General Information / Anatomy / Function / Statistics

• Longest segment of the gastrointestinal tract
• Tubelike structure extending from the stomach and continuous with the large intestine
• Approximately 1 inch in diameter and 20 feet in length
• Consists of three parts: the duodenum, the jejunum and the ileum
• Most of the digestion of food takes place here
• Cancer of the small intestine is quite rare
• Less than 50 new cases are diagnosed each year in Canada
• 1.8 % of malignancies in the gastrointestinal tract
• Most patients are over 45 and 60% are men
• Usually reaches an advanced stage before diagnosis

Symptoms / Signs

• Jaundice may appear when the tumor is in the mid-duodenum and blocks the bile ducts
• Vague non-specific symptoms make diagnosis difficult
• Chronic intestinal bleeding
• Intermittent obstruction of the bowel
• Recurring abdominal pain and cramps
• Possible weight loss, nausea and vomiting, fever, change in bowel habits

Etiology / Carcinogens / Risks

• The presence of a Helicobacter pylori infection may lead to small bowel inflammation that may lead to the initiation of a lymphoma
• Major predisposing factor appears to be long-standing disease, particularly Crohn's Disease (regional enteritis), or sprue (gluten enteropathy)
• Those over the age of 60, especially those with a history of bowel disease, are at higher risk
• Those with inherited gastrointestinal disorders, familial polyposis, and inflammatory bowel disease, are at higher risk

Prevention

• There are no general screening methods

Diagnosis / Staging / Grading / Types

• Blood tests
• Endoscopy with biopsy
• X-rays (Small bowel examination with barium)
• Laparotomy
• CT scan

Staging

Stage 0	in situ disease only
Stage I	wall involvement - inner layers
Stage II	extensive wall involvement
Stage III	lymph node involvement
Stage IV	distant metastases

Types

• Adenocarcinomas: develop in glandular tissue
• Lymphomas: 14% of small bowel tumors; most are non-Hodgkin's lymphomas
• Carcinoid tumors: slow-growing cancers that secrete hormones causing circulatory and digestive problems. Patients can live several years. These tumors account for 30% of small bowel malignancies
• Sarcomas: slow-growing tumors which account for 11% of small bowel cancers. They include: liposarcomas (fat cells), angiosarcomas (blood vessels), nerofibrosarcomas (nerves), leiomyosarcomas (75% of the sarcomas, originate from the smooth muscles encircling the bowel called "stromal tumours")

Treatment

• Adenocarcinomas are treated by surgical removal. Usually metastasis has occurred in half the patients
• Lymphomas are treated by surgery, radiation, and combination chemotherapy--outcome more favorable
• If the cancer involves the duodenum, the pancreas and duodenum may have to be removed (Whipple surgical procedure)
• Radiation has limited usefulness as the bowel is extremely sensitive to radiation
• Radiation can complement surgery and is often recommended in lymphomas
• Chemotherapy is less effective than surgery. Only recommended for disease that cannot be surgically removed or for metastases
• Carcinoid tumors--some patients benefit by surgical reduction of large tumors plus chemotherapy. Drugs are given to counteract the distressing effect of the tumor hormone
• Sarcomas are treated by surgical removal. Radiotherapy may be helpful for bleeding

Revised May 1999