Following surgical removal of rectal cancer, the cancer is referred to as stage I (A) rectal cancer if the final pathology report shows that the cancer is confined to the lining of the rectum. Stage I (A) cancer does not penetrate the wall of the rectum into the abdominal cavity, does not involve any adjacent organs, has not spread to any of the local lymph nodes and cannot be detected in other locations in the body.

A variety of factors ultimately influence a patient's decision to receive treatment of cancer. The purpose of receiving cancer treatment may be to improve symptoms through local control of the cancer, increase a patient's chance of cure, or prolong a patient's survival. The potential benefits of receiving cancer treatment must be carefully balanced with the potential risks of receiving cancer treatment.

The following is a general overview of the treatment of stage I rectal cancer. Circumstances unique to your situation and prognostic factors of your cancer may ultimately influence how these general treatment principles are applied. The information on this Web site is intended to help educate you about your treatment options and to facilitate a mutual or shared decision-making process with your treating cancer physician.

Most new treatments are developed in clinical trials. Clinical trials are studies that evaluate the effectiveness of new drugs or treatment strategies. The development of more effective cancer treatments requires that new and innovative therapies be evaluated with cancer patients. Participation in a clinical trial may offer access to better treatments and advance the existing knowledge about treatment of this cancer. Clinical trials are available for most stages of cancer. Patients who are interested in participating in a clinical trial should discuss the risks and benefits of clinical trials with their physician. In order to receive optimal treatment of cancer, it is important to stay informed and follow the cancer news in order to learn about new treatments and the results of clinical trials.

Surgical Treatment

Stage I (A) adenocarcinoma of the rectum is relatively uncommon and is curable by surgical removal of the cancer. Depending on features of the cancer under the microscope, approximately 90% of patients are cured without evidence of cancer recurrence following treatment with surgery alone. The standard surgical procedures used to remove stage I rectal cancer include a low anterior resection (LAR) or abdominoperineal resection (APR). The choice of operation depends on the location of the rectal cancer in relation to the rectal sphincter or anus. For cancers that are located well above the anus, an LAR procedure can be performed. For cancers close to the anus, an APR procedure is often necessary. Following LAR procedure, the cut ends of the rectum are sewn together and anal function is preserved. Following an APR procedure, the anus is removed with the cancer, and the cut end of the large bowel is attached to the abdominal wall to form a permanent colostomy. The colostomy is covered by a bag, which collects stool as it empties from the bowel. Because of the inconvenience of a colostomy, physicians will attempt to use sphincter-sparing treatments that allow the patient to keep the anus.

Sphincter-Sparing Treatment

Sphincter-sparing treatment refers to cancer therapy that avoids removal of the rectal sphincter for rectal cancers that lie close to the anus. The standard surgical procedure used to remove rectal cancer that lies close to the anus is an abdominoperineal resection (APR). Following an APR procedure, the anus is removed with the cancer, and the cut end of the large bowel is attached to the abdominal wall to form a colostomy. The colostomy is covered by a bag, which collects stool as it empties from the bowel. Because of the inconvenience of a colostomy, physicians are using sphincter-sparing treatments that allow the patient to keep the anus. Sphincter-sparing treatment for stage I rectal cancer involves limited surgery, often followed by a combination of chemotherapy and radiation therapy. The limited surgery is designed to remove the cancer and a small rim of normal bowel, but not the anus. The surgery may be performed through the anus (transanal excision) or through the coccyx (transcoccygeal) or the tailbone. A transanal excision can be performed for small cancers that lie close (within 2 inches) to the anus. Other small cancers higher in the rectum can be removed with a transcoccygeal excision.

A combination of chemotherapy and radiation therapy may be administered after surgery to cleanse the area of the operation of microscopic cancer cells that may be remaining. The decision to treat with chemotherapy and radiation therapy after excision is based on the depth of invasion of the cancer and how aggressive the cancer appears under the microscope. For certain rectal cancers, sphincter-sparing treatment can be nearly as effective as an APR.

Adjuvant Therapy

Despite undergoing complete surgical removal of cancer, a minority of patients with stage I rectal cancer may experience recurrence of their cancer. It is important to realize that a few patients with stage I disease already had small amounts of cancer upon diagnosis that had spread outside the rectum and were not removed by surgery. These cancer cells are referred to as micrometastases and cannot be detected with any of the currently available tests. The presence of micrometastases causes the relapses that follow treatment with surgery alone. An effective treatment is needed to cleanse the body of micrometastases in order to improve the cure rate achieved with surgical removal of the cancer. Efforts are currently underway to find such a therapy. The delivery of cancer treatment following local treatment with surgery is referred to as "adjuvant" therapy and may include chemotherapy, radiation therapy and/or biologic therapy. Adjuvant therapy is administered with the goal of reducing cancer recurrences.

Adjuvant therapy for rectal cancer may involve both radiation therapy and chemotherapy. Adjuvant chemotherapy and radiation therapy has been used as treatment for patients with stage II and III rectal cancer to reduce cancer recurrences. Because of the very high cure rate achieved with surgery alone, clinical trials have not been performed to evaluate adjuvant treatment in patients with stage I cancers.

Strategies to Improve Treatment

The progress that has been made in the treatment of rectal cancer has resulted from improved surgical techniques and the development of adjuvant treatments in patients with more advanced stages of cancer and participation in clinical trials. Future progress in the treatment of rectal cancer will result from continued participation in appropriate clinical trials.

Improvement in Predicting Need for Adjuvant Chemotherapy: Undetectable areas of cancer outside the rectum are referred to as micrometastases. The presence of micrometastases causes the cancer to relapse follow treatment with surgery. Adjuvant chemotherapy treatment has been demonstrated to decrease the risk of cancer recurrence in patients with stage II-III rectal cancer, but not stage I rectal cancer. New methods of determining which patients with stage I rectal cancer are at highest risk of cancer recurrence are needed in order to appropriately utilize adjuvant treatment.

Although staging is currently important in order to determine proper treatment and outcome, current tests are not reliable enough to accurately predict patients who will relapse if they do not receive adjuvant chemotherapy. Because surgical resection of stage I cancer cures approximately 90% of patients, adjuvant therapy must be able to decrease the approximate 10% risk of cancer recurrence without significant side effects.

One technique that may help predict an increased risk of cancer recurrence is Doppler ultrasound. Doppler ultrasound has been used to measure blood flow in the artery to the liver (hepatic artery) and total liver flow in patients with rectal cancer. This measurement may be helpful because abnormalities occurring in hepatic artery blood flow can be used to detect early cancer metastasis to the liver. In one recent clinical study, 120 patients with colorectal cancer underwent curative surgery. Patients with stage I (A) or II (B) cancer had a recurrence-free survival rate of 57% and patients with stage III (C) had a recurrence-free survival of 39%. Of the 47 patients who had a normal Doppler perfusion before surgery, the survival was 89%, with no recurrence of cancer. Of 73 patients who had an abnormal value, only 22% survived with no recurrence of cancer. This study suggests that Doppler ultrasound may identify patients who need additional adjuvant treatment.