Rectal Cancer

The rectum is the last part of the intestine before the anus. There are two characteristics unique to the rectum, which makes it totally different from any other part of the digestive tract and are very important to the surgery of this organ.

1. The rectum ends up within the anal sphincter muscles. These are the muscles that are responsible for fecal continence. When a rectal tumor arises very close to these sphincter muscles, there is a true possibility that these muscles are actually involved with this tumor. Traditionally, the result was that in order to have this tumor removed, the anus and its involved sphincters had to be removed as well. This would result to a permanent colostomy for the rest of the patientʼs life. However, modern surgical technology and technique, along with critical developments in management strategies aim at the elimination of this unpleasant colostomy, which may interfere with the quality of the patientʼs life.

2. While the wall of all the rest of the intestinal tract consists of 4 distinct layers, the wall of the rectum consists of only three. Thus, a tumor arising from the inner layer of the rectum (the mucosa) may penetrate through the whole width of the rectal wall much easier and quicker. If this does happen, then the cancer cells move into the fatty tissue around the rectum and to the lymph nodes invested in this fatty tissue. This is why a rectal cancer may give metastases in the perirectal fat and lymph nodes at an earlier stage compared to colon cancer.

Patients with rectal cancer usually present with rectal bleeding (red blood) and difficulty in bowel movements, which progressively gets worse. The diagnosis is established with colonoscopy and biopsy. It is crucial to note the actual distance of the tumor to the anal sphincter muscles. Two are the main aspects of surgery of the rectum:

• Radical resection of the tumor; this involves not only the diseased rectum, but also all the fatty tissues around the rectum, along with the lymph nodes (“total mesorectal excision- TME”), and

• Sphincter preservation, or saving the patient a permanent colostomy without compromising the radicality of resection.

Because the cancer may have progressed through the rectal wall into the fatty tissues around it, this has to be well recognized before the operation. This extremely important information comes from a diagnostic modality called endoscopic ultrasonography (EUS). EUS will precisely demonstrate the true depth of wall involvement and penetration. In case of more advanced disease, it is prudent for the patient to undergo chemotherapy and radiation first, before the operation. This strategy of “neoadjuvant chemoradiation therapy” will “downstage” the disease, or shrink it both in size, as well as in depth of wall penetration, so a subsequent operation will both provide maximal radicality, but also save the sphincter as well. More importantly, this strategy is clearly associated also with improved long term outcome, which means a lower risk of cancer recurrence, or metastasis and a longer survival.