Helicobacter ISSN 1523-5378 © 2006 The Authors Journal compilation © 2006 Blackwell Publishing Ltd, Helicobacter 11: 569–573 569 Blackwell Publishing Ltd Oxford, UK HEL Helicobacter 1083-4389 Blackwell Publishing Ltd, 2006 8 Original Article Outcome of MALT Lymphoma after Eradication Therapy Hong et al. A Prospective Analysis of Low-Grade Gastric MALT Lymphoma after Helicobacter pylori Eradication Seong Soo Hong, † Hwoon-Yong Jung, * Kee Don Choi, * Ho June Song, * Gin Hyug Lee, * Tae Hoon Oh, * Ji-Yun Jo, * Kyu-Jong Kim, * Jeong-Sik Byeon, * Seung-Jae Myung, * Suk-Kyun Yang, * Weon-Seon Hong, * Jin-Ho Kim * and Young Il Min † * Division of Gastroenterology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea, and † Department of Internal Medicine, Dongkuk University International Hospital, Ilsan, Korea Abstract Background: Primary gastric low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) is known to be successfully treated with anti- Helicobacter pylori ( H. pylori ) therapy alone. However, there are few reports on long-term results after eradication therapy. The aims of this study were to analyze the rate and the interval to reach complete remission (CR), and to assess the rate and the factors affecting recurrence of MALT lymphoma. Materials and Methods: Between 1996 and 2003, a total of 90 H. pylori -infected patients with low-grade MALT lymphoma were included in this study. For initial staging, endoscopic ultrasonography, chest–abdomen–pelvis CT scans, and bone marrow examination were taken. All patients were made to take anti- H. pylori therapy for 14 days. Tumoral response was assessed by endoscopy every 3 months till CR and every 6 months after achieving CR. Results: Among 90 treated patients, 85 (94.4%) reached CR. The median interval to CR was 3 months (range, 1–24). Seventy-nine (92.9%) patients were in CR at 12 months. Median follow-up period after CR was 45 months (range 15 –109). Among 77 patients who were followed-up after CR, 8 (10.4%) patients were proved with recurrence of MALT lymphoma. Cumulative recurrence rate was 2.7, 11.5, and 12.2% at 1, 2, and 3 years. The presence of H. pylori was only a significant risk factor affecting recurrence. Conclusions: The status of H. pylori is the most important risk factor affecting recurrence. Therefore, adequate eradication regimen and accurate regular evalua- tion for H. pylori status are needed during follow up of primary gastric low-grade B-cell MALT lymphoma. Keywords mucosa-associated lymphoid tissue (MALT) lymphoma, long-term outcome, Helicobacter pylori, eradication, recurrence. Reprint requests to: Hwoon-Yong Jung, MD, PhD, Division of Gastroenterology, University of Ulsan College of Medicine, Asan Medical Center, 388–1 Pungnap-dong, Songpa-gu, Seoul 138–736, Korea. Tel: 82-2-3010-3190; Fax: 82-2-485-5782; E-mail: hyjung@amc.seoul.kr Mucosa-associated lymphoid tissue (MALT) lymphoma, first described in 1983 by Isaacson and Wright [1,2], is characterized by a proliferation of neoplastic marginal zone-related cells that invade epithelial structures and form characteristic lymphoepithelial lesions. The normal gastric tissue does not have lymphoid tissue, but after Helicobacter pylori infection, a subset of patients can have auto-reactive lymphoid tissues [3]. It is thought that this lymphoid tissue can give rise to lymphoma after acquisition of genetic mutations. Recent studies found H. pylori infection rate of 72 to 98% in patients with MALT lymphoma [4,5]. Eradication of H. pylori has proven to be effective in regression of primary gastric MALT lymphoma [6]. Recently published series confirmed a 50–95% complete remission (CR) rate in stage-IE or -IIE patients [7–11]. The interval to reach CR of gastric MALT lymphoma after eradication of H. pylori infection is variable, and takes longer than 12 months in some cases [12]. In the German MALT Lymphoma Study Group, after a mean follow-up period of 48 months, 81% of patients were in CR [13]. In a French study of 48 stage-IE low- grade MALT lymphoma patients, 69% of patients were in CR at 6 months after H. pylori therapy [14]. Although several groups have shown the treatment out- come of gastric MALT lymphoma after H. pylori eradica- tion, reports about recurrence and its associated factors are rare. In an Italian study of early-stage MALT lymphoma patients, after histologic remission of 71 patients, five relapses of low-grade and one relapse of high-grade MALT lymphoma were found 12 – 48 months after eradication.