Medical Health Encyclopedia

Local Excision or Polypectomy for Early Stages. In order to preserve the function of the anal sphincter and prevent the need for colostomy, Stage I and Stage II tumors may be removed by local excision, sometimes followed by chemotherapy and radiation. In this procedure, the tumor is cut out without removal of a major section of rectum. In some cases cancer recurs, but a second operation may be possible. Another treatment for early-stage rectal cancer called electrocoagulation, which destroys tumors using a high frequency electric current, is being tested but should only be used in the setting of clinical trials.

Radical Resection. In about a third of cases of rectal cancer, the cancer occurs in the lower part of the rectum, where between 70% and 80% of cancers have spread beyond the rectal wall. In such cases, a radical resection is required, in which surrounding structures, including the sphincter muscles that control bowel movements, must often be removed.

The use of chemotherapy and radiation prior to surgery may prevent the need for permanent colostomy in some patients. This is an active area of clinical research and current trials are under way to address this issue. An alternative technique called coloanal anastomosis reconstructs the area to avoid the need for colostomy, and may be appropriate in selected patients.

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Total Mesorectal Excision. Total mesorectal excision (TME) involves dissection and removal of the entire cancerous area of the rectum along with surrounding fatty regions where the lymph nodes are located (the mesorectum). When successful, TME preserves the sphincter muscle, reducing the need for a permanent colostomy. Increasing use of this procedure is resulting in lower recurrence rates, lower levels of impotence and incontinence, and better overall survival rates compared to other resection techniques. Some experts now recommend that it be the first choice for certain patients with locally advanced rectal cancer.