Small intestine cancer is a rare disease in which malignant (cancer) cells form in the tissues of the small intestine.
The small intestine is part of the body's digestive system, which also includes the esophagus, stomach, and large intestine. The digestive system removes and processes nutrients (vitamins, minerals, carbohydrates, fats, proteins, and water) from foods and helps pass waste material out of the body. The small intestine is a long tube that connects the stomach to the large intestine. It folds many times to fit inside the abdomen.
Anatomy of the lower digestive system, showing the colon and other organs.
There are five types of small intestine cancer.
The types of cancer found in the small intestine are adenocarcinoma, sarcoma, carcinoid tumors, gastrointestinal stromal tumor, and lymphoma. This summary discusses adenocarcinoma and leiomyosarcoma (a type of sarcoma).
Adenocarcinoma starts in glandular cells in the lining of the small intestine and is the most common type of small intestine cancer. Most of these tumors occur in the part of the small intestine near the stomach. They may grow and block the intestine.
Leiomyosarcoma starts in the smooth muscle cells of the small intestine. Most of these tumors occur in the part of the small intestine near the large intestine.
See the following PDQ summaries for more information on small intestine cancer:
- Adult Soft Tissue Sarcoma Treatment
- Childhood Soft Tissue Sarcoma Treatment
- Adult Non-Hodgkin Lymphoma Treatment
- Childhood Non-Hodgkin Lymphoma Treatment
- Gastrointestinal Carcinoid Tumors Treatment
- Gastrointestinal Stromal Tumors Treatment
Diet and health history can affect the risk of developing small intestine cancer.
Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn't mean that you will not get cancer. Talk with your doctor if you think you may be at risk. Risk factors for small intestine cancer include the following:
- Eating a high-fat diet.
- Having Crohn disease.
- Having celiac disease.
- Having familial adenomatous polyposis (FAP).
Possible signs of small intestine cancer include abdominal pain and unexplained weight loss.
These and other symptoms may be caused by small intestine cancer or by other conditions. Check with your doctor if you have any of the following problems:
- Pain or cramps in the middle of the abdomen.
- Weight loss with no known reason.
- A lump in the abdomen.
- Blood in the stool.
Tests that examine the small intestine are used to detect (find), diagnose, and stage small intestine cancer.
Procedures that make pictures of the small intestine and the area around it help diagnose small intestine cancer and show how far the cancer has spread. The process used to find out if cancer cells have spread within and around the small intestine is called staging.