Small bowel cancer, also known as small intestine cancer, is a rare malignancy that develops in the small bowel/intestine. The small bowel is a long tube that carries food from your stomach to the large bowel/intestine.
The small bowel is located towards the end of the body’s gastrointestinal (GI) tract, which is located in the abdomen. The lower GI tract is divided into three separate areas: the small bowel, the large bowel, and the anus. The small bowel receives food from the stomach and absorbs the nutrients from the food. It is comprised of three separate parts (the duodenum, jejunum, and ileum). The food is then passed onto the large bowel, where water and salts are absorbed. The large bowel also consists of three parts (the caecum, colon, and rectum). What is left over is turned into solid waste (faeces or stool), and is sent to the anus to be removed from the body.
Small bowel cancer is more common in men, and is generally diagnosed in patients over 60 years old. However, anyone can develop this disease.
Types of Small Bowel Cancer
There are several types of small bowel cancers, which are categorised by the types of cells they originate in.
Adenocarcinomas
Small bowel adenocarcinomas are the most common form of small bowel cancer. They start in the cells that line the mucus-producing glands in the small bowel, usually in the duodenum segment. This type of cancer is less aggressive than other subtypes of small bowel cancer, and can have a good prognosisto predict how a disease/condition may progress and what the outcome might be when caught early.
Gastrointestinal Stromal Tumours (GISTs)
A gastrointestinal stromal tumour (GIST) is a rare type of sarcoma that forms in lining of the gastrointestinal tract. More specifically, they develop in interstitial cells of Cajal (ICC), which play a critical role in the intestinal contractions required for digestion. For more information on GISTs, please refer to the Rare Cancers Australia Gastrointestinal Stromal Tumours (GIST) page.
Leiomyosarcomas
Leiomyosarcomas are a type of sarcoma that develops in the muscles. While rhabdomyosarcomas develop in skeletal muscles, leiomyosarcomas develop in smooth muscles, which form walls of organs, glands, and blood vessels within the body. They often develop in the ileum of the small bowel, and can be aggressive. Leiomyosarcomas can have a good prognosis when caught early. For more information on leiomyosaromas, please refer to the Rare Cancers Australia Leiomyosarcoma page.
Carcinoid Tumours
Carcinoid tumours of the small bowel are a very rare subtype of small bowel cancers that develop from neuroendocrine cells, often in the ileum. Neuroendocrine cells, which are responsible for receiving signals from the nervous system and producing hormones and peptides (small proteins) in response. For more information on small bowel neuroendocrine tumours, please refer to the Rare Cancers Australia Small Bowel Neuroendocrine Tumours page.
Lymphomas
Small bowel lymphomas are a rare form of small bowel cancer that form from lymphocytes in the jejunum. It is a type of non-Hodgkin lymphoma that affects the immune system. Small bowel lymphoma can be aggressive, but they can have a good prognosis wen caught early.
Treatment
If small bowel cancer is detected, it will be staged and graded based on size, metastasis, and how the cancer cells look under the microscope. Staging and grading helps your doctors determine the best treatment for you.
Cancers can be staged using the TNM staging system:
- T (tumour) indicates the size and depth of the tumour.
- N (node) indicates whether the cancer has spread to nearby lymph nodessmall bean-shaped structures that filters harmful substances from lymph fluid.
- M (metastasis) indicates whether the cancer has spread to other parts of the body.
This system can also be used in combination with a numerical value, from stage 0-IV:
- Stage 0: this stage describes cancer cells in the place of origin (or ‘in situ’) that have not spread to nearby tissue.
- Stage I: cancer cells have begun to spread to nearby tissue. It is not deeply embedded into nearby tissue and had not spread to lymph nodes. This stage is also known as early-stage cancer.
- Stage II: cancer cells have grown deeper into nearby tissue. Lymph nodes may or may not be affected. This is also known as localised cancer.
- Stage III: the cancer has become larger and has grown deeper into nearby tissue. Lymph nodes are generally affected at this stage. This is also known as localised cancer.
- Stage IV: the cancer has spread to other tissues and organs in the body. This is also known as advancedat a late stage, far along or metastatic cancer.
Cancers can also be graded based on the rate of growth and how likely they are to spread:
- Grade I: cancer cells present as slightly abnormal and are usually slow growing. This is also known as a low-grade tumour.
- Grade II: cancer cells present as abnormal and grow faster than grade-I tumours. This is also known as an intermediate-grade tumour.
- Grade III: cancer cells present as very abnormal and grow quickly. This is also known as a high-grade tumour.
Once your tumour has been staged and graded, your doctor may recommend genetic testinga procedure that analyses DNA to identify changes in genes, chromosomes and proteins, which can be used to analyse tumour DNA to help determine which treatment has the greatest chance of success, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.
Treatment is dependent on several factors, including location, stage of disease and overall health.
Treatment options for small bowel cancer may include:
- Surgery, potentially including:
- Right Hemicolectomyremoval of a portion of the colon; can be the right side (right hemicolectomy) or the left side (left hemicolectomy).
- Pancreaticoduodenectomyremoval of part of the pancreas (generally the head), the first part of the small intestine (duodenum), part of the stomach, the gallbladder, and part of the common bile duct; also known as a Whipple procedure, also known as a Whipple procedureremoval of part of the pancreas (generally the head), the first part of the small intestine (duodenum), part of the stomach, the gallbladder, and part of the common bile duct; also known as a pancreaticoduodenectomy.
- Lymphadenectomysurgical removal of lymph node(s).
- Chemotherapya cancer treatment that uses drugs to kill or slow the growth of cancer cells, while minimising damage to healthy cells.
- Radiation therapya treatment that uses controlled doses of radiation to damage or kill cancer cells.
- Immunotherapya treatment that uses a person's immune system to fight cancer.
- Clinical trialsresearch studies performed to test new treatments, tests or procedures and evaluate their effectiveness on various diseases.
- Complementary therapiesa variety of practices and exercises used alongside conventional treatment methods that may improve wellbeing and sense of control (e.g. meditation, art therapy, yoga etc.)
- Palliative carea variety of practices and exercises used to provide pain relief and improve quality of life without curing the disease.
Risk factors
While the cause of small bowel cancers remains unknown, the following factors may increase the risk of developing the disease:
- Having certain genetic conditions, such as:
- Familial adenomatous polyposis (FAP).
- Lynch syndrome (also known as hereditary nonpolyposis colorectal cancer or HNPCC).
- Peutz-Jeghers syndrome (PJS).
- Cystic fibrosis (CF).
- Multiple endocrine neoplasia type 1 (MEN 1).
- Having Crohn’s disease.
- Having coeliac disease.
- Having a diet rich in animal fats, proteins, and processed meats.
Not everyone with these risk factors will develop the disease, and some people who have the disease may have none of these risk factors. See your general practitioner (GP) if you are concerned.
Symptoms
Symptoms of small bowel cancers may include:
- Abdominal pain.
- Unexplained weight loss.
- A lump in the abdomen.
- Blood in stools.
- Changes in bowel habits, such as:
- Diarrhoea.
- Constipation.
- Nausea and/or vomiting.
- Fatigue.
- Anaemiaa condition where there aren't enough red blood cells in the blood, causing fatigue, weakness and pale skin and affecting how the body responds to infection.
- Jaundiceyellowing of the skin and the whites of the eyes caused by an increase of bile in the blood.
Not everyone with the symptoms above will have cancer but see your general practitioner (GP) if you are concerned.
Diagnosis
If your doctor suspects you have small bowel cancer, they may order the following tests to confirm the diagnosis and refer you to a specialist for treatment:
- Physical examinationan examination of your current symptoms, affected area(s) and overall medical history.
- Imaging tests, potentially including:
- CT (computed tomography) scana type of medical imaging that uses x-rays and computer technology to create detailed images of the body.
- MRI (magnetic resonance imaging)a type of medical imaging that uses radiowaves, a strong magnet and computer technology to create detailed images of the body.
- PET (positron emission tomography) scana type of medical imaging that uses radioactive tracers to create detailed images of the body.
- Barium studiesa type of x-ray where barium powder is either swallowed (barium swallow) or introduced via the colon (barium enema) to coat the organs of the digestive tract and provide clearer x-ray images.
- Ultrasounda type of medical imaging that uses soundwaves to create detailed images of the body .
- Blood teststesting done to measure the levels of certain substances in the blood.
- Endoscopya procedure that involves inserting a long, flexible tube with a light and small camera (endoscope) into the body to view internal organs.
- Biopsyremoval of a section of tissue to analyse for cancer cells.
