National Bowel Cancer Screening Program – The evidence base

Australia has one of the highest rates of bowel cancer in the world.1 To reduce deaths from bowel cancer, the National Health and Medical Research Council (NHMRC) recommends faecal occult blood testing (FOBT) at least every two years for people over the age of 50 who are at, or slightly above, average risk for bowel cancer (about 98% of the population). In line with this, the National Bowel Cancer Screening Program (NBCSP) is expanding in stages so that by 2020 all eligible Australians aged 50-74 years will be invited to screen every two years. Age eligibility information is available here.

A 2014 study by the Australian Institute of Health and Welfare linked NBCSP, cancer incidence and mortality data. It found that NBCSP invitees had 15% less risk of dying from bowel cancer, and were more likely to have less-advanced bowel cancers when diagnosed, than non-invitees.2 The study also found that the FOBT used in the program has a high degree of accuracy (estimated 83% sensitivity and 93% specificity). A recent Healthpact report found that immunochemical FOBT, as is used in the NBCSP, is the best performing screening test for use in population screening.3

Despite the strong evidence-base for regular bowel cancer screening, current participation in the NBCSP is low at 37%. Modelling predicts that the NBCSP could prevent more than 70,000 deaths over the next 40 years at the current participation rate.4 If participation rose to 60%, it is predicted that an additional 20,000 deaths could be prevented over that period.

Research has consistently demonstrated that a recommendation from a GP to screen for bowel cancer using an FOBT is an important motivator for participation.5,6,7 GP involvement is particularly important to encourage screening by under-screened groups, including people from culturally and linguistically diverse and low-socioeconomic backgrounds and Aboriginal and Torres Strait Islander people. GPs are critical in managing participants with a positive FOBT and referring them for further examination as clinically indicated, such as for colonoscopy.

The FOBT is safe, non-invasive and easy to complete at home. In 2016, people aged 50, 55, 60, 64, 65, 70, 72 and 74 years will be invited to screen. We encourage GPs to talk to their patients about the benefits of bowel cancer screening.

For more information, including an eligibility tool where you can find out when an individual will receive a kit by entering their birthdate visit:

1. Section of Cancer Surveillance, International Agency for Research on Cancer, Lyon, France, 2012
2. Australian Institute of Health and Welfare 2014. Analysis of bowel cancer outcomes for the National Bowel Cancer Screening Program. Cat. no. CAN 87. Canberra: AIHW.
3. HealthPACT report. July 2015. Blood and stool based biomarker testing for colorectal cancer. Queensland Department of Health.
4. Cenin, Dayna R. “Optimising the expansion of the National Bowel Cancer Screening Program,” Medical Journal of Australia 2014; 201: p458-463
5. Zajac IT, Whibley AH, Cole SR, Byrne D, Gou J. Morcom J & Young GP. Endorsement by the primary care practitioner consistently improves participation in screening for colorectal cancer: a longitudinal analysis. J Med Screen 2010; 17, 19-24.
6. Salkeld GP, Solomon MJ, Short L, Ward J. Measuring the importance of attributes that influence consumer attitudes to colorectal cancer screening. ANZ J Surg 2003 Mar;73(3):128-32
7. Cole SR, Young GP, Byrne D, Guy JR, Morcom J. Participation in screening for colorectal cancer based on a faecal occult blood test is improved by endorsement by the primary care practitioner. J Med Screen 2002;9 (4):147-52