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Gastrointestinal Cancers

Small Intestinal Cancer


The small intestine is the longest section of the gastrointestinal tract and connects the stomach to the large intestine and it's divided into three sections: the duodenum, jejunum, and ileum. Most small intestine cancers develop in the duodenum.

The main types of intestinal cancer include:

  • Adenocarcinomas: the most common type of intestinal cancer, which usually develop in the cells that line the walls of the small intestine.
  • Sarcoma: a type of cancer that develops in the connective tissue of the small intestine.
  • Gastrointestinal stromal tumors: variants of soft tissue sarcoma that arise from the muscle layer of the intestine.
  • Carcinoid tumors: these form in the lining of the intestines, are often slow growing, and may secrete substances, such as serotonin or prostaglandins, causing carcinoid syndrome (skin flushing, diarrhea).
  • Lymphomas: an immune system disease that may originate within the intestines.


Signs and symptoms of intestinal cancer may include:

  • Abdominal pain (from bowel blockage)
  • Anemia (iron deficiency from cancer bleeding)
  • Weight loss (non-intentional)
  • Weakness or fatigue (sometimes a result of anemia)
  • Bloody or tarry stools (from cancer bleeding)
  • A noticeable mass in the abdomen

Risk Factors

Known risk factors for small intestinal cancer include:

  • Ages 67 and older
  • Alcohol use
  • Smoking
  • Diseases that affect the gastrointestinal tract, such as Celiac disease, or Crohn's disease
  • Genetic or inherited conditions associated with small intestine adenocarcinoma, including: Familial adenomatous polyposis (FAP), hereditary nonpolyposis colorectal cancer (HNPCC), also called Lynch syndrome, Peutz-Jeghers syndrome, or Cystic fibrosis


Stage I: Cancer has grown beyond the mucosa (inner muscle) but has not spread beyond the small intestines to other sites or lymph nodes.

Stage II: Cancer has grown into or through the intestinal wall. At this stage, it may or may not have reached nearby organs. There is no evidence of spreading to lymph nodes or distant sites.

Stage III: Cancer has metastasized and spread to nearby lymph nodes. The tumor may be any size (T1-T4). The cancer may or may not have reached nearby organs. Distant sites, such as the lung or liver, remain unaffected.

Stage IV: Cancer may be any size and has spread throughout the body to distant sites, such as the liver, lung, or lining of the abdominal cavity.


Small Intestine Adenocarcinoma
When possible, treatment of small intestine adenocarcinoma will involve surgical resection. When that is not possible, treatment may include:

  • Surgery or endoscopically place stent placement to bypass the tumor, i.e. palliative (not meant to be curative)
  • Radiation therapy as palliative therapy to relieve symptoms and improve the patient's quality of life
  • A clinical trial of radiation therapy with radiosensitizers, with or without chemotherapy

Clinical trials
The National Cancer Institute provides more detailed information about pancreatic cancer and available clinical trials.

National Cancer Institute, Mayo Clinic, Cancer Treatment Centers of America.