What Is Intestinal Cancer?

Intestinal cancer, which is also called duodenal cancer, ileal cancer, jejunal cancer, and small intestine cancer, is a rare type of cancer. The small intestine is the part of the digestive tract between the esophagus and the stomach. It is where food is digested and vitamins and minerals are absorbed.

While this type of cancer represents less than 1% of all yearly cancer diagnoses in the United States, cases have been increasing by about 2% each year. Some of the risk factors for small intestine cancer include having a diagnosis of Crohn's disease or celiac disease, a history of polyps (growths) in the colon, and eating a diet that's high in fat.

Types of Intestinal Cancer

There are five types of cancer that occur in the small intestine: adenocarcinoma, carcinoid tumors, gastrointestinal stromal tumor, lymphoma, and sarcoma.

Adenocarcinoma

The most common type of cancer in the small intestine is adenocarcinoma. This form starts in the glandular cells that line the small intestine.

The tumors that occur in this type of cancer most often start at the beginning of the small intestine, closer to the stomach. If a tumor grows large enough, it may cause a blockage in the small intestine.

Carcinoid Tumors

This form of cancer starts in a type of cell that's found throughout the body, including the small intestine, called neuroendocrine cells. These cells make the hormones that are involved in digestion. A carcinoid tumor may start in these cells, though it is rare. This type of cancer is slow-growing.

Gastrointestinal Stromal Tumor

This type of cancer is not common. It begins in cells in the small intestine that are called interstitial cells of Cajal. These cells serve as a kind of traffic signal for the muscles in the digestive system (including the small intestine). Cancer can begin in these cells.

A gastrointestinal stromal tumor (GIST) may require different treatments than other types of small intestine cancers.

Lymphoma

This type of cancer starts in the lymph nodes. These nodes are part of the lymphatic system that runs throughout the body, including in the abdomen, and aids our immune system. Non-Hodgkin lymphoma is the type most often seen in the small intestine. This type of small intestine cancer is associated with celiac disease.

Sarcoma

The type of sarcoma that occurs in small intestine cancer is called leiomyosarcoma. The small intestine is lined with smooth muscle cells. These muscles move food along through the intestines as they contract. A leiomyosarcoma starts in these smooth muscle cells.

This type of cancer is located more commonly in the last section of the small intestine, which is closer to the large intestine.

Intestinal Cancer Symptoms

The signs and symptoms of cancer in the small intestine are not very specific. Many of these symptoms can also be caused by other diseases and conditions, including those that are more common and noncancerous.

It's important to seek out help from a healthcare professional if any digestive symptoms become bothersome. Blood in the stool is never normal, even if it has happened before, and should be discussed with a healthcare provider.

Extreme abdominal pain, vomiting, and constipation could mean that the intestine has become blocked. These symptoms are a reason to seek care immediately.

The signs and symptoms of intestinal cancer can include:

• Abdominal cramps
• Bloody stools
• Lump in the abdomen
• Pain in the middle abdomen
• Unexplained weight loss

Causes

In some cases, it's not well understood what can cause small intestine cancer. There are, however, several risk factors that are known:

• Age: This type of cancer is more likely to occur in people who are over the age of 65 years.
• Alcohol use: A large analysis of several studies found that alcohol use might be a factor in the development of small intestine cancer. However, there might be nuances, with heavier drinking presumed to be associated.
• Celiac disease: There is an increased risk of an intestinal cancer called enteropathy-associated T-cell lymphoma in people who live with celiac disease. It is thought that gluten causes inflammation in the intestine which, over a long period of time, may lead to precancerous changes in the cells there.
• Crohn's disease: There is a slightly increased risk of small intestine cancer in Crohn's disease. The risk starts to increase about 10 years after diagnosis. One study showed the lifetime risk as being 1.6%, which is three times higher than in Americans who don't have Crohn's disease.
• Diet: Eating a diet that's high in red meat and sugary drinks and low in fiber may be associated with a higher risk of small intestine cancer.
• Genetic disorders: There are several hereditary conditions that may carry a higher risk of developing small intestine cancer. These include Lynch syndrome, Peutz–Jeghers syndrome, multiple endocrine neoplasia syndrome type 1, and neurofibromatosis type 1.
• Race and ethnicity: African Americans, and Black men in particular, are more likely to be diagnosed with small intestine cancer.
• Sex: Males are slightly more likely to develop small intestine cancer than females.
• Smoking: Some studies have shown that people who smoke are at a higher risk of developing small intestinal cancer. Some other studies, however, do not show the same results. It's thought that there may be a link between this cancer and smoking but it's still unclear how significant it is.

Diagnosis

A diagnosis of small intestine cancer may be made through the use of various tests. Some of the imaging tests that might be used to diagnose this type of cancer include:

• Barium X-rays
• Capsule endoscopy
• Computed tomography (CT) scan
• Endoscopic retrograde cholangiopancreatography
• Endoscopy
• Enteroscopy
• Fecal occult blood test
• Lab work such as blood chemistry and liver function tests
• Lymph node biopsy
• Magnetic resonance imaging (MRI)

Treatment

The first line treatment for small intestine cancer is surgery. The type of surgery used will depend on the location of the cancer.

One common type of surgery is an intestinal resection. During this surgery, a portion of the small intestine is removed and the two healthy ends of the intestine are rejoined.

The Whipple procedure is a more complex surgery that involves removing the first section of the small intestine, the duodenum, the gallbladder, part of the pancreas, the common bile duct, and the surrounding lymph nodes. A portion of the stomach might also be removed. 

Other treatments may be used in the case that surgery will not result in a good outcome, such as if the surgery has grown into other organs or the patient is frail. These treatments can include chemotherapy, radiation therapy, and immunotherapy.

Prognosis

The prognosis for small bowel cancer depends greatly on the stage at which it is diagnosed. The five-year survival rates, which is how many people are alive five years after diagnosis, are estimated to be:

• Early stage: 86%
• Spread to surrounding tissues, organs or lymph nodes: 76%
• Spread to a distant part of the body: 42%

A Word From Verywell

A cancer diagnosis is difficult and comes with significant challenges. Small intestine cancer is not common, which can make decision making about treatments more challenging. It may be necessary to research treatments and possible outcomes and to get more than one opinion before moving forward.

This can be exhausting, so the support of friends and family is crucial. After a cancer diagnosis, people often offer to help with everything from running errands to coming along to doctor appointments.

Cancer treatment centers also may offer support groups as well as appointments with support professionals such as a therapist or a dietitian. Having the guidance of many different people, from friends and family to healthcare providers, is important in the journey through treatment and recovery.