Treatment Options*

What are the treatment options and their side effects? What treatment is best for me? Which methods have proven most effective? When you’ve been diagnosed with cancer, these questions and many more are likely running through your head.

Here you can find answers to your questions, learn what to expect during and after treatment, and find information to discuss with your physician. Ultimately you and your doctor will make the decision on what treatment is best for you.

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, used together or in sequence. In deciding what treatment is best, it is important to ask questions and seek a second opinion.


In deciding with your doctor which therapy or combination of therapies are best, you will want to discuss side effects and complications of each treatment strategy. The three primary forms of colon and rectal cancer therapy are:


Surgery is the most common treatment for both colon and rectal cancer. Sometimes very early colorectal cancer can be removed using a colonoscope, eliminating the need to cut into the abdomen.

To treat colon cancer surgically, 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. Standard open surgery requires a large incision in the abdomen to access the surgical site. In many cases, colon cancer surgery can also be performed using a minimally invasive approach called laparoscopy. During laparoscopic surgery, several small incisions (rather than one large one) are made to insert the laparoscope (a lighted tube for viewing the surgery) and surgical instruments into the body and surgical instruments are inserted into. A laparoscopic approach for colon cancer surgery has been clinically proven to work as well as the standard open approach when performed by a surgeon experienced in laparoscopic surgery. Typically, patients recover faster from laparoscopic surgery compared to open surgery. For colon cancer, a colostomy (an opening in the abdomen for getting rid of body wastes) is not usually required, although sometimes a temporary colostomy may be necessary.

Surgery is usually the primary 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 inserted into the anus, without having to cut through the skin. These minimally invasive methods might be used to remove some stage I cancers that are fairly small and close to the anus.

For some stage I and most stage II or III rectal cancers, other types of surgery may be performed. 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.


Chemotherapy is usually recommended for treatment of both colon and rectal cancer when the cancer is diagnosed beyond its earliest stages. Chemotherapy is the use of anticancer drugs injected into a vein, given by mouth or delivered directly to the tumor.

When injected by IV, drugs enter the bloodstream and spread throughout the body, making the treatment useful for cancers that have spread to distant organs. Some chemotherapy drugs are delivered orally by taking pills, and others are delivered directly to the tumor via internal pumps. In some cases, chemotherapy drugs can be injected into an artery leading to the part of the body with the tumor. This approach is called regional chemotherapy. Since the drugs go straight to the cancer cells, there may be fewer side effects.

Chemotherapy after surgery can increase the survival rate for patients with some stages of colorectal cancer. Chemotherapy can also help relieve symptoms of advanced cancer.

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.

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.

*This information represents the views of the doctors and nurses serving on the American Cancer Society's Cancer Information Database Editorial Board. These views are based on their interpretation of studies published in medical journals, as well as their own professional experience.
The treatment information shared on this website is not official policy of Olympus America Inc. or the American Cancer Society and is not intended as medical advice to replace the expertise and judgment of your cancer care team. It is intended to help you and your family make informed decisions, together with your doctor.

Your doctor may have reasons for suggesting a treatment plan different from these general treatment options. Don't hesitate to ask him or her questions about your treatment options.