Symptoms of cancer of the small intestine include cramps or pain in the middle abdomen, blood in the stool, unexplained weight loss or a lump felt in the abdomen, according to the National Cancer Institute. These symptoms are also common with other conditions.
Small intestine cancer is rare, the National Cancer Institute reports. Five different types of cancer can occur in the small intestine, including adenocarcinoma, a malignancy that develops in glandular cells in the small intestine's lining. It is the most common small intestine cancer. Another type is leiomyosarcoma, a sarcoma cancer that starts in the smooth muscle cells, usually in the part of the small intestine close to the large intestine.
Several conditions are risk factors for small intestine cancer, the National Cancer Institute states. People diagnosed with Crohn's or celiac disease have a higher risk of developing small intestine cancer. Familial adenomatous polyposis, an inherited condition that also increases the risk of colorectal cancer, is also a risk factor, as is a high-fat diet.
Prognosis depends on a variety of factors, the National Cancer Institute says. These factors include whether the cancer has spread beyond the small intestine, which type of cancer it is, whether the cancer has spread from the inner lining of the small intestine or to the outer wall and whether the cancer can be removed surgically.