REVIEW : Screening Colonoscopy for Average Risk Individuals in Singapore

( Tiing Leong Ang ),( Kwong Ming Fock ) 대한장연구학회 2012 Intestinal Research Vol.10 No.3

In Singapore colorectal cancer (CRC) is the most common cancer for males, second most common cancer for females and most common cancer overall. A national CRC screening program for average risks individuals was started in July 2011, with the primary test modality being the faecal immunochemical test. Individuals may choose to undergo screening colonoscopy directly. Colonoscopy has two roles in CRC screening. It is performed either as a primary screening test or used to evaluate abnormal results from another screening test. Colonoscopy is a safe and effective procedure but potential risks exist. Local complications such as perforation and bleeding, cardiopulmonary events and even mortality may occur. Additionally there could be failed cecal intubation and missed lesions. It is imperative that prior to colonoscopy, there is a proper discussion of risks, benefits and alternatives. To provide quality assurance for colonoscopy in the CRC screening program, a set of quality indicators and criteria for endoscopists and endoscopy centres was established. The endoscopists must be qualified specialists with a lifetime experience of at least 500 colonoscopies and 50 polypectomies, and need to meet annual monitoring parameters that include at least 50 colonoscopies, >95% cecal intubation rate, >95% recovery rate of excised polyps, and withdrawal time of at least 6 minutes. In addition, complication rates must be within acceptable limits such as perforation rate of less than 0.1% and postpolypectomy bleeding rate less than 1%. (Intest Res 2012;10:219-228)

Helicobacter pylori Treatment Strategies in Singapore

( Tiing Leong Ang ),( Daphne Ang ) 대한간학회 2021 Gut and Liver Vol.15 No.1

The management of Helicobacter pylori infection in Singapore remains a clinical challenge. Similar to other regions, there has been an increase in antibiotic resistance rates through the years. Nonetheless, over the past two decades, clarithromycin-based triple therapy has continued to be used as the first line treatment option, with an eradication rate exceeding 90%, although the accepted treatment duration must now be lengthened from 1 to 2 weeks to maintain efficacy. Concomitant and sequential therapies did not demonstrate superiority over standard triple therapy. Current empiric second line treatment utilizes either bismuth-based quadruple therapy or levofloxacin-based triple therapy, but outcomes remain less than ideal. Identifying options to further improve treatment success rates is challenging. Strategies being considered include the use of potent acid suppressants, such as vonoprazan, and H. pylori culture and antibiotic susceptibility testing-guided therapy. (Gut Liver 2021;15:13-18)

Diagnostic Endoscopic Ultrasound: Technique, Current Status and Future Directions

( Tiing Leong Ang ),( Andrew Boon Eu Kwek ),( Lai Mun Wang ) 대한간학회 2018 Gut and Liver Vol.12 No.5

Endoscopic ultrasound (EUS) is now well established as an important tool in clinical practice. From purely diagnostic imaging, it has progressed to include tissue acquisition, which provided the basis for therapeutic procedures. Even as interventional EUS developed, there has been ongoing progress in EUS diagnostic capabilities due to improved imaging systems, better needles for tissue acquisition and development of enhanced imaging functions such as contrast harmonic EUS (CHEUS) and EUS elastography. EUS is well established for differentiation of subepithelial lesions, for T-staging of luminal gastrointestinal and pancreaticobiliary malignancies, for differentiation of benign pancreaticobiliary disorders and for diagnostic tissue acquisition, which can be achieved by EUS-guided fine needle aspiration or by EUS-guided fine needle biopsy using dedicated biopsy needles. This review briefly describes the technique of performing EUS and then discusses its clinical utility in terms of gastrointestinal cancer staging, the evaluation of pancreaticobiliary disorders and tissue acquisition. Enhanced imaging techniques such as CHEUS and EUS elastography are briefly reviewed. (Gut Liver 2018;12:483-496)

Asian Consensus Report on Functional Dyspepsia

( Hiroto Miwa ),( Uday C Ghoshal ),( Sutep Gonlachanvit ),( Kok-Ann Gwee ),( Tiing-Leong Ang ),( Full-Young Chang ),( Kwong Ming Fock ),( Michio Hongo ),( Xiaohua Hou ),( Udom Kachintorn ),( Meiyun Ke 대한소화기기능성질환·운동학회 2012 Journal of Neurogastroenterology and Motility (JNM Vol.18 No.2

Background/Aims Environmental factors such as food, lifestyle and prevalence of Helicobacter pylori infection are widely different in Asian countries compared to the West, and physiological functions and genetic factors of Asians may also be different from those of Westerners. Establishing an Asian consensus for functional dyspepsia is crucial in order to attract attention to such data from Asian countries, to articulate the experience and views of Asian experts, and to provide a relevant guide on management of functional dyspepsia for primary care physicians working in Asia. Methods Consensus team members were selected from Asian experts and consensus development was carried out using a modified Delphi method. Consensus teams collected published papers on functional dyspepsia especially from Asia and developed candidate consensus statements based on the generated clinical questions. At the first face-to-face meeting, each statement was reviewed and e-mail voting was done twice. At the second face-to-face meeting, final voting on each statement was done using keypad voting system. A grade of evidence and a strength of recommendation were applied to each statement according to the method of the GRADE Working Group. Results Twenty-nine consensus statements were finalized, including 7 for definition and diagnosis, 5 for epidemiology, 9 for pathophysiology and 8 for management. Algorithms for diagnosis and management of functional dyspepsia were added. Conclusions This consensus developed by Asian experts shows distinctive features of functional dyspepsia in Asia and will provide a guide to the diagnosis and management of functional dyspepsia for Asian primary care physicians.

Clinical Features and Predictors of Dysplasia in Proximal Sessile Serrated Lesions

Yi Yuan Tan,Gary Sei Kiat Tay,Yu Jun Wong,James Weiquan Li,Andrew Boon Eu Kwek,Tiing-Leong Ang,Lai Mun Wang,Malcolm Teck Kiang Tan 대한소화기내시경학회 2021 Clinical Endoscopy Vol.54 No.4

Background/Aims: Proximal colorectal cancers (CRCs) account for up to half of CRCs. Sessile serrated lesions (SSLs) are precursorsto CRC. Proximal location and presence of dysplasia in SSLs predict higher risks of progression to cancer. The prevalence of dysplasiain proximal SSLs (pSSLs) and clinical characteristics of dysplastic pSSLs are not well studied. Methods: Endoscopically resected colonic polyps at our center between January 2016 and December 2017 were screened for pSSLs. Data of patients with at least one pSSL were retrieved and clinicopathological features of pSSLs were analysed. pSSLs with andwithout dysplasia were compared for associations. Results: Ninety pSSLs were identified, 45 of which had dysplasia giving a prevalence of 50.0%. Older age (65.9 years vs. 60.1 years,p=0.034) was associated with the presence of dysplasia. Twelve pSSLs were 10 mm or larger. After adjusting for age, pSSLs ≥10 mmhad an adjusted odds ratio of 5.98 (95% confidence interval, 1.21–29.6) of having dysplasia compared with smaller pSSLs. Conclusions: In our cohort of pSSLs, the prevalence of dysplasia is high at 50.0% and is associated with lesion size ≥10 mm. Endoscopic resection for all proximal serrated lesions should be en-bloc to facilitate accurate histopathological examination fordysplasia as its presence warrants shorter surveillance intervals.

Use of artificial intelligence in the management of T1 colorectal cancer: a new tool in the arsenal or is deep learning out of its depth?

James Weiquan Li,Lai Mun Wang,Katsuro Ichimasa,Kenneth Weicong Lin,James Chi-Yong Ngu,Tiing Leong Ang 대한소화기내시경학회 2024 Clinical Endoscopy Vol.57 No.1

The field of artificial intelligence is rapidly evolving, and there has been an interest in its use to predict the risk of lymph node metastasis in T1 colorectal cancer. Accurately predicting lymph node invasion may result in fewer patients undergoing unnecessary surgeries; conversely, inadequate assessments will result in suboptimal oncological outcomes. This narrative review aims to summarize the current literature on deep learning for predicting the probability of lymph node metastasis in T1 colorectal cancer, highlighting areas of potential application and barriers that may limit its generalizability and clinical utility.

The impact of unrestricted access to direct-acting antiviral among incarcerated hepatitis C virus-infected patients

( Yu Jun Wong ),( Prem Harichander Thurairajah ),( Rahul Kumar ),( Kwong Ming Fock ),( Ngai Moh Law ),( Sin-yoong Chong ),( Fria Gloriba Manejero ),( Tiing-leong Ang ),( Eng Kiong Teo ),( Jessica Tan 대한간학회 2021 Clinical and Molecular Hepatology(대한간학회지) Vol.27 No.3

Background/Aims: Despite the disproportionally high prevalence rates of hepatitis C virus (HCV) amongst the incarcerated population, eradication remains challenging due to logistic and financial barriers. Although treatment prioritization based on disease severity is commonly practiced, the efficacy of such approach remained uncertain. We aimed to compare the impact of unrestricted access to direct-acting antiviral (DAA) among incarcerated HCV-infected patients in Singapore. Methods: In this retrospective study, we reviewed all incarcerated HCV-infected patients treated in our hospital during the restricted DAA era (2013-2018) and unrestricted DAA access era (2019). Study outcomes included the rate of sustained virological response (SVR), treatment completion and treatment default. Subgroup analysis was performed based on the presence of liver cirrhosis, HCV genotype and HCV treatment types. Results: A total of 1,001 HCV patients was followed-up for 1,489 person-year. They were predominantly male (93%) with genotype-3 HCV infection (71%), and 38% were cirrhotic. The overall SVR during the restricted DAA access era and unrestricted DAA access era were 92.1% and 99.1%, respectively. Unrestricted access to DAA exponentially improved the treatment access among HCV-infected patients by 460%, resulting in a higher SVR rate (99% vs. 92%, P=0.003), higher treatment completion rate (99% vs. 93%, P<0.001) and lower treatment default rate (1% vs. 9%, P<0.001). Conclusion: In this large cohort of incarcerated HCV-infected patients, we demonstrated that unrestricted access to DAA is an impactful strategy to allow rapid treatment up-scale in HCV micro-elimination. (Clin Mol Hepatol 2021;27:474-485)