Bagla N, Schofield J B
Department of Cellular Pathology, Preston Hall Hospital, Maidstone, Kent, UK.
Colorectal Dis. 2007 Sep;9(7):606-8. doi: 10.1111/j.1463-1318.2007.01329.x.
Rectal cancers are currently defined as tumours below 15 cm from the anal verge on rigid sigmoidoscopy. Clinical trials have used this criterion to select patients for neoadjuvant chemoradiotherapy, but several authors have shown that the distance between the fully peritonealized sigmoid colon and the anal canal varies significantly between individuals. A fixed anatomical landmark would be a more reliable and reproducible method of demarcating the junction between the colon and the rectum. The distinction between rectal and sigmoid colon cancers is of particular importance as treatment protocols for rectal cancer management often involve neoadjuvant treatment in contrast to colonic cancers, so it is vital to get the anatomy right. As all rectal cancers are now assessed preoperatively by MRI, the use of a bony landmark is possible. We postulate that the fixed landmark to define the upper limit of the rectum should be the sacral promontory.
目前，直肠癌被定义为在硬性乙状结肠镜检查时距肛缘15厘米以下的肿瘤。临床试验已采用这一标准来选择接受新辅助放化疗的患者，但几位作者表明，完全腹膜化的乙状结肠与肛管之间的距离在个体之间存在显著差异。一个固定的解剖标志将是划分结肠与直肠交界处更可靠且可重复的方法。直肠癌与乙状结肠癌的区分尤为重要，因为与结肠癌相比，直肠癌的治疗方案通常涉及新辅助治疗，所以正确了解解剖结构至关重要。由于现在所有直肠癌术前都通过磁共振成像（MRI）进行评估，使用骨性标志是可行的。我们推测，定义直肠上限的固定标志应为骶岬。
