Purpose: Clinical prognostic criteria using preoperative factors were not developed for post–neoadjuvant therapy (NAT) surgery of pancreatic ductal adenocarcinoma (PDAC). We aimed to identify preoperative factors associated with overall survival (OS) in PDAC patients who underwent post-NAT curative-intent surgery and develop risk stratification criteria. Materials and Methods: Consecutive PDAC patients who underwent post-NAT curative-intent surgeries between 2007 and 2020 were retrospectively analyzed. Demographic, laboratory, surgical, and histopathologic variables were collected. Baseline, preoperative, and interval changes of computed tomography (CT) findings proposed by the Society of Abdominal Radiology and the American Pancreatic Association were analyzed. Cox proportional hazard analysis was used to select preoperative variables associated with OS. We developed risk stratification criteria composed of the significant preoperative variables, i.e., post-NAT response criteria. We compared the discrimination performance of post-NAT response criteria with that of post-NAT pathological (yp) American Joint Cancer Committee TNM staging system. Results: One hundred forty-five PDAC patients were included. Stable or increased tumor size on CT (hazard ratio [HR], 2.58; 95% confidence interval [CI], 1.58 to 4.21; p < 0.001) and elevated preoperative carbohydrate antigen 19-9 (CA19-9) level (HR, 1.98; 95% CI, 1.11 to 3.55; p=0.021) were independent factors of OS. The OS of the patient groups stratified by post-NAT response criteria which combined changes in tumor size and CA19-9 showed significant difference (p < 0.001). Such stratification was comparable to ypTNM staging in discrimination performance (difference of C-index, 0.068; 95% CI, –0.012 to 0.142). Conclusion “Any degree of decrease in tumor size on CT” and CA19-9 normalization or staying normal were independent favorable factors of OS. The combination of the two factors discriminated OS comparably to ypTNM staging.

Background/Aims: Endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS-FNA/B) is essential in diagnosing solid pancreatic lesions (SPLs), but without rapid on-site evaluation (ROSE), a repeat EUS-FNA/B is crucial for clarifying an inconclusive diagnosis. We aimed to evaluate factors associated with improved diagnostic performance of repeat EUS-FNA/B for initially inconclusive SPL diagnoses without ROSE. Methods: Of 5,894 patients subjected to EUS-FNA/B, 237 (4.0%) with an initially inconclusive diagnosis of SPLs were retrospectively enrolled from five tertiary medical centers between January 2016 and June 2021. Diagnostic performance and procedural factors of EUS-FNA/B were analyzed. Results: The diagnostic accuracies of first and repeat EUS-FNA/B were 96.2% and 67.6%, respectively. Of 237 patients with an inconclusive diagnosis from initial EUS-FNA/B, 150were pathologically diagnosed after repeat EUS-FNA/B. In multivariate analysis of repeat EUS-FNA/B, tumor location (body/tail vs head: odds ratio [OR], 3.74; 95% confidence inter-val [CI], 1.48 to 9.46), number of needle passes (≥4 vs ≤3: OR, 4.80; 95% CI, 1.44 to 15.99),needle type (FNB vs FNA: OR, 3.26; 95% CI, 1.44 to 7.36), needle size (22 gauge vs 19/20 gauge: OR, 2.35; 95% CI, 1.19 to 4.62), and suction method (suction vs others: OR, 5.19;95% CI, 1.30 to 20.75) were associated with a significantly improved diagnostic performance. Conclusions Repeat EUS-FNA/B is essential for patients with an inconclusive EUS-FNA/B without ROSE. To improve the diagnostic performance of repeated EUS-FNA/B, it is recom-mended that 22-gauge FNB needles, ≥4 needle passes, and suction methods are used.

Purpose: Cannulation of the major papilla is the most challenging part of endoscopic retrograde cholangiopancreatography (ERCP) for which physician-controlled wire-guided cannulation (PCWGC) and assistant-controlled wire-guided cannulation (ACWGC) are used as the cannulation techniques. PCWGC can reportedly save up to about 30% of the labor cost by reducing the number of assistants. This study aims to compare the safety and efficacy of PCWGC and ACWGC. Materials and Methods: Of the 2151 patients aged >20 years (4193 cases) who underwent ERCP at Yonsei University Medical Center between January 2015 and December 2016, 989 were included in this study. Results: Among efficacy outcomes, cannulation success rate, rate of precut sphincterotomy (PCWGC vs. ACWGC: 21.3% vs.25.9%), bile duct cannulation time (PCWGC vs. ACWGC: median 3.0 minutes vs. 3.6 minutes), and total procedure time (PCWGC vs. ACWGC: median 13.6 minutes vs. 13.1 minutes) were not significantly different. Among safety outcomes, lower rates of postERCP pancreatitis were observed with PCWGC than with ACWGC (PCWGC vs. ACWGC: 5.8% vs. 8.8%, p=0.128). Among other post-ERCP adverse events (bleeding, perforation, and cholangitis), the difference was not significant between the groups. Radiation exposure (total dose area product, PCWGC vs. ACWGC: median 1979.9 µGym2 vs. 2062.0 µGym2 , p=0.194) and ERCP cost excluding labor cost (PCWGC vs. ACWGC: $1576 vs. $1547, p=0.606) were not significantly different. Conclusion Requiring less assistants, PCWGC showed comparable efficacy and safety to ACWGC. PCWGC can be considered as an alternative option, especially in facilities lacking manpower and resources.

Background/Aims: Programmed death-ligand 1 (PD-L1) expression in tumor cells is associated with a poor biliary tract cancer (BTC) prognosis; tumor-infiltrating immune cells in the tumor microenvironment are associated with a better prognosis. The effect of PD-L1 expression on immune cells on survival is unclear. We investigated the relationship between PD-L1 expression in immune cells and BTC prognosis. Methods: PD-L1 expression was evaluated using an anti-PD-L1 22C3 mouse monoclonal primary antibody, and its relationships with clinical characteristics and prognosis were analyzed using the Cox proportional hazard model to investigate the prognostic performance of PD-L1 in BTC. Results: Among 144 analyzed cases, patients with positive PD-L1 expression in tumor cells and negative PD-L1 expression in immune cells showed poorer overall survival rates than those exhibiting other expressions (tumor cells: hazard ratio [HR]=1.023, p<0.001; immune cells: HR=0.983, p=0.021). PD-L1 expression in tumor cells was an independent predictor of poor overall survival (HR=1.024, p<0.001). In contrast, PD-L1 expression in immune cells was a predictive marker of good prognosis (HR=0.983, p=0.018). Conclusions PD-L1 expression in immune cells may be used as an independent factor to evaluate the prognosis of patients with BTC.

Purpose: Hypoxaemia is a significant adverse event during endoscopic retrograde cholangiopancreatography (ERCP) under monitored anaesthesia care (MAC); however, no model has been developed to predict hypoxaemia. We aimed to develop and compare logistic regression (LR) and machine learning (ML) models to predict hypoxaemia during ERCP under MAC. Materials and Methods: We collected patient data from our institutional ERCP database. The study population was randomly divided into training and test sets (7:3). Models were fit to training data and evaluated on unseen test data. The training set was further split into k-fold (k=5) for tuning hyperparameters, such as feature selection and early stopping. Models were trained over k loops; the i-th fold was set aside as a validation set in the i-th loop. Model performance was measured using area under the curve (AUC). Results: We identified 6114 cases of ERCP under MAC, with a total hypoxaemia rate of 5.9%. The LR model was established by combining eight variables and had a test AUC of 0.693. The ML and LR models were evaluated on 30 independent data splits. The average test AUC for LR was 0.7230, which improved to 0.7336 by adding eight more variables with an l 1 regularisation-based selection technique and ensembling the LRs and gradient boosting algorithm (GBM). The high-risk group was discriminated using the GBM ensemble model, with a sensitivity and specificity of 63.6% and 72.2%, respectively. Conclusion We established GBM ensemble model and LR model for risk prediction, which demonstrated good potential for preventing hypoxaemia during ERCP under MAC.

Background/Aims: Sphincterotomes are essential for endoscopic sphincterotomy (EST) and can also be used for cannulation in ERCP.A domestic new pull-type sphincterotome (Optimos™, Taewoong, Goyang, Korea) provides acceptable technical feasibility and safety, but there are no comparison results. Thus, this study compared the clinical performance and safety of Optimos™ sphincterotome to a conventional sphincterotome (CleverCut3™, Olympus, Tokyo, Japan) in patients who underwent ERCP. Methods: From April 2021 to July 2021, a randomized prospective comparative study was conducted on 104 consecutive patients who underwent ERCP in three medical centers. The primary endpoint was the clinical performance and safety of sphincterotomes during ERCP. Results: One hundred and four patients were assigned randomly to the Optimos™ group (n=51) or CleverCut3™ group (n=53). All demographic characteristics did not differ between the groups except the BMI. The technical success rate for cannulation, performance of EST, and total procedure time were similar in the two groups. The adverse events did not differ, even though two cases of post-ERCP pancreatitis occurred in CleverCut3™. On the other hand, in questionnaire analysis, CleverCut™ showed a better user’s convenience (median [interquartile range] 4.0 [3.0-4.0] vs. 3.0 [3.0-4.0], p=0.013) and manipulability (median [interquartile range], 4.0 [3.0-4.0] vs. 3.0 [3.0-4.0], p=0.039) than Optimos™, even though the other profiles did not reveal any differences. Conclusions New domestic pull-type sphincterotome can offer comparable clinical performance and safety profiles to conventional sphincterotome, but it needs refinements to increase the user’s convenience and manipulability. Further improvement and innovation will be required to advance domestic medical devices.

Background/Aims: Controversy regarding the effectiveness of neoadjuvant therapy for resectable pancreatic ductal adenocarcinoma (PDAC) still exists. Here, we aimed to identify the potential benefits of neoadjuvant therapy followed by surgery for resectable PDAC. Methods: We reviewed radiologically resectable PDAC patients who received resection with curative intent at a tertiary hospital in South Korea between January 2012 and August 2019. A total of 202 patients underwent curative resection for resectable PDAC: 167 underwent surgical resection first during this period, and 35 received neoadjuvant chemotherapy/chemoradiation therapy followed by surgery. Resectable PDAC patients were subdivided, and 1:3 propensity score matching (PSM) was performed to reduce selection bias. Results: Compared with the group that received surgery first, the group that received neoadjuvant treatment followed by surgery had significantly smaller tumors (22.0 mm vs 27.0 mm, p=0.004), a smaller proportion of patients with postoperative pathologic T stage (p=0.026), a smaller proportion of patients with lymphovascular invasion (20.0% vs 40.7%, p=0.022), and a larger proportion of patients with negative resection margins (74.3% vs 51.5%, p=0.049). After PSM, the group that received neoadjuvant therapy had a significantly longer progression-free survival than those in the group that underwent surgery first (29.6 months vs 15.1 months, p=0.002). Overall survival was not significantly different between the two groups after PSM analysis. Conclusions We observed significantly better surgical outcomes and progression-free survival with the addition of neoadjuvant therapy to the management of resectable PDAC. However, despite PSM, there was still selection bias due to the use of different regimens between the groups receiving surgery first and neoadjuvant therapy. Large homogeneous samples are needed in the future prospective studies.

Background/Aims: The benefit of second-line chemotherapy (SL) after failed first-line chemotherapy (FL) in patients with advanced pancreatic cancer has not yet been established. We evaluated the clinical characteristics affecting the benefits of SL compared to best supportive care (BSC), identified the prognostic factors, and ultimately devised a model of clinical parameters to assist in making decision between SL and BSC after the failure of gemcitabine-based FL. Methods: The records of patients who received gemcitabine-based FL for advanced pancreatic cancer at Yonsei University Hospital between January 2010 and December 2015 were retrospectively reviewed. Significant clinical parameters were assessed for their potential as predictive factors. Results: SL patients received a longer duration of FL compared with BSC patients with median duration being 16.0 weeks (range, 8.0 to 26.0 weeks) and 8.0 weeks (range, 4.0 to 16.0 weeks), respectively (p<0.001). When the SL group was stratified by their modified overall survival (mOS) (longer and shorter than 6 months), we found significant differences for several clinical factors, namely, metastasis to the peritoneum (p<0.001), number of metastases (p<0.001), thrombotic events (p=0.003), and level of carbohydrate antigen 19-9 (CA19-9; p=0.011). In multivariate analysis, more than one site of metastasis, occurrence of thrombotic event during FL, and a CA19-9 level above 90 U/mL were significant independent prognostic factors for mOS in the SL group (p<0.05). When an attempt was made to devise a prognostic nomogram, Harrell’s C-index of the final prognosis prediction model was 0.62. Conclusions SL may be beneficial for patients without peritoneal metastasis or thrombotic events who have a single metastasis and a level of CA19-9 less than 90 U/mL. This prognostic nomogram can be used to predict mOS before the administration of SL after the failure of gemcitabine-based FL.

Pancreatic cancer is still one of the most aggressive malignancy, showing 10% of 5-year survival. Among the several reasons of the grave prognosis, the poor response to chemotherapeutic agents and the absence of effective tool for early detection are the most important. Regarding treatments, surgical resection is still positioned as the only one for expecting the cure of pancreatic cancer. However, the rate of recurrence after surgery is still high as more than 50%. And the portion of patients who are diagnosed at the resectable stage is still less than 15% of all cases. So, chemotherapy and radiotherapy are the main players for combating with pancreatic cancer. After the introduction of outcomes of FOLFIRINOX, and gemcitabineabpaclitaxel for metastatic pancreatic cancer, two-digit overall survival can be expected. And, neoadjuvant treatments including concurrent chemoradiation therapy for borderline resectable pancreatic cancer and/or resectable pancreatic cancer are reported as superior to upfront surgery. More recently, several target agents including polyadenosine diphosphate-ribose polymerase inhibitors and immunologic drugs are under evaluation for pancreatic cancer. So, herein, current status of chemotherapy and radiation therapy for pancreatic cancer will be addressed.

PURPOSE: Patients with liver cirrhosis are considered to be at risk for additional adverse events during endoscopic retrograde cholangiopancreatography (ERCP). The present study was designed as a propensity-score matched analysis to investigate whether cirrhotic liver increases the risk of bleeding complications in patients undergoing ERCP. MATERIALS AND METHODS: In total, 8554 patients who underwent ERCP from January 2005 to December 2015 were retrospectively analyzed. To adjust for the imbalance between patients with and those without liver cirrhosis, 1:3 propensity score matching was performed according to age and sex. RESULTS: Liver cirrhosis was identified in 264 (3.1%) patients. After propensity score matching, a total of 768 patients were included in each of the cirrhotic (n=192) and non-cirrhotic groups (n=576). Post-procedure bleeding (10.9% vs. 4.7%, p=0.003) was more frequently observed in patients with liver cirrhosis than in those without. In multivariate analyses, liver cirrhosis was identified as an independent risk factor associated with post-ERCP bleeding (p=0.003) after further adjustment for prothrombin time, antiplatelet/coagulant, duration of ERCP, and stent insertion. Child-Pugh (CP) class C was found to be associated with an increased incidence of post-ERCP bleeding in patients with cirrhosis (odds ratio 6.144, 95% confidence interval 1.320–28.606; p=0.021). CONCLUSION: The incidence of post-ERCP bleeding in patients with liver cirrhosis was higher than that in patients without liver cirrhosis. In particular, CP class C cirrhosis was significantly associated with post-ERCP bleeding.
Cholangiopancreatography, Endoscopic Retrograde ; Fibrosis ; Hemorrhage ; Humans ; Incidence ; Liver Cirrhosis ; Liver ; Multivariate Analysis ; Propensity Score ; Prothrombin Time ; Retrospective Studies ; Risk Factors ; Stents