Long-term Outcomes and Prognostic Factors of Gastric MALT Lymphoma.

Purpose: This study aimed to evaluate the long-term prognosis of patients with gastric mucosa-associated lymphoid tissue (MALT) lymphoma, including overall survival (OS), remission, and factors associated with an aggressive disease course.

Materials and methods: Medical records of 153 patients diagnosed with gastric MALT lymphoma between 2013 and 2020 were retrospectively reviewed. Patients experiencing relapse, progression, high-grade transformation, or residual diseasewere included in the aggressive group and were compared with those in the indolent group. Additionally, the endoscopic findings of Helicobacter pylori-negative patients were reviewed.

Results: Patient characteristics were as follows: mean age (56.9±11.2 years), sex (male, 51.0%), H. pylori infection (positive, 79.7%), endoscopic location (distal, 89.5%), endoscopic feature (superficial, 89.5%), clinical stage (stage I, 92.8%), invasion depth by endoscopic ultrasound (mucosa, n=115, 75.7%), and bone marrow result (no involvement, n=77, 100.0%). The median follow-up period was 59 months (mean, 61; range, 36-124) and the continuous remission period (n=149) was 51 months (mean, 50; range, 3-112). The 5-year survival rate was 97.7% while the 5-year continuous remission was 88.3%. Factors associated with the patients in the aggressive group were old age, sex(male), and clinical stage II or higher. H. pylori-negative patients' endoscopy revealed a high incidence of atrophic gastritis in the antrum.

Conclusions: The long-term prognosis of gastric MALT lymphoma appears indolent and is indicated by the 5-year OS and continuous remission rates. Aggressive disease courses are associated with old age, sex (male), and clinical stage II or higher, but are not related to OS.