Bowel cancer, also called colorectal cancer, is the second biggest cause of cancer death in Australia. It is diagnosed in about 3,900 Victorians and over 15,000 Australians every year. If you are 50 or over, you are at higher risk of bowel cancer. It can develop with no symptoms, but if detected early, more than 90 per cent of bowel cancers can be successfully treated.
The bowel cancer care pathway, produced by Cancer Council Victoria, can help you make sense of what should happen during your experience with bowel cancer.
How bowel cancer develops
The colon and rectum together are known as the large bowel. Bowel cancer usually affects the large bowel. Cancer of the large bowel is also known as colorectal cancer.
Illustration above adapted from original illustration, courtesy of the Cancer Council Victoria.
The bowel is the long ‘tube’ that absorbs water and nutrients from food and processes waste products into faeces (poo). It includes the small bowel, colon and rectum.
As people get older, little lumps called polyps may grow inside the colon or rectum, and can become cancerous. A polyp looks like small spots on the bowel lining or like cherries on stalks. Not all polyps become cancerous. If polyps are removed, the risk of bowel cancer is reduced.
The development of bowel cancer generally takes many years. It usually begins in the lining of the colon or rectum. Often, very small amounts of blood, which may not be able to be seen, are leaked from these cancers long before any symptoms develop. This blood is then passed into the faeces.
If untreated, it spreads deeper into the wall of the bowel. From there, it can spread to lymph nodes in the area. Later, bowel cancer can spread to the liver or lungs.
Risk factors for bowel cancer
The causes of bowel cancer are not clearly understood. Regular screening is important because bowel cancer can develop without noticeable symptoms.
The risk of bowel cancer is greater if you:
- are aged 50 and over (your risk increases with age)
- have had an inflammatory bowel disease, such as Crohn’s disease or ulcerative colitis
- have previously had special types of polyps, called adenomas, in the bowel
- have a significant family history of bowel cancer or polyps.
If you are worried about your risk of bowel cancer, speak to your doctor.
Screening for bowel cancer
If detected early, more than 90 per cent of bowel cancers can be successfully treated.
The National Bowel Cancer Screening Program is an Australian Government screening program. From 2020, this program will send a free at-home bowel cancer screening test to all eligible Australians aged 50 to 74, every two years.
Bowel cancer screening is looking for early changes in the bowel lining, or signs of a bowel cancer in healthy people who do not have symptoms, but are at higher risk because they are in the 50 to 74-year age group.
Screening can find polyps so they can be removed before they turn into cancer. The National Bowel Cancer Screening Program is one of the most effective ways to prevent bowel cancer developing.
The screening test that is used is called the faecal occult blood test (FOBT). This involves taking tiny samples from two separate bowel motions (poo) using a test kit. The samples are then posted to a laboratory for testing.
If blood is detected, the doctor is likely to refer you for a colonoscopy. Most positive tests are not the result of cancer. However, if cancer is detected early, there is a higher chance of it being treated successfully.
Cancer Council recommends all Australians aged 50 to 74 years take part in the National Bowel Cancer Screening Program, and complete the at-home test every two years. It could save your life.
For more information, see National Bowel Cancer Screening Program. or phone 1800 118 868. You can also find out more about FOBTs and where to get one at the Cancer Council website.
Symptoms of bowel cancer
Bowel cancer can develop with no symptoms. This is why it is important to participate in screening.
Symptoms can include:
- blood in your poo or in the toilet bowl
- a recent and persistent change in your toilet habits, such as looser poo, severe constipation or if you need to poo more often than usual
- unexplained tiredness or weight loss
- stomach pain.
Having these symptoms does not mean that you have bowel cancer. People experiencing these symptoms should speak to their doctor.
Types of bowel cancer
More than 95 per cent of colorectal cancers are adenocarcinomas. This means they started in the gland cells in the lining of the bowel. Other rare types include squamous cell cancers (in the skin like cells of the bowel lining), carcinoid tumours, sarcomas and lymphomas.
Squamous cells are the skin-like cells that make up the bowel lining along with the gland cells.
Diagnosis of bowel cancer
Several tests can be used to diagnose bowel cancer including:
- rectal examination
- colonoscopy and sigmoidoscopy
- barium enema
- ultrasound, PET scan, rectal ultrasound, CT scan or MRI scan
- blood tests, including a carcinoembryonic antigen (CEA) test – CEA is produced in high quantities by some cancer cells, especially in bowel cancer.
Test results can take a few days to come back. It is very natural to feel anxious waiting to get your results. It can help to talk to a close friend or relative about how you’re feeling. You can also contact the Cancer Council on 13 11 20 and speak with a cancer nurse.
Bowel cancer stages
Knowing if and how far the cancer has spread is called ‘staging’ the disease. Staging helps your doctors to work out the best treatment for you.
In Australia, the staging system for bowel cancer is the Australian Clinico-Pathological Staging (ACPS) System, being:
- Stage A – the cancer is confined to the bowel wall
- Stage B – the cancer has spread to the outer surface of the bowel wall
- Stage C – cancer is found in lymph nodes near the bowel
- Stage D – cancer is found at distant sites, for example, in the liver or lungs.
You may also hear about the ‘Dukes’ system, which is very like the ACPS. Another staging system being used more often is called the TNM system. It records how far the tumour (T) has spread through the bowel wall, if lymph nodes (N) are affected by the cancer, and whether the cancer has spread (metastasised) to other parts of the body (M).
Ask your doctor to explain the stage of your cancer in a way you can understand. This will help you to choose the best treatment for your situation.
Treatment for bowel cancer
Surgery is the main treatment for bowel cancer. The surgeon removes the section of the bowel affected by cancer and then joins the two ends. A stoma (an opening of the bowel onto the abdomen) is sometimes made during the surgery. Your bowel motions will come through the stoma into a bag.
Stomas are usually temporary, while the bowel heals, but some people will need them permanently. Understandably, many people find this difficult to deal with. Before your surgery, you will be given a lot of education and support about having a stoma. Chemotherapy or radiotherapy is nearly always used in addition to surgery. Your doctor will discuss your treatment in detail with you.
It’s common for people with cancer to seek out complementary or alternative treatments. When used alongside your conventional cancer treatment, some of these therapies can make you feel better and improve quality of life. Others may not be so helpful and, in some cases, may be harmful.
It is important to tell all your healthcare professionals about any complementary medicines you are taking. Never stop taking your conventional treatment without consulting your doctor first. The Cancer Council booklet Understanding complementary therapies can be a useful resource.
All treatments have side effects. These will vary depending on the type of treatment you are having. Many side effects are temporary, but some may be permanent. Your doctor will explain all the possible side effects before your treatment begins.
Living with a stoma
Most people find it takes time to come to terms with having a stoma. It is a big change in your life. People often worry about how they will care for their stoma. A stomal nurse will explain how to care for your stoma and tell you about support services.
You may also be very concerned about the effect it may have on your personal relationships, sexuality and lifestyle. You may find it difficult or embarrassing to talk about cancer and sexuality. However, most doctors and nurses are very understanding, and even if they're unable to help, they can refer you to a doctor or therapist who specialises in sexual problems.
If you have a partner, it also helps to be as open as possible with them about how you are feeling. The Cancer Council booklet Sexuality, intimacy and cancer may also be helpful to read.
Research into bowel cancer
Early detection and better treatment have improved survival for people with bowel cancer. The research is ongoing. Clinical trials can test the effectiveness of promising new treatments or new ways of combining cancer treatments. Always discuss treatment options with your doctor. The Cancer Research UK website has information about research into bowel cancer.
Reducing your risk of bowel cancer
For people aged 50 to 74 and at average risk of bowel cancer, participating in the National Bowel Cancer Screening Program is the most effective way to reduce your risk of bowel cancer.
You can also help to reduce your risk of bowel cancer by:
- eating a healthy diet, including plenty of fresh vegetables and fruit
- eating limited amounts of red meat
- eating limited amounts of processed meats
- maintaining a healthy body weight
- daily physical activity
- not smoking.
Following this advice doesn’t mean that you will never get bowel cancer, but it can reduce your risk and has other health benefits too.
Caring for someone with bowel cancer
Caring for someone with cancer can be a difficult and emotional time. If you or someone you know is caring for someone with bowel cancer, there is support available. The Cancer Council booklet Caring for someone with cancer [https://www.cancervic.org.au/downloads/resources/booklets/Caring-for-someone-with-cancer.pdf] may also be helpful to read.
When a cure isn’t possible
If the bowel cancer has spread to other parts of the body, it is not always possible to cure. However, in a lot of people, it is still likely that the cancer can be kept under control for quite a long time.
This depends on:
- where and how far the cancer has spread
- what treatment you have had in the past
- the type of bowel cancer you have.
Treatment for control of cancer may include chemotherapy, radiotherapy, surgery, immunotherapy or pain-relieving medications (or a combination of these). You may hear your doctor call your treatment ‘palliative’. This means treatment designed to relieve symptoms rather than cure. The Cancer Council booklet Treatment for advanced cancer may be helpful to read.
Where to get help