Calculating the impact of bowel cancer screening

Background

Australia has one of the highest rates of bowel cancer in the world. The lifetime risk of developing bowel cancer before the age of 75 is around 1 in 21 for men and 1 in 30 for women. This makes bowel – or colorectal – cancer the third most common cancer in Australia and the second most common cause of cancer death.

Finding bowel cancer early can substantially improve a person’s chance of surviving the disease. Australia’s National Bowel Cancer Screening Program was introduced in 2006. The program aims to reduce deaths from bowel cancer through prevention and early detection of the disease by providing free biennial screening using the immunochemical faecal occult blood test (iFOBT) for people aged 50-74 years. However, only 40% of Australians who are eligible for bowel screening currently participate in the national program.

The research

The team evaluated the impact of the National Bowel Cancer Screening Program over the next 40 years. The findings showed the program would prevent 92,200 cancer cases and 59,000 deaths between now and 2040 at current participation levels.

The team further examined the potential benefits of improved participation rates. They found that an additional 24,300 cases of bowel cancer and 16,800 deaths could be prevented if participation in the program increased to 50%. If participation increased to 60%, they calculated an additional 37,300 cases and 24,800 deaths would be prevented. This means that if just 20% more Australians completed the free test sent by the National Bowel Cancer Screening Program, 83,800 lives could be saved between now and 2040.

They also found the program is highly cost-effective, predicting overall cost savings within a decade of full roll out due to reduced number bowel cancer incidences.