Cholangiocarcinoma (CCA) is an aggressive cancer arising from epithelial cells of the bile duct. Most patients with CCA have an unresectable tumor at the time of diagnosis. In Western countries, the risk of CCA increases in patients with primary sclerosing cholangitis, whereas liver fluke infection appears to be the major risk factor for CCA in Asian countries. A diagnosis of liver fluke infection often relies on stool samples, including microscopic examination, polymerase chain reaction-based assays, and fluke antigen detection. Tests of serum, saliva and urine samples are also potentially diagnostic. The presence of liver fluke along with exogenous carcinogens magnifies the risk of CCA in people living in endemic areas. The “liver fluke-cholangiocarcinoma” carcinogenesis pathways consist of mechanical damage to the bile duct epithelium, immunopathologic and cellular reactions to the liver fluke's antigens and excretory/secretory products, liver fluke-induced changes in the biliary tract microbiome and the effects of repeated treatment for liver fluke. A vaccine and novel biomarkers are needed for the primary and secondary prevention of CCA in endemic areas. Importantly, climate change exerts an effect on vector-borne parasitic diseases, and awareness of liver fluke should be enhanced in potentially migrated habitat areas.
Asian Continental Ancestry Group ; Bile Ducts ; Biliary Tract Neoplasms* ; Biliary Tract* ; Biomarkers ; Carcinogenesis ; Carcinogens ; Cholangiocarcinoma ; Cholangitis, Sclerosing ; Climate Change ; Clonorchiasis ; Diagnosis ; Ecosystem ; Epithelial Cells ; Epithelium ; Fasciola hepatica ; Humans ; Liver* ; Microbiota ; Opisthorchiasis ; Parasitic Diseases ; Risk Factors ; Saliva ; Secondary Prevention ; Trematoda

Background/Aims: As the number of colonoscopies and polypectomies performed continues to increase in many Asian countries, there is a great demand for surveillance colonoscopy. The aim of this study was to investigate the adherence to postpolypectomy surveillance guidelines among physicians in Asia. Methods: A survey study was performed in seven Asian countries. An email invitation with a link to the survey was sent to participants who were asked to complete the questionnaire consisting of eight clinical scenarios. Results: Of the 137 doctors invited, 123 (89.8%) provided valid responses. Approximately 50% of the participants adhered to the guidelines regardless of the risk of adenoma, except in the case of tubulovillous adenoma ≥10 mm combined with high-grade dysplasia, in which 35% of the participants adhered to the guidelines. The participants were stratified according to the number of colonoscopies performed: ≥20 colonoscopies per month (high volume group) and <20 colo-noscopies per month (low volume group). Higher adherence to the postpolypectomy surveillance guidelines was evident in the high volume group (60%) than in the low volume group (25%). The reasons for nonadherence included concern of missed polyps (59%), the low cost of colonoscopy (26%), concern of incomplete resection (25%), and concern of medical liability (15%). Conclusions A discrepancy between clinical practice and surveillance guidelines among physicians in Asia was found. Physicians in the low volume group frequently did not adhere to the guidelines, suggesting a need for continuing education and appropriate control. Concerns regarding the quality of colonoscopy and complete polypectomy were the main reasons for nonadherence.

Background/Aims: The clinical practice pattern of polypectomy is not well-investigated in Asian countries. We aimed to survey Asian endoscopists about their preferred polypectomy techniques for given conditions and images of polyps. Methods: A survey was performed using questionnaires composed of two parts: a scenariobased questionnaire using scenarios of polyps, which were adopted from the European Society of Gastrointestinal Endoscopy guidelines, and an image-based questionnaire using provided endoscopic images of polyps. Results: A total of 154 endoscopists participated in this survey. The most preferred resection techniques for diminutive (≤5 mm), small (6–9 mm), and benign-looking intermediate (10–19 mm) nonpedunculated polyps were cold forceps polypectomy, hot snare polypectomy, and endoscop-ic mucosal resection (EMR), respectively, in both the scenario- and image-based questionnaires. For benign-looking large (≥20 mm) nonpedunculated polyps, EMR and endoscopic submucosal dissection (ESD) were preferred in the scenario- and image-based surveys, respectively. In case of malignant nonpedunculated polyps, EMR and ESD were preferred for intermediate-sized and large lesions, respectively, according to the scenario-based survey. However, ESD was preferred in both intermediate-sized and large malignant nonpedunculated polyps according to the imagebased survey. Trainee endoscopists, endoscopists working in referral centers, and endoscopistsin the colorectal cancer–prevalent countries were independently associated with preference of cold snare polypectomy for removing small polyps. Conclusions The polypectomy practice patterns of Asian endoscopists vary, and cold snare polypectomy was not the most preferred resection method for polyps <10 mm in size, in contrast to recent guidelines.

Background/Aims: The clinical practice pattern of polypectomy is not well-investigated in Asian countries. We aimed to survey Asian endoscopists about their preferred polypectomy techniques for given conditions and images of polyps. Methods: A survey was performed using questionnaires composed of two parts: a scenariobased questionnaire using scenarios of polyps, which were adopted from the European Society of Gastrointestinal Endoscopy guidelines, and an image-based questionnaire using provided endoscopic images of polyps. Results: A total of 154 endoscopists participated in this survey. The most preferred resection techniques for diminutive (≤5 mm), small (6–9 mm), and benign-looking intermediate (10–19 mm) nonpedunculated polyps were cold forceps polypectomy, hot snare polypectomy, and endoscop-ic mucosal resection (EMR), respectively, in both the scenario- and image-based questionnaires. For benign-looking large (≥20 mm) nonpedunculated polyps, EMR and endoscopic submucosal dissection (ESD) were preferred in the scenario- and image-based surveys, respectively. In case of malignant nonpedunculated polyps, EMR and ESD were preferred for intermediate-sized and large lesions, respectively, according to the scenario-based survey. However, ESD was preferred in both intermediate-sized and large malignant nonpedunculated polyps according to the imagebased survey. Trainee endoscopists, endoscopists working in referral centers, and endoscopistsin the colorectal cancer–prevalent countries were independently associated with preference of cold snare polypectomy for removing small polyps. Conclusions The polypectomy practice patterns of Asian endoscopists vary, and cold snare polypectomy was not the most preferred resection method for polyps <10 mm in size, in contrast to recent guidelines.