Methods of colorectal cancer screening
Stool-based colorectal cancer (CRC) screening should be the preferred method of CRC screening in Malaysia, according to Dato Dr Muhammad Radzi Abu Hassan, the Head of Gastroenterology Services in Ministry of Health, Malaysia, who presented the Malaysian experience on CRC screening at the Annual Scientific Meeting of the Society of Gastroenterology and Hepatology (GUT) 2018 held recently in Penang.
“Even though the endoscopy method of screening has higher positive predictive value and is more reliable,” said Muhammad Radzi. “Stool-based CRC screening, especially the immunochemical faecal occult blood Test (iFOBT), has higher safety, acceptance, and convenience and is more cost effective.” Muhammad Radzi said iFOBT is the preferred method to screen CRC in average risk population—should the iFOBT be positive, then an early endoscopy is necessary; should the iFOBT be negative, then a yearly test should be performed. CRC is the second most common cancer in Malaysia, second to breast cancer. According to The Second Annual Report of the National Cancer Patient Registry—Colorectal Cancer 2008-2013, Malaysia has an age-adjusted incidence rate of 21.32 and a mortality rate of 9.79 per 100,00 population.
His view was supported by Professor Dr April Camilla Roslani, Head of Division of General Surgery & Colorectal Unit, Department of Surgery, Universiti Malaya. April also highlighted that there is a trend of increase in incidence of CRC among the young adults. [JAMA Surg. 2015;150(1)17-22]. She emphasized that based on a local economic evaluation conducted by the Malaysian Health Technology Assessment Section (MaHTAS), Ministry of Health, Malaysia, iFOBT followed by colonoscopy is the most cost-effective screening strategy compared with no screening or colonoscopy alone with an estimated incremental cost-effectiveness ratio of RM9,377.65. [Health Technology Assessment Section (MaHTAS) MDD, Ministry of Health Malaysia. Colorectal Cancer Screening Using Colonoscopy and Economic Evaluation, 2016 (Technology Review) 010/2016].
Debating in favour of endoscopy-based CRC screening in the expert forum, Dr Ooi Choon Jin, Consultant Gastroenterologist, Gleneagles and Farrer Park Medical Centre and Visiting Consultant, IBD Centre, Singapore General Hospital, stated that colonoscopy is the only screening test that combines detection with prevention by polypectomy. “The reduction of mortality was significantly higher in endoscopic screening (sigmoidoscopy 38 percent, colonoscopy >59 percent) as compared to faecal occult blood test (15to 33 percent).”
Professor Dr Rupert Leong, Director of Endoscopy, Head of IBD Services and Professor of Medicine UNSW, University of Sydney, Concord Hospital, Sydney, Australia spoke on the long-term colorectal cancer incidence reduction after a negative colonoscopy. [New Eng J Med 2013;369:12] He also cited the UK experience in sigmoidoscopy with reduction of all CRC incidence, (HR+0.65, 95% CI 0.59-0.71) and all CRC mortality, (HR=0.59, 95% CI 0.49-0.70) [Lancet 2017 doi.org/10.1016/S1470-2045(17)30187-0].
The above debate took place in Expert Forum: Colorectal Cancer Screening in Malaysia & Beyond, Debate on Methods of Screening & Sharing of Experiences, organized by Malaysian Society of Gastroenterology and Hepatology annual scientific meeting, GUT 2018. The topic of the symposium was chosen in conjunction with the recent launch of Malaysian Clinical Practice Guidelines of Colorectal Cancer Management, by the Ministry of Health Malaysia.