小腸原発悪性リンパ腫の治療

Therapeutic Strategy in Primary Small Intestinal Lymphoma

要旨　小腸原発悪性腫瘍の15～20％がリンパ腫であり，非ホジキンリンパ腫（NHL）の30％を占める胃腸原発リンパ腫の中で，9～30％が小腸原発NHLである．小腸原発NHLで最も頻度の高いびまん性大細胞型B細胞リンパ腫（DLBCL）の治療方針は，初発限局期には病変部位の外科的切除後にR-CHOP療法6コース，初発進行期にはR-CHOP療法6～8コース，救援化学療法に奏効した65歳以下再発例には自家造血幹細胞移植併用の大量化学療法が標準的治療法である．十二指腸原発濾胞性リンパ腫は限局期症例が多く，緩徐な経過を示すため，リツキシマブ単剤治療や注意深い経過観察（watch & wait）も考慮すべき治療オプションである．小腸原発T細胞リンパ腫の予後はDLBCLと比べて不良であり，分子標的薬など新たな治療戦略の開発が望まれる．

　About 15～20％ of neoplasms of the small intestine are lymphomas with most occurring in the ileum and jejunum. DLBCL（diffuse large B-cell lymphoma）including transformed MALT lymphoma is the most common histologic subtype in the primary small intestinal lymphoma that accounts for 9～30％ of the primary gastrointestinal lymphomas. Standards of care of newly diagnosed localized and advanced DLBCL of small intestine are surgical resection followed by 6 cycles of R-CHOP and 6 to 8 cycles of R-CHOP, respectively. High-dose chemotherapy followed by autologous hematopoietic stem cell transplantation after the response by salvage chemotherapy is a standard of care in patients with relapsed small intestinal DLBCL. For primary duodenal follicular lymphoma, especially with localized disease, rituximab monotherapy or watch and wait are the optional treatment. There is no sufficient standard of care in T-cell lymphoma of small intestine. The development of new molecular targeted drugs such as brentuximab vedotine or alisetib have been awaited.