Bowel cancer is the third most common cancer in both men and women in Australia. Australia has one of the highest rates of bowel cancer in the world with 1 in 13 Australians will develop the disease in their lifetime. The risk of developing bowel cancer rises progressively from age of fifty, but there is a steady increase in incidence in the younger population worldwide. That’s why it’s important to know the symptoms and undergo early investigations. Colorectal cancers are preventable and can treated successfully when detected early.
Colorectal cancers can be diagnosed by either screening or in patients with symptoms. For people at average or near average risk, Australian medical guidelines recommend screening using a faecal immunochemical test (FIT) every 2 years between ages 50-74. In 2018, the American Cancer Society has changed its screening guidelines to recommend lowering the starting age from 50 to 45 years in response to the rising rates of bowel cancer in young and middle-aged populations. The process involves collecting faecal materials, placing them on a card or in a container, and mailing them to a pathology laboratory for analysis. The results are then sent back to the individual and their GP. A positive result means blood in faeces has been detected. It does not necessarily mean bowel cancer is present but does require further investigation with a colonoscopy within 30 days. A negative result does not guarantee no cancer is present or that the person will never develop bowel cancer.
On the other hands, symptoms of colorectal cancers often overlap with benign anorectal diseases, these include change in bowel habits, blood in stool, weight loss, iron deficiency anaemia and abdominal pain. If symptoms persist two weeks or longer, patients should be referred by their GP to a specialist for colonoscopy within 30 days in order to investigate the cause. A colonoscopy encompasses a careful bowl preparation and a detailed examination looking specifically at the lining of the entire large bowel. When an abnormality is encountered biopsies are taken for histological confirmation, at the same time precursor lesion such as polyps can be removed.
Following the diagnosis, staging of the cancer will be arranged to determine the extent of spread with a combination of blood test, CT, magnetic resonance imaging (MRI) and positron emission tomography (PET scan). Treatment is tailored to each individual’s situation, this can include surgery, chemotherapy, radiation or a combination of these. Follow-up after initial treatment will be at various intervals for 5 years, often 3-6 monthly in the 2 years, 6-12 monthly for the next 3 years. During this time blood tests to measure levels of carcinoembryonic antigen (CEA), surveillance colonoscopies and CT scans may be necessary to detect recurrence.
Many people who have had colorectal cancer live normal lives. The treatments available today offer favourable outcomes with emphasis on early detection. Remember to tell your doctor about any changes in your health. This will help him or her decide if you need any additional tests.
Dr Jennifer Liang 