Colorectal cancer (CRC) is the second most common internal malignancy affecting Australians. Age-standardised incidence and mortality rates are falling, yet CRC still kills more Australians than any other cancer except for lung cancer despite the fact that CRC biology offers a window of opportunity for prevention and cure.
The adenoma-cancer sequence means that appropriately timed colonoscopy could dramatically reduce both CRC incidence and mortality by detecting and completely removing conventional and serrated adenomas, from which the majority of CRC arises. To maximise this potential benefit, colonoscopy must be performed to a very high standard at appropriate intervals.
Purpose and scope
These guidelines update the 2011 edition by reviewing literature published in the interim. They focus on the appropriate use of colonoscopy in CRC prevention and address three main questions:
- when to repeat colonoscopy after removal of adenomatous polyps?
- when to repeat colonoscopy after curative resection of CRC?
- when to perform colonoscopy in those patients with inflammatory bowel disease (IBD) who have an increased risk of developing CRC?
These guidelines are intended for use by health professionals advising patients who are at increased risk of CRC (due to a personal past history of precancerous polyps, CRC or IBD) about the need for and timing of future colonoscopy. They may also be of interest to policy makers and educators providing training in medicine or other health sciences.
They are not intended as health information for the general public.
These guidelines cover a range of Australian populations, including:
- people with precancerous lesions detected on colonoscopy
- people with a diagnosis of CRC
- some people with a diagnosis of IBD (ulcerative colitis or Crohn’s disease).
These guidelines are not intended to apply to people for whom colonoscopy is indicated for screening or investigation of symptoms rather than for the purpose of surveillance:
- people with a family history of CRC or known familial syndromesGenetic disorders in which inherited genetic mutations in one or more genes predispose a person to developing cancer, particularly at an early age.
- people with symptoms and signs that may suggest CRC
- people with a positive faecal occult blood testA test that can detect microscopic amounts of blood in stools..
Clinicians should consider the specific needs of patients with CRC from culturally diverse groups, including younger people, Aboriginal and Torres Strait Islander peoples and culturally and linguistically diverse communities.
It is worth noting that for each systematic review, the search strategies specifically included terms designed to identify data relevant to Aboriginal and Torres Strait Islander peoples. However, the literature searches did not identify any studies specifically relevant to Aboriginal and Torres Strait Islander populations that met the inclusion criteria.
Healthcare settings in which the guideline will be applied
These guidelines apply to the range of public and private healthcare settings in which services are provided for the target populations. These include:
- general practice;
- specialist clinics;
- imaging services;
- pathology services;
- allied health care services.
The Australian Government Department of Health commissioned and funded Cancer Council Australia to undertake the current revision and update of this guideline.
NHMRC approved recommendation types and definitions
This guideline includes evidence-based recommendations, consensus-based recommendations and practice points as defined by the Level and Grades for Recommendations for Guidelines Developers (see NHMRC approved recommendation types and definitions in the Summary of recommendations section).
The methodology adopted for this guideline revision has been recorded in the Technical Report, which outlines the development process, lists the clinical questions and detailed technical documentation.
Scheduled review of these guidelines
It is inevitable that parts of this guideline will become out of date as further literature is published. Newly published evidence relevant to each systematic review question will be monitored. If strong evidence supporting a change in the guideline is published, the working party will consider if an update is required for a specific section. We recommend that the guideline as a whole should be reviewed and updated every 5 years.
The update of the guidelines was overseen by a multidisciplinary working party with input by subcommittees. We thank the members of the working party, subcommittees, systematic reviewers and all others who contributed to the development of these guidelines.
Medical writing and editing of the content were provided by Jenni Harman, medical writer and editor, Meducation Australia.
- Australian Institute of Health and Welfare (AIHW). Reports and data: Health conditions, disability & deaths (Cancer). [homepage on the internet] Australian Government; 2019 [cited 2019 Aug 16; updated 2019 Jan 9]. Available from: https://www.aihw.gov.au/reports-data/health-conditions-disability-deaths/cancer/overview.
- National Health and Medical Research Council. NHMRC levels of evidence and grades for recommendations for guideline developers. Canberra: National Health and Medical Research Council; 2009 Available from: https://www.nhmrc.gov.au/_files_nhmrc/file/guidelines/developers/nhmrc_levels_grades_evidence_120423.pdf.