When bowel cancer has spread to the liver, lung or lining of the abdomen and pelvis (omentum and peritoneum), this is known as stage 4 bowel cancer.
To control the cancer, slow its growth and manage symptoms, such as pain, you may have a combination of chemotherapy, targeted therapy, radiotherapy and surgery.
Advanced bowel cancer is commonly treated with drugs that reach cancer cells throughout the body. This is called systemic treatment, and includes chemotherapy. Sometimes a targeted therapy is used together with chemotherapy.
Targeted therapy drugs work differently from chemotherapy drugs. While chemotherapy affects all rapidly dividing cells and kills cancerous cells (cytotoxic), targeted therapy drugs affect specific molecules within cells to block cell growth (cytostatic).
Two types of targeted therapy drugs are commonly used in Australia for advanced bowel cancer.
This drug blocks the growth of blood vessels that supply cancer cells. It is given as an injection into a vein (intravenously) every two weeks, with chemotherapy.
Epidermal growth factor receptor inhibitors (EGFR-Is)
These target special receptors on cancer cells. They only work for people who have a normal RAS gene. You will be tested for changes (mutations) in these genes before you are offered these drugs. EGFR-Is are usually given with chemotherapy but sometimes on their own after other chemotherapy drugs have stopped working.
If your medical oncologist thinks that a targeted therapy may help, they will discuss this with you. However, some targeted therapy drugs may be available only through a clinical trial.
Scans and blood tests will be used to monitor your response to systemic treatments. If results shows that the cancer is shrinking or is under control, chemotherapy and/or targeted therapy will continue. If the cancer is growing, you will stop the treatment and alternative treatments will be discussed.
Side effects of targeted therapy
The side effects of targeted therapy vary depending on the drugs used. Common side effects of bevacizumab include high blood pressure, tiredness, bleeding, low white blood cell counts, headaches, mouth sores, loss of appetite and diarrhoea. The most common side effects of EGFR-Is include acne-like rash, headache, tiredness, fever and diarrhoea.
Radiotherapy can also be used as a palliative treatment for both colon and rectal cancer. It can be used to stop bleeding and if the cancer has spread to the bone or formed a mass in the pelvis, it can reduce pain.
If the cancer has spread to other parts of the body, you may still be offered surgery. This can help remove small secondary cancers (e.g. in the liver or lungs) or clear up a bowel obstruction.
You may have surgery to remove parts of the bowel along with all or part of other organs. This is called an en-bloc resection.
The type of operation used for advanced bowel cancer will depend on your situation, so talk to your surgeon about what to expect.
Your medical team will advise what kind of follow-up and treatment is recommended after surgery. Regular check-ups have been found to improve survival for people after surgery for bowel cancer, so you should have check-ups for several years.
Hyperthermic intraperitoneal chemotherapy
If the cancer has spread to the lining of the abdomen (peritoneum), you may have chemotherapy during surgery. This is called hyperthermic intraperitoneal chemotherapy (HIPEC). First, as many tumours as possible are removed (cytoreductive surgery) and then heated chemotherapy is delivered to the abdomen.
The chemotherapy circulates around the abdomen for a short time, and then it is drained and the cut closed. Heating the chemotherapy allows it to be better absorbed by the cancer cells and reduces side effects to other parts of the body. Cytoreductive surgery and HIPEC are best performed in a specialised centre.
If the cancer is advanced when it is first diagnosed or returns after treatment, your doctor will discuss palliative treatment for symptoms caused by the cancer, such as pain.
Palliative treatment aims to manage symptoms without trying to cure the disease. It can be used at any stage of advanced bowel cancer to improve quality of life. It is not just for people who are about to die and does not mean giving up hope. Rather, it is about living for as long as possible in the most satisfying way you can.
As well as slowing the spread of cancer, palliative treatment can relieve pain and help manage other symptoms. Treatment may include surgery, radiotherapy, chemotherapy, targeted therapy or other medicines.
Palliative treatment is one aspect of palliative care, in which a team of health professionals aim to meet your physical, emotional, practical and spiritual needs. For more information, see Understanding Palliative Care and Living with Advanced Cancer or call Cancer Council 13 11 20.
- Advanced cancer means the cancer has spread from where it started to another part of the body.
- Recurrent cancer means the cancer has come back some time after you were first treated.
- Drug treatment that reaches the cancer cells throughout the body is commonly used for advanced bowel cancer. This is called systemic treatment. It includes chemotherapy and targeted therapy drugs.
- Two types of targeted therapy drugs are commonly used in Australia for advanced bowel cancer.
- The drug bevacizumab blocks the growth of blood vessels that supply cancer cells.
- Epidermal growth factor receptor inhibitors (EGFR-Is) target specific receptors on cancer cells. They only work for bowel cancer that have a normal RAS gene.
- Radiotherapy may be used for advanced cancer of the colon or rectum. It can help stop bleeding and reduce pain.
- In some cases, surgery can remove small secondary cancers or a blockage in the bowel. If the cancer has spread to the lining of the abdomen, you may have chemotherapy during surgery. This is called hyperthermic intraperitoneal chemotherapy (HIPEC).
- People with advanced cancer might be offered palliative treatment, such as radiotherapy and chemotherapy. Palliative treatment is given to ease the symptoms of the cancer.
- All of the treatments can cause side effects, such as pain, fatigue or diarrhoea. Talk to your doctor about how to manage any side effects.
Expert content reviewers:
A/Prof Craig Lynch, Colorectal Surgeon and Chair, Lower Gastrointestinal Cancer Service, Peter MacCallum Cancer Centre, VIC; Merran Findlay, Executive Research Lead–Cancer Nutrition, and Oncology Specialist Dietitian, Royal Prince Alfred Hospital, NSW; Jackie Johnston, Palliative Care and Stomal Therapy Clinical Nurse Consultant, St Vincent’s Private Hospital, NSW; A/Prof Susan Pendlebury, Radiation Oncologist, St Vincent’s Clinic, NSW; Jan Priaulx, 13 11 20 Consultant, Cancer Council NSW; A/Prof Eva Segelov, Professor of Oncology, Monash Health and Monash University, VIC; Heather Turner, Consumer; Lynne Wolowiec, Consumer.