Liu T.-Y.Dei P.-H.SUNG-HSIN KUOCHUNG-WU LIN2020-03-032020-03-0320100929-6646https://www.scopus.com/inward/record.uri?eid=2-s2.0-77953667536&doi=10.1016%2fS0929-6646%2810%2960078-2&partnerID=40&md5=7eea90b1b65a737e762a0d7c3498cc14https://scholars.lib.ntu.edu.tw/handle/123456789/468880Background/Purpose: Gastric mucosa-associated lymphoid tissue lymphoma (MALToma) usually presents at an early stage involving only the stomach and/or regional lymph nodes. Although a sequential transformation from low-grade gastric MALToma (GM) to high-grade GM to secondary diffuse large B-cell lymphoma (DLBCL) is commonly assumed, documented cases of transformation are rare. We aim to determine the frequency of transformation. Methods: We identified 55 early low-grade GMs, 18 early high-grade GMs, and 13 advanced GMs at the National Taiwan University Hospital from 1995 to 2005. The median follow-up time was 59 months. Results: We found that only one early low-grade GM and two early high-grade GMs transformed into secondary DLBCLs and progressed outside the stomach and regional lymph nodes. Significantly, we identified 13 low-grade GMs that were refractory to Helicobacter eradication therapy or relapsed after initial response. All 13 cases had been followed-up for at least 3 years without development of secondary DLBCLs. The frequency of transformation for early low-grade GM was less than 2% (1/55). Although two lymphoma-unrelated mortalities were identified, none of the 55 patients with early-low grade GMs died of the disease. Conclusion: Compared with chronic lymphocytic leukemia, which has a 16% transformation rate and a median transformation time of 24 months, we conclude that early low-grade GM rarely transforms into secondary DLBCL or progresses beyond the stomach. Without transformation or progression, patients with early low-grade GM rarely die of the disease and should be treated conservatively. ? 2010 Formosan Medical Association & Elsevier.[SDGs]SDG3adult; aged; article; B cell lymphoma; cancer growth; chronic lymphatic leukemia; eradication therapy; female; follow up; Helicobacter; human; large cell lymphoma; lymph node metastasis; major clinical study; male; malignant transformation; mucosa associated lymphoid tissue lymphoma; treatment response; Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Biopsy; Cell Transformation, Neoplastic; Disease Progression; Female; Follow-Up Studies; Gastric Mucosa; Hospitals, University; Humans; Kaplan-Meiers Estimate; Lymph Nodes; Lymphoma, B-Cell, Marginal Zone; Lymphoma, Large B-Cell, Diffuse; Male; Middle Aged; Neoplasm Staging; Taiwan; Treatment Outcomejournal article10.1016/S0929-6646(10)60078-2206101482-s2.0-77953667536