The small intestine is a long tube in the abdomen that connects the stomach to the large intestine. It is part of the body's digestive system. The digestive system removes and processes nutrients from foods and helps pass waste material out of the body.
The wall of the small intestine has several layers: the lining (mucosa), submucosa, thick muscle layer (muscularis propria), and outer layers (subserosa and serosa). Small intestine cancer starts in one of these layers.
Small intestine cancer begins when a normal cell becomes abnormal. Normal cells grow and divide to form new cells as the body needs them. When normal cells grow old or get damaged, they die and the body makes new cells to replace them. Sometimes, however, this process goes wrong. New cells form when the body doesn't need them, and old or damaged cells don't die when they should. The buildup of extra cells can form a mass of tissue called a growth or tumor. Tumors can be benign (not cancer) or malignant (cancer).
There are five types of small intestine cancer:
- Adenocarcinoma (cancer that starts in the cells that line the small intestine)
- Sarcoma (cancers that start in the fat, muscle, blood vessels, or other connective or supportive tissue in the body; visit our sarcoma website for more information)
- Gastrointestinal stromal tumors (A type of tumor that begins in cells in the wall of the gastrointestinal tract)
- Carcinoid tumors (A slow-growing type of tumor found in the gastrointestinal system; see our gastrointestinal carcinoid tumors website for more information)
- Lymphoma (cancer that begins in cells of the immune system; see our non-Hodgkin lymphoma and Hodgkin lymphoma websites for more information)
This document discusses adenocarcinoma and leiomyosarcoma (a type of sarcoma that starts in the smooth muscle cells of the small intestine).
The sources for this information include the National Cancer Institute and American Cancer Society's Small Intestine Cancer Detailed Guide.
Doctors can't always explain why one person gets small intestine cancer and another doesn't. However, certain risk factors may make a person more likely than others to develop small intestine cancer. A risk factor is something that may increase the chance of getting a disease.
Having a risk factor does not mean that a person will get cancer. Many people who get small intestine cancer have none of these risk factors, and many people who have known risk factors never get cancer. A person with one or more of these risk factors should talk with his or her doctor about cancer risk.
Risk factors for small intestine cancer include the following:
- Eating a high-fat diet
- Having Crohn's disease
- Having celiac disease
- Having familial adenomatous polyposis (FAP)
Small intestine cancer may cause these symptoms:
- A lump in the abdomen
- Blood in the stool
- Pain or cramps in the middle of the abdomen
- Weight loss with no known reason
Most often, these symptoms do not mean cancer. A person with these symptoms should tell his or her doctor so any health problem can be diagnosed and treated as early as possible.
Currently, there are no screening methods for small intestine cancer.
If symptoms suggest small intestine cancer, the doctor will try to find out what's causing the problems. Tests and procedures to diagnose and stage small intestine cancer are usually done at the same time.
The doctor may order one or more of the following tests:
- Physical exam and history: The doctor will check for signs of disease, such as lumps or anything else that seems unusual.
- Blood tests: The doctor sends blood to the lab to check the number of blood cells and to measure the amounts of certain substances released into the blood by organs and tissues in the body. A higher or lower than normal amount of a substance can be a sign of disease.
- Liver function tests: The doctor sends blood to the lab to measure the amounts of certain substances released into the blood by the liver. A higher than normal amount of a substance can be a sign of liver disease that may be caused by small intestine cancer.
- X-ray of the abdomen: An x-ray of the organs and tissues inside the abdomen.
- Barium enema: The patient is given an enema with a barium solution. Several x-ray pictures are taken of the colon and rectum. The barium helps the colon and rectum show up on the pictures.
- Fecal occult blood test: A test to check stool (solid waste) for blood that can only be seen with a microscope. Small samples of stool are placed on special cards and returned to the doctor or a lab for testing. Because some cancers bleed, blood in the stool may be a sign of cancer.
- Upper endoscopy: The doctor passes a thin, lighted tube (endoscope) through the patient's mouth to look at the esophagus, stomach, and part of the small intestine. The endoscope may also have a tool to remove tissue samples, which are checked under a microscope for signs of cancer.
- Upper GI series with small bowel follow-through: The patient is given a liquid to drink that contains barium. The liquid coats the esophagus, stomach, and small intestine (bowel). A series of x-rays are taken as the barium travels through the esophagus, stomach, and small intestine.
- Biopsy: The doctor removes tissue from the body and sends it to a lab. Tissue samples may be taken during an endoscopy. The doctor in the lab looks at the tissue under a microscope for signs of cancer. The removal of tissue to look for cancer cells is called a biopsy.
- CT scan: An x-ray machine linked to a computer takes a series of detailed pictures of the inside of the body. The patient may receive contrast material by mouth or by injection into a blood vessel. The contrast material makes abnormal areas easier to see.
- MRI: A strong magnet linked to a computer is used to make detailed pictures of areas inside the body. Sometimes contrast material is given by injection into the blood vessel. The contrast material makes abnormal areas show up more clearly on the picture.
- Lymph node biopsy: A surgeon removes all or part of a lymph node and sends it to a lab. The doctor in the lab uses a microscope to check the tissue for cancer cells.
- Laparotomy: A surgeon makes an incision (cut) in the wall of the abdomen to check for signs of disease. Sometimes organs are removed or tissue samples are taken and checked under a microscope for signs of disease.
If small intestine cancer is diagnosed, the doctor needs to learn the extent (stage) of the disease to choose the best treatment. Staging is a careful attempt to find out whether the cancer has spread, and if so, to what parts of the body.
The tests and procedures used to diagnose and stage small intestine cancer are usually done at the same time. Read about these under the Screening and Diagnosis tab.
Stages of Small Intestine Cancer
Different types of small intestine cancer are staged in different ways. A patient can discuss his or her specific type and stage of small intestine cancer with the doctor.
These stages are used for adenocarcinoma of the small intestine:
Stage 0: The cancer cells are found only in the top layer of cells in the mucosa of the small intestine. The doctor may call this carcinoma in situ.
Stage I: The cancer has grown deeper into the submucosa or muscularis propria of the small intestine.
Stage II: The cancer has grown through the subserosa, serosa, or into tissues or organs near the small intestine.
Stage III: The cancer has spread to lymph nodes near the small intestine.
Stage IV: Cancer cells have spread to distant organs.
At Huntsman Cancer Institute, small intestine cancer is treated by a team of specialists, including gastroenterologists (doctors who specialize in treating problems of the digestive organs), surgeons, medical oncologists (doctors who treat cancer with medicine), radiation oncologists (doctors who treat cancer with radiation), nurses, dietitians, and social workers.
These are common treatment options for small intestine cancer:
- Radiation therapy
- Clinical trials
A patient may have a combination of treatments. The treatment that's right for each patient depends on many factors:
- The type of small intestine cancer
- Whether the cancer is in the inner lining of the small intestine only or has spread into or beyond the wall of the small intestine
- Whether the cancer can be completely removed by surgery
- Whether the cancer has spread to other parts of the body
- The patient's age and general health
The health care team can describe all of the treatment choices, the expected results of each, and the possible side effects. Because cancer therapy often damages healthy cells and tissues, side effects are common. Side effects may not be the same for each person, and they may even change from one treatment session to the next. Patients are encouraged to discuss treatment side effects with their health care team.
Surgery is the most common treatment used for small intestine cancer. One of the following types of surgery may be done:
- Resection: A surgeon removes all or part of the small intestine. The resection may include removing nearby organs (if the cancer has spread). The doctor may remove the section of the small intestine that contains cancer and perform an anastomosis (joining the cut ends of the intestine together). The doctor will usually remove lymph nodes near the small intestine and send them to a lab where they can be examined under a microscope to see whether they contain cancer.
- Bypass: Surgery to allow food in the small intestine to go around (bypass) a tumor that is blocking the intestine but cannot be removed.
Even if the doctor removes all the cancer that can be seen at the time of the surgery, the patient may be given other treatments 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.
This treatment uses drugs to destroy or control cancer throughout the body. Learn more about this treatment in our introduction to chemotherapy video.
Radiation therapy uses high-energy rays to kill cancer cells. A large machine aims the rays at the cancer. Patients go to a hospital or clinic for treatment. This type of treatment uses computers to closely target the cancer, which protects healthy tissue.
These studies discover and evaluate new and improved cancer treatments. Patients are encouraged to talk with their doctors about participating in a clinical trial or any questions regarding research studies. For more information, also visit HCI's clinical trials website.
When you or someone you love is diagnosed with cancer, concerns about treatments and side effects, hospital stays, and medical bills are common. You may also worry about caring for your family, work, or normal daily life.
There are several places you can go for support:
- Your health care team can answer your questions and talk to you about your concerns. They can help you with any side effects and keep you informed of all your treatments, test results, and future doctor visits.
- Our Patient and Family Support Services offer emotional support and resources for coping with cancer and its impact on daily life to HCI patients and their families.
- The Linda B. and Robert B. Wiggins Wellness-Survivorship Center offers many programs to increase the quality of life and well-being of HCI patients and their families.
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Gastrointestinal Cancer Program
Did You Know?
- There are five types of small intestine cancer: adenocarcinoma, sarcoma, gastrointestinal stromal tumors, carcinoid tumors, and lymphoma.
- Tests and procedures to stage and stage small intestine cancer are usually done at the same time.
- Having Crohn's disease or celiac disease can increase a person's risk of developing small intestine cancer.