Duodenal and small intestine cancers

The small intestine (also called small bowel) is part of the body’s digestive system. It is a long, coiled tube that connects the stomach to the large intestine. The small intestine receives food from the stomach, helps break it down, and absorbs nutrients that are used by the body. The three parts of the small intestine are the duodenum, jejunum, and ileum. The duodenum connects to the stomach, and the ileum connects to the colon.

Small intestine cancer often starts in the duodenum. The most common type of small intestine cancer is adenocarcinoma (cancer that begins in cells that make and release mucus and other fluids). Other types of small intestine cancer are sarcomas, carcinoid tumors, gastrointestinal stromal tumors, and lymphomas.

• Small intestine cancer is a rare disease in which malignant (cancer) cells form in the tissues of the small intestine.
• There are five types of small intestine cancer.
• Diet and health history can affect the risk of developing small intestine cancer.
• Signs and symptoms of small intestine cancer include unexplained weight loss and abdominal pain.
• Tests that examine the small intestine are used to detect (find), diagnose, and stage small intestine cancer.
• Certain factors affect prognosis (chance of recovery) and treatment options.
• 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.

The types of cancer found in the small intestine are:

• Adenocarcinoma
• Sarcoma
• Carcinoid tumors
• Gastrointestinal stromal tumor
• 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.

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).

These and other signs and symptoms may be caused by small intestine cancer or by other conditions. Check with your doctor if you have any of the following:

• Pain or cramps in the middle of the abdomen.
• Weight loss with no known reason.
• A lump in the abdomen.
• Blood in the stool.

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.

In order to plan treatment, it is important to know the type of small intestine cancer and whether the tumor can be removed by surgery. Tests and procedures to detect, diagnose, and stage small intestine cancer are usually done at the same time. 

The following tests and procedures may be used:

The prognosis (chance of recovery) and treatment options depend on the following:

• 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 has spread to other places in the body, such as the lymph nodes, liver, or peritoneum (tissue that lines the wall of the abdomen and covers most of the organs in the abdomen).
• Whether the cancer can be completely removed by surgery.
• Whether the cancer is newly diagnosed or has recurred.