There are many treatment options available for colorectal cancer. Each one of the treatments is described in detail in a separate section of this site, but let’s begin with a bird’s eye view of the options. Understanding how and why these treatments might be used in your case will enable to play an active role in your treatment planning.
The goal of colorectal cancer treatment is to eliminate all the cancer cells present in the body. That is, to cure the cancer. This includes the cells within the tumor itself, and the undetectable cells (micrometastases) that may have broken off the main tumor and traveled to other parts of the body, where they will be a threat later on.
Treatment that targets cancer in the location where it was first found—the primary site—is called local therapy. Surgery and radiation therapy are considered local treatments.
Treatment that can reach all parts of the body to eliminate runaway cells is called systemic treatment. Chemotherapy, and immunotherapy are examples.
Treatment that is given as an addition, or an adjunct, to the main local therapy, it is also called adjuvant therapy. When additional therapy (adjuvant therapy) is given before the main therapy, (for example, radiation therapy to pre-shrink a tumor before surgery) it is referred to as neo-adjuvant therapy.
Sometimes the goal of treatment is not to cure the disease (curative therapy), but to decrease the effects of the disease on the body—for example, to achieve pain relief. In this case the treatment is called palliative therapy.
Surgery is the main form of therapy for most types of colorectal cancer. The goal of surgery is to remove the tumor and cure the cancer. Surgery generally removes the entire tumor with an area of healthy tissue around it to ensure no cancerous cells are left behind. If the cancer is in the colon, the procedure will involve the removal of the tumor and adjacent lymph nodes. This is called colorectal resection. If the cancer is in the rectum, surgery may involve local or transanal excision of the tumor. A new surgical approach is now available: minimally invasive surgery, or MIS.
If the cancer is larger, if it is located above the rectum, or it has spread beyond the first layer of the bowel, a simple local excision may not be an option, because it will probably leave tumor cells behind. A more complex operation is required. This will include the removal of a segment of the colon, with the cancer and a small length of healthy bowel around it. A procedure called an anastomosis will usually be done to reconnect the parts of the large intestine to each other.
If the cancer is located in the rectum, where it is difficult to reach surgically, you may be treated with radiation therapy to shrink the tumor and make the operation less challenging. On the rare occasion when the two ends of the colon cannot be sewn back together, a stoma (opening) is made connecting the bowel to the outside of the body, so that waste can pass through into a bag. This is called a colostomy. It may or may not be permanent, depending on the case. You may want to seek a second opinion before agreeing to have a permanent colostomy.
If the cancer is in the rectum, if it is found to be early stage (T1 or T2), and if it has not spread, the surgeon may be able to remove it using a transanal resection. This procedure is done through the anus, without cutting through the wall of the abdomen.
Chemotherapy uses drugs that can reach all parts of the body to stop the growth of cancer cells, either by killing them or by stopping the cells from dividing. Chemotherapy is taken by mouth or injected into a vein or muscle. Sometimes chemotherapy drugs are placed into the abdomen, where they can have a more direct effect on escaped cancer cells. Chemotherapy is an adjuvant systemic treatment.
Radiation therapy uses high-energy x-rays to kill cancer cells. There are two types of radiation therapy.
External beam radiation therapy, or EBRT, uses a machine to send a radiation beam through the area from where the cancer was removed. EBRT is sometimes used before surgery to shrink the tumor. Brachytherapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer site. Both are considered local adjuvant therapies and are designed to ensure that no cancer cells remain behind at the site of the tumor.
Which treatment, or combination of treatments, is right for you? In some cases, the decision is very simple. No one would consider major surgery for a tiny polyp. Other treatment decisions are much more complex, and there may be no clearly right or wrong choice. Choosing the most appropriate cancer treatment is a decision that should involve you, the patient, and your family and the healthcare team.
The final choice depends on many factors, including:
• The stage of your cancer (whether the cancer has spread, and if so, what other parts of your body are affected.)
• Your age and general health (health problems in addition to colon cancer may make certain treatments more risky for you.)
• Your feelings about the treatments available to you and their possible long- and short-term side effects.
Remember that generally there is no rush to come to a conclusion. Take the time—a few weeks if you need to—to learn whatever you want to know about the treatment. Discuss your concerns with the healthcare team. Consider using a friend or a loved one as a sounding board. Interview other patients who have undergone the treatment you are contemplating. Then make your decision.