Small Bowel Tumours
The small bowel is part of the digestive system, and its function is to break down food and nutrients to be absorbed into the body. The small bowel is also called the small intestine. It links the stomach to the colon or large intestine.
The small bowel is divided into three parts:
- The duodenum. The part closest to the stomach
- The jejunum. The middle portion
- The ileum. The bottom section, which connects to the large intestine, or colon.
The small bowel is approximately 6 metres long and folds many times to fit inside the abdomen.
These are related to the size and location of the tumour.
Patients may experience some of the following –
- Blood in the stool (feces)
- Dark/black stools
- A change in bowel habits especially diarrhoea
- Unexplained weight loss
- Pain or cramps in the abdomen
These symptoms may be caused by many things other than small bowel cancer but symptoms that are severe, get worse, or last for a few weeks should always be checked by your doctor.
Occasionally, the cancer can cause a blockage (obstruction) in the bowel, which may be complete or partial. The symptoms of this are vomiting, constipation, griping pain and a bloated feeling in the abdomen.
Sometimes a blockage in the small bowel can cause the bowel to tear. This is a serious condition that usually occurs suddenly and needs to be treated with surgery. The symptoms include severe pain, shock (a drop in blood pressure) and abdominal swelling.
Types of small bowel tumours
Small bowel tumours start when healthy cells in the lining of the small bowel change and grow uncontrollably, forming a mass called a tumor. A tumor can be cancerous (malignant) and grow and spread or benign (non-cancerous) and remain located at the site of development. While the specific causes of small bowel cancer are not well understood, chronic inflammation is a major factor in the development of adenocarcinoma. Genetic and environmental factors are also factors in the development of small bowel tumours.
Small bowel tumours can be non-cancerous (benign) or cancerous (malignant). Malignant tumours of the small intestine include adenocarcinoma, lymphoma and carcinoid tumours.
There are five main types of malignant small bowel tumours:
- Adenocarcinoma. Adenocarcinoma is the most common type of small bowel cancer, usually occurring in the duodenum or jejunum. Adenocarcinoma begins in the gland cells of the small bowel.
- Sarcoma. Small bowel sarcoma is generally a leiomyosarcoma, which is a tumor that arises in the muscle tissue that makes up part of the intestine. This type of tumor most often occurs in the ileum.
- Gastrointestinal stromal tumor (GIST). GIST is an uncommon tumor that is believed to start in cells found in the walls of the gastrointestinal (GI) tract, called interstitial cells of Cajal (ICC). GIST belongs to a group of cancers called soft tissue sarcomas.
- Carcinoid tumor. Carcinoid tumors are classified as neuroendocrine tumors. These are tumors that originate in the hormone-producing cells of various organs and generally occur in the ileum.
- Lymphoma. Lymphoma is a cancer of the lymph system, which is part of the body’s immune system. Lymphoma that occurs in the small bowel usually occurs in the jejunum or ileum and is most commonly non-Hodgkin lymphoma.
- A full medical history and physical examination will be undertaken by your surgeon.
- Blood tests – Liver function tests (LFT’s) to check the health of your liver and full blood examination (FBE) to check overall heath and look for signs of anaemia.
- Faecal occult blood test may be ordered to check for hidden blood in the stool.
- Endoscopy – Some small bowel tumours may be diagnosed through endoscopy, however most are beyond the reach of the endoscope. However, if the tumour can be visualised endoscopically, a small sample of tissue, a biopsy, may be taken. Biopsies can’t always be taken, so a definitive diagnosis may be made during an operation.
- Colonoscopy – Colonoscopy is a procedure used to view the large intestine (colon and rectum) using an instrument called a colonoscope, a flexible tube with a small camera and light source attached to its tip.
- Capsule endoscopy
- Computerised tomography (CT scan)
- Magnetic resonance imaging (MRI) scan
- Barium X-Ray – Small bowel follow through
Surgery for small bowel cancer
Surgery is the main treatment for cancer of the small bowel. It may be necessary to surgically remove the affected section of the bowel or to bypass it completely if the tumour is causing a blockage.
The position of the tumour within the bowel and how much of the bowel is involved will determine how extensive the surgery is. It may be necessary to remove part of the stomach, colon, the gall bladder or the surrounding lymph nodes during the surgery.
If the cancer is large and has caused a blockage in the small bowel it is sometimes possible to bypass the tumour. This can be used to relieve the symptoms, even if it’s not possible to completely remove the tumour. Your surgeon will explain the operation to you and can answer any questions you may have.
An ileostomy may be needed in the post-operative period. In this procedure, an artificial opening is created in your abdomen, called a stoma. One or both ends of the intestine are then attached to the opening allowing waste to exit your bowel. The waste material is collected in a pouch called an "ostomy" bag. An ileostomy may be temporary or permanent.
A temporary ileostomy allows the intestine to rest and heal. When your intestine has healed properly, you may be able to undergo another operation to rejoin the ends of the intestine.
Chemotherapy for small bowel cancer
Chemotherapy is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells. Chemotherapy may occasionally be used to treat cancer of the small bowel, either in combination with radiotherapy or surgery, or on its own.
Chemotherapy may be considered for malignant tumours depending on their type and may be considered either before or after surgery.
After your treatment has finished, your surgeon will ask you to return for regular check-ups and potentially for follow-up scans.
However, if you notice any new symptoms or are anxious about anything else between appointments, contact your doctor or nurse for early advice.