Primary gastrointestinal non-Hodgkin's lymphoma: a clinicopathologic study of 128 cases in Greece. A Hellenic Cooperative Oncology Group study (HeCOG).

The aim of this retrospective study was to illustrate the clinicopathologic data and the treatment results in patients with primary gastrointestinal tract non-Hodgkin's lymphoma (GI NHL). Among 810 patients with NHL, 128 cases (15.8%) were diagnosed as primary GI tract NHL. There were 79 males and 49 females with median age of 62 years. The most common primary site was the stomach (68%). Overall, 67.2% of the patients were in stages I - II, and 32.8% in stages III - IV. Simultaneous involvement of the GI tract and other extranodal sites was observed in 26 patients (20%). Extranodal marginal zone B-cell lymphoma (MZBL) (i.e., low-grade lymphoma of mucosa-associated lymphoid tissue type) accounted for 48.4% of lymphomas. Aggressive lymphomas (diffuse large B-cell lymphoma [DLBL]) accounted for 44.5%. Eighty-three patients (67.5%) achieved complete response (CR), either by surgery (43/43 patients, 17 with DLBL and 25 with MZBL) or by primary chemotherapy (40/64 patients, 22 with DLBL and 17 with MZBL). Sixty-two patients remain in CR; 33/43 after surgical resection (13/17 with DLBL and 20/25 patients with MZBL), and 29/40 after only chemotherapy (18/22 with DLBL and 10/17 with MZBL). The major prognostic factor for outcome in the present study was the stage of the disease. Patients with localized lymphoma (stage I and II) had significantly longer DFS and OS (DFS and OS at 3-year: 83% and 87%, respectively) than patients with extended disease (stage III and IV) (DFS and OS at 3-year: 46% and 60%, respectively) (P < 0.0001). The International Prognostic Index (IPI) for patients with aggressive lymphomas was prognostic only for DFS (79% for low-risk patients [IPI score 0 - 1] vs 49% for higher risk groups [IPI score >1] at 3-year, P = 0.0131).