Background: Endoscopic treatments, such as endoscopic submucosal dissection (ESD) and laparoscopic gastrectomy, are increasingly used to treat a subset of patients with early gastric cancer (EGC). To achieve successful outcomes, it is very important to accurately determine the lateral extent of the tumor. Therefore, we investigated the diagnostic performance of chromoendoscopy using indigo carmine dye added to acetic acid (AI chromoendoscopy) in delineating differentiated or undifferentiated adenocarcinomas in patients with EGC. Methods: We prospectively included 151 lesions of 141 patients that had an endoscopic diagnosis of EGC. All the lesions were examined by conventional endoscopy and AI chromoendoscopy before ESD or laparoscopic gastrectomy. The border clarification between the lesion and the normal mucosa was classified as distinct or indistinct before and after AI chromoendoscopy. Results: The borders of the lesions were distinct in 66.9% (101/151) with conventional endoscopy and in 84.1% (127/151) with AI chromoendoscopy (P < 0.001). Compared with conventional endoscopy, AI chromoendoscopy clarified the border in a significantly higher percentage of differentiated adenocarcinomas (74/108 [68.5%] vs 97/108 [89.8%], respectively, P < 0.001). However, the border clarification rate for undifferentiated adenocarcinomas did not differ between conventional endoscopy and AI chromoendoscopy (27/43 [62.8%] vs 30/43 [70.0%], respectively, P = 0.494). Conclusions: AI chromoendoscopy is useful in determining the lateral extent of EGCs. However, its usefulness is reduced in undifferentiated adenocarcinomas.

Background: Gastric intestinal metaplasia (IM) usually appears in flat mucosa and shows few morphologic changes, making diagnosis using conventional endoscopy unreliable. Magnifying narrow-band imaging (NBI) endoscopy enables evaluation of detailed morphological features that correspond with the underlying histology. The aim of this study was to investigate and clarify the diagnostic efficacy of magnifying NBI endoscopic findings for the prediction and diagnosis of IM. Methods: Forty-seven patients were prospectively enrolled, and magnifying NBI examinations were performed in the lesser curvature of the midbody and the greater curvature of the upper body. The marginal turbid band (MTB) was defined as an enclosing white turbid band on the epithelial surface/gyri; light blue crest (LBC), as a fine, blue-white line on the crest of the epithelial surface/gyri. Immediately after observation under magnifying endoscopy, biopsy specimens were obtained from the evaluated areas. Results: The degree of IM significantly increased with increasing MTB/LBC positivity (MTB^-/LBC^-, 0.00 ± 0.00; MTB⁺/LBC^-, 0.44 ± 0.51; MTB⁺/LBC⁺, 0.94 ± 0.24; p < 0.001). Moderate-to-severe IM was more common in MTB⁺/LBC⁺ areas than in MTB⁺/LBC^- areas (p < 0.001). For the diagnosis of IM, MTB had a sensitivity, specificity, and accuracy of 100%, 66.0%, and 81.7%, respectively, and the corresponding values for LBC were 72.1%, 96.0%, and 84.9%. Conclusion: MTB and LBC observed in the gastric mucosa with magnifying NBI endoscopy are highly accurate indicators of the presence of IM. MTB likely represents a sign of early gastric IM, while LBC appears with progression to severe IM.

Pembrolizumab, an anti-programmed cell death (PD)-1 monoclonal antibody, is an anticancer agent showing substantial benefit in lung cancer and melanoma treatment. Biliary tract cancer (BTC) has been shown to respond to pembrolizumab; however, no credible data of such treatment outcomes exist. Therefore, we assessed the clinical outcomes and safety of pembrolizumab in patients with gemcitabine/cisplatin-refractory BTC. In this multicenter study, we retrospectively analyzed 51 patients with programmed cell death 1-ligand 1 (PD-L1)-positive gemcitabine/cisplatin-refractory BTC treated with pembrolizumab in four tertiary hospitals in Korea. PD-L1 positivity was defined as the expression of PD-L1 in ≥1% of tumor cells based on immunohistochemical staining (22C3, SP263, and E1L3N assays). The median age of the patients was 66 (range, 43–83) years and 29 (56.9%) were male. Extrahepatic cholangiocarcinoma was the most common cancer type (n = 30, 58.8%). Partial response and stable disease were achieved in 5 (9.8%) and 13 (25.5%) patients, respectively. Median progression-free survival and overall survival were 2.1 (95% CI, 1.7–2.4) and 6.9 (95% CI, 5.4–8.3) months, respectively. Overall, 30 (58.8%) patients experienced treatment-related adverse events (AEs). Only four (7.8%) patients experienced grades 3 and 4 AEs. In PD-L1-positive gemcitabine/cisplatin-refractory BTC, pembrolizumab presented durable efficacy, with a 9.8% response rate and manageable toxicity.

The usefulness of bilateral stent placement for malignant hilar obstruction is still under debate. Nevertheless, many endoscopists advocate the placement of an endoscopic bilateral metal stent using various new devices and techniques. We compared the technical and clinical efficacy, and the short-term and long-term complications of the 'stent-in-stent' method using a Y-stent for malignant hilar obstruction between the early and the late period of this study. Ninety-seven patients treated with Y-stent implantation for malignant hilar obstruction were enrolled retrospectively. In 31 patients treated during the early period, bilateral Y-configured metal stents were placed for malignant hilar obstruction using the older designed Y-stent and a closed-cell second stent. The newly designed Y-stent and a slimmer open-cell second stent were introduced in 66 patients treated during the late period. New techniques learned through experience were gradually applied throughout the entire study period. The rate of successful placement of bilateral stents was significantly higher in patients treated during the late period than those treated during the early period (58.1 vs. 87%; P=0.001). The functional success rate was 97.3%, with no difference between the early and the late periods. Cholangitis occurred as an early complication more frequently during the early period than during the late period (16.1 vs. 1.5%; P=0.012). Cholecystitis as a late complication occurred in 21 of 76 patients (27.6%). The incidence of late complications was similar between the early and the late periods. With the development of new devices and increased technical experience, there were better outcomes during the late period compared with the early period. Endoscopic bilateral metal stenting using a Y-stent is an attractive option for the palliative treatment of malignant hilar obstruction.

Needle-knife fistulotomy (NKF) is used as a rescue technique for difficult cannulation. However, the data are limited regarding the use of NKF for primary biliary cannulation, especially when performed by beginners. To assess the effectiveness and safety of primary NKF for biliary cannulation, and the role of the endoscopist’s expertise level (beginner vs expert). We retrospectively evaluated the records of 542 patients with naïve prominent bulging papilla and no history of pancreatitis, who underwent bile duct cannulation at a tertiary referral center. The patients were categorized according to the endoscopist’s expertise level and the technique used for bile duct cannula tion. We assessed the rates of successful cannulation and adverse events. The baseline characteristics did not differ between the experienced and less-experienced endoscopists. The incidence rate of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) was significantly affected by the endoscopist’s expertise level in patients who received conventional cannulation with sphincterotomy (8.9% vs 3.4% for beginner vs expert, P = 0.039), but not in those who received NKF. In the multivariable analysis, a lower expertise level of the biliary endoscopist (P = 0.037) and longer total procedure time (P = 0.026) were significant risk factor of PEP in patients who received conventional cannulation with sphincterotomy but only total procedure time (P = 0.004) was significant risk factor of PEP in those who received NKF. Primary NKF was effective and safe in patients with prominent and bulging ampulla, even when performed by less-experienced endoscopist. We need to confirm which level of endoscopist’s experience is needed for primary NKF through prospective randomized study.