Treatment Options*

Setting the Stage for Treatment

In the first step of cancer diagnosis, your doctor will conduct tests and tissue biopsies to determine your cancer stage. Cancer staging is the process of classifying how far a cancer has progressed. The most commonly used system for staging colorectal cancers, developed by the American Joint Committee on Cancer (AJCC), is known as TNM (Tumor, Nodes, Metastasis). This method takes into account the tumor size, lymph node involvement and whether the cancer has spread—or metastasized—to other organs.

Once the stage is determined, the course of treatment may include more than one therapy together or in sequence. In deciding what treatment is best, it is important to ask questions and seek a second opinion.

Surgery

Surgery is the most common treatment for both colon and rectal cancer. Sometimes very early colorectal cancer can be removed using a colonoscope. When this is done, the doctor does not have to cut into the abdomen.

For surgery to treat colon cancer, usually the cancer and a length of normal colon on either side of the cancer (as well as nearby lymph nodes) are removed. The two ends of the colon are then sewn back together. Surgery for colon cancer can sometimes be done with a new approach called laparoscopic or keyhole surgery. In this method, a lighted tube and special instruments are placed inside the body through a few small incisions, rather than one large one. Keyhole surgery for colon cancer has been clinically proven to work as well as the standard approach when performed by a surgeon experienced in this type of surgery. Also, patients usually recover faster than they do after the usual operation! For colon cancer, a colostomy (an opening in the abdomen for getting rid of body wastes) is not usually needed, although sometimes a temporary colostomy may be done.

Surgery is also usually the main treatment for rectal cancer, although radiation and chemotherapy will often be given before surgery. There are several types of surgery for rectal cancer. Some operations (polypectomy, local excision, and local transanal resection) can be done with instruments placed into the anus, without having to cut through the skin. One of these methods might be used to remove some stage I cancers that are fairly small and not too far from the anus.

For some stage I and most stage II or III rectal cancers, other types of surgery may be done. A low anterior resection is used for cancers near the upper part of the rectum, close to where it connects with the colon.

For cancers in the lower part of the rectum, close to its outer connection to the anus, an abdominoperineal resection is done. After this surgery, a colostomy is usually needed. A colostomy is an opening of the colon in the front of the abdomen, and may be temporary or permanent. It is used for the elimination of solid body waste (feces or stool).

If the rectal cancer is growing into nearby organs, more extensive surgery is needed. In a pelvic exenteration the surgeon removes the rectum as well as nearby organs such as the bladder, prostate, or uterus if the cancer has spread to these organs. A colostomy is needed after this.

Radiation Therapy

Radiation therapy is most often used after a diagnosis of rectal cancer. Radiation is treatment with high-energy rays (such as x-rays) used to kill or shrink cancer cells. The radiation may come from outside the body (external radiation) or from radioactive materials placed directly in the tumor (internal or implant radiation). After surgery, radiation can kill small areas of cancer that may not be seen during surgery. If the size or location of a tumor makes surgery hard, radiation may be used before the surgery to shrink the tumor. Radiation can also be used to ease symptoms of advanced cancer such as intestinal blockage, bleeding, pain or metastases.

The main use for radiation therapy in people with colorectal cancer is when the cancer has attached to an internal organ or the lining of the abdomen. If this happens, the doctor cannot be sure that all the cancer has been removed, and radiation therapy is used to kill the cancer cells left behind after surgery. For rectal cancer, radiation is also given to prevent the cancer from coming back in the place where it started and to treat local recurrences that are causing symptoms such as pain.

External radiation is most often used for people with colon or rectal cancer. Treatments are given 5 days a week for several weeks. Each treatment lasts only a few minutes and is something like having an x-ray for a broken bone. A different approach may be used for some cases of rectal cancer. The radiation can be aimed through the anus and reaches the rectum without passing through the skin of the abdomen.

A different approach may be used for some cases of rectal cancer. The radiation can be aimed through the anus and reaches the rectum without passing through the skin of the abdomen.

For internal radiation therapy, small pellets of radioactive material are placed next to or directly into the cancer. This method is sometimes used in treating people with rectal cancer, particularly sick or older people who would not be able to withstand surgery.