The rectum forms the distal end of the large bowel, approximately 12–15 cm in length extending from the taenia to the puborectalis ring. The dentate line forms the distal limit, which is the point where the squamous mucosa of the anus transitions to the columnar mucosa of the rectum. The rectum is divided into upper, middle, and lower regions. The peritoneum covers the upper third and anterior wall of the mid third but not the lower third of the rectum. Rectal cancer refers to carcinoma that arises from the rectal tissue. The location of a rectal cancer is defined by the distance from the dentate line.
Colorectal cancer is the third and second most common cancer in males and females respectively, based on the World Health Organization GLOBOCAN database. Rectal cancers comprise a third of these cases but carry a worse prognosis than colon cancers.
Primary colorectal cancers can present with rectal bleeding,...
KeywordsRectal Cancer Total Mesorectal Excision Transanal Endoscopic Microsurgery Tumor Regression Grade Radiation Cystitis
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