Barrett食道腺癌pT1a-SM1の治療方針UPDATE

Updated Treatment Strategies for pT1a-SM1 Barrett's Adenocarcinoma

要旨●本邦において，Barrett食道腺癌（BAC）のpT1a-SM1は粘膜下層浸潤500μm以内と定義される．pT1a-SM1 BACにおける内視鏡治療後の方針に関しては一定の見解がなく，本稿では過去の多施設研究と当院のデータを用いて治療成績と内視鏡治療後の転移リスクを検討した．粘膜下層浸潤500μm以内で，脈管侵襲や低分化腺癌成分がなく，腫瘍径≦30mmの低リスク群は，内視鏡治療単独でも全例で再発・転移なく長期生存が得られた．一方，これらの条件を満たさない高リスク群では再発例も認められ，追加治療の適応検討が必要と考えられた．とりわけ低リスクのpT1a-SM1 BACに関しては，今後のさらなるデータ集積と治療方針の再検討が望まれる．

　In Japan, pT1a-SM1 Barrett's adenocarcinoma（BAC）is defined as submucosal invasion within a depth of 500μm. Currently, no consensus exists regarding post-endoscopic treatment management for pT1a-SM1 BAC. The present study aimed to evaluate the treatment outcomes and metastasis risk of patients following endoscopic resection using data from previous multicenter studies as well as our institutional cohort. Among low-risk patients—defined as those with submucosal invasion depth of ≤500μm, without lymphovascular invasion and poorly differentiated components, and with tumor size of ≤30mm—no recurrence or metastasis was observed. Moreover, endoscopic treatment alone aided in long-term survival of low-risk patients. Contrarily, recurrence was observed in the high-risk group not meeting these criteria, suggesting the need for additional treatment modalities. Further accumulation of evidence and re-evaluation of treatment strategies are warranted, particularly for low-risk patients with pT1a-SM1 BAC.