A malignant tumor arising from the inner wall of the final part of the large intestine — the rectum. Although colon cancer and rectal cancer share many features, there are important differences between these two diseases including, especially, the tendency for rectal cancer — but not colon cancer — to recur locally. Local recurrence of rectal cancer is common (15-45%) after standard surgery and is often catastrophic. It is difficult to cure, and the associated symptoms are debilitating. Accordingly, preventing local recurrence is one of the main treatment goals with rectal cancer.
The prognosis (outlook) with rectal cancer is clearly related to the degree of penetration of the tumor through the bowel wall and the presence or absence of lymph node involvement. These two characteristics form the basis for all staging systems developed for this disease. Locally advanced or locally recurrent rectal cancer causes disabling symptoms and is difficult to treat.
The standard surgical procedure is called abdominal perineal resection with total mesorectal excision and a permanent end colostomy. Preoperative chemoradiotherapy has been found to reduce the risk of local recurrence and to cause fewer long-term toxic effects than if the chemoradiotherapy is given postoperatively. At five years, the overall survival among patients with locally advanced rectal cancer, irrespective of whether they have had preoperative or postoperative chemoradiotherapy, is about 75%.
Risk factors for rectal cancer include heredity (family history), colorectal polyps, and long-standing ulcerative colitis. Most cancers of the rectum, like those in colon, develop from polyps. Polyp removal can thus prevent rectal cancer. Polyps and early cancer can have no symptoms so regular screening is important. Diagnosis of rectal cancer can be made by proctoscopy or by colonoscopy with biopsy confirmation of the cancer.
- Rectal exam, digital (DRE)
An exam done to detect abnormalities that can be felt (palpated) from within the rectum. The doctor inserts a lubricated, gloved finger into the rectum and feels for anything that is not normal. The digital rectal exam is an important screening test for the detection of tumors of the rectum and prostate abnormalities, including benign […]
- Rectal incontinence
Inability to hold feces in the rectum due to failure of voluntary control over the anal sphincters with involuntary passage of feces and gas. Also called fecal incontinence.
Bulging of the front wall of the rectum into the vagina. Rectocele is due to weakening of the pelvic support structures and thinning of the rectovaginal septum (the tissues separating the rectum from the vagina). Also called a proctocele. Risk factors for a rectocele include a history of multiple, difficult or prolonged deliveries, forceps or […]
- Rectouterine pouch
Culdoscopy, the introduction of an endoscope through the vagina into the cul-de-sac; Culdoscope, the endoscope that is used to look into the cul-de-sac; and Culdocentesis, the aspiration (withdrawal) of fluid from the cul-de-sac. In French, “cul-de-sac” literally is “bottom of (a)sack.” As early as the 13th century, a cul-de-sac was a dead-end street (or a […]
The last 6 to 8 inches of the large intestine. The rectum stores solid waste until it leaves the body through the anus.