Small intestine cancer risk factors: who is more likely to get it

What small intestine cancer is

The small intestine is a long tube that connects the stomach to the large intestine. It folds many times to fit inside the abdomen and helps the body take in nutrients from food (NCI PDQ). Small intestine cancer is a rare disease in which cancer cells form in its tissues (NCI PDQ), and it is rarer than cancers in other parts of the digestive tract such as the colon and stomach (NCI).

NCI's health professional summary gives an estimate of 13,920 new cases and 2,060 deaths from small intestine cancer in the United States in 2025, about 3.8% of all digestive system cancers (NCI PDQ HP).

Types of small intestine cancer

NCI names five types: adenocarcinoma, sarcoma, neuroendocrine tumors, gastrointestinal stromal tumor and lymphoma (NCI PDQ).

• Adenocarcinoma starts in gland cells in the lining of the small intestine and is the most common type. Most of these tumors occur in the part near the stomach, and they may grow and block the intestine (NCI PDQ).
• Leiomyosarcoma, a type of sarcoma, starts in the smooth muscle cells of the small intestine. Most of these tumors occur in the part near the large intestine (NCI PDQ).

The NCI risk factor list below comes from its summary on adenocarcinoma and leiomyosarcoma. NCI covers neuroendocrine tumors and gastrointestinal stromal tumors in separate summaries (NCI PDQ).

Who is more likely to get small intestine cancer

NCI says diet and health history can affect the risk. It lists these risk factors (NCI PDQ):

• Eating a high-fat diet.
• Having Crohn disease. See our Crohn's disease risk factors guide.
• Having celiac disease. NIDDK lists a cancer of the small intestine (adenocarcinoma) among the rare complications of celiac disease (NIDDK). See our celiac disease risk factors guide.
• Having familial adenomatous polyposis (FAP).

MedlinePlus names a high-fat diet, Crohn's disease and celiac disease too, and adds a history of colonic polyps (MedlinePlus).

Not every person with one or more of these risk factors will develop small intestine cancer, and it will develop in some people who don't have any known risk factors. NCI says to talk with your doctor if you think you may be at risk (NCI PDQ). The NCI and MedlinePlus pages we use do not list further risk factors, so we do not add any here.

How it is diagnosed

Besides your personal and family health history and a physical exam, doctors may use blood chemistry studies, liver function tests, endoscopy (including capsule endoscopy, where you swallow a pill-sized camera, and double balloon endoscopy), imaging, laparotomy (surgery to look inside the abdomen) and a biopsy, a tissue sample checked under a microscope (NCI PDQ).

NCI says surgery is the main treatment when the cancer can be removed, and the chance of cure depends on whether it can be removed completely (NCI PDQ HP).

Common questions

If I have Crohn's or celiac disease, will I get small intestine cancer?

Not necessarily. Both are on NCI's risk factor list, but not every person with a risk factor develops small intestine cancer (NCI PDQ), and NIDDK calls it a rare complication of celiac disease (NIDDK). Ask your doctor what your own risk is.

Is there a screening test for small intestine cancer?

The NCI and MedlinePlus pages we use do not describe a screening test for people without symptoms. They describe tests used to diagnose it once there are signs (NCI PDQ) (MedlinePlus).

What are the first signs?

NCI lists unexplained weight loss and abdominal pain as signs, along with a lump in the abdomen and blood in the stool (NCI PDQ); see the box at the top of this page.

Also see colorectal cancer risk factors and stomach cancer risk factors.