The Farber Center: For Radiation Oncology

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 anal cancer in the United States are 5,290 new cases of anal cancer will be diagnosed. 710 deaths from anal cancer. Women get anal cancer slightly more often than men. Anal cancer is found mainly in adults, with the average age being in the early 60s.

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:

• Bleeding or itching around the anus
• Pain in the anal area
• Change in the shape or width of the stool--stool may be narrower than usual
• Swollen lymph nodes in the anal or groin area
• Abnormal discharge from the anus

Risk Factors:

• HPV (human papilloma virus): has been associated with squamous cell cancer. There are several subtypes of the virus, but the one most likely to cause anal cancer is called HPV-16. HPV-16, as well as HPV-18, HPV-31, HPV-33, and HPV-45 are called high-risk types of HPV because they are strongly linked to cancer. HPV is spread during sex and therefore is more likely to be found in people who have had many sex partners.
• HIV infection: People who have the human immunodeficiency virus (HIV), the virus that causes AIDS, are much more likely to get anal cancer than those who do not. Drug treatment for HIV has lowered the risk for many AIDS-related diseases, but it hasn't lowered the anal cancer rate.
• Behavioral: Having many sex partners increases the risk of HIV and HPV infection. Having anal sex is a risk factor for both men and women, especially for those under the age of 30 (see above risk factors).
• Smoking: Current smokers are several times more likely to have cancer of the anus compared with people who never smoked. Quitting smoking reduces this risk. People who used to smoke but have quit are only slightly more likely to get anal cancer compared with people who never smoked.
• Weakened immune system: People with weak immune systems are at higher risk for anal cancer. This includes people who have had organ transplants and who must take drugs to suppress their immune systems.

Endoscopy is the use of a tube with a lens or video camera on the end (called a scope) to look inside the body. Endoscopy may be used to look for the cause of anal symptoms. For these tests you either lie on your side on top of an examining table, with your knees bent up to your chest, or you bend forward over the table. The doctor coats the scope with a lubricant and then gently pushes it into the anus and rectum. By shining a light into this tube, the doctor has a clear view of the lining of the lower rectum and anus and sometimes the lower part of the colon. This is usually not painful.

Ultrasound: uses sound waves to make a picture of the inside of the body.  For anal cancer, a probe is be placed in the rectum. This test can show how far the cancer might have grown into nearby tissues.

Computed tomography (CT, CAT) scan: This test uses a special x-ray machine that takes pictures from many angles. Before any pictures are taken, you may be asked to drink 1 to 2 pints of a liquid called oral contrast. This helps outline the intestine so that certain areas are not mistaken for tumors. You may also receive an IV (intravenous) line through which a different kind of contrast dye (IV contrast) is injected. This helps better outline structures in your body. A computer then combines these pictures into images of slices of the part of your body being studied. The CT scan can help show where the cancer is and where it has spread. CT scans can also be used to guide a biopsy needle into a place that might have cancer. The patient stays on the CT scanning table while a doctor moves a biopsy needle through the skin toward the tumor. A small piece of the tumor is removed and looked at under a microscope.

Magnetic resonance imaging (MRI): 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.

Biopsy: removal of a small piece of tissue. There are several types of biopsies.

Fine-needle aspiration biopsy: Since anal cancer can spread through the lymph system, your doctor may want to do a biopsy of your lymph nodes, too. Lymph nodes are bean-sized collections of immune system cells. A small (fine) needle is placed into the lymph node. Cells and fluid are removed and sent to a lab. In some cases, an operation to remove the lymph nodes near the anus may be done.

Sentinel node biopsy: In this test, a needle is used to put a radioactive substance, often with a blue dye, into the tumor. The dye moves into the nodes that carry fluid away from the tumor. This helps tell how far the cancer may have spread.  The surgeon takes out any blue-stained nodes and looks at them to see if they contain cancer cells. It is not yet clear how helpful this procedure is for anal cancer.

Staging of Gastrointestinal 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.

The following stages are used for anal cancer:

Stage 0 (Carcinoma in Situ)
In stage 0, abnormal cells are found in the innermost lining of the anus. 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 the tumor is 2 centimeters or smaller.

Stage II
In stage II, the tumor is larger than 2 centimeters.

Stage IIIA
In stage IIIA, the tumor may be any size and has spread to either:

• lymph nodes near the rectum; or
• nearby organs, such as the vagina, urethra, and bladder.

Stage IIIB
In stage IIIB, the tumor may be any size and has spread:

• to nearby organs and to lymph nodes near the rectum; or
• to lymph nodes on one side of the pelvis and/or groin, and may have spread to nearby organs; or
• to lymph nodes near the rectum and in the groin, and/or to lymph nodes on both sides of the pelvis and/or groin, and may have spread to nearby organs.

Stage IV
In stage IV, the tumor may be any size and cancer may have spread to lymph nodes or nearby organs and has spread to distant parts of the body.

RADIATION THERAPY
such as 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: radiation (sometimes along with chemotherapy) delivered prior to surgery to shrink a tumor and make it more manageable
Adjuvant therapy: radiation (sometimes along with chemotherapy) given after surgery to kill any cancer cells that may have been left behind
Primary therapy: radiation given as the main treatment.
Concurrent therapy: radiation 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. 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. 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.
• Concurrent (chemoradiation) therapy: radiotherapy given along with chemotherapy

SURGERY
such as a local resection is a surgical procedure in which the tumor is cut from the anus along with some of the healthy tissue around it. Local resection may be used if the cancer is small and has not spread. This procedure may save the sphincter muscles so the patient can still control bowel movements. Tumors that develop in the lower part of the anus can often be removed with local resection.

Abdominoperineal resection: A surgical procedure in which the anus, the rectum, and part of the sigmoid colon are removed through an incision made in the abdomen. The doctor sews the end of the intestine to an opening, called a stoma, made in the surface of the abdomen so body waste can be collected in a disposable bag outside of the body. This is called a colostomy. Lymph nodes that contain cancer may also be removed during this operation.

Having the human immunodeficiency virus can affect treatment of anal cancer.

Cancer therapy can further damage the already weakened immune systems of patients who have the human immunodeficiency virus (HIV). For this reason, patients who have anal cancer and HIV are usually treated with lower doses of anticancer drugs and radiation than patients who do not have HIV.

Radiosensitizers: drugs that make tumor cells more sensitive to radiation therapy. Combining radiation therapy with radiosensitizers may kill more tumor cells.

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