Bowel cancer (also known as colorectal cancer) occurs in the colon or rectum. Most bowel cancers start as polyps, which are an abnormal growth on the lining of the bowel. Not all polyps become cancerous. Polyps can be easily removed during a colonoscopy which will eliminate the chances of them developing into a cancer. When a polyp is cancerous it can grow uncontrollably, causing blockages and often bleeding. In the later stages the cancer can spread from the bowel to other organs.

Bowel cancer is most often curable if found early and is removed by surgery. It is imperative to be screened regularly to avoid diagnosis of the disease in its later stage as the survival rate is much lower. Late stage bowel cancer treatment may include both chemotherapy and radiation therapy.



People of any age can be diagnosed with bowel cancer though it is more common in those over the age of 50 as risk increases with age. People at a higher risk also include those who have polyps or bowel cancer in their family history. Smoking, poor diet, lack of exercise and high alcohol consumption can also increase the possibility of being diagnosed with the disease.

In the early stages of bowel cancer there are often no symptoms, making it important to be tested even when feeling healthy.




Blood in or on the stool (faeces) - please note polyps and cancers may bleed intermittently


A recent and persistent change in bowel habit


General stomach discomfort


Frequent gas or pains


Unexplained weight loss

If you have any of these symptoms, please discuss them with your GP.

REMEMBER: However old you are, you should never be told by your doctor that you are too young to have bowel cancer. Whilst bowel cancer is more common in people aged 50+, bowel cancer increasingly affects all age groups.

If you have higher-risk symptoms, do not accept ‘you’re too young to have bowel cancer’ as an explanation for your symptoms - ask your doctor to be referred for further investigations.




While no cancer is completely preventable, you can lower your bowel cancer risk by maintaining a healthy weight, eating a sensible diet which includes plenty of fresh fruit and vegetables, and doing regular physical activity. Not smoking and lowering alcohol consumption can also reduce the chances of developing the disease.



Bowel Screen Australia

Every Australian over the age of 50 should have regular medical checks and screen for bowel cancer using a Faecal Occult Blood tests (FOBT) at least once every two years or annually. The aim is to find any polyps or to find cancer early when they are easier to treat and cure. The FOBT looks for invisible blood in stools. If blood is found you should contact your doctor as further examination will be required, by colonoscopy, to determine the source of the bleeding. FOBT test kits are available from your community pharmacy or Bowel Cancer Australia.

Bowel Screen Australia â„¢ is an initiative of Bowel Cancer Australia and the Pharmacy Guild of Australia.

Visit and use the online locator tool to find your nearest pharmacy.



What causes bowel cancer to spread?

If the cancer in the bowel is not detected and removed at an early stage, part of the tumour can break off from the main bowel tumour and spread, usually via the lymphatic system or bloodstream, to nearby lymph nodes or other parts of the body.

Your cancer may be advanced when it is first diagnosed.  Or it may come back some time after you are first treated. 


Local spread

If the cancer has broken through the wall of the bowel and cancer cells have spread into surrounding tissues in the abdomen and pelvis, this is known as local spread. 


Secondary spread (metastasis)

If the cancer has spread to another part of the body (for example, the liver or lungs) is it called secondary cancer or metastatic cancer.  

The liver is second only to the lymph nodes as the most common part of the body for bowel cancer cells to spread to.   The liver is a common site for bowel cancer cells to spread to as the liver receives most of its blood supply from the portal vein (the vein that carries blood from the intestines and spleen to the liver).

If your bowel cancer has spread in this way, you have secondary bowel cancer in your liver – not liver cancer.  Your treatment is dependent on where the cancer started and therefore the treatment you have must work on bowel cancer and not liver cancer cells.

The next most common part of the body for bowel cancer cells to spread to is the lungs.


Treatment for Advanced Bowel Cancer

Once a bowel cancer has spread to another part of the body, it is unlikely to be curable.  If your cancer is advanced when it is first diagnosed you may be offered chemotherapy to keep it under control.  You may have just one drug or a combination of drugs. 

Some people with bowel cancer that has spread receive a monoclonal antibody, a type of biological therapy and are a different type of treatment to chemotherapy.  Ask your oncologist about the choices available to you, and the combination option.

In some circumstances you may have surgery. 

The choice of treatment depends on –

  • The type of cancer you have
  • The size and number of secondaries and where they are in the body
  • The treatment you had already had


Surgery for Advanced Bowel Cancer

Surgery can be used in some situations to treat advanced bowel cancer -

  • To slow the cancer
  • When the bowel is blocked
  • To remove secondary cancer


Surgery to control the cancer

Sometimes when there is a recurrence of bowel cancer in the bowel, it is possible to remove it.  This is unlikely to cure the cancer because there are usually cancer cells elsewhere in the body.  Removal of the bowel tumour may however relieve any symptoms you may have.  It may also be some time before the cancer starts to grow anywhere else.


Surgery for blocked bowel cancer

Sometimes bowel cancer can grow so that it completely blocks the bowel.  This is called a bowel obstruction.  The waste from the food you have digested cannot get past the blockage.  This can cause a number of symptoms such as feeling bloated and full, pain, feeling sick, vomiting, or constipation.  To relieve symptoms, it is sometimes possible to unblock the bowel by putting in a stent. 
Another way to remove an obstruction is to operate and remove the affected part of the bowel, provided you are fit enough.  It may be possible to close up the bowel again during the operation or you may need to have a colostomy.


Surgery to remove small secondary cancers

If bowel cancer spreads, it often goes to the liver or lungs.  Sometimes when the cancer secondaries in the liver or lungs are small and there are only one or two, you can have surgery to remove them.  This is not suitable treatment in every situation and is done more often for liver secondaries than for lung secondaries.  If you have this type of surgery, you may also have chemotherapy before and after the operation.

To decide if this treatment is suitable for you, your doctor will look at -

  • Your general health
  • How advanced your cancer was when you were diagnosed
  • How quickly your cancer came back
  • How many secondaries you have and their size
  • Where they are in the liver or lungs
  • How close they are to major blood vessels


Chemotherapy for Advanced Bowel Cancer

Chemotherapy to shrink a cancer and control symptoms is called palliative chemotherapy.  Treatment with chemotherapy at this stage is unlikely to cure your cancer, but it can help you live longer and may shrink the cancer.

For advanced bowel cancer, the aim of chemotherapy is to help you feel better.  If however, you are unhappy about the side effects, you do not have to continue with the treatment.


How do you know if chemotherapy is working?

Your oncologist will arrange a scan before you start treatment and again three months later.  Your oncologist can measure the tumour on the scan and so will be able to see how well the treatment is working.  The tumour may have become smaller or larger or remained the same size.

If it has remained the same size, your oncologist will want to talk to you about whether or not it is worth continuing with your treatment.

If the tumour has become bigger, despite your treatment, your oncologist will stop the chemotherapy and may suggest trying a different treatment.

If it has become smaller, you may have a break and then have more treatment. 


Monoclonal Antibodies (MAB)

Some people with bowel cancer that has spread receive a monoclonal antibody, a type of biological therapy and are a different type of treatment to chemotherapy.

  • ‘Monoclonal’ means all one type.
  • ‘Antibody’ is a protein in your immune system that recognises and attacks foreign substances.

So a ‘monoclonal antibody’ is a treatment designed to recognise and target only one type of foreign substance (e.g. cancer cells).

The development of monoclonal antibody treatments is an exciting development in the treatment of cancer as it may be possible to kill cancer cells without damaging other healthy cells.

The monoclonal antibodies bind to bowel cancer cells.  They interfere with cancer cell growth and the spread of cancer.  People receive monoclonal antibodies through a vein at the doctor's office, hospital, or clinic.  Some people receive chemotherapy at the same time.

During treatment, your health care team will watch for signs of problems.  Some people get medicine to prevent a possible allergic reaction.  The side effects depend mainly on the monoclonal antibody used.  Side effects may include rash, fever, abdominal pain, vomiting, diarrhoea, blood pressure changes, bleeding, or breathing problems.  Side effects usually become milder after the first treatment.

Radiotherapy for Advanced Bowel Cancer

Some patients may be given radiotherapy as palliative treatment.  In other words, it will be used to relieve the symptoms of the cancer or to reduce pain.  Radiotherapy is not used much for colon cancers but may be used for rectal cancers.  Internal radiotherapy may be used for secondaries in the liver.


Surgery & Chemotherapy for Liver Metastases

Only a relatively small number of patients with liver tumours are suitable for surgery, and whether or not this operation is an option for you depends on:

  • Whether the tumour in your bowel has been treated / is treatable
  • How much of the liver is affected
  • The size of the tumour(s)
  • Where in the liver the cancer cells are located
  • How well the liver is functioning
  • Whether there are any tumours outside the liver, their locations and how many there are
  • Your general level of fitness

Surgery can only be performed if there is no sign of cancer anywhere else in the body.  If the liver tumour is too large to operate on, you may have chemotherapy to try and shrink the tumour so it can be removed.  If the liver tumour is small, you may have chemotherapy before and after the surgery.

Chemotherapy may be given to improve the ability to undertake surgery, to reduce the number of tumour cells, or to slow their growth to provide symptom relief and extend survival.