胃原発B細胞性リンパ腫の治療と予後―MALTリンパ腫の治療戦略を中心に

Treatment and Prognosis of Primary Gastric B-cell Lymphoma―Special Reference to Therapeutic Strategy for MALT Lymphoma

要旨　胃原発B細胞性リンパ腫322例（低悪性度MALTリンパ腫186例，diffuse large B-cell lymphoma（DLBL）82例，DLBL併存MALTリンパ腫54例）を対象として治療法と予後の関連を遡及的に解析し，このうちH.pylori除菌を行った96例については長期経過および除菌無効例に対する二次治療の効果を検討した．胃温存治療群（除菌，放射線または化学療法;n＝100）は外科切除群（n＝222）より高い全生存率を示したが，非増悪率に差はなく，多変量解析では，治療法の違いは予後に影響しなかった．除菌により55例（57％）で完全寛解が得られ，経過中に4例（7％）で一時的に組織学的再燃を認めた．除菌無効例のうち34例に二次治療（cyclophosphamide経口単剤化学療法11例，放射線療法9例，CHOP化学療法10例，胃切除4例）を行い，29例（85％）で完全寛解に導入できた．これらの結果より，胃B細胞性リンパ腫の治療には胃温存治療が望ましく，除菌無効例に対しては組織型と病期に応じて，化学療法または放射線療法を追加することにより良好な予後が期待できると考えられた．

　To evaluate the influence of therapeutic methods on the prognosis of primary gastric B-cell lymphoma, we analyzed the prognostic factors for 322 patients, comprised of 186 with low-grade MALT lymphoma, 54 with diffuse large B-cell lymphoma (DLBL) plus MALT lymphoma, and 82 with DLBL without MALT lymphoma. Among them, the clinical course of 96 patients who were treated by Helicobacter pylori eradication was also evaluated. Patients who underwent stomach-conserving treatment (H. pylori eradication, chemotherapy or radiation ; n＝100) showed a better overall survival probability than those treated by surgery (n＝222), but the progression-free probability did not differ between the two groups. After H. pylori eradication, complete remission was achieved in 55 patients, of whom histologic relapse was observed in 4 patients (7％). Second line treatment for 34 patients, who failed to respond to eradication therapy, including oral monochemotherapy with cyclophosphamide, radiation, CHOP chemotherapy, and gastrectomy resulted in complete remission in 29 patients (85％). These results suggest stomach-conserving treatment to be an optimal therapeutic modality for primary gastric B-cell lymphoma.

　1) Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan