Pathways to a cancer-free future: a protocol for modelled evaluations to minimise the future burden of colorectal cancer in Australia

Abstract

Introduction: With almost 50% of cases preventable and the Australian National Bowel Cancer Screening Program in place, colorectal cancer (CRC) is a prime candidate for investment to reduce the cancer burden. The challenge is determining effective ways to reduce morbidity and mortality and their implementation through policy and practice. Pathways-Bowel is a multistage programme that aims to identify best-value investment in CRC control by integrating expert and end-user engagement; relevant evidence; modelled interventions to guide future investment; and policy-driven implementation of interventions using evidence-based methods. METHODS AND ANALYSIS: Pathways-Bowel is an iterative work programme incorporating a calibrated and validated CRC natural history model for Australia (Policy1-Bowel) and assessing the health and cost outcomes and resource use of targeted interventions. Experts help identify and prioritise modelled evaluations of changing trends and interventions and critically assess results to advise on their real-world applicability. Where appropriate the results are used to support public policy change and make the case for optimal investment in specific CRC control interventions. Fourteen high-priority evaluations have been modelled or planned, including evaluations of CRC outcomes from the changing prevalence of modifiable exposures, including smoking and body fatness; potential benefits of daily aspirin intake as chemoprevention; increasing CRC incidence in people aged <50 years; increasing screening participation in the general and Aboriginal and Torres Strait Islander populations; alternative screening technologies and modalities; and changes to follow-up surveillance protocols. Pathways-Bowel is a unique, comprehensive approach to evaluating CRC control; no prior body of work has assessed the relative benefits of a variety of interventions across CRC development and progression to produce a list of best-value investments.

Ethics and dissemination: Ethics approval was not required as human participants were not involved. Findings are reported in a series of papers in peer-reviewed journals and presented at fora to engage the community and policymakers.

Keywords: colorectal cancer; early detection; prevention; screening.

Figure 1

Schematic diagram of the Policy1-Bowel microsimulation model platform. *Cancer patients surviving five years after diagnosis and treatment become cancer survivors. Cancer survivors in the model were assumed to have no additional risk of death due to colorectal cancer compared with the average population with no colorectal cancer. CRC, colorectal cancer; HG, high grade; LG, low grade.

Figure 2

Screening delivery pathway (based on NBCSP) modelled in the Policy1-Bowel microsimulation model platform. #Including people who were not recommended to attend colonoscopy due to coexistent disease or other health issues and people who did not comply with GP’s colonoscopy referral. *Barclay, K. Cancer Council Australia Surveillance Colonoscopy Guidelines Working Party. Algorithm for colonoscopic surveillance intervals–adenomas, 2013. Available at: http://www.gastroservices.com.au/pdf/algorithm-for-colonoscopic-surveillance-intervals-adenomas.pdf (accessed 28 December 2016). AA, advanced adenoma; GP, general practitioner; iFOBT, immunochemical faecal occult blood test; NBCSP, National Bowel Cancer Screening Program; SSL, sessile serrated lesion.