The Farber Center: For Radiation Oncology

Gastrointestinal Cancer: Colon; Rectal; Colorectal Cancers

Colorectal cancer is a type of gastrointestinal cancer. Gastrointestinal cancer refers to malignant disease of the gastrointestinal tract. It includes cancers of the esophagus, stomach (also called gastric cancer), liver, biliary system, pancreas, colon, rectum, and anus.

The American Cancer Society's most recent estimates for colorectal cancer in the United States are for 2009: 106,100 new cases of colon cancer, 40,870 new cases of rectal cancer 49,920 deaths from colorectal cancer. Not counting skin cancers, colorectal cancer is the third most common cancer found in men and women in this country. The risk of a person having colorecal cancer in their lifetime is about 1 in 19. The death rate from colorectal cancer has been going down for the past 15 years. One reason is that there are fewer cases. Thanks to colorectal cancer screening, polyps can be found and removed before they turn into cancer. And colorectal cancer can also be found earlier when it is easier to cure. Treatments have improved, too.

There are several signs and symptoms in patients found to have gastrointestinal cancer, which vary from person to person and depend on the anatomic location. Not all patients exhibit any or all symptoms, which may include:

Colorectal Cancer:

• Change in frequency of bowel movements
• Constipation
• Change in consistency of stool (loose or watery stools)
• Blood in stools (either as bright red spots or dark "tarry" stools)
• Rectal bleeding
• Abdominal pain (gas or cramps)
• Feeling you cannot completely empty your bowels
• General abdominal discomfort
• Unexplained weight loss
• Bloating

Risk Factors

Colorectal Cancer:

• Diet high in fat and red meat and low in fruits and vegetables
• Obesity
• Diabetes
• History of polyps in the colon, ulcerative colitis, Crohn's disease, or colon cancer
• Personal or family history of a genetic syndrome known as hereditary non-polyposis colon cancer (HNPCC), or familial adenomatous polyposis (FAP)

Colorectal Cancer:

• Physical exam with a digital rectal exam to assess the rectum for abnormalities

Colonoscopy: which uses a longer lighted tube to view the inside of the rectum and entire colon for polyps or other abnormalities. A colonoscope is inserted through the rectum into the colon. A colonoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove polyps or tissue samples, which are checked under a microscope for signs of cancer. During a colonoscopy some tissue may be removed and examined under a microscope to determine if cancer is present.

Virtual colonoscopy: examines the entire colon and rectal passages by a CT scan of the abdomen that allows the radiologist to create computer images similar to those seen by a standard colonoscopy. (Although this test is able to visualize the colon, polyps cannot be removed or biopsied using this technique.)

Sigmoidoscopy: A procedure to look inside the rectum and sigmoid (lower) colon for polyps (small pieces of bulging tissue), abnormal areas, or cancer. A sigmoidoscope is inserted through the rectum into the sigmoid colon. A sigmoidoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove polyps or tissue samples, which are checked under a microscope for signs of cancer. During a sigmoidoscopy some tissue may be removed and examined under a microscope to determine if cancer is present.

CT scan (computed tomography): an x-ray test that produces detailed cross-sectional images of your body. A CT scanner takes many pictures as it rotates around. A computer combines these pictures into images of slices of the part of your body being studied. Unlike a regular x-ray, a CT scan creates detailed images of the soft tissues in the body. CT scans can be helpful in finding out the where and how big the cancer is. CT scans can also be used to guide a biopsy needle (see below) into an area that might be cancer. The needle is used to remove a sample of tissue for study in the lab.

MRI (magnetic resonance imaging): Provide detailed images of soft tissues in the body. They use radio waves and strong magnets instead of x-rays, which are absorbed and then released in a pattern formed as they penetrate through different types of body tissue and by certain diseases. A computer translates the pattern into a very detailed image of parts of the body.

PET scan (positron emission tomography): a special type of scanner that uses a form of sugar that contains a radioactive atom. Because cancer cells in the body are growing rapidly, they absorb large amounts of the radioactive sugar. This allows for cancer cells to show up brighter in the images because they absorb more sugar than normal cells. PET scans are also useful to check if the cancer may have spread elsewhere in the body. PET can reveal spread of cancer to the liver, bones, adrenal glands, or some other organs. Some machines are able to perform both a PET and CT scan at the same time (PET/CT scan).

Chest x-rays: may be done to see whether the cancer has spread to the lungs.

COLORECTAL CANCERS
When cancer cells break away from the primary (original) tumor and travel through the lymph or blood to other places in the body, another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.

Colorectal Cancer:
Stage 0 (Carcinoma in Situ)
In stage 0, abnormal cells are found in the innermost lining of the colon. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.

Stage I
In stage I, cancer has formed and spread beyond the innermost tissue layer of the colon wall to the middle layers.
Stage I colon cancer is sometimes called Dukes A colon cancer.

Stage II
Stage II colon cancer is divided into stage IIA and stage IIB.

• Stage IIA: Cancer has spread beyond the middle tissue layers of the colon wall or has spread to nearby tissues around the colon or rectum.
• Stage IIB: Cancer has spread beyond the colon wall into nearby organs and/or through the peritoneum.

Stage II colon cancer is sometimes called Dukes B colon cancer.

Stage III
Stage III colon cancer is divided into stage IIIA, stage IIIB, and stage IIIC.

• Stage IIIA: Cancer has spread from the innermost tissue layer of the colon wall to the middle layers and has spread to as many as 3 lymph nodes.
• Stage IIIB: Cancer has spread to as many as 3 nearby lymph nodes and has spread:
• beyond the middle tissue layers of the colon wall; or
• to nearby tissues around the colon or rectum; or
• beyond the colon wall into nearby organs and/or through the peritoneum.
• Stage IIIC: Cancer has spread to 4 or more nearby lymph nodes and has spread:
• to or beyond the middle tissue layers of the colon wall; or
• to nearby tissues around the colon or rectum; or
• to nearby organs and/or through the peritoneum.

Stage III colon cancer is sometimes called Dukes C colon cancer.

Stage IV
In stage IV, cancer may have spread to nearby lymph nodes and has spread to other parts of the body, such as the liver or lungs. Stage IV colon cancer is sometimes called Dukes D colon cancer.


RECTAL CANCERS
Stage 0 (Carcinoma in Situ)
In stage 0, abnormal cells are found in the innermost lining of the rectum. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.

Stage I
In stage I, cancer has formed and spread beyond the innermost lining of the rectum to the second and third layers and involves the inside wall of the rectum, but it has not spread to the outer wall of the rectum or outside the rectum. Stage I rectal cancer is sometimes called Dukes A rectal cancer.

Stage II
In stage II, cancer has spread outside the rectum to nearby tissue, but it has not gone into the lymph nodes (small, bean-shaped structures found throughout the body that filter substances in a fluid called lymph and help fight infection and disease). Stage II rectal cancer is sometimes called Dukes B rectal cancer.

Stage III
In stage III, cancer has spread to nearby lymph nodes, but it has not spread to other parts of the body. Stage III rectal cancer is sometimes called Dukes C rectal cancer.

Stage IV
In stage IV, cancer has spread to other parts of the body, such as the liver, lungs, or ovaries. Stage IV rectal cancer is sometimes called Dukes D rectal cancer.

COLORECTAL CANCER

SURGERY
(removing the cancer in an operation) is the most common treatment for all stages of colon cancer. A doctor may remove the cancer using one of the following types of surgery:

• Local excision: If the cancer is found at a very early stage, the doctor may remove it without cutting through the abdominal wall. Instead, the doctor may put a tube through the rectum into the colon and cut the cancer out. This is called a local excision. If the cancer is found in a polyp (a small bulging piece of tissue), the operation is called a polypectomy.
• Resection and colostomy: If the doctor is not able to sew the 2 ends of the colon back together, a stoma (an opening) is made on the outside of the body for waste to pass through. This procedure is called a colostomy. A bag is placed around the stoma to collect the waste. Sometimes the colostomy is needed only until the lower colon has healed, and then it can be reversed. If the doctor needs to remove the entire lower colon, however, the colostomy may be permanent.
• Radiofrequency ablation: The use of a special probe with tiny electrodes that kill cancer cells. Sometimes the probe is inserted directly through the skin and only local anesthesia is needed. In other cases, the probe is inserted through an incision in the abdomen. This is done in the hospital with general anesthesia.
• Cryosurgery: A treatment that uses an instrument to freeze and destroy abnormal tissue, such as carcinoma in situ. This type of treatment is also called cryotherapy.

Even if the doctor removes all the cancer that can be seen at the time of the operation, some patients may be given chemotherapy or radiation therapy after surgery to kill any cancer cells that are left. Treatment given after the surgery, to lower the risk that the cancer will come back, is called adjuvant therapy.

CHEMOTHERAPY
is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy).

Chemoembolization of the hepatic artery may be used to treat cancer that has spread to the liver. This involves blocking the hepatic artery (the main artery that supplies blood to the liver) and injecting anticancer drugs between the blockage and the liver. The liver’s arteries then deliver the drugs throughout the liver. Only a small amount of the drug reaches other parts of the body. The blockage may be temporary or permanent, depending on what is used to block the artery. The liver continues to receive some blood from the hepatic portal vein, which carries blood from the stomach and intestine.

The way the chemotherapy is given depends on the type and stage of the cancer being treated.

RADIATION THERAPY
External beam radiation treatment is most often used in conjunction with surgery, but it can also be combined with chemotherapy as an alternative to surgery.

• Neoadjuvant therapy: radiotherapy (sometimes along with chemotherapy) delivered prior to surgery to shrink a tumor and make it more manageable
• Adjuvant therapy: radiotherapy (sometimes along with chemotherapy) given after surgery to kill any cancer cells that may have been left behind
• Primary therapy: radiotherapy given as the main treatment (sometimes along with chemotherapy) for more advanced cancers or for some people who are not deemed to be surgical candidates
• Concurrent (chemoradiation) therapy: radiotherapy given along with chemotherapy

EXTERNAL BEAM RADIATION THERAPY
involves focusing a beam of ionizing radiation to the tumor while sparing the surrounding tissue. It is delivered by a series of painless outpatient treatments over several weeks. Treatments are given Monday through Friday and last less than 30 minutes.

• 3-Dimensional Conformal Radiotherapy (3D-CRT) is a method of treatment delivery that combines multiple radiation treatment fields using 3-Dimensional computer planning to produce a high-dose area of radiation that conforms to the shape of the area to be treated. This technique allows the tailoring of delivery of precise doses of radiation to the targeted area while sparing surrounding normal healthy tissue.
• Intensity modulated radiation therapy (IMRT) is an advanced form of 3D-CRT that modifies the intensity or strength of each radiation beam. It utilizes a sophisticated system of treatment delivery that allows a precise adjustment of the radiation beam intensity to the tissue within the target area while minimizing effects on surrounding tissue. This may allow for a higher dose of radiation to be delivered to the tumor from multiple angles.
• IGRT or Image Guided Radiation Therapy is another technology that can also be used to ensure better targeting of daily radiation treatments. 
• Stereotactic body radiation therapy (SBRT) is a specialized form of 3D-CRT that delivers high doses of radiation over a period of five to ten days. Instead of giving small doses of radiation each day for several weeks, SBRT involves delivery of very focused beams of high-dose radiation. Several beams are aimed at the tumor from different angles. In order to precisely target the radiation, a specially designed body frame is used for each treatment. This helps to minimize the movement of the lung tumor during breathing. If it is delivered in a single fraction it is known as stereotactic body radiosurgery. Like other forms of external radiation, these treatments are painless. It can be used for some very early stage (small) cancers when surgery isn't an option usually for other medical reasons. There is emerging data that have demonstrated that this technique may provide an alternative first-line approach to surgery.
• Brachytherapy (internal radiation therapy) is used most often to shrink tumors to relieve symptoms caused by the cancer. In some cases it may be part of a larger treatment regimen trying to cure the cancer.
• High-dose-rate brachytherapy (HDR): a small source of radioactive material is placed directly into the cancer or into the airway next to the cancer. It involves placing thin plastic tubes (catheters) into the area to treat. These tubes are connected to a special HDR delivery machine. A small amount of radioactive material is computer-driven through these catheters allowing a high dose of radiation to be delivered to a small, precise area while sparing surrounding normal healthy tissue. The radiation and catheters are removed at the end of each treatment.

TARGETED THERAPY
is a type of treatment that uses drugs or other substances to identify and attack specific cancer cells without harming normal cells. Monoclonal antibody therapy is a type of targeted therapy being studied in the treatment of colon cancer.

Monoclonal antibody therapy uses antibodies made in the laboratory from a single type of immune system cell. These antibodies can identify substances on cancer cells or normal substances that may help cancer cells grow. The antibodies attach to the substances and kill the cancer cells, block their growth, or keep them from spreading. Monoclonal antibodies are given by infusion. They may be used alone or to carry drugs, toxins, or radioactive material directly to cancer cells.

RECTAL CANCER

SURGERY
is the most common treatment for all stages of rectal cancer. The cancer is removed using one of the following types of surgery:

• Polypectomy: If the cancer is found in a polyp (a small piece of bulging tissue), the polyp is often removed during a colonoscopy.
• Local excision: If the cancer is found on the inside surface of the rectum and has not spread into the wall of the rectum, the cancer and a small amount of surrounding healthy tissue is removed.
• Resection: If the cancer has spread into the wall of the rectum, the section of the rectum with cancer and nearby healthy tissue is removed. Sometimes the tissue between the rectum and the abdominal wall is also removed. The lymph nodes near the rectum are removed and checked under a microscope for signs of cancer.
• Pelvic exenteration: If the cancer has spread to other organs near the rectum, the lower colon, rectum, and bladder are removed. In women, the cervix, vagina, ovaries, and nearby lymph nodes may be removed. In men, the prostate may be removed. Artificial openings (stoma) are made for urine and stool to flow from the body to a collection bag.

After the cancer is removed, the surgeon will either:

• do an anastomosis (sew the healthy parts of the rectum together, sew the remaining rectum to the colon, or sew the colon to the anus);
or
• make a stoma (an opening) from the rectum to the outside of the body for waste to pass through. This procedure is done if the cancer is too close to the anus and is called a colostomy. A bag is placed around the stoma to collect the waste. Sometimes the colostomy is needed only until the rectum has healed, and then it can be reversed. If the entire rectum is removed, however, the colostomy may be permanent.

RADIATION THERAPY
External beam radiation treatment is most often used in conjunction with surgery, but it can also be combined with chemotherapy as an alternative to surgery.

• Neoadjuvant therapy: radiotherapy (sometimes along with chemotherapy) delivered prior to surgery to shrink a tumor and make it more manageable
• Adjuvant therapy: radiotherapy (sometimes along with chemotherapy) given after surgery to kill any cancer cells that may have been left behind
• Primary therapy: radiotherapy given as the main treatment (sometimes along with chemotherapy) for more advanced cancers or for some people who are not deemed to be surgical candidates
• Concurrent (chemoradiation) therapy: radiotherapy given along with chemotherapy

EXTERNAL BEAM RADIATION THERAPY
involves focusing a beam of ionizing radiation to the tumor while sparing the surrounding tissue. It is delivered by a series of painless outpatient treatments over several weeks. Treatments are given Monday through Friday and last less than 30 minutes.

• 3-Dimensional Conformal Radiotherapy (3D-CRT) is a method of treatment delivery that combines multiple radiation treatment fields using 3-Dimensional computer planning to produce a high-dose area of radiation that conforms to the shape of the area to be treated. This technique allows the tailoring of delivery of precise doses of radiation to the targeted area while sparing surrounding normal healthy tissue.
• Intensity modulated radiation therapy (IMRT) is an advanced form of 3D-CRT that modifies the intensity or strength of each radiation beam. It utilizes a sophisticated system of treatment delivery that allows a precise adjustment of the radiation beam intensity to the tissue within the target area while minimizing effects on surrounding tissue. This may allow for a higher dose of radiation to be delivered to the tumor from multiple angles.
• IGRT or Image Guided Radiation Therapy is another technology that can also be used to ensure better targeting of daily radiation treatments. 
• Stereotactic body radiation therapy (SBRT) is a specialized form of 3D-CRT that delivers high doses of radiation over a period of five to ten days. Instead of giving small doses of radiation each day for several weeks, SBRT involves delivery of very focused beams of high-dose radiation. Several beams are aimed at the tumor from different angles. In order to precisely target the radiation, a specially designed body frame is used for each treatment. This helps to minimize the movement of the lung tumor during breathing. If it is delivered in a single fraction it is known as stereotactic body radiosurgery. Like other forms of external radiation, these treatments are painless. It can be used for some very early stage (small) lung cancers when surgery isn't an option usually for other medical reasons. There is emerging data that have demonstrated that this technique may provide an alternative first-line approach to surgery.

Brachytherapy (internal radiation therapy) is used most often to shrink tumors to relieve symptoms caused by the cancer. In some cases it may be part of a larger treatment regimen trying to cure the cancer.

High-dose-rate brachytherapy (HDR): a small source of radioactive material is placed directly into the cancer or into the airway next to the cancer. It involves placing thin plastic tubes (catheters) into the area to treat. These tubes are connected to a special HDR delivery machine. A small amount of radioactive material is computer-driven through these catheters allowing a high dose of radiation to be delivered to a small, precise area while sparing surrounding normal healthy tissue. The radiation and catheters are removed at the end of each treatment.

CHEMOTHERAPY
is the use of anticancer drugs injected into a vein or taken by mouth to destroy certain types of tumors and is utilized in different stages of lung cancer. These drugs enter the bloodstream and go throughout the body, making this treatment useful for cancer that has spread (metastasized) to distant organs. Depending on the type and stage of lung cancer, chemotherapy may be used in different situations (see Radiation Therapy Section):

• Neoadjuvant therapy: chemotherapy (sometimes along with radiation therapy) delivered prior to surgery to shrink a tumor and make it more manageable
• Adjuvant therapy: chemotherapy (sometimes along with radiation therapy) given after surgery to kill any cancer cells that may have been left behind
• Primary therapy: chemotherapy given as the main treatment (sometimes along with radiation therapy) for more advanced cancers or for some people who are not deemed to be surgical candidates.

TARGETED THERAPY
is a type of treatment that uses drugs or other substances to identify and attack specific cancer cells without harming normal cells. Monoclonal antibody therapy is a type of targeted therapy being studied in the treatment of rectal cancer.

Monoclonal antibody therapy uses antibodies made in the laboratory from a single type of immune system cell. These antibodies can identify substances on cancer cells or normal substances that may help cancer cells grow. The antibodies attach to the substances and kill the cancer cells, block their growth, or keep them from spreading. Monoclonal antibodies are given by infusion. They may be used alone or to carry drugs, toxins, or radioactive material directly to cancer cells.

Possible Treatment Side Effects
Dr. Farber, Dr. Spierer, and their staff at The Farber Center for Radiation Oncology located in Tribeca NYC will discuss potential side effects with you before, during, and after treatment, and ensure that your experience is personalized.