BACKGROUND & AIMS: Appropriate management of primary gastric lymphoma is 
controversial. This prospective, multicenter study aimed to evaluate the 
accuracy of endoscopic biopsy diagnosis and clinical staging procedures and 
assess a treatment strategy based on Helicobacter pylori status and tumor stage 
and grade.
METHODS: Of 266 patients with primary gastric B-cell lymphoma, 236 with stages 
EI (n = 151) or EII (n = 85) were included in an intention-to-treat analysis. 
Patients with H. pylori-positive stage EI low-grade lymphoma underwent 
eradication therapy. Nonresponders and patients with stage EII low-grade 
lymphoma underwent gastric surgery. Depending on the residual tumor status and 
predefined risk factors, patients received either radiotherapy or no further 
treatment. Patients with high-grade lymphoma underwent surgery and chemotherapy 
at stages EI/EII, complemented by radiation in case of incomplete resection.
RESULTS: Endoscopic-bioptic typing and grading and clinical staging were 
accurate to 73% and 70%, respectively, based on the histopathology of resected 
specimens. The overall 2-year survival rates for low-grade lymphoma did not 
differ in the risk-adjusted treatment groups, ranging from 89% to 96%. In 
high-grade lymphoma, patients with complete resection or microscopic tumor 
residuals had significantly better survival rates (88% for EI and 83% for EII) 
than those with macroscopic tumor residues (53%; P < 0.001).
CONCLUSIONS: There is a considerable need for improvement in clinical diagnostic 
and staging procedures, especially with a view toward nonsurgical treatment. 
With the exception of eradication therapy in H. pylori-positive low-grade 
lymphoma of stage EI and the subgroup of locally advanced high-grade lymphoma, 
resection remains the treatment of choice. However, because there is an 
increasing trend toward stomach-conserving therapy, a randomized trial comparing 
cure of disease and quality of life with surgical and conservative treatment is 
needed.