Shift to earlier stage at diagnosis as a consequence of the National Bowel Cancer Screening Program
Stage at diagnosis is critical in determining the probability of survival with colorectal cancer (CRC). In randomised controlled trials, population screening using faecal occult blood tests (FOBT) results in earlier stage at diagnosis for screen-detected cancers,1 and reduced mortality from colorectal malignancy compared with controls.2–4 Evaluations of cancer prevention programs with mortality as an end point take many years to complete. However, we know that early stage at diagnosis is linked to better prognosis and reduced mortality from CRC, so stage at diagnosis can serve as a surrogate marker for population mortality, and provides an early signal of program benefit.
After a pilot study in 2003, a faecal immunochemical test (FIT)-based National Bowel Cancer Screening Program (NBCSP) has been progressively rolled out across Australia. Participants in the program receive a free two-sample FIT kit by mail from a central register, collect samples and return them for testing. Results are mailed to participants and their nominated primary care practitioner (PCP). The PCP arranges follow-up of people with positive FIT results.