How bowel cancer screening works
60-74 year old group. ❚ The bowel screening programme is only for people who don’t have any symptoms of cancer – people who do have any suggestive symptoms need assessment of their bowel using either a camera (known as sigmoidoscopy or colonoscopy) or a CT scan. ❚ The screening programme uses a Faecal Immunochemical Test (FIT) to pick up microscopic traces of blood in small samples of stool – as bleeding is one of the first signs of polyps or bowel cancer (even if it can’t be seen by the naked eye). A positive FIT is a good indication that something could be wrong. ❚ The FIT kit is delivered to the homes of people who are eligible for screening; it contains a small tube to collect your sample, a ziplock bag to put it in, a consent form that needs to be signed, and a freepost envelope to send it back for testing. ❚ The following people are eligible for screening under the current criteria – anyone in the 60-74 age range, as long as they don’t have any symptoms that might suggest cancer; people are excluded if they have current symptoms, have had cancer in the past, or are being treated for ‘‘inflammatory’’ bowel diseases such as Crohn’s disease or colitis. ❚ Results from the FIT will be available within three weeks of sending the test in – if you don’t hear in that timeframe, it is important to chase it up and ensure all is well. ❚ A negative result means that it is very unlikely you have any bowel cancer or pre-cancer – however, it isn’t impossible, as no screening test is perfect. It is important you get screened again in two years’ time if you are still eligible at that stage. ❚ A positive result does NOT necessarily mean you have cancer – lots of other common conditions (such as haemorrhoids) can cause blood in your bowel motion; however, if you have a positive FIT, you will be referred for further assessment of your bowel to exclude polyps or cancer. This will usually include a colonoscopy, where a camera is inserted into the bowel to get a closer look and take samples. Of all people in the pilot programme who were referred for colonoscopy, 70 per cent turned out to have polyps which were removed, and 7 per cent turned out to have cancer.
The programme was launched in Wairarapa and Hutt Valley last month, and other district health boards will follow in the next two years. To find out when it will be available in your area, or for more information, visit nsu.govt.nz/national-bowelscreening-programme ❚ Dr Cathy Stephenson is a GP and forensic medical examiner.