Treatment of Stages I - III of Rectal Cancer
Medically reviewed by Dr. C.H. Weaver M.D. Medical Editor (08/2018)
The following is a general overview of the treatment of stage I - III rectal cancer. 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.
Stage I -III adenocarcinoma of the rectum is relatively uncommon and is often curable by surgical removal of the cancer. Different types of surgery may be recommended depending on the location and specific characteristics of the cancer.
Low anterior or abdominoperineal resection: A low anterior resection (LAR) involves an incision across the abdomen and removal of the cancerous part of the rectum along with some surrounding tissue and lymph nodes. This is often done for cancers that are in the upper part of the rectum. Lower cancers may be treated with removal of the rectum along with extensive removal of surrounding tissues (total mesorectal excision). Depending on where the cancer was and how much of the rectum was removed, the colon may be reconnected to the remaining part of the rectum or to the anus. When possible, the surgery will allow a patient to continue to pass waste through the anus. Some patients, however, may require a temporary or permanent colostomy (an artificial opening that allows waste to pass from the colon to the outside of the body).
If the cancer is very low in the rectum (near the anus), a patient may need to have an abdominoperineal resection (APR). This involves an incision in the abdomen and an incision around the anus. Because both the rectum and the anus are removed, an APR requires a permanent colostomy.
Trans-anal resection or trans-anal endoscopic microsurgery: In some cases it may be possible to remove the cancer through the anus without making an incision in the abdomen. Techniques for removing the cancer in this way include trans-anal resection and trans-anal endoscopic microsurgery (TEM). The operations involve 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. If the cancer is found to have certain high-risk features, more extensive surgery may be recommended. These local treatments of rectal cancer offer the advantage of quicker recovery after surgery, but may be linked with a higher risk of cancer recurrence than more extensive types of surgery.1
Neoadjuvant therapy refers to treatment given prior to surgery. Many patients with Stage II - III rectal cancer receive neoadjuvant chemotherapy and radiation therapy; the goals are to reduce the risk of cancer recurrence and to shrink the cancer prior to surgery. If patients are in poor health and unable to tolerate chemotherapy and/or radiation therapy, surgery may be the initial treatment.
The goal of providing additional treatment after surgery (adjuvant therapy) is to reduce the risk of cancer recurrence by eliminating any remaining cancer. For patients who received neoadjuvant (before-surgery) chemotherapy and radiation therapy, additional chemotherapy is often given after surgery. If patients did not receive neoadjuvant therapy, they may be treated with both chemotherapy and radiation therapy after surgery.
Strategies to Improve Treatment
The progress that has been made in the treatment of rectal cancer has resulted from improved surgical techniques, the development of adjuvant and neoadjuvant chemotherapy and radiation therapy treatments and participation in clinical trials. Currently, there are several areas of active exploration aimed at improving the treatment of stage III rectal cancer.
New Adjuvant Chemotherapy Regimens: Several new chemotherapy drugs show promising activity for the treatment of advanced or recurrent rectal cancer. Development of new multi-drug chemotherapy treatment regimens that incorporate new or additional anti-cancer therapies for use as neoadjuvant and/or adjuvant treatment is an active area of clinical research.
Laparoscopic 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 rectum 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 rectum 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.1 However, there is still limited information from randomized trials about the approach. 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.
Improved Approaches to Radiation Therapy: As the technology for radiation therapy has evolved, important advances have been made in the ability of physicians to precisely target the area of the cancer. The goal is to deliver effective doses of radiation to the cancer while sparing healthy tissue to the extent possible. One newer approach to delivering radiation therapy is intensity modulated radiation therapy (IMRT). IMRT starts with a three-dimensional image of the cancer, and allows physicians to deliver different doses of radiation to different areas. The potential advantages for patients include both better tumor control and fewer side effects.
Targeted Therapies: Targeted therapies are anticancer drugs that interfere with specific pathways involved in cancer cell growth or survival. Some targeted therapies block growth signals from reaching cancer cells; others reduce the blood supply to cancer cells; and still others stimulate the immune system to recognize and attack the cancer cell. Depending on the specific “target”, targeted therapies may slow cancer cell growth or increase cancer cell death. Targeted therapies may be used in combination with other cancer treatments such as conventional chemotherapy. Targeted therapies that have shown a benefit for selected patients with advanced rectal cancer include Avastin® (bevacizumab), Erbitux® (cetuximab), and Vectibix® (panitumumab).
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.2 Future studies may help better identify patients who need adjuvant therapy.
1 Nash GM, Weiser MR, Guillem JG et al. Long-term survival after transanal excision of T1 rectal cancer. Diseases of the Colon & Rectum. 2009;52:577-82.
2 Willett CG, Compton CC, Shillito PC, et al. Selection factors for local excision or abdominoperineal resection in early stage rectal cancer.Cancer 1994;73:2716-2720.
3 Jayne DG, Thorpe HC, Copeland J et al. Five-year follow-up of the Medical Research Council CLASICC trial of laparoscopically assisted versus open surgery for colorectal cancer. British Journal of Surgery. 2010;97:1638-45.