IBCL-344: Marginal Zone Lymphoma: Epidemiology and Outcomes in a Mexican Center

Abstract

Context: Marginal zone lymphoma (MZL) is a rare entity, representing 5% of non-Hodgkin lymphomas with straightforward differences in presentation. The treatment is diverse and depends on the location and the medical practice of each center. There is no information in Mexico regarding its presentation and long-term results. Objective: To describe and analyze the epidemiology and the prognostic factors of MZL relating to treatment response and survival. Design: Retrospective observational analytical study. Setting: Instituto Nacional de Cancerologia, a hemato-oncological reference center. Patients: 113 diagnosed with MZL between 2008 and 2019. Interventions: No interventions. Main outcome measures: Descriptive statistics were used. Bivariate risk analysis with X2 and Fisher's exact test were utilized to search for prognostic factors for survival. OS and DFS were assessed with Kaplan Mayer and Log Rank curves. Results: Patients' average age was 57 and predominantly female (57.5%). The median follow-up was 44 months (1–141). MALT was the most common histological WHO variant (87.6%, 99), followed by nodal (8.8%, 10) and splenic (3.5%, 4) ones. For MALT, the most frequent location was conjunctiva and eye attachments (59.6%), followed by stomach (23.2%) and salivary glands (8.1%). H. Pylori was identified in 48% of stomach MALT. DHL was elevated in 8%. Most (108) received treatment: chemotherapy (46.9%) followed by RT (28%). The global response was 76%. The 8-year OS was 75% for the entire group. Regarding MALT, favorable prognostic factors for OS were complete response p = 0.043 (OR 1.4, 95% CI 0.89-2.2) and location of ocular annexes p = 0.009 (OR 0.49 (95% CI 0.32–0.76). The stomach location was the unfavorable one p = 0.01 (OR 1.76, 95% CI 1.09-2.86). The 5-year OS for gastric localization was 57.5%, with a median of 72 months. Other areas did not reach the median (log rank Conclusions: MZL has a heterogeneous presentation. In our series, conjunctival and ocular annexes MALT is found as the main variant–different from that reported in the international literature. The long-term prognosis is favorable, unlike in patients with gastric MALT lymphoma, in which it is less than what is described in other series.