Bowel cancer

What is bowel cancer?

Bowel cancer is the third most common cancer affecting Australians. It is estimated around 15,500 people are diagnosed with bowel cancer every year. It is most common in people over 50, but it can occur at any age.

In its early stages, bowel cancer may have no symptoms, but if detected early, it can be successfully treated.

A lot can happen in a hurry when you’re diagnosed with cancer. The guide to best cancer care for bowel cancer can help you make sense of what should happen. It will help you with what questions to ask your health professionals to make sure you receive the best care at every step.

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 and might be called colon cancer or rectal cancer, depending on where it starts in the bowel.

Small bowel cancer is a rare type of cancer.

Illustration above adapted from original illustration, courtesy of the Cancer Council Victoria.

The bowel is part of the digestive system. The digestive system starts at the mouth and ends at the anus. It helps the body break down food and turn it into energy. It also gets rid of the parts of food the body does not use.

The bowel is the long ‘tube’ that absorbs water and nutrients from food and processes waste products into faeces (poo).

The development of bowel cancer generally takes many years. It usually begins in the lining of the colon or rectum.

If untreated, bowel cancer can grow 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.

Bowel cancer may begin with polyps

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.

Symptoms of bowel cancer

Bowel cancer can develop with no symptoms. So, it is important to participate in screening.

Symptoms may include:

• Blood in your poo, on the toilet paper or in the toilet bowl.
• A change in your bowel habits (such as diarrhoea or constipation)
• Feeling like you need to poo more often or the feeling of incomplete emptying.
• Feeling full or bloated in your belly or a strange sensation in the rectum, often during a bowel movement.
• A change in the appearance of your poo (such as thin stools).
• Anal or rectal pain.
• A lump in the anus or rectum.
• Unexplained tiredness, anaemia or weight loss.
• Abdominal (stomach) pain, cramps, or bloating.
• A blockage in the bowel.

Having these symptoms does not mean that you have bowel cancer. People experiencing these symptoms should speak to their doctor.

Bowel cancer risk factors

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 (risk increases with age).
• Have had an inflammatory bowel disease (such as Crohn’s disease or ulcerative colitis), particularly if you have had it for more than 8 years.
• Have previously had special types of polyps (called adenomas) in the bowel or a large number of polyps in the bowel.
• Have a significant family history of bowel cancer or polyps.
• Are overweight or obese.
• Eat a lot of red meat, especially processed meats (such as salami, ham, bacon, sausages)
• Smoke tobacco
• Have a high alcohol intake.

If you are worried about your risk of bowel cancer, speak to your GP (doctor).

Types of bowel cancer

About 9 out of 10 bowel cancers are adenocarcinomas. This means they start 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)
• neuroendocrine tumours (NETs)
• small bowel cancer
• gastrointestinal stromal tumours
• lymphomas.

Diagnosis of bowel cancer

Several tests can be used to diagnose bowel cancer including:

• Physical and rectal examination.
• Blood tests – including a carcinoembryonic antigen (CEA) test and immunochemical faecal occult blood test (iFOBT).
• Colonoscopy and biopsy.
• PET-CT scan.
• CT scan.
• MRI scan.
• Molecular testing – may be used with a diagnosis of advanced bowel cancer to check the biopsy sample for gene mutations or other cell features. If this is the case, further genetic testing may be required.
• CT colonography.
• Flexible sigmoidoscopy.

Waiting for test results

Test results may take a few days to come back. It is 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 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 doctor 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).

Another staging system used in Australia is the TNM (tumour nodes-metastasis) 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

Your health care 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.

Surgery

Surgery is the main treatment for bowel cancer. The aim of surgery is to remove as much of the cancer as possible and nearby lymph nodes.

Surgery may be performed as keyhole or open surgery.

The most common type of surgery is a colectomy – where a part of the bowel, lymph nodes near the colon and some normal bowel around the cancer is removed.

The surgeon removes the section of the bowel affected by cancer and then joins the two ends. If the end is made from the large bowel it is called a colostomy. If it is made from the small bowel it is called an ileostomy.

Colostomy

Ileostomy

Types of stomas, courtesy of Cancer Council Victoria.

A stoma (an opening of the bowel onto the abdomen) is sometimes made during the surgery. Your bowel motions (poo) will come through the stoma into a bag.

Some stomas are temporary – to allow the bowel to heal, while others are permanent. Around 1 in 10 people with rectal cancer need a permanent stoma.

Before your surgery, you will be given a lot of education and support about having a stoma.

Chemotherapy and radiotherapy

Chemotherapy or radiotherapy (also known as radiation therapy) is nearly always used in addition to surgery.

Radiation therapy is often used before surgery and may be used with chemotherapy to reduce the size and number of cancer cells.

Radiation therapy is not used for early colon cancer.

Occasionally, if the cancer is more advanced, radiation therapy may be used after surgery to destroy any remaining cancer cells.

If the cancer has spread outside the bowel to lymph nodes or to other organs, chemotherapy may be recommended:

• Before surgery – to shrink the tumour and make it easier to remove.
• After surgery – to kill any remaining cancer cells and reduce the chance of the cancer coming back.
• On its own – if the cancer has spread to other organs.

Your doctor will discuss your treatment in detail with you.

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.

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.

Complementary therapies

Complementary therapies are designed to be used alongside conventional medical treatments (such as surgery and radiation therapy). They can increase your sense of control, decrease stress and anxiety, and improve your mood.

It is important to tell your treating team about any complementary medicines you are taking. Never stop taking your conventional treatment without consulting your doctor first.

Side effects of bowel cancer treatment

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.

Radiation therapy to the pelvis and rectum can affect your sexual function and ability to have children (fertility). It is important to discuss your options with your doctors before you start treatment.

Some side effects can be upsetting and difficult, but there is help if you need it. Call Cancer Council 13 11 20 or email askanurse@cancervic.org.au to speak with a caring cancer nurse for support.

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.

Sexuality and bowel cancer

Having bowel cancer and treatment can change the way you feel about yourself, other people, relationships and sex. These changes can be very upsetting and hard to talk about. Doctors and nurses are very understanding and can give you support. You can ask for a referral to a counsellor or therapist who specialises in body image, sex and relationships.

Living with advanced cancer

Advanced cancer usually means cancer that is unlikely to be cured. Some people can live for many months or years with advanced cancer. During this time palliative care services can help.

Most people continue to have treatment for advanced cancer as part of palliative care, as it helps manage the cancer and improve their day-to-day lives.

Many people think that palliative care is for people who are dying but palliative care is for any stage of advanced cancer. There are doctors, nurses and other people who specialise in palliative care.

Treatment for advanced bowel cancer may include chemotherapy, radiation therapy, surgery or another type of treatment. It can help in these ways:

• slow down how fast the cancer is growing
• shrink the cancer
• help you to live more comfortably by managing symptoms, like pain.

Treatment depends on:

• where the cancer started
• how far it has spread
• your general health
• your preferences and what you want to do.

Ask your doctor about treatment and palliative care services that may help you.

Caring for someone with bowel cancer

Caring for someone with cancer can be a difficult and emotional time. If you are caring for someone with bowel cancer, these organisations can help:

• Cancer Council Victoria 13 11 20
• Carer Gateway 1800 422 737
• Carers Australia 1800 242 636

Reducing your risk of bowel cancer

For people aged 50 to 74 and at average risk of bowel cancer, having regular screening for bowel cancer 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 with plenty of fresh vegetables and fruit
• limiting your consumption of red meat and processed meats
• maintaining a healthy body weight
• daily physical activity
• quitting smoking
• reducing your alcohol intake.

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.

Screening for bowel cancer

Screening is the process of looking for cancer, or abnormalities that could lead to cancer, in people who do not have any symptoms. It is particularly important for bowel cancer, which often has no symptoms in its early stages.

The National Bowel Cancer Screening Program (NBCSP) sends free at-home bowel cancer screening test to all eligible Australians aged 50 to 74, every 2 years.

A test kit can also be purchased from some pharmacies.

The screening test used is called the faecal occult blood test (iFOBT). 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.

You can access more information about bowel cancer screening from the national Department of Health and the Indigenous Bowel Screen websites.

Where to get help

• Your GP (doctor)
• Your cancer specialist (oncologist)
• Your treatment team
• Cancer Council Victoria Tel. 13 11 20 (to speak to someone in a language other than English call 13 14 50 and ask to speak to Cancer Council)
• Cancer Council Victoria, My Cancer Guide - Find support services that are right for you.