Small intestine cancer is a

cancer Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Po ...

of the

small intestine The small intestine or small bowel is an organ (anatomy), organ in the human gastrointestinal tract, gastrointestinal tract where most of the #Absorption, absorption of nutrients from food takes place. It lies between the stomach and large intes ...

. It is relatively rare compared to other gastrointestinal malignancies such as

gastric cancer Stomach cancer, also known as gastric cancer, is a malignant tumor of the stomach. It is a cancer that develops in the lining of the stomach. Most cases of stomach cancers are gastric carcinomas, which can be divided into a number of subtypes ...

(stomach cancer) and

colorectal cancer Colorectal cancer (CRC), also known as bowel cancer, colon cancer, or rectal cancer, is the development of cancer from the Colon (anatomy), colon or rectum (parts of the large intestine). Signs and symptoms may include Lower gastrointestinal ...

. Small intestine cancer can be subdivided into duodenal cancer (the first part of the small intestine) and cancer of the

jejunum The jejunum is the second part of the small intestine in humans and most higher vertebrates, including mammals, reptiles, and birds. Its lining is specialized for the absorption by enterocytes of small nutrient molecules which have been pr ...

and

ileum The ileum () is the final section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms posterior intestine or distal intestine may ...

(the latter two parts of the small intestine). Duodenal cancer has more in common with

stomach cancer Stomach cancer, also known as gastric cancer, is a malignant tumor of the stomach. It is a cancer that develops in the Gastric mucosa, lining of the stomach. Most cases of stomach cancers are gastric carcinomas, which can be divided into a numb ...

, while cancer of the jejunum and ileum have more in common with

Five-year survival rates The five-year survival rate is a type of survival rate for estimating the prognosis of a particular disease, normally calculated from the point of diagnosis. Lead time bias from earlier diagnosis can affect interpretation of the five-year surviva ...

are 65%. Experts believe that small intestine cancer develops much like colorectal cancer. It first begins as a small growth on the inner lining of the intestine (polyp), which over time becomes cancer. Approximately 50% of

adenoma An adenoma is a benign tumor of epithelium, epithelial tissue with glandular origin, glandular characteristics, or both. Adenomas can grow from many glandular organ (anatomy), organs, including the adrenal glands, pituitary gland, thyroid, prosta ...

s of the small intestine arise in the

duodenum The duodenum is the first section of the small intestine in most vertebrates, including mammals, reptiles, and birds. In mammals, it may be the principal site for iron absorption. The duodenum precedes the jejunum and ileum and is the shortest p ...

even though this location comprises only 4% of the length of the small intestine. These adenomas occur mainly close to the

ampulla of Vater The ampulla of Vater, hepatopancreatic ampulla or hepatopancreatic duct is the common duct that is usually formed by a union of the common bile duct and the pancreatic duct within the wall of the duodenum. This common duct usually features a di ...

, the outlet of the common bile duct from which bile acids are released. This area is also closely associated with the pancreas, so they are treated as pancreatic cancer. The small intestine works by mixing food and gastric juices into a thick fluid in the stomach and then emptied into the small intestine. It then continues to break down and absorb the nutrients. Although it is referred to as the small intestine, it is the longest section of the GI tract being approximately 20 feet long. The length of the small intestine comprises 75% of the length of the entire gastrointestinal tract There are three parts of the small intestine. The duodenum is the 1st section of small intestine and only about a foot long. The jejunum and ileum make up most of the small intestine. Most of the nutrients in food are absorbed into the bloodstream in these two parts.

Histopathologic types

Small intestinal cancers by incidence and prognosis

Subtypes of small intestine cancer include: *

Adenocarcinoma Adenocarcinoma (; plural adenocarcinomas or adenocarcinomata ; AC) is a type of cancerous tumor that can occur in several parts of the body. It is defined as neoplasia of epithelial tissue that has glandular origin, glandular characteristics, or ...

– this cancer begins in the gland cells that line the inside of the intestine. Adenocarcinomas account for about 1 in 3 small intestine cancers. *

Gastrointestinal stromal tumor Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. GISTs arise in the smooth muscle pacemaker interstitial cell of Cajal, or similar cells. They are defined as tumors whose behavior i ...

– this type of cancer starts in connective tissues. The most common sarcoma in the intestine are gastrointestinal stromal tumors (GISTs) *

Lymphoma Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). The name typically refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enlarged lymph node ...

– these cancers start in lymphocytes. *

Carcinoid tumor A carcinoid (also carcinoid tumor) is a slow-growing type of neuroendocrine tumor Neuroendocrine tumors (NETs) are neoplasms that arise from cells of the endocrine (hormonal) and nervous systems. They most commonly occur in the intestine, whe ...

s of the midgut – this is a type of neuroendocrine tumor (NET). They tend to be slow growing and are the most common type of small intestine tumor. Most small intestine cancers (especially adenocarcinomas) develop in the duodenum. Cancers developed in the duodenum are often found at the ampulla of Vater. File:Light microscopy of small intestinal adenocarcinoma.jpg, Adenocarcinoma File:Histopathology of small intestinal well-differentiated grade 1 (G1) carcinoid.jpg, Carcinoid

Risk factors

Risk factors for small intestine cancer include: * Age: Cancer risk increases with age. The average age diagnosis is 65.(Cleveland Clinic, 2022) * Race: In the U.S., small intestine cancer is slightly more common among people who identify as African Americans. Although lymphoma is more common among people who identify as white.(Cleveland Clinic, 2022) * HIV/AIDS: treatments like radiation therapy may weaken your immune system and make you more susceptible to small intestine cancer. Drugs that suppress your immune system may also increase your risk.(Cleveland Clinic, 2022) * Sex: Males are 25% more likely to develop the disease.(Cleveland Clinic, 2022) * Diet: Various research has suggested that diets high in red meat and salted or smoked foods may raise the risk of small intestine cancer.(Cleveland Clinic, 2022). A human prospective study observed a markedly elevated risk for

carcinoid A carcinoid (also carcinoid tumor) is a slow-growing type of neuroendocrine tumor originating in the cells of the neuroendocrine system. In some cases, metastasis may occur. Carcinoid tumors of the midgut (jejunum, ileum, appendix, and cecum) ...

tumors of the small intestine associated with dietary intake of

saturated fat A saturated fat is a type of fat in which the fatty acid chains have all single bonds between the carbon atoms. A fat known as a glyceride is made of two kinds of smaller molecules: a short glycerol backbone, and fatty acids that each cont ...

Crohn's disease Crohn's disease is a type of inflammatory bowel disease (IBD) that may affect any segment of the gastrointestinal tract. Symptoms often include abdominal pain, diarrhea, fever, abdominal distension, and weight loss. Complications outside of the ...

Celiac disease Coeliac disease (British English) or celiac disease (American English) is a long-term autoimmune disorder, primarily affecting the small intestine. Patients develop intolerance to gluten, which is present in foods such as wheat, rye, spel ...

Radiation exposure Radiation exposure is a measure of the ionization of air due to ionizing radiation from photons. It is defined as the electric charge freed by such radiation in a specified volume of air divided by the mass of that air. As of 2007, "medical radia ...

* Hereditary gastrointestinal

cancer syndrome A hereditary cancer syndrome (familial/family cancer syndrome, inherited cancer syndrome, cancer predisposition syndrome, cancer syndrome, etc.) is a genetic disorder in which inherited genetic mutations in one or more genes predispose the affec ...

familial adenomatous polyposis Familial adenomatous polyposis (FAP) is an autosomal dominant inherited condition in which numerous adenomatous polyps form mainly in the epithelium of the large intestine. While these polyps start out benign, malignant transformation into colon ...

hereditary nonpolyposis colorectal cancer Hereditary nonpolyposis colorectal cancer (HNPCC) is a hereditary predisposition to colon cancer. HNPCC includes (and was once synonymous with) Lynch syndrome, an autosomal dominant genetic condition that is associated with a high risk of colon ...

Peutz–Jeghers syndrome Peutz–Jeghers syndrome (often abbreviated PJS) is an dominance (genetics), autosomal dominant genetic disorder characterized by the development of benign hamartomatous Polyp (medicine), polyps in the human gastrointestinal tract, gastrointestinal ...

Cholecystectomy Cholecystectomy is the surgical removal of the gallbladder. Cholecystectomy is a common treatment of symptomatic gallstones and other gallbladder conditions. In 2011, cholecystectomy was the eighth most common operating room procedure performed i ...

, which alters the flow of bile to the small intestine, increases the risk of small intestinal adenocarcinomas,Lagergren J, Ye W, Ekbom A. Intestinal cancer after cholecystectomy: is bile involved in carcinogenesis. Gastroenterology 2001;121:542–7 and this risk declines with increasing distance from the common bile duct.

Additional images

Image:Small intestine neuroendocrine tumour low mag.jpg,

Micrograph A micrograph is an image, captured photographically or digitally, taken through a microscope or similar device to show a magnify, magnified image of an object. This is opposed to a macrograph or photomacrograph, an image which is also taken ...

of a

neuroendocrine tumour Neuroendocrine tumors (NETs) are neoplasms that arise from cells of the endocrine (hormonal) and nervous systems. They most commonly occur in the intestine, where they are often called carcinoid tumors, but they are also found in the pancreas, lu ...

H&E stain Hematoxylin and eosin stain ( or haematoxylin and eosin stain or hematoxylin–eosin stain; often abbreviated as H&E stain or HE stain) is one of the principal tissue stains used in histology. It is the most widely used stain in medical diag ...

References

Cleveland Clinic. (2022). ''Small intestine cancer: Symptoms, causes, Prognosis & Treatment''. Cleveland Clinic. Retrieved April 4, 2023, from https://my.clevelandclinic.org/health/articles/6225-small-intestine-cancer Markman, M. (2022, July 20). ''Intestinal cancer: Causes, symptoms & treatments''. Cancer Treatment Centers of America. Retrieved April 4, 2023, from https://www.cancercenter.com/cancer-types/intestinal-cancer Radhakrishnan, R. (2021, May 6). ''Is small intestine cancer curable?'' MedicineNet. Retrieved April 4, 2023, from https://www.medicinenet.com/is_small_intestine_cancer_curable/article.htm

External links

{{Digestive system neoplasia Gastrointestinal cancer