A narrative review of colorectal cancer screening – current screening modalities, barriers and facilitators, strategies, future challenges, and the application in the local context

Introduction Colorectal cancer (CRC) remains a significant global health burden, with a significant impact in the local context as well. It is however preventable and treatable if detected at an early stage through screening. This review aims to provide a comprehensive cover of the current state of CRC screening, including current screening guidelines and modalities, barriers to screening, strategies to improve screening uptake, as well as future developments and challenges, and application of these findings in our local context. Methods A comprehensive search was performed in PubMed, Web of Science, and EMBASE electronic databases. Manual searches of references of all included studies were performed to identify other relevant publications. Only studies published in English were included. Results Currently, there are several modalities for CRC screening, ranging from invasive, direct-visualisation modalities to non-invasive blood- and stool-based tests, each with its own unique performance characteristics. However, screening remains underused due to a myriad of reasons: intrapersonal behavioural factors, interpersonal issues of family, culture and religion, and broader systemic issues of cost, access to healthcare and policy. Whilst various interventions have been designed to improve screening uptake, evidence suggests that multi-pronged, multi-targeted approaches are most effective. Nonetheless, CRC screening is continually evolving with newer screening modalities, and updated guidelines, all of which can impact screening uptake directly or indirectly. Conclusion With these in mind, future research should also continue to focus on strategies to improve screening uptake by integrating behavioural interventions with sociocultural, and health systems level considerations. These efforts should go in tandem with analyses on cost effectiveness and implementation science.