Bowel cancer and the key to prompt colonoscopy referral
If Australia’s National Bowel Cancer Screening Program can reach and maintain a 60% participation rate in the next couple of years, 84,000 premature bowel cancer deaths could be avoided by 2040. GPs will be pivotal to achieving this goal, as will greater use of bowel cancer guidelines throughout the health system.
The mortality reduction projections were published as part of a review of clinical practice guidelines for the prevention, detection and management of colorectal cancer in Australia, approved by the National Health and Medical Research Council in October 2017.
With so much to gain, it’s timely to emphasise the life-saving benefits of the NBCSP and to highlight the new guidelines’ recommendation for prompt colonoscopy referral:
“Colonoscopy should be performed as promptly as possible after a positive iFOBT to minimise the risk of psychological harm, although there is no evidence that prognosis is worsened within 120 days if cancer is present.”
The advice is the same for the symptomatic patient, as both recommendations drew on the same systematic review evidence. The reference to “120 days” was based on an analysis of nine cohort studies that met the systematic review inclusion criteria and were deemed relevant to the clinical question.
The finding, however, is not a recommendation to wait 120 days. The guidelines are explicit in recommending patients with a positive iFOBT or symptoms are referred for investigation “as promptly as possible”. The 120 days does however draw a line in the sand, based on evidence, and states that any delay beyond this could have an adverse clinical outcome.
Waiting for a colonoscopy after a positive iFOBT or presentation with symptoms is likely to cause anxiety in some patients and could cause some to drop out of the screening program. So it is critical that such patients are investigated as promptly as possible.
Which brings us to the problem of colonoscopy waiting times.
Around 1 million colonoscopies are performed in Australia each year. In 2015 (the most recent data), only 29,000 colonoscopies were conducted for people who had tested positive for iFOBT through the NBCSP – about 3% of total colonoscopies.
Even allowing for people who screen with iFOBT outside the program, and for other priority patients (those with symptoms or family history), we can still assume tens of thousands of average-risk people are screening with colonoscopy. Is it any wonder there are reports of pressures on colonoscopy waiting times, when there is such widespread inappropriate use of colonoscopy as a first-line screening tool?
The best way to free up colonoscopy services for people with the highest need is for more average-risk Australians to screen with iFOBT.
The first recommendation in the population screening chapter of the colorectal cancer guidelines is for iFOBT to be used “as the screening modality for the detection of colorectal cancer in the average-risk population”. iFOBT has a sensitivity rate within the screening program of 83%, was shown in pilot studies to be acceptable to the population and is a fraction of the cost of colonoscopy – and for NBCSP participants, iFOBT is free.
Evidence shows the NBCSP has the potential to prevent more premature cancer deaths in the short, medium and long term than any other public health intervention introduced in Australia. The benefits increase in step with the rate of program participation.
Based on current evidence of clinical and cost benefit, and overall feasibility, there is no other way to save 84,000 Australians from a premature bowel cancer death within 20 years. We should be promoting what promises to be one of the world’s great cancer control initiatives – and prioritising healthcare services to help ensure it reaches its potential.
If Australia has capacity to perform 1 million colonoscopies in a year, surely we have capacity to ensure people who test positive for iFOBT or have bowel cancer symptoms are investigated within a matter of weeks. We need more clinicians supporting the NBCSP and adhering to guidelines to help ensure limited healthcare resources are prioritised for those who need them most on a population basis.
Professor Tim Price is a medical oncologist and the chair of the multidisciplinary expert management group that oversaw the development of the NHMRC-approved clinical practice guidelines for the prevention, detection and management of colorectal cancer.