively. After analyses of 10 patients with localized disease, we found that these patients had received a total 38 cycles, with a median of 3 cycles per patient. Of 10 patients, one patient had 2 cycles of R-CHOP, 4 had 3 cycles, and one had 4 cycles, all 6 patients above followed by consolidation radiotherapy. Remaining one patient and 4 patients had 5 cycles and 6 cycles of R-CHOP, respectively. In patients with localized disease, CR was observed in 10 of 10 patients (100%), and both 3-year EFS and OS was 100% (10 of 10 patients). In analyses with 16 patients with disseminated disease, all patients had received a total 91 cycles, with a median of 6 cycles per patient. In these patients, two patients had radiation therapy after R-CHOP, one patient had CR before consolidation radiation therapy, and another had partial response before radiation therapy. CR after R-CHOP treatment was observed in 10 of 16 patients (62.5%), partial response in 3 patients, stable disease in 1 patient, and progressive disease in 1 patient. Three-year EFS and OS was 61.1% and 57.8% in patients with disseminated disease. Conclusions: R-CHOP regimen showed a promising result in primary gastric DLBCL. Combination with rituximab in CHOP regimen showed excellent prognosis especially in patients with localized disease. In localized disease, CR was 100%, 3-year EFS and OS was 100%. In disseminated disease, CR was 62.5%, 3-year EFS and OS was 61.1% and 57.8%. No significant financial relationships to disclose.