Purpose: Characteristics and outcome of 108 patients with mucosa-associated lymphoid tissue (MALT) lymphoma were analyzed according to initial location of the lymphoma, within or outside of the gastrointestinal (GI) tract.
Patients and methods: One hundred eight patients with MALT lymphoma were studied. Fifty-five patients (51%) had GI involvement and 53 patients (49%) had another involved extranodal site: 13 orbit; 11 lung; 10 skin; seven parotid; six thyroid; three Waldeyer's ring; two breast; and one pancreas involvement. At diagnosis, 47 patients (44%) had stage IE, 26 (24%) had stage IIE, and 35 (32%) had disseminated disease. No significant difference in the clinical or biologic characteristics was observed between GI and non-GI patients.
Results: Complete response after the first treatment was reached in 76% of the patients, with no difference between the two subgroups. With a median follow-up of 52 months, median survival was not reached and was identical in the two subgroups, but GI MALT patients had a longer time to progression (8.9 years compared with 4.9 years in non-GI patients; P = .01). The different non-GI locations seemed to have a similar outcome.
Conclusion: MALT lymphoma is an indolent disease that usually presents as localized extranodal tumor without accompanying adverse prognostic factor, and these patients have a good outcome. However, non-GI patients seem to progress more often than GI patients.