Professor El-Omar has selected Professors Francis KL Chan, Siew C Ng, Martin CS Wong, Raja Affendi Raja Ali, and Kaichun Wu to do the next #GUTBlog.
Prof. Francis Chan is the Dean of Faculty of Medicine and Chair Professor of the Department of Medicine and Therapeutics, the Chinese University of Hong Kong (CUHK). Prof. Siew Ng is Croucher Professor in Medical Sciences and Director, Microbiota-I Center (MagIC). Prof. Martin Wong is Professor and Director of the Centre for Health Education and Health Promotion, JC School of Public Health and Primary Care, CUHK. Prof. Ali is Professor of Medicine, Consultant Physician in Gastroenterology & Hepatology of the National University of Malaysia. Prof. Wu is Professor and the Deputy Chair of Xijing Hospital of Digestive Diseases, the Fourth Military Medical University.
The #GUTBlog focusses on the article “Joint Asian Pacific Association of Gastroenterology (APAGE)–Asian Pacific Society of Digestive Endoscopy (APSDE) clinical practice guidelines on the use of non-invasive biomarkers for diagnosis of colorectal neoplasia” which was published online in GUT on 5th April 2023.
“Colorectal cancer (CRC) remains highly prevalent in many countries worldwide. CRC screening has been proven to be effective in reducing CRC-related mortality. In the past decade, there is an increasing number of publications reporting the use of non-invasive biomarkers for CRC screening. Whilst most countries in the Asia-Pacific region rely on faecal immunochemical test (FIT) as a primary screening modality, emerging number of biomarkers have shown promising accuracy for CRC detection, with some having high sensitivity to also detect advanced adenomas. Colonoscopy is effective to detect advanced colorectal neoplasia but is relatively invasive, expensive, labour-intensive and requires bowel preparation making it a less feasible option as a primary screening test in resource-limited countries. A clinical practice update produced by the American Gastroenterological Association (AGA) has reported the use of non-invasive biomarkers for CRC screening in the Western populations. There is a knowledge gap on how these biomarkers should be utilised in the Asian population.
In 2023, we developed an evidence-based guideline on the use of non-invasive biomarker for CRC screening in the Asia-Pacific region which is witnessing an escalating market growth for CRC screening. To produce a high-quality guideline to inform clinical application of non-invasive biomarkers, we collaborated with APAGE/APSDE and assembled a steering committee with expertise in CRC screening involved in regional or national guidelines as key members. The steering committee invited over 10 global researchers with a broad range of expertise across all relevant disciplines to form a guideline development group (GDG). This committee conducted a systematic review of literature up to February 2023, and identified 769 relevant diagnostic studies, prospective cohort studies, randomised controlled trials, and guidelines containing data relevant to the Asia-Pacific region. The committee examined (i) the general principles of using these biomarkers in CRC screening; (ii) the current evidence on the use of blood-based tumour biomarkers, stool-based tumour biomarkers and stool-based microbial biomarkers, and (iv) future directions on their use. The committee drafted 32 consensus statements with reviewed the quality of evidence and level of recommendation and subsequently adopted a two-stage modified Delphi process via online meetings and voting to develop a final consensus.
This clinical practice guideline has highlighted several major and new findings. First, the target population to consider using non-invasive biomarkers for CRC screening include average-risk individuals who wish to know their risk of adenomas or CRC, and high-risk individuals who are reluctant to receive colonoscopy as the primary screening test. Second, FIT should not be used as a screening test for advanced adenomas due to its low sensitivity. Third, plasma microRNA and certain stool-based methylation biomarkers with high sensitivity and specificity can be considered as a primary screening test for CRC. Fourth, the use of a multi-panel of biomarkers has a higher discriminatory capability for the diagnosis of CRC than a single panel biomarker. Fifth, stool bacteria gene markers (eg. M3CRC) have high sensitivity and specificity to detect both CRC and advanced adenomas. These stool bacteria gene markers also have the advantage of high sensitivity detecting recurrent advanced adenomas after screening or surveillance colonoscopy. Lastly, there are accumulating preclinical and clinical evidence to show that modulation of gut microbiome may influence CRC risk and prognosis after chemotherapy or immunotherapy.
Large, prospective studies and clinical trials using non-invasive biomarkers for CRC screening are ongoing and would provide further evidence to inform clinical practice. The application of non-invasive biomarkers in clinical practice will provide new options and less invasive modalities for physicians and patients and complement current screening strategies to enhance uptake of CRC screening worldwide. Their clinical application for risk stratification and screening for interval cancers during surveillance appear promising and exciting and should be tested in large clinical trials across different populations.”
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