Small Intestinal Adenocarcinoma

Other Names: Adenocarcinoma of small instestine; Adenocarcinoma of the small bowel; Adenocarcinoma of the small instestine; Adenocarcinoma of Small Bowel; Small bowel adenocarcinoma

Small intestine adenocarcinoma is one type of small bowel cancer, usually occurring in the duodenum or jejunum, that begins in the gland cells. The small intestine is part of the body’s digestive system, which also includes the esophagus, stomach, and large intestine.

Epidemiology

For Western countries, adenocarcinomas generally represent the largest fraction of these series, while lymphomas predominate in other countries . Population-based data from the Surveillance, Epidemiology and End-Results Program (SEER) of the U.S. National Cancer Institute for 1973–1982, which represents approximately 10% of the US population, indicate that 48.4% of adenocarcinomas of the small bowel are located in the duodenum, with 32.5% in the jejunum and 19.2% in the ileum . In general, adenocarcinoma of the small bowel predominates in males as compared to females, with a male to female ratio of approximately 1.4 . Our study indicates a higher incidence of adenocarcinoma in blacks than in whites.

Cause

The exact cause is still unknown, but it may be due to DNA changes in the small intestine adenocarcinoma cells.

Riskfactors

The strongest known risk factor for small bowel adenocarcinoma is prior Crohn's disease, initially reported by Ginsburg et al., in 1956 . The risk of adenocarcinoma does not begin until at least 10 years after the onset of Crohn's disease and typically occurs more than 20 years afterward. One study has suggested that animal fat intake was correlated with the incidence of small bowel carcinoma . Another study suggested that the intake of red meat or salt cured or smoked food raised the risk of small bowel cancer. Other risk factors have also been suggested for adenocarcinoma of the small bowel, including cigarette smoking, alcohol consumption, prior peptic ulcer disease, familial adenomatous polyposis, prior colon cancer, celiac sprue, and cystic fibrosis . Bile may also be involved since prior cholecystectomy may be related to the incidence of adenocarcinoma . In particular, familial adenomatous polyposis raises the risk for both malignancies since it is associated with diffuse small and large bowel polyps. Recent preliminary studies exploring molecular genetic changes in small bowel adenocarcinomas have suggested that they also parallel the molecular genetic changes which occur in colorectal carcinogenesis.

Signs and symptoms

The symptoms of small bowel tumors are often vague. The most common symptoms are pain in the belly (which may be the first symptom), weight loss, weakness, fatigue and low red blood cell counts (anemia).

Diagnosis

Plain radiographs may reveal evidence of obstruction, but their sensitivity is low. In contrast to the duodenum, which may be routinely visualized by barium contrast studies and/or endoscopy, Bauer found that routine UGI series with small intestinal follow-through was diagnostic in only 36% and 20% of jejunal and ileal lesions, respectively .

Enteroclysis increases the sensitivity of small intestinal barium studies , and pushtype jejunal endoscopy enhances the diagnostic accuracy of jejunal lesions with its capability of visualizing the jejunum to a level of 40–100 cm past the ligament of Treitz .

CT scanning is a useful adjunctive study to assess the extent of local and/or metastatic disease . CT characteristics of adenocarcinoma may include “annular narrowing with abrupt concentric or irregular ‘overhanging edges’, a discrete tumor mass, or an ulcerative lesion” .

Treatment

The treatment and prognosis for small intestine cancer depends on its stage (tumor size and site) and the presence of metastases. For early stage cancer, surgery may be all that is needed. For more advanced cancer chemotherapy or radiation therapy may be required.

NIH genetic and rare disease info

• NIH info on Small Intestinal Adenocarcinoma

Small Intestinal Adenocarcinoma is a rare disease.

Small Intestinal Adenocarcinoma Resources
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