Rationale for radiotherapy as a treatment modality in gastric mucosa-associated lymphoid tissue lymphoma

Abstract

Purpose To provide a rationale for the use of local radiotherapy (RT) for the treatment of low-grade mucosa-associated lymphoid tissue lymphoma of the stomach (MLS). In addition, the clinicopathologic characteristics were analyzed. Methods and materials The data of 72 patients with MLS, who underwent radical surgery between 1991 and 2001, were retrospectively reviewed. The depth of invasion into the gastric wall and the pattern of lymph node spread according to pathologic grade were analyzed. Results The patient age range was 24–77 years (median, 51 years). Of the 72 patients, 45 (62.5%) had low-grade and 27 (37.5%) had high-grade MLS; 44 (61%) had Stage I and 28 (39%) Stage II. The tumors were confined to the mucosa or submucosa in 43 patients (58.9%). Sixty-seven percent of low-grade tumors and 48% of high-grade tumors were confined to the mucosa and submucosa. Lymph node involvement was identified in 24.4% of the low-grade MLS patients and 63.0% of the high-grade MLS patients. In the low-grade group, lymph node involvement was limited to the perigastric lymph nodes in all cases except for one. One patient with tumor infiltration beyond the serosa had extensive lymph node involvement into the paraaortic and omental lymph nodes. Conclusion Local RT to the stomach and regional lymphatics can be applied preferably instead of gastrectomy in patients with low-grade MLS who are negative for Helicobacter pylori or are refractory to anti- H. pylori therapy. The timing of RT and the exclusion criteria for RT should be determined in the future.