An Epidemiological Study on Survival in Lymphoma of Mucosa-Associated Lymphoid Tissue: A Comparative Analysis by Primary Tumor Location.

Purpose: To investigate outcome and local treatment strategy for extranodal mucosa-associated lymphoid tissue (MALT) lymphoma patients.

Methods: Retrospectively collected patients using the data from the Surveillance, Epidemiology, and End Results database, including tumor sites with over 200 cases.

Results: The cohort comprised 3842 patients, with the gastric region being the most prevalent site (34.9%), followed by salivary gland (16.8%), cutaneous (16.5%), pulmonary (13.3%), intestinal (13.2%), and head and neck (5.4%). The 10-year cancer-specific survival (CSS) was 88.1%, 92.6%, 86.5%, 87.7%, 89.7%, and 97.7% in patients with tumors located in the gastric, salivary gland, pulmonary, head and neck, intestinal, and cutaneous, respectively (p < 0.001). Compared to gastric MALT lymphoma, the cutaneous site exhibited superior CSS (p < 0.001), whereas other sites showed comparable outcomes (all p ≥ 0.05). In gastric MALT lymphoma cases, radiotherapy was associated with better CSS than surgery alone (p < 0.001), while no significant difference was observed between surgery plus radiotherapy versus surgery alone (p = 0.561). Treatment outcomes were similar across the three therapeutic modalities for non-gastric sites.

Conclusions: Our findings underscore the biological and clinical heterogeneity of extranodal MALT lymphoma. While localized treatments provide equivalent results across most non-gastric sites, radiotherapy is recommended as the primary noninvasive treatment option.