The multicenter study evaluated the accuracy of endoscopic biopsy diagnosis and clinical staging procedures. It also assessed treatment strategy based on Helicobacter pylori status, and tumor stage and grade.
Of the 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. Non-responders 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 after incomplete resection.
Based on the histopathology of resected specimens, typing and grading of the endoscopic biopsies, and clinical staging, were accurate to 73% and 70%, respectively.
2-year lymphoma survival rates: Low-grade 89-96%
High-grade: complete resection 83-88%
High-grade: residual tumor 53%
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 residual macroscopic tumor (53%; P < 0.001).
The study concluded that there is a considerable need for improvement in clinical diagnostic and staging procedures, especially with a view toward non-surgical treatment. Resection remains the treatment of choice, 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.
It was recommended that, in view of the increasing trend toward stomach-conserving therapy, a randomized trial, comparing cure of disease and quality of life with surgical and conservative treatment, should be carried out.