Department of General Surgery, Peking University Third Hospital, Haidian, Beijing, China.
Department of Radiation Oncology, Peking University Third Hospital, Haidian, Beijing, China.
Int J Surg. 2020 Aug;80:168-174. doi: 10.1016/j.ijsu.2020.06.039. Epub 2020 Jul 7.
The diversity in definitions for the rectosigmoid junction is becoming a major obstacle in standardizing optimal treatment of rectal cancers. The study aimed to determine the average distance of the sigmoid take-off from the anal verge and its association with individual factors.
Patients diagnosed with rectal and sigmoid colon cancer in our centre from January 2010 to December 2018 were retrospectively enrolled in the cancer group. The results of 200 controls without colorectal disease were also reviewed (normal group). The distance of different landmarks and margins of cancer from the anal verge were retrieved from computed tomography (CT), magnetic resonance imaging (MRI), and endoscopy findings.
The cancer group comprised 635 patients (381 men, median age: 64 years). The average distances of the sigmoid take-off from the anal verge measured in CT and MRI were comparable (P = 0.483). On MRI, the average distance of the sigmoid take-off from the anal verge in the cancer group was comparable with that of the normal group (P = 0.070). Multivariate regression revealed that the distance of the sigmoid take-off from the anal verge was associated with the distances of the sacral promontory (P < 0.001) and peritoneal reflection (P < 0.001) from the anal verge.
The cancer distributions of patients varied widely with the application of different definitions. The point of sigmoid take-off is an intuitive landmark influenced by individual factors. The measurement of the sigmoid take-off by different researchers in both CT and MRI revealed good consistency. Further studies regarding the clinical significance of this definition are still needed.
直肠乙状结肠交界的定义存在多样性，这成为标准化直肠肿瘤治疗的主要障碍。本研究旨在确定乙状结肠转折的平均距离及其与个体因素的关系。
回顾性纳入 2010 年 1 月至 2018 年 12 月在本中心诊断为直肠和乙状结肠癌的患者为癌症组。还回顾了 200 名无结直肠疾病的对照者（正常组）的结果。从计算机断层扫描（CT）、磁共振成像（MRI）和内镜检查结果中检索不同标志物和癌症边缘与肛缘的距离。
癌症组包括 635 例患者（男性 381 例，中位年龄：64 岁）。CT 和 MRI 测量的乙状结肠转折距肛缘的平均距离相当（P=0.483）。在 MRI 上，癌症组乙状结肠转折距肛缘的平均距离与正常组相当（P=0.070）。多变量回归显示，乙状结肠转折距肛缘的距离与骶骨岬（P<0.001）和腹膜反射（P<0.001）距肛缘的距离有关。
不同定义下患者的癌症分布差异很大。乙状结肠转折点是一个受个体因素影响的直观标志物。不同研究者在 CT 和 MRI 上测量乙状结肠转折点的一致性较好。关于该定义的临床意义还需要进一步研究。
