Outcome and patterns of relapse in primary gastric diffuse large B cell lymphoma treated with RCHOP.

OBJECTIVES: Patterns and predictors of relapse in primary gastric diffuse large B cell lymphoma (DLBCL) were variably reported. Our study aims to evaluate the patterns and predictors of relapse in early-stage gastric DLBCL treated with Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, and Prednisolone (RCHOP). METHODS: From 2005 to 2019, the medical records of 72 patients with stage I or stage II gastric DLBCL treated with six cycles of RCHOP without radiotherapy were reviewed. Different variables were correlated with progression free survival (PFS), overall survival (OS), and local relapse free survival (LRFS). RESULTS: 64 (88.1%) patients achieved a complete response (CR), while 8 (11.9%) had refractory disease. After CR, 9 (14%) patients relapsed; 7 (78%) relapses were loco-regional. Abnormal LDH (p = 0.028), H. pylori negative (p = 0.032) and, stage adjusted international prognostic index (sa-IPI) > 1 (p = 0.013) correlated with loco-regional failure. The 5-year PFS, OS, and LRFS were 74.8%, 75.3%, and 87.5%, respectively, after a median follow-up of 58 (range: 6-185) months. The median time to progression or relapse was 9 months (range: 5-54 months). In multivariate analysis, a sa-IPI >1 (HR: 3.56, CI: 1.35-8.8, p = 0.01) was associated with PFS while low albumin (HR: 8.85, CI: 1.09-71.4, p = 0.041) was associated with worse OS. None of the variables were associated with LRFS. CONCLUSION: Treatment of primary gastric DLBCL with RCHOP results in a high CR rate. The majority of treatment failures were loco-regional. Sa-IPI and H. pylori status may be used to identify patients who may benefit from combined modality treatment.