Bowel cancer

Bowel cancer affects men and women, young and old, but is more common in people over the age of 50.  While the risk of developing bowel cancer rises after the age of 50, the number of Australians diagnosed under 50 is increasing. About 30 per cent of bowel cancer is hereditary, leaving 70 per cent of patients with no family link.

Healthy cells grow and divide in an orderly way. Bowel cancer begins when healthy cells are damaged and develop changes in their DNA or instructions that tell the cell what to do. When a cell’s DNA is damaged, it can become cancerous by continuing to divide and accumulate cells that form into a tumour. Over time, those cells invade and destroy normal tissue and, if untreated, travel to other parts of the body.

Aging, smoking, eating large amounts of red meat, processed meats, alcohol, being sedentary and being overweight increase the risk of developing bowel cancer. Screening and surveillance, including regular colonoscopies, can reduce these risks. In addition, diet and lifestyle factors that help reduce the risk of developing bowel cancer include not smoking, eating plenty of fruit, vegetables and whole grains, limiting red and processed meats, exercising and maintaining a healthy body weight.

Some bowel cancer risks cannot be changed. These include family history and existing inflammatory intestinal conditions like inflammatory bowel diseases such as Crohn’s and Ulcerative Colitis.

Most bowel cancer starts as small, benign or non-cancerous growths called polyps on the wall or lining of the bowel. Polyps can be removed during a screening test or colonoscopy to prevent them becoming cancerous.  Untreated polyps grow into the bowel wall and can spread to lymph nodes and eventually, other organs such as the liver or lungs.

Diagnosis of bowel cancer

After an initial medical examination, your doctor may send you for tests. Bowel cancer tests include blood test, immunochemical faecal occult blood test, a colonoscopy, an MRI, a CT scan, PET scan or an immunochemical faecal occult blood test.

Treatment

Nearly 99 per cent of bowel cancers can be treated successfully if detected early, through screening and surveillance. Treatments for bowel cancer include surgery, chemotherapy, radiation therapy or a combination of these.

Because there are no early bowel cancer symptoms, only 50 per cent of cancers are detected at the early stages, highlighting the importance of regular screening.