Marginal zone lymphoma (MZL) is the second most frequent histologic subtype of non-Hodgkin lymphoma (NHL) following diffuse large B-cell lymphoma in Korea. In 2008 WHO classification, MZL comprise the splenic B-cell MZL (SMZL), the extranodal MZL of mucosa-associated lymphoid tissue (MALT lymphoma, ENMZL), and the nodal MZL (NMZL). In Korea, ENMZL account for 16.7% and NMZL accounts for 0.6% of all NHLs. In Korean MZL analysis, the principal clinical features were limited stage, small tumor burden, excellent performance status, and normal LDH. Patients with NMZL, however, are distinguished by male predominance, higher incidence of B symptoms, bone marrow involvement, poor performance status, and advanced stage.
Because ENMZL of stomach is the most common and extensively studied MZL, this presentation will show non-gastric MZL studies conducted in Korea. For stage I–II non-gastric MZL patients, local treatment/radiotherapy should be considered for the principal treatment modality. For stage III–IV MZL, we have conducted a multicenter, phase II trial with rituximab plus CVP. In 40 patients with a total of 287 cycles R-CVP chemotherapy, overall response rate was 88% with 24 complete responses (60%). The median duration of response was 28.3 months. After a median follow-up of 38.2 months, the estimated 3-year progression-free survival and overall survival were 59% and 95%, respectively. There were 11% and 2% of grade 3 or 4 neutropenia and febrile neutropenia, respectively. The R-CVP regimen is the first recommended regimen for untreated advanced stage MZL in Korea.
Further studies should explore the still unanswered strategies. The optimal first-line treatment of localized or advanced MZL, the usefulness of maintenance therapy for MZL, the proper salvage treatment modalities for relapsed cases, and so on.