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Overview

Following surgical removal of rectal cancer, the cancer is referred to as stage I (Duke Stage 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 usually 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. However, some patients with Stage I rectal cancer are treated with adjuvant (post-surgery) radiation therapy and/or chemotherapy.

Low Anterior or Abdominoperineal Resection

The standard surgical procedures used to remove Stage I rectal cancer include a low anterior resection (LAR) or abdominoperineal resection (APR). For an LAR the surgeon makes an incision only in the abdomen. Then the surgeon removes the cancer and a margin of normal tissue on either side of the cancer, along with nearby lymph nodes and a large amount of fatty and fibrous tissue around the rectum. The colon is then reattached to the rectum that is remaining so that a colostomy is not necessary. APR is more involved than a LAR. The surgeon makes one incision in the abdomen and another in the perineal area around the anus. This incision allows the surgeon to remove the anus and the tissues surrounding it, including the sphincter muscle. Because the anus is removed, a permanent colostomy is required to allow stool to pass out of the body.

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. Because of the inconvenience of a colostomy, physicians will attempt to use sphincter-sparing treatments that allow the patient to keep the anus. Using these techniques 90% of patients with Stage I rectal cancer appear to be cured.

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. 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. One study of sphincter-sparing surgery included 27 patients with Stage I disease.[1] Most of these patients did not receive radiation therapy, and there was only one local-regional recurrence (a recurrence in the area of the original cancer). In another study involving 59 patients with Stage I rectal cancer, there were three recurrences, and none of these patients received adjuvant radiation therapy.[2] Thus, it would appear that many patients with Stage I rectal cancer do not require adjuvant radiotherapy. One of the major outstanding issues is to define which patients do and which do not require radiation therapy.

Trans-Anal Resection

Local transanal resection is done with an endoscope inserted through the anus, without making an opening in the skin of the abdomen. This operation involves cutting through all layers of the rectum to remove invasive cancer as well as some surrounding normal rectal tissue. This procedure can be used to remove some Stage I rectal cancers that are relatively small and not too far from the anus. Recently, an increasing number of small rectal cancers have been treated with endoscopic local excision in order to avoid a major operation.[3] In this setting adjuvant therapy (radiation and/or chemotherapy) is often used to decrease the risk of disease recurrence, which is expected to be somewhat higher than observed with major surgical procedures.

Patients in Poor Health

If patients are too sick to withstand surgery, rectal cancer may be treated only with radiation therapy delivered by conventional external beam techniques, endocavitary radiation therapy (aiming radiation through the anus), or brachytherapy (placing radioactive pellets directly into the cancer). However, this has not been proven to be as effective as surgery. Patients can also receive chemotherapy in addition to radiation therapy.

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 Staging

A small fraction of patients with Stage I rectal cancer will relapse following surgery. This is thought to be due to inadequate staging with failure of ultrasound to detect nodal metastases. Other factors, such as how the cancer looks under the microscope, may also have an impact on survival. Patients with poorly differentiated tumors (tumors with more abnormal-looking cells), and those with vascular invasion may have an increased risk of relapse, especially after local trans-anal incision.[4] Future studies may help better identify patients who need adjuvant therapy.

Improvements in Surgery

Laparoscopic surgery is used for many types of surgery with the short-term advantages of less pain, fewer wound complications, quicker post-operative recovery, and shorter hospital stays. Instead of making one long incision in the abdomen, the surgeon makes several smaller incisions. Special long instruments are inserted through these incisions to remove part of the colon and lymph nodes. One of the instruments has a small video camera on the end, which allows the surgeon to see inside the abdomen. Once the diseased part of the colon has been freed, one of the incisions is made larger to allow for its removal.

Laparoscopic-assisted surgery appears to be about as likely to be curative as the standard approach for earlier-stage cancers. However, there have been few randomized trials in colon cancer and none in rectal cancer. Previous studies have suggested that uncomplicated colon cancer surgery can be performed with laparoscopic assistance with safety and without an increase in local or metastatic recurrences. However, there is still concern about long-term safety. In addition, laparoscopic surgery requires special expertise and patients need to be treated by a skilled surgeon who has done a lot of these operations.

Improvements in Radiation Therapy

Intensity Modulated Radiation Therapy (IMRT) is a technique that allows increased doses of radiation to tumor tissue while sparing normal tissue.  Most of the studies of IMRT have been in patients with stage II–III rectal cancer, but for patients unsuitable for surgery, IMRT would be the best non-surgical treatment.

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