Treatment for advanced bowel cancer

When bowel cancer has spread to the liver, lung, or lining of the abdomen and pelvis (omentum and peritoneum), this is known as advanced or metastatic (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, radiation therapy and surgery. For some people, the best option may be to join a clinical trial.

Learn more about:

• Systemic treatment
• Radiation therapy
• Surgery
• Other treatments
• Palliative treatment
• Video: What is palliative care?

Systemic treatment

Advanced bowel cancer is commonly treated with drugs that reach cancer cells throughout the body. This is called systemic treatment, and includes chemotherapy and targeted therapy. The drugs used are rapidly changing as clinical trials find newer drugs. Talk to your medical oncologist about the latest options for you.

Targeted therapy drugs work differently from chemotherapy drugs. While chemotherapy drugs affect all rapidly dividing cells and kill cancerous cells, targeted therapy drugs affect specific molecules within cells to block cell growth.

Targeted therapy

Monoclonal antibodies are the main type of targeted therapy drug used
in Australia for advanced bowel cancer. They include:

Bevacizumab – This drug stops the cancer developing new blood cells
and growing. It is given as a drip into a vein (intravenous infusion) every 2–3 weeks, with chemotherapy.

Cetuximab and panitumumab – These drugs target specific features of cancer cells known as epidermal growth factor receptors (EGFR). They only work for people who have a normal RAS gene (known as RAS wild-type). The tumour will be tested for changes (mutations) in these genes before you are offered these drugs. These drugs are usually given as a drip into a vein (intravenous infusion). They may be given with chemotherapy or on their own after other chemotherapy drugs have stopped working.

Other types of targeted therapy drugs may be available on a clinical trial. Ask your doctor about the latest developments and whether you are a suitable candidate.

Scans and blood tests will be used to monitor your response to systemic treatments. If results show that the cancer is shrinking or is under control, you’ll continue to have chemotherapy or targeted therapy or both. If the cancer is growing, that treatment will stop and your doctor will discuss other treatments.

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 and headaches.

The most common side effects of cetuximab and panitumumab include:

• skin problems (redness, swelling, an acne-like rash or dry, flaky skin)
• tiredness
• diarrhoea.

For a detailed list of side effects, visit eviq.org.au.

For more on this treatment, see Targeted therapy.

Radiation therapy

Radiation therapy can be used as a palliative treatment for both advanced colon and advanced rectal cancer. It can be used to control the growth of the tumour and relieve symptoms such as bleeding. If the cancer has spread to the bone or formed a mass in the pelvis, radiation therapy can reduce pain. For further details, see Radiation therapy.

If the tumour has spread to the liver, you may be offered a specialised type of radiation therapy. Options may include selective internal radiation therapy (SIRT) or stereotactic body radiation therapy (SBRT). For more on this, see Secondary liver cancer.

Surgery

You may have surgery if bowel cancer has spread to the liver or lungs, or if the cancer blocks your bowel.

Surgery may remove parts of the bowel along with all or part of other affected organs. This may be called an en-bloc resection or, if the cancer is in your pelvis, an exenteration.

If the cancer has spread to the lining of the abdomen (peritoneum), you may have surgery to remove as many tumours as possible. This is known as a peritonectomy or cytoreductive surgery. Sometimes, a heated chemotherapy solution is put into the abdomen during a peritonectomy. This is called hyperthermic intraperitoneal chemotherapy (HIPEC). Recent studies suggest that having surgery only may be as effective as surgery followed by HIPEC.

Your medical team will advise what kind of follow-up and treatment
is recommended after surgery.

Other treatments

If the cancer cannot be removed with surgery, but has spread to only a small number of places in a single area, your doctor may recommend thermal ablation. This uses heat to destroy the tumour. It is best performed in a specialised centre.

Palliative treatment

Palliative treatment helps to improve people’s quality of life by managing the symptoms of cancer without trying to cure the disease. It is best thought of as supportive care.

Many people think that palliative treatment is for people at the end of their life, but it may help at any stage of advanced bowel cancer. It is about living for as long as possible in the most satisfying way you can.

Sometimes treatments such as surgery, chemotherapy, radiation therapy or targeted therapy are given palliatively. The aim is to help relieve symptoms such as pain or bleeding by shrinking or slowing the growth of the cancer.

Palliative treatment is one aspect of palliative care, in which a team of health professionals aims to meet your physical, emotional, cultural, social and spiritual needs. The team also provides support to families and carers.

For more on this, see Palliative care and Living with advanced cancer, and listen to our advanced cancer podcast.

Video: What is palliative care?