Mucosa-associated lymphoid tissue gastrointestinal and nongastrointestinal lymphoma behavior: analysis of 108 patients.

Abstract

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. 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. 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. 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.