背景和目的：瀰漫性大B 型淋巴瘤為最常見淋巴瘤分類，而腸胃道則是淋巴瘤在非淋巴結侵犯最常見部位。此回溯性研究試圖釐清腸胃道及非腸胃道瀰漫性大B 型淋巴瘤的臨床表現及預後。研究方法：2000 年1 月及2009 年12 月期間新診斷602 名淋巴瘤病患，其中37 位為腸胃道而196 位為非腸胃道瀰漫性大B 型淋巴瘤，原發自中樞神經系統或未接受化學治療者均予以排除。研究結果：兩組病患特徵大致相似，但腸胃道組表現較高的白血球及血小板數值（p 值分別為0.005 及0.013）、較低的血色素及血鈣平均值（p值分別為 0.020 及0.034），同時有較高比例的病患接受手術治療（p 值< 0.001），而其它介入性治療（所有p 值> 0.05）及治療反應則兩組相似（p 值為0.593）。但腸胃道分組有較佳的整體存活率及無疾病進展存活率（p 值分別為0.0226 及0.0436），此外多變項分析更證實腸胃道起源為整體存活期（危險比0.358； 95% 信賴區間0.164~0.780；p 值0.010）及無疾病進展存活期（危險比0.429；95% 信賴區間 0.210~-0.878；p 值0.021）的獨立預後因子。研究結論：腸胃道淋巴瘤存活率優於非腸胃道原發腫瘤，然而此回溯性分析研究受限於收案病患個數偏少，未來還需要更大型研究證實上述結論。

Background and purpose: Diffuse large B cell lymphomas (DLBCLs) are the most common histological subtype of lymphomas, and gastrointestinal (GI) lymphomas are the leading cause of extranodal lymphomas. In this retrospective study, we tried to identify differences in clinical manifestations and treatment outcomes between DLBCLs with and without a GI origin. Methods: Among 602 newly diagnosed lymphoma patients between January 2000 and December 2009, 37 patients with GI DLBCLs and 196 patients with non-GI DLBCLs were enrolled. Primary central nervous system lymphomas and patients who did not receive immunochemotherapy were excluded. Results: Except for significantly higher counts of white blood cells and platelets (p = 0.005 and 0.013) and lower levels of hemoglobin and serum calcium in the GI group (p = 0.020 and 0.034), other patient characteristics were similar in these groups. While surgery was more frequently used in the GI group (p < 0.001), the other treatment modalities (all p > 0.05) and clinical responses (p = 0.593) were comparable in the two groups. Nevertheless, the GI group demonstrated superior overall survival (OS) and progression-free survival (PFS) than its non-GI counterpart (p = 0.0226 and 0.0436). Furthermore, a GI origin was proven to be an independent prognostic indicator of both OS (hazard ratio (HR) 0.358; 95% confidence interval (CI), 0.164~0.780; p = 0.010) and PFS (HR 0.429; 95% CI, 0.210~0.878; p = 0.021) according to the multivariate analysis. Conclusions: Extranodal involvement of the GI tract in DLBCLs demonstrated survival dominance and predictive values in the immunochemotherapy era. Because of limited numbers of patients included in the retrospective study, further large-scale studies are warranted to verify these results.