非乳頭部十二指腸SM以深浸潤癌の病理組織学的特徴—外科的切除例の国内多施設検討より

Clinicopathological Features of Non-ampullary Duodenal Cancer with Tumor Clinicopathological Characteristics of Non-ampullary Duodenal Cancer with Submucosal or Deeper Invasion：A Nationwide Survey of Surgical Outcomes in Japan

要旨●非乳頭部十二指腸癌の臨床病理学的特徴および予後から至適治療方針を明らかにするため，国内多施設共同研究を実施した．2008〜2017年の期間に外科的切除された1,083例を対象として検討を行ったところ，粘膜下層以深浸潤癌のリンパ節転移範囲は腫瘍占居部位や深達度に関わらず膵頭後部および上腸間膜動脈リンパ節への頻度が高く，これらを郭清する術式が予後改善に寄与すると考えられた．また，propensity score matchingを用いた解析で，漿膜下層以深浸潤癌，リンパ節転移陽性，術前CA19-9高値例に対する6か月以上の術後補助化学療法で無再発生存期間が有意に延長する可能性が示唆された．

　Non-ampullary duodenal cancer is a relatively rare malignancy, and the optimal treatment strategy—including the choice of surgical procedure and the role of adjuvant chemotherapy—remains undefined. This nationwide study aimed to elucidate the pattern of lymph node metastasis and to determine appropriate treatment approaches using a large-scale patient database. We retrospectively analyzed data from 1,083 patients with non-ampullary duodenal cancer who underwent surgical resection at training institutions certified by the Japanese Society of Hepato-Biliary-Pancreatic Surgery. To minimize confounding factors, propensity score-matched analyses were performed. The extent of lymph node dissection varied notably depending on the primary tumor location and depth of invasion. Lymph node metastases were frequently identified in peripancreatic regions and along the superior mesenteric artery, regardless of tumor location. Dissection of these lymph nodes appeared to confer a survival benefit. In the propensity-matched cohort, adjuvant chemotherapy administered for more than 6 months was significantly associated with improved recurrence-free survival. This benefit was particularly evident in patients with tumor invasion into the subserosa or beyond, presence of lymph node metastasis, or elevated serum carbohydrate antigen 19-9（CA 19-9）levels. These findings underscore the importance of tailored surgical approaches and the potential role of prolonged adjuvant chemotherapy in improving outcomes for patients with advanced non-ampullary duodenal cancer.