Clinical Features, Management and Prognostic Factors of Patients with Gastric Mucosa-Associated Lymphoid Tissue Lymphoma

Background: Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is the most common extranodal marginal zone lymphoma. It could occur at any age, but was often seen in older patients, and most of whom were in low-grade with slow disease progression. There have been limited reports on long-term follow-up of patients with gastric MALT lymphoma. This study aims to identify clinical features, management and prognostic factors of gastric MALT lymphoma patients.

Methods: A total of 293 patients were included in this retrospective study who were diagnosed as gastric MALT lymphoma and treated in Fudan University Shanghai Cancer Center, China from 2002 to 2022. The demographic details, clinico-pathologic characteristics of the patients were summarized. Kaplan-Meier survival curves were constructed for survival analyses, and differences were tested by the log-rank test. The prognostic factors were determined by univariate and multivariate Cox analyses.

Results: 131(44.7%) men and 162 (55.3%) women were enrolled with median age of 56 (range 14-88) years. According to the 1994 Lugano modifications of the Musshoff staging classification, 229 patients were diagnosed with stage I, 41 and 23 patients were diagnosed with stage II and IV, respectively. 112 patients were positive for H. Pylori at diagnosis. Forty-eight patients only received antibiotics for eradication of H. Pylori, including 43 patients with stage I and five patients with stage II disease. Among them, 19 (39.58%) patients had disease-free survival of more than 24 months and the maximum duration exceeds 126 months and is still in complete remission. Radiotherapy was applied in 188 patients. Eleven patients received surgery at diagnosis or during treatment. 46 patients received rituximab alone or in combination with chemotherapy after diagnosis. Nine (3%) patients had histological transformation during follow-up. The differences of progression-free survival (PFS) and overall survival (OS) between stage I and stage II patients were statistically significant (P= 0.008; P<0.001). Analyses showed that 5-year and 10-year PFS of the stage I gastric MALT lymphoma patients were 94.5% and 89.7%, whereas those of the stage II gastric MALT lymphoma patients were 77% and 68.5%, respectively. The 5-year and 10-year OS rate of the patients with stage I gastric MALT lymphoma was 99.2% and 95.3%, while those of the stage II patients were 84.1% and 73.6%, respectively. Multivariate Cox regression analysis showed that gastric MALT patients characterized by elder age (HR= 13.271, 95% CI 1.788-98.511, P= 0.011), and stage II2/IV (HR= 3.561, 95% CI 1.603-7.709, P= 0.002) had a shorter PFS. And stage II2/IV (HR= 3.968, 95% CI 1.287-12.233, P= 0.016), and HBsAg positive (HR= 4.471, 95% CI 1.28-15.619, P= 0.019) were independent adverse prognostic factors.

Conclusions: Gastric MALT lymphoma has a relatively good prognosis due to its clinical response to treatment and favorable disease-free survival as well as overall survival. Our study showed that late stage (II2/IV), HBsAg positive were independent adverse prognostic factors.