除菌後に長期間完全寛解しているびまん性大細胞型B細胞リンパ腫の3例―胃高悪性度リンパ腫に対する除菌治療

Long-term Results of Anti-Helicobacter pylori Therapy in Early-stage Gastric Diffuse Large B-cell Lymphoma, Report of Three Cases

要旨　胃MALTリンパ腫に対する除菌効果は，既に明らかであるが，高悪性度化した混合型やDLBCLではH. pylori感染よりも遺伝子変異への依存度が大きくなり除菌効果は基本的に無効とされている．しかし，出血や穿孔を除き高悪性度リンパ腫でも非手術的な放射線化学療法や抗体化学療法が選択され，高悪性度のDLBCLでも除菌治療の奏効例が散見されるようになった．今回，患者希望により胃限局期のH. pylori陽性DLBCLに対して除菌治療を試みた結果，6例中3例（50％）で腫瘍が消失し48～92週の長期間にわたる完全寛解を認めている．高悪性度リンパ腫に対する除菌治療の報告はまだ少ないが，H. pylori陽性例の特に高齢者における非手術的治療の選択肢の1つとして試みる価値はあると考えられ，その有効性を確認する大規模な前向き研究が望まれる．

　Spontaneous remission of diffuse large B-cell lymphoma (DLBCL) of the stomach is extremely rare. Although regression of gastric DLBCL after eradication of Helicobacter pylori (H. pylori) has recently been reported, the effect that cure of H. pylori infection has on high-grade gastric lymphoma is uncertain. To evaluate the effect of anti-H. pylori therapy on high-grade gastric lymphomas, we performed H. pylori eradication therapy in 6 patients with stage I, H. pylori-positive gastric DLBCL. In 3 patients, eradication was accompanied by rapid gross tumor regression and the disappearance of large lymphoma cells. The complete remission rate was 50.0％. The median duration of complete response was 84.7 months (range:48 to 92 months) and tumor recurrence was not observed.

　We present 3 consecutive cases of stage I, DLBCL of the stomach which disappeared after H. pylori eradication theraphy. These results suggest that anti-H. pylori therapy may be considered as one of the initial treatment options for early-stage H. pylori-positive gastric DLBCL and that large-scale prospective studies to validate its use as a first-line therapy for such tumors should be undertaken.