Small Intestine Cancer
What is the Small Intestine?
The small intestine, also called the small bowel, is part of the body’s gastrointestinal
tract or digestive system. Its jobs are to:
ξ Break down food the stomach.
ξ Absorb the nutrients (carbohydrates, fats, proteins, vitamins, minerals, and water)
ξ Move the extra waste to the large intestine or colon to pass out of the body by
The average small intestine is 22 feet long. It folds and loops around many times so that it
can fit in the belly. It is lined with finger-like projections, or villi (Latin for “shaggy
hair”) that make it easier for absorbing nutrients. The small intestine has 3 parts:
ξ The duodendum is the first and shortest section of the small intestine. It is about
8 inches long. The stomach passes food into the duodenum through a muscle
called the pylorus. The pancreatic and bile ducts attach to the duodenum at the
ampulla of Vater. They release digestive juices (enzymes) into the duodenum.
Enzymes break down nutrients so they can be absorbed. The pancreas also
releases a substance into the small intestine to neutralize stomach acid. Iron is
absorbed in the duodenum.
ξ Most nutrients in food are absorbed into the bloodstream in the jejunum.
ξ The ileum is slightly longer than the jejunum. Vitamin B12 and bile salts are
absorbed at the end of the ileum. Water and lipids (fats) are absorbed throughout
the small intestine. The appendix is found near the section where the ileum
meets the large intestine.
What is small intestinal cancer?
There are 5 main types of small intestinal cancers:
1. Carcinoid tumors
2. Gastrointestinal stromal tumors (GIST)
Cancers of the small intestine are rare. The first four make up 60-70% of all cancers
of the small intestine. (These are outlined in other handouts.)
Adenocarcinomas are 30-40% of small intestinal cancers.
Most of these cancers are found in the duodenum. They may start as a polyp, like
cancers of the large intestine. These are treated like colon cancers.
Duodenal cancers may form at the Ampulla of Vater, very close to the pancreas.
These tumors are treated like either a pancreas cancer or a colon cancer. The
treatment is decided after a doctor decides their subtype or tissue they most resemble.
Adenocarcinomas that grow in the jejunum or ileum are treated like colon cancers.
What are the risk factors?
A high-fat diet
Celiac disease (gluten intolerance)
Persons with some genetic conditions have a higher risk of getting adenocarcinomas
of the small intestine. Those include:
o Familial adenomatous polyposis (FAP)
o Hereditary nonpolyposis colorectal cancer (HNPCC/Lynch Syndrome)
o Peutz-Jeghers syndrome (PJS)
o MUTYH-associated polyposis
o Cystic fibrosis
Small intestinal adenocarcinoma happens slightly more often in men. The average age at
diagnosis is 60.
What are the symptoms?
The early symptoms of a small bowel tumor can be hard to notice. They include:
Pain in the mid-abdomen (belly) – may get worse with eating
A lump in the abdomen
Blood in the stool/black stools
Feeling tired due to anemia
As the tumor grows it may cause an obstruction or blockage of the small bowel causing
severe pain, nausea and vomiting.
What is the prognosis?
The prognosis (chance of recovery) depends upon many factors:
The type of tumor
The size of the tumor and how deep it has grown into the lining of the small
If it can be completely taken out by surgery
If it has spread to other parts of the body
If it is a new diagnosis or has come back
How is it diagnosed?
These tests may be used to diagnose cancer of the small intestine. They will also help to
figure out the stage, or extent of the cancer. This is important information to have when
making a treatment plan.
History and physical exam – review of your symptoms, health habits, past
illnesses and treatments.
Blood tests – CBC (complete blood count) checks the white blood cells (WBC),
platelets, and hemoglobin and hematocrit. Blood chemistries and liver function
tests look for signs that the cancer is hurting other organs.
Barium swallow – X-rays upper gastrointestinal tract taken after you swallow
barium. (Barium is a contrast liquid.)
Endoscopy – a procedure that looks at the upper gastrointestinal tract through a
long, lighted tube. While you are sedated, the doctor may take pictures and
CT scan – a series of computerized pictures of the inside of the body taken after
oral or IV contrast.
MRI – magnetic resonance imaging uses a magnet, radio waves and a computer
to take pictures of the inside of the body.
Colonoscopy – may be helpful in finding tumors in the lower part of the small
Laparoscopy – a surgery done with a scope that lets the surgeon check the belly
for signs of cancer.
Biopsy – Checking tissue under a microscope to learn if it is cancer and where it
came from. Biopsies may be done during surgery, during an upper endoscopy
(EGD) or colonoscopy, and through the abdominal wall with the help of a CT
scan or ultrasound.
Doctors use the TNM Staging System as a way to describe how far the cancer has spread.
A doctor looks at tissue under the microscope to learn:
ξ The extent of the primary tumor (T)
ξ Whether the tumor has metastasized (spread) to nearby lymph nodes (N)
ξ Whether the tumor has spread to distant organs (M)
The TNM categories are grouped together and the stages are defined with Roman
The cancer has grown through the first few layers of the small intestine wall. It has not
spread to the lymph nodes.
Stage II is divided into 2 parts:
The cancer has grown through most of the layers of the intestinal wall. It has not
spread to the lymph nodes.
The cancer has grown through the small intestine wall or into nearby tissues or
organs. It has not metastasized or spread to nearby lymph nodes or distant
Stage III is divided into 3 parts:
The cancer has grown through the first few layers of the small intestine wall and
has spread to 1-3 regional or close lymph nodes.
The cancer has grown through most of the layers of the small intestine and has
spread to 1-3 lymph nodes, or it has grown through the intestinal wall, spread to
other parts of the small intestine, and spread to 1-3 lymph nodes.
The cancer has grown through at least one layer of the intestinal wall, may have
spread to other parts of the intestine, and has spread to more than 4 lymph nodes
The cancer has spread to other organs such as the liver, lungs, peritoneum (the
lining of the abdominal cavity), or ovaries.
How is it treated?
Surgery is the most common treatment for cancers of the small intestine. A surgeon may
take out part or all of an organ that has cancer. Lymph nodes in the area are taken out
and checked under the microscope to see if the cancer has spread. Sometimes the tumor
cannot be taken out, but surgery may be needed to bypass or go around a blockage and
allow food to pass.
Radiation therapy is a treatment that uses high energy x-rays or other types of radiation
to kill cancer cells, or slow their growth. Radiation treats a very specific area. This is
called regional therapy. Chemotherapy and radiation are sometimes both used. This
makes the radiation work better. When used this way, the chemotherapy is called a
Chemotherapy uses drugs to kill cancer cells or to stop them from growing. When
chemotherapy medicine is injected intravenously (IV) or taken orally in pill form it
enters the blood stream and can reach cancer cells throughout the body. This is called
You may have the chance to take part in a clinical trial. Clinical trials are controlled
research studies done to find out if new cancer treatments are safe and effective, or better
than the standard treatments. Clinical trials are voluntary and help find better treatments
During your treatments you will need blood tests and scans to see how well the treatment
is working. These tests help make choices to keep going, stop, or change treatments.
This is called restaging.
Blood tests and scans will be done from time to time after you have finished your
treatments. They can show if your condition has changed or the cancer has recurred, or
Your health care team may have given you this information as part of your care. If so, please use it and call
if you have any questions. If this information was not given to you as part of your care, please check with
your doctor. This is not medical advice. This is not to be used for diagnosis or treatment of any medical
condition. Because each person’s health needs are different, you should talk with your doctor or others on
your health care team when using this information. If you have an emergency, please call 911. Copyright ©
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