Bowel cancer is also called cancer of the colon, cancer of the rectum, or colorectal cancer. This cancer occurs when the cells in some part of the bowel grow abnormally and form a lump or tumour which has the ability to spread to other parts of the body.
Most bowel cancers are in the large bowel, which is made up of the colon and the rectum. Occasionally the cancer is in the small bowel, but this is quite unusual.
Usually bowel cancer starts in the cells of a polyp, a mushroom-like growth that occurs inside the bowel (colon or rectum). Only about 5% of polyps develop into cancer but all but the smallest polyps should be removed to ensure they don't turn into cancer.
In 2008, bowel cancer was the second most common cancer in New Zealand, and the second highest cause of cancer death. Our death rate from bowel cancer is one of the highest in the developed world. In 2008, 2801 people were diagnosed with bowel cancer, and 1280 people died from the disease.
It may occur at any age, although 90 percent of cases are in individuals over the age of 50
Causes and symptoms of Bowel Cancer
Scientists are still unsure what causes bowel cancer. It often starts as a benign (not cancerous) polyp that turns into cancer over time.
People are more likely to develop bowel cancer as they grow older, with the number rising steeply from the age of 50 and it affects more men than women. Scientists believe a diet high in animal fats and low in fruit and vegetable fibre may contribute to the development of bowel cancer.
You are more at risk of developing bowel cancer if:
- You have a history of a number of family members over two or three generations being affected with bowel cancer
- You or a close family member have been diagnosed with bowel cancer at a young age
- There is concern that you and your family may have a genetic bowel cancer syndrome
- There is a known genetic bowel cancer syndrome in your family
- You have had extensive inflammatory bowel disease such as ulcerative colitis for more than 10 years.
Common signs and symptoms of bowel cancer may include:
- A change in bowel habit – i.e. your regular pattern of going to the toilet
- Diarrhoea, constipation, or feeling that your bowel doesn’t empty completely
- Blood in your bowel motion
Although these symptoms are usually caused by other conditions it is important to get them checked by your primary health care provider or doctor.
Treatment and Screening
People who are diagnosed with bowel cancer, and receive treatment when it is at an early stage, have a 90 percent chance of surviving five years. After five years they have the same survival rate as someone who has never had bowel cancer. If there is a delay in diagnosis and treatment, and the cancer spreads regionally, the five year survival rate drops to 70 percent, and then plummets to 10 percent where there is distant spread.
Bowel screening involves people within a certain age range being asked to take a screening test called an immunochemical faecal occult blood test (iFOBT). An iFOBT is used to detect blood in faeces (bowel motions). People with blood in their faeces will be offered a diagnostic colonoscopy, which can detect polyps and cancers if they are present. Polyps can usually be removed during a colonoscopy.
A four year bowel screening pilot began in 2012 to determine whether a bowel screening programme should be rolled out nationally. No decision will be made on implementing a national programme until all monitoring and evaluation data from the pilot has been analysed.
Waitemata District Health Board was selected to run the four year programme. The programme has recently been extended for two more years until the end of 2017. This means that most eligible people will receive a third invitation and test kit through the mail when it's their turn to participate.
More than 6000 people have received a colonoscopy through the WDHB bowel screening pilot since January 2012. Early evaluation results are psoitive and it is providing valuable information for a potential national roll out of the programme.
For more information on Bowel Screening and the pilot programme visit the Ministry of Health Website
While no cancer is completely preventable, you may be able to lower your risk of bowel cancer by eating a healthy diet and exercising regularly.
Enjoy a wide variety of nutritious foods –
- Eat plenty of vegetables, legumes (dried beans, peas or lentils), fruits & cereals (breads, rice, pasta & noodles), preferably wholegrain.
- Include lean meat, fish and poultry.
- Include milks, yoghurts and cheeses. Reduced fat varieties should be chosen where possible.
- Drink plenty of water.
Take care to -
- Limit saturated fat and moderate total fat intake.
- Limit your intake of red meat and processed meat.
- Choose foods low in salt.
- Limit your alcohol intake if you choose to drink.
- Consume only moderate amounts of sugars and foods containing added sugars.
Other Websites of Interest