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  • Treatment for bowel cancer


    Treatment for bowel cancer will depend on the type (colon, rectal or anal) and stage of cancer you have.

    Your medical team will recommend treatment based on:

    • what will give you the best outcome
    • where the cancer is in the bowel
    • whether and how the cancer has spread
    • your general health
    • your preferences

    Treatment for early bowel cancer

    Treatment options by type of bowel cancer

    Colon cancer—surgery is the main treatment for early colon cancer. If cancer has spread to the lymph nodes, you may have chemotherapy after surgery. This is called adjuvant chemotherapy. Radiotherapy is not used for early colon cancer.

    Rectal cancer—surgery is the main option for early rectal cancer. If the cancer has spread beyond the rectal wall and/or into nearby lymph nodes (locally advanced cancer), you will have either radiotherapy or both radiotherapy and chemotherapy (chemoradiotherapy or chemoradiation). This is called neoadjuvant treatment, and the aim is to make the cancer as small as possible before it is removed. This will be followed by surgery and then adjuvant chemotherapy.


    There are different types of surgery for bowel cancer. The aim of surgery is to remove all the cancer and nearby lymph nodes.

    Surgery for cancer in the colon

    The most common type of surgery is called a colectomy. There are different types of colectomies depending on whether part or all of the colon is removed. Lymph nodes near the colon and some normal bowel around the cancer will also be removed.

    The surgeon usually cuts the colon on either side of the cancer and then joins the two ends of the colon back together. This join is called an anastomosis.

    Sometimes one end of the bowel is brought through an opening made in your abdomen and stitched onto the skin. This procedure is called a colostomy (if made from the colon in the large bowel) or ileostomy (if made from the ileum in the small bowel). The opening—called a stoma—allows faecal waste to be removed from the body and collected into a bag.

    The stoma is usually temporary, and the operation is reversed later. In some cases, the stoma is permanent. Advances in surgical techniques have led to very few people needing a permanent stoma.

    After surgery, you will have a scar. Most people who have open surgery have a scar from above their navel to their pubic area.

    Surgery for cancer in the rectum

    There are different types of operations for cancer in the rectum. The type of operation you have depends on where the cancer is located, whether the bowel can be rejoined, and where in the rectum the join can be made.

    You may have an anterior resection or abdominoperineal resection (also known as an abdominoperineal excision). The surgery may be open style or minimally invasive.

    An anterior resection is the most common operation. This will include creating a temporary stoma, which will be reversed later.

    An abdominoperineal resection may be recommended if the cancer is near the sphincter muscles or if it is too low to be removed without causing incontinence (accidental loss of urine or faeces) or erection problems. After an abdominoperineal resection you will need a permanent stoma (colostomy). Speak to your surgeon about any concerns you may have.

    Other types of surgery

    Local excision. People who have very early stage bowel cancer or are not fit for a major operation may have a local excision. The surgeon inserts an endoscope into the anus to remove the cancer. This is called transanal endoscopic microsurgery (TEMS).

    If the cancer is very low in the rectum, the surgeon may be able to remove the cancer by passing an instrument up the anus rather than using an endoscope. This is called transanal excision (TAE).

    A less commonly used method is a colonoscopic excision, which can remove small tumours from the colon.

    The type of surgery you have will depend on the location of the cancer. The surgeon will also consider your preferences.

    If there are two cancers—​​​​​​​in a small number of people, two separate cancers may be found in the large bowel at the same time. The cancers may be discovered through diagnostic tests or during surgery. In this case, there are three options for surgery:

    1. remove two sections of the bowel
    2. remove one larger section of the bowel, containing both areas with cancer
    3. remove the entire colon and rectum (proctocolectomy) to prevent any chance of another cancer forming

    The type of surgery your doctor recommends depends on several factors including the location of the tumours in the colon, genetic and other risk factors, and your preferences.

    Surgery for a blocked bowel (bowel obstruction)

    Sometimes as the bowel cancer grows it completely blocks the bowel. This is called bowel obstruction. Waste matter cannot pass through the blocked bowel easily, and may cause:

    • bloating and abdominal pain
    • constipation
    • nausea and vomiting

    Sometimes the obstruction is cleared during surgery to remove the cancer. In some cases, the bowel obstruction will mean you have to have emergency surgery. It may be possible to close up the bowel during the surgery, but some people may need a stoma. Sometimes a stoma is made ‘upstream’ from the obstruction to relieve the blockage to allow time for staging scans of the cancer or chemoradiotherapy before surgery, to make sure the cancer is removed appropriately.

    Not everyone with a blockage will want an operation or be fit enough to have it. To help keep the bowel open so that bowel motions can pass through again, your surgeon may be able to put in a small tube (stent). A stent may also help manage the blockage until you are well enough for an operation. A flexible tube with a light at the end, called an endoscope, is passed through the rectum. This helps the surgeon see the blockage, and the stent is inserted through it.

    If you are unable to have surgery or a stent, you may be given medicine to help control the symptoms of a bowel obstruction.


    Radiotherapy (also known as radiation therapy) uses radiation, such as protons, to kill cancer cells. The radiation is targeted to the specific site of the cancer, and treatment is carefully planned to do as little harm as possible to your normal body tissue near the cancer.

    Commonly, radiotherapy is used before surgery for locally advanced rectal cancer. It is often combined with chemotherapy and radiotherapy (called chemoradiotherapy or chemoradiation). This is because chemotherapy makes cancer cells more sensitive to radiotherapy, and reducing the number of cancer cells will make it easier for the surgeon to completely remove the tumour.

    Radiotherapy is not used to treat early colon cancer.

    Radiotherapy can be delivered in different ways, including IMRT (intensity-modulated radiation therapy) and VMAT (volumetric modulated arc therapy). These techniques deliver a dose to the affected area without damaging surrounding tissue. These improvements have reduced the side effects from radiotherapy.

    During treatment, you will lie on a treatment table under a machine called a linear accelerator. Each treatment takes only a few minutes, but a session may last 10–20 minutes because of the time it takes to set up the machine.

    If radiotherapy is given with chemotherapy, you will have it once a day for five or six weeks. You may have a shorter course of radiotherapy if it is given by itself, usually for five days, Monday to Friday.

    For more information about radiotherapy, call Cancer Council 13 11 20 or you can download the booklet Understanding Radiation Therapy.

    Side effects of radiotherapy

    Common side effects of radiotherapy include:

    • diarrhoea
    • tiredness
    • urinary or faecal incontinence
    • redness and soreness in the treatment area
    • reduced fertility
    • problems with sexual function

    People react to treatment differently, so some people may have few side effects, while others have more. Your treatment team will give you advice about how to manage radiotherapy side effects.


    Chemotherapy is the treatment of cancer with anti-cancer (cytotoxic) drugs. It aims to kill cancer cells while doing the least possible damage to healthy cells. If the cancer has spread outside the bowel to lymph nodes or to other organs, chemotherapy is usually needed. Chemotherapy may be used for several reasons:

    Before surgery (neoadjuvant)—​​​​​​​some people with locally advanced rectal cancer have chemotherapy before surgery to shrink the tumour and make it easier to remove during surgery. You are likely to have chemotherapy together with radiotherapy (called chemoradiotherapy or chemoradiation).

    After surgery (adjuvant)—​​​​​​​chemotherapy is used after surgery for either colon or rectal cancer to reduce the chance of the cancer coming back by eliminating any cancer cells that may have spread after surgery. You will probably start chemotherapy as soon as your wounds have healed and you’ve recovered your strength, usually within eight weeks.

    If the cancer has spread to other organs, such as the liver or lungs, chemotherapy may be used to reduce symptoms and make you more comfortable.

    You may have chemotherapy injected into a vein (intravenously) or as tablets. If you have chemotherapy intravenously, you can have the drugs through a thin plastic tube called a central venous access device (CVAD). The CVAD may be placed under the skin with a local anaesthetic. This type of CVAD is called a port-a-cath.

    Some people have chemotherapy through a portable bottle called an infusor pump. It is made of hard plastic and looks like a baby bottle. It is usually worn in a bag around your waist or on your hip. The bottle gives a continuous dose over 48 hours while you are at home. You will be shown how to care for the infusor pump. You will probably have chemotherapy as a course of several sessions (cycles) over four to six months. Your medical oncologist will explain your treatment schedule.

    Side effects of chemotherapy

    Most chemotherapy drugs cause some side effects. The side effects depend on the drugs used and the dosage levels.

    Common side effects include:

    • tiredness
    • feeling sick (nausea and vomiting)
    • diarrhoea
    • mouth sores and ulcers
    • changes in appetite and loss of taste
    • a drop in levels of blood cells (your blood count), which may increase the risk of infection
    • sore hands or feet
    • pins and needles, numbness, redness or swelling in the fingers and toes—​​​​​​​more common if using the chemotherapy drug called oxaliplatin
    • skin peeling and increased sensitivity to sunlight—​​​​​​​more common if using the chemotherapy drug called fluorouracil (or 5-FU)

    People react to chemotherapy differently—​​​​​​​some people have few side effects, while others have many. Most side effects are temporary, and there are ways to prevent or reduce them. Your doctor will prescribe medication to prevent and manage the side effects. It is uncommon to need a break or change in your treatment.

    Keep a record of the doses and names of your chemotherapy drugs handy. This will save time if you become ill and need to visit the emergency department.

    For more information about chemotherapy, call Cancer Council 13 11 20 or you can download the booklet Understanding Chemotherapy.

    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 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.

    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. 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.

    Bevacizumab—​​​​​​​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.

    For more information about targeted therapy, call Cancer Council 13 11 20 or you can download the factsheet Understanding Targeted Therapy.


    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.

    For more information about radiotherapy, call Cancer Council 13 11 20 or you can download the booklet Understanding Radiation Therapy.


    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.

    Palliative treatment

    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 about palliative treatment, call Cancer Council 13 11 20 or you can download the booklets Understanding Palliative Care and Living with Advanced Cancer.

    This website page was last reviewed and updated November 2018

    Information reviewed by: 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.

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