Bowel cancer
Your bowels are made up of two sections - the small and the large bowel (or colon). If cells begin to develop and multiply abnormally in your bowel they can become cancerous.
Reviewed by Mr Andrew Day and Mr Justin Davies
What is bowel cancer?
Bowel cancer is a general term for cancer that starts in the large bowel. Depending on where the cancer starts, bowel cancer is sometimes called colon, rectal or colorectal cancer.
Your bowel may develop a polyp, which is an abnormal overgrowth of the lining of the bowel, over time this can progress to a bowel cancer. Screening to detect these pre-cancerous growths is vital. Not only does this provide the opportunity for removal of the polyps before they become cancerous, but it enables patients to start a surveillance programme that could help prevent problems in the future.
How common is bowel cancer?
Bowel cancer affects over 42,000 people per year in the UK and is the 4th most common cancer in the UK.
(Source: Cancer Research UK)
Risks and causes for bowel cancer?
Approximately 1 in 15 men and 1 in 18 women will be diagnosed with bowel cancer in their lifetime.
The exact cause of bowel cancer is still unknown. However, there are a number of lifestyle factors that are associated with bowel cancer, including:
- age - almost 9 in 10 cases occur in people aged 60 and over
- diet - a diet that is high in processed meat and low in vegetable fibre
- weight - bowel cancer is more common in those who are overweight or obese
- inactivity - being inactive with little exercise
- family history - having a close relative with bowel cancer under the age of 50, or several relatives having bowel cancer, may put you at a greater risk of developing the condition.
- smoking - 7% of bowel cancers in the UK are linked to smoking
- chronic bowel disease - those with chronic bowel diseases such as ulcerative colitis and Crohn's disease increase the risk of bowel cancer
Changes to these lifestyle factors can reduce your risk of developing bowel cancer.
What are the symptoms of bowel cancer?
The symptoms of bowel cancer are:
- A change in bowel habit – looser poos, pooing more often or constipation
- Blood in the stool (faeces) or bleeding from your rectum (back passage)
- A lump in your abdomen (stomach) or rectum (back passage)
- The need to strain even after opening your bowels
- Unexplained weight loss
- Pain in your abdomen (stomach)
- Pain in your rectum (back passage)
- Tiredness (anaemia)
Sometimes, bowel cancer can block digestive waste passing through the bowel. This is called a bowel obstruction and the symptoms include:
- Pain or cramping in the abdomen (stomach)
- Constipation
- Vomiting
- Feeling bloated
If you suspect that you have bowel obstruction, please contact your GP immediately, call 111 or go to your nearest A&E.
How is bowel cancer diagnosed?
If you have any of the following symptoms outlined above, your GP may recommend the following tests to check for bowel cancer:
- Check your abdomen (stomach) - your doctor will examine your stomach for any lumps
- Digital rectal examination (DRE) - Your doctor will place a finger in your rectum and to check for any lumps in your rectum (back passage)
- Blood test - to check for anaemia and abnormal kidney and liver function
- Faecal immunochemical test (FIT test) - to check for blood in the stool (poo)
- Colonoscopy - A flexible tube with a camera at the end (colonscope) will be inserted into your back passage and through your bowel. Your doctor will look for look at the lining of the whole of the large bowel and take some tissue samples
- Flexible sigmoidoscopy - A flexible tube with a camera at the end (colonscope) will be inserted into your back passage and through your bowel. Your doctor will look at the lining and take tissue samples of the sigmoid colon (lower bowel)
- MRI scan or CT scan - to provide detailed images of your bowel and to see if the cancer has spread to other parts of the body
Early diagnosis of bowel cancer significantly improves your chances of survival. The earlier we can find the cancer the easier and more successful treatment can be. Sometimes we can treat it without the need for surgery.
If diagnosed early, more than 92% of people with bowel cancer will survive for five years or more.
(Source: Cancer Research UK)
What is bowel cancer screening?
The bowel cancer screening programme is delivered by the NHS. In England, if you are aged between 60 and 74 you will be invited to submit a stool sample every two years.
A kit will be sent to you called a faecal immunochemical test (FIT); this measures any microscopic levels of blood that may be present in the stool. Depending on the level recorded you may be invited to attend a screening centre for a colonoscopy.
The FIT test help to detect bowel cancer before symptoms appear, making treatment more successful and improving the chances of survival.
How is bowel cancer treated?
There are several treatment options for bowel cancer. However, your recommended treatment will be based on several factors including which part of your bowl is affected and how far the cancer has spread.
The most common treatments for bowel cancer include:
- Surgery – to remove the cancer
- Chemotherapy - uses drugs to destroy cancer cells
- Radiotherapy – uses high-powered X-ray beams to kill cancer cells
- Biological therapy – uses the body’s immune system to kill cancer cells. It can prevent or slow tumour growth and prevent the spread of cancer. Biological therapy for cancer often causes fewer toxic side effects than other cancer treatments.
Treatment for colon cancer
Depending on the stage of your colon cancer and how far it spread, your doctor will suggest the following treatment:
Stage 1 colon cancer:
Surgery
- Open colectomy – Your surgeon will remove a section of your where the cancer is and join the 2 ends of your colon back together.
- Laparoscopic (keyhole) colectomy – Your surgeon will make small cuts in your abdomen (stomach) and inflate it with carbon dioxide. They will then insert surgical instruments and a telescope to see inside your abdomen and remove a section of your where the cancer is and join the 2 ends of your colon back together
- Robot-assisted keyhole colectomy – Similar to a laparoscopic (keyhole) colectomy, your surgeon will control the surgical instruments from a console
Stage 2 colon cancer:
Surgery
- Open colectomy – Your surgeon will remove a section of your where the cancer is and join the 2 ends of your colon back together.
- Laparoscopic (keyhole) colectomy – Your surgeon will make small cuts in your abdomen (stomach) and inflate it with carbon dioxide. They will then insert surgical instruments and a telescope to see inside your abdomen and remove a section of your where the cancer is and join the 2 ends of your colon back together
- Robot-assisted keyhole colectomy – Similar to a laparoscopic (keyhole) colectomy, your surgeon will control the surgical instruments from a console
Chemotherapy – After surgery, your surgeon may suggest chemotherapy if you have a higher chance of the cancer returning
Stage 3 colon cancer:
Surgery
- Open colectomy – Your surgeon will remove a section of your where the cancer is and join the 2 ends of your colon back together.
- Laparoscopic (keyhole) colectomy – Your surgeon will make small cuts in your abdomen (stomach) and inflate it with carbon dioxide. They will then insert surgical instruments and a telescope to see inside your abdomen and remove a section of your where the cancer is and join the 2 ends of your colon back together
- Robot-assisted keyhole colectomy – Similar to a laparoscopic (keyhole) colectomy, your surgeon will control the surgical instruments from a console
Chemotherapy – After surgery, your surgeon may suggest chemotherapy if you have a higher chance of the cancer returning
Stage 4 colon cancer:
Surgery
- Open colectomy – Your surgeon will remove a section of your where the cancer is and join the 2 ends of your colon back together.
- Laparoscopic (keyhole) colectomy – Your surgeon will make small cuts in your abdomen (stomach) and inflate it with carbon dioxide. They will then insert surgical instruments and a telescope to see inside your abdomen and remove a section of your where the cancer is and join the 2 ends of your colon back together
- Robot-assisted keyhole colectomy – Similar to a laparoscopic (keyhole) colectomy, your surgeon will control the surgical instruments from a console
Chemotherapy – After surgery, your surgeon may suggest chemotherapy if you have a higher chance of the cancer returning
Radiotherapy - uses high-powered X-ray beams to kill cancer cells.
Immunotherapy – Immunotherapy is a type of biological therapy. It helps the immune system to recognise and kill cancer cells.
Targeted cancer drugs – uses drugs to target specific genes and proteins that help cancer cells survive and grow
Treatment for rectal cancer
If the rectal cancer hasn’t spread, the main treatments include:
Surgery
- Local resection – Your surgeon will insert an endoscope (a thin tube with a camera at the end) and remove the cancer from the wall of the rectum.
- Trans anal endoscopic microsurgery (TEM) – Your surgeon will remove the cancer from the wall of the rectum as well as a border of rectal tissue that is cancer free.
- Total mesenteric excision (TME) – Your surgeon will remove the cancer from the wall of the rectum as well as a border of rectal tissue that is cancer free. They will also remove fatty tissue from around the rectum (mesentery)
- Low anterior resection – Low anterior resection is used to treat cancer in the upper section of your rectum. Your surgeon will remove the upper section of your rectum with cancer and reconnect the remaining part of the rectum to your colon. You may require a temporary stoma to give the joined section time to heal
- Abdominoperineal resection – Your surgeon will remove the whole of your rectum and anus, and part of the sigmoid colon. The end of your colon will be attached to an opening at the surface of the abdomen and body waste is collected in a disposable bag outside of the body. This is called a colostomy or stoma.
Chemotherapy – uses drugs to destroy cancer cells. Chemotherapy may be used to shrink the cancer before surgery or kill of cancer cells left after cancer.
Radiotherapy – uses high-powered X-ray beams to kill cancer cells. Radiotherapy may be used before, after or instead of surgery. If the cancer is too large t operate on, you may be offered radiotherapy to shrink the cancer and improve the chance of the surgery being successful
Treatment for advanced bowel cancer
If the bowel cancer has spread to other parts of the body, you may be offered the following treatments:
- Chemotherapy- uses drugs to destroy cancer cells.
- Radiotherapy- uses high-powered X-ray beams to kill cancer cells.
- Immunotherapy- a type of biological therapy that helps the immune system to recognise and kill cancer cells.
- Targeted cancer drugs - uses drugs to target specific genes and proteins that help cancer cells survive and grow
Bowel cancer treatments can have significant side effects that affect the quality of life. Your doctor will discuss the benefits and possible side effects with you.