Single-cell transcriptome analysis reveals subtype-specific clonal evolution and microenvironmental changes in liver metastasis of pancreatic adenocarcinoma and their clinical implications.

BACKGROUND: Intratumoral heterogeneity (ITH) and tumor microenvironment (TME) of pancreatic ductal adenocarcinoma (PDAC) play important roles in tumor evolution and patient outcomes. However, the precise characterization of diverse cell populations and their crosstalk associated with PDAC progression and metastasis is still challenging. METHODS: We performed single-cell RNA sequencing (scRNA-seq) of treatment-naïve primary PDAC samples with and without paired liver metastasis samples to understand the interplay between ITH and TME in the PDAC evolution and its clinical associations. RESULTS: scRNA-seq analysis revealed that even a small proportion (22%) of basal-like malignant ductal cells could lead to poor chemotherapy response and patient survival and that epithelial-mesenchymal transition programs were largely subtype-specific. The clonal homogeneity significantly increased with more prevalent and pronounced copy number gains of oncogenes, such as KRAS and ETV1, and losses of tumor suppressor genes, such as SMAD2 and MAP2K4, along PDAC progression and metastasis. Moreover, diverse immune cell populations, including naïve SELLhi regulatory T cells (Tregs) and activated TIGIThi Tregs, contributed to shaping immunosuppressive TMEs of PDAC through cellular interactions with malignant ductal cells in PDAC evolution. Importantly, the proportion of basal-like ductal cells negatively correlated with that of immunoreactive cell populations, such as cytotoxic T cells, but positively correlated with that of immunosuppressive cell populations, such as Tregs. CONCLUSION: We uncover that the proportion of basal-like subtype is a key determinant for chemotherapy response and patient outcome, and that PDAC clonally evolves with subtype-specific dosage changes of cancer-associated genes by forming immunosuppressive microenvironments in its progression and metastasis.

Establishment of a patient-specific avatar organoid model derived from EUS-guided fine-needle biopsy for timely clinical application in pancreatic ductal adenocarcinoma (with video).

BACKGROUND AND AIMS: Pancreatic ductal adenocarcinoma (PDAC) has the worst survival rate among tumors. At the time of diagnosis, more than 80% of PDACs are considered to be surgically unresectable, and there is an unmet need for treatment options in these inoperable PDACs. This study aimed to establish a patient-derived organoid (PDO) platform from EUS-guided fine-needle biopsy (EUS-FNB) collected at diagnosis and to determine its clinical applicability for the timely treatment of unresectable PDAC. METHODS: Patients with suspected PDAC were prospectively enrolled at the Samsung Medical Center from 2015 to 2019. PDAC tissues were acquired by means of EUS-FNB to establish PDAC PDOs, which were comprehensively analyzed for histology, genomic sequencing, and high-throughput screening (HTS) drug sensitivity test. RESULTS: PDAC PDOs were established with a success rate of 83.2% (94/113). It took approximately 3 weeks from acquiring minimal EUS-FNB specimens to generating sufficient PDAC PDOs for the simultaneous HTS drug sensitivity test and genomic sequencing. The high concordance between PDAC tissues and matched PDOs was confirmed, and whole-exome sequencing revealed the increased detection of genetic alterations in PDOs compared with EUS-FNB tissues. The HTS drug sensitivity test showed clinical correlation between the ex vivo PDO response and the actual chemotherapeutic response of the study patients in the real world (13 out of 15 cases). In addition, whole-transcriptome sequencing identified candidate genes associated with nab-paclitaxel resistance, such as ITGB7, ANPEP, and ST3GAL1. CONCLUSIONS: This PDAC PDO platform allows several therapeutic drugs to be tested within a short time window and opens the possibility for timely personalized medicine as a "patient avatar model" in clinical practice.

Bleeding after endoscopic papillectomy and its risk factors: A single center experience of 196 cases.

BACKGROUND: Endoscopic papillectomy (EP) is an effective method to remove an ampulla of Vater (AoV) adenoma with minimal invasiveness. We reviewed the clinical outcomes and prognosis of patients undergoing EP, including tumor recurrence and adverse events. METHODS: A total of 196 patients who underwent EP from January 2004 to December 2017 were included. Clinical information was collected through electronic medical records, and risk factors to predict post-procedural bleeding were analyzed using a multivariate logistic regression model. RESULTS: A total of 93.9% patients (184/196) underwent complete resection. During the follow-up period, 14.7% patients (27/184) experienced tumor recurrence, and two of seven surgically resected tumors were malignant. A total of 45.4% patients (89/196) experienced adverse events related to EP. Delayed bleeding occurred in 16.3% of the patients (32/196), and they were all successfully treated with endoscopic hemostasis and conservative management. The most frequent site of delayed bleeding was the distal end of the papillary orifice, and 56.2% (18/32) patients of delayed bleeding were classified as having mild severity, the others had moderate severity. Familial adenomatous polyposis (FAP) [odds ratio (OR) = 3.80, 95% confidence interval (CI): 1.01-14.29; P < 0.05] and male sex (OR = 2.82, 95% CI: 1.04-7.63; P = 0.04) showed statistical significance in predicting delayed post-EP bleeding. CONCLUSIONS: EP for AoV adenoma was a highly effective and safe procedure. The risk of post-EP delayed bleeding was increased in patients with FAP syndrome and male patients, and post-EP bleeding occurred most commonly in the distal part of the AoV.

Genetic assessment of pathogenic germline alterations in lysosomal genes among Asian patients with pancreatic ductal adenocarcinoma.

BACKGROUND: Lysosomes are closely linked to autophagic activity, which plays a vital role in pancreatic ductal adenocarcinoma (PDAC) biology. The survival of PDAC patients is still poor, and the identification of novel genetic factors for prognosis and treatment is highly required to prevent PDAC-related deaths. This study investigated the germline variants related to lysosomal dysfunction in patients with PDAC and to analyze whether they contribute to the development of PDAC. METHODS: The germline putative pathogenic variants (PPV) in genes involved in lysosomal storage disease (LSD) was compared between patients with PDAC (n = 418) and healthy controls (n = 845) using targeted panel and whole-exome sequencing. Furthermore, pancreatic organoids from wild-type and KrasG12D mice were used to evaluate the effect of lysosomal dysfunction on PDAC development. RNA sequencing (RNA-seq) analysis was performed with established PDAC patient-derived organoids (PDOs) according to the PPV status. RESULTS: The PPV in LSD-related genes was higher in patients with PDAC than in healthy controls (8.13 vs. 4.26%, Log2 OR = 1.65, P = 3.08 × 10-3). The PPV carriers of LSD-related genes with PDAC were significantly younger than the non-carriers (mean age 61.5 vs. 65.3 years, P = 0.031). We further studied a variant of the lysosomal enzyme, galactosylceramidase (GALC), which was the most frequently detected LSD variant in our cohort. Autophagolysosomal activity was hampered when GALC was downregulated, which was accompanied by paradoxically elevated autophagic flux. Furthermore, the number of proliferating Ki-67+ cells increased significantly in pancreatic organoids derived from Galc knockout KrasG12D mice. Moreover, GALC PPV carriers tended to show drug resistance in both PDAC cell line and PDAC PDO, and RNA-seq analysis revealed that various metabolism and gene repair pathways were upregulated in PDAC PDOs harboring a GALC variant. CONCLUSIONS: Genetically defined lysosomal dysfunction is frequently observed in patients with young-onset PDAC. This might contribute to PDAC development by altering metabolism and impairing autophagolysosomal activity, which could be potentially implicated in therapeutic applications for PDAC.

Long-term outcomes of endoscopic papillectomy for ampullary adenoma with high-grade dysplasia or adenocarcinoma: a propensity score-matched analysis.

BACKGROUND: Evidence of endoscopic papillectomy (EP) for ampullar adenoma with high-grade dysplasia (HGD) or adenocarcinoma is insufficient. Here we investigated the long-term outcomes of the advanced ampullary tumors treated by EP with careful surveillance comparing to subsequent surgery after EP. METHODS: Patients treated with EP for ampullary adenoma with HGD or adenocarcinoma from the multi-center retrospective Korean cohort of ampulla of Vater tumor were categorized into EP alone versus EP with subsequent surgery groups. The overall survival (OS) and recurrence-free survival (RFS) were analyzed for unmatched and matched cohorts using propensity score with nearest neighbor method. RESULTS: During a median 43.3 months of follow-up, 5-year OS was not significantly different between the EP alone and EP surgery groups (91.9% vs. 82.3%, P = 0.443 for unmatched cohort; 89.2% vs. 82.3%, P = 0.861 for matched cohort, respectively). Furthermore, 5-year RFS was not significantly different between the two groups (82.1% vs. 86.7%, P = 0.520 for unmatched cohort; 66.1% vs. 86.7%, P = 0.052 for matched cohort, respectively). However, the patients with positive both (lateral and deep) margins showed significantly poorer survival outcomes than those with negative margins within the EP alone group (P = 0.007). CONCLUSION: EP alone with careful surveillance showed comparable survival outcomes to those of EP with subsequent surgery for ampullar HGD or adenocarcinoma. Resection margin status could be a parameter to determine whether to perform subsequent radical surgery after EP.

Prognosis and prognostic factors in patients with advanced biliary tract cancer depending on its anatomical location.

Objective: Previous studies have revealed that biliary tract cancer (BTC) has different clinical characteristics depending on its anatomical location. However, clinical studies about the prognosis of BTC according to its anatomical location are lacking. We aimed to compare the prognosis of BTC according to its anatomical location. Methods: We retrospectively reviewed records of 311 patients with advanced BTC who received gemcitabine based palliative chemotherapy from January 2006 to December 2015 at Samsung medical Center. Results: During median follow-up of 7.67 months, the median overall survival (OS) times for patients with gallbladder (GB) cancer, intrahepatic cholangiocellular carcinoma (ICCC) and extrahepatic cholangiocellular carcinoma (ECCC) were 8.1 months, 7.7 months and 13.4 months, respectively. Median progression free survival (PFS) times for those with GB cancer, ICCC and ECCC were 4.1 months, 5.4 months and 7.2 months respectively. In multivariate analysis, anatomical location of cancer was a statistically significant factor for OS and PFS (p < .001). Prognostic factors associated with OS were also different according to the anatomical location of cancer: CA 19-9 and chemotherapy response for GB cancer; disease status, albumin and chemotherapy response for ICCC; performance status and chemotherapy response for ECCC. Conclusions: Prognosis and prognostic factors of BTC were significantly different depending on its anatomical location.

Long-term outcome and recurrence factors after percutaneous cholecystostomy as a definitive treatment for acute cholecystitis.

BACKGROUND AND AIM: Percutaneous cholecystostomy (PC) has been frequently used as an alternative treatment for acute cholecystitis in seriously ill patients unfit for surgery. The aim of this study was to investigate the recurrence rate and risk factors of recurrence. METHODS: Medical records of 102 patients who were followed up for more than 1 year after PC tube removal among 716 patients who underwent PC for acute cholecystitis treatment were retrospectively analyzed. RESULTS: The recurrence rate of acute cholecystitis after PC tube removal was 20.6% (21/102), and the mean time to recur was 660 days. Underlying cancer (odds ratio [OR]: 3.369; 95% confidence interval [CI]: 1.006-11.282; P = 0.0489), PC duration shorter than 44 days (OR: 5.596; 95% CI: 1.35-23.201; P = 0.0176), and the presence of common bile duct stone in initial imaging studies (OR: 24.393; 95% CI: 2.696-220.746; P = 0.0045) were positively correlated with recurrence. Tubogram before PC tube removal did not significantly lower the recurrence. However, PC tube clamping for several days significantly lowered the recurrence (OR: 0.108; 95% CI: 0.015-0.794; P = 0.0288). Fifty-nine (57.8%) had acalculous cholecystitis. Calculous cholecystitis was negatively correlated with recurrence (OR: 0.267; 95% CI: 0.074-0.967; P = 0.0444). Receiver operating characteristic curve of the prediction model for recurrence verified its accuracy (area under the curve: 0.8475). CONCLUSION: We should try to keep PC more than 6 weeks and clamp for 1-2 weeks before removal. For those with the presence of common bile duct stones, calculous cholecystitis, and underlying malignancy, we should keep PC for longer duration and carefully observe symptoms and signs of recurrence.

Efficacy of EUS-guided and ERCP-guided biliary drainage for malignant biliary obstruction: prospective randomized controlled study.

BACKGROUND AND AIMS: ERCP-guided biliary drainage (ERCP-BD) is a criterion standard treatment for malignant biliary obstruction when curative surgery is not an option. Alternative methods such as percutaneous transhepatic biliary drainage would significantly lower the quality of life. EUS-guided biliary drainage (EUS-BD) has been developed and performed by experienced endoscopists. Therefore, the aims of this study were to evaluate the efficacy and safety of EUS-BD compared with ERCP in malignant biliary obstruction. METHODS: The prospective randomized controlled study was conducted, and 30 patients were enrolled: 15 for each EUS-BD and ERCP-BD arms. The technical success, procedural time, clinical success, and adverse events were evaluated. RESULTS: Thirty patients had extrahepatic malignant biliary tract obstruction (19 men, 11 women). Twenty-seven patients had unresectable pancreatic ductal adenocarcinomas, 1 patient had distal common bile duct cancer, and 2 patients had metastatic malignant lymphadenopathy. There were no significant differences both in terms of technical success rate and clinical success rate (100% vs 93% and 93% vs 100% in ERCP-BD vs EUS-BD, respectively; P = 1.00, P = 1.00). Four patients (31%) had tumor ingrowth-caused stent dysfunction in the ERCP-BD group, whereas 2 patients had food impaction and 2 patients had stent migration in the EUS-BD group. No significant procedure-related adverse events occurred in either group. CONCLUSIONS: This prospective randomized controlled study suggests that EUS-BD has similar safety to ERCP-BD. EUS-BD was not superior to ERCP-BD in terms of relief of malignant biliary obstruction. EUS-BD may have fewer cases of tumor ingrowth but may also have more cases of food impaction or stent migration. (Clinical trial registration number: NCT01421836.).

Preoperative EUS-guided FNA: effects on peritoneal recurrence and survival in patients with pancreatic cancer.

BACKGROUND AND AIMS: EUS-guided FNA (EUS-FNA) is an accurate and relatively safe tissue confirmation method for pancreatic cancer. However, there is concern that this procedure may spread tumor cells along the needle track or within the peritoneum. We aimed to estimate the effect of preoperative EUS-FNA on the risk of peritoneal recurrence and long-term outcomes in resected pancreatic cancer. METHODS: We retrospectively reviewed records of patients diagnosed with pancreatic cancer who had undergone curative resection between 2009 and 2013 to investigate the overall survival, cancer-free survival, and peritoneal recurrence. Peritoneal recurrence was diagnosed based on image findings or cytology-confirmed ascites. RESULTS: Of 411 patients, 90 underwent preoperative EUS-FNA (EUS-FNA group), whereas 321 did not (non-EUS-FNA group). The median length of follow-up was 16.2 months (range, 2-46). Peritoneal recurrence occurred in 131 patients: 30% (27/90) in the EUS-FNA group versus 32% (104/321) in the non-EUS-FNA group (P = .66). Cancer-free survival or overall survival was not significantly different between the 2 groups: median overall survival of 25.3 months in the EUS-FNA group versus 23.7 months in the non-EUS-FNA group (P = .36) and median cancer-free survival of 12.7 months in the EUS-FNA group versus 11.6 months in the non-EUS-FNA group (P = .38). CONCLUSIONS: Preoperative EUS-FNA for pancreatic cancer was not associated with an increased rate of peritoneal recurrence or mortality. Therefore, EUS-FNA is an accurate and safe method to obtain suspicious pancreatic mass tissue.

Predictive Model for Neoplastic Potential of Gallbladder Polyp.

GOAL: To provide the statistical predictive model for neoplastic potential of gallbladder polyp (GBP). BACKGROUND: Many studies have attempted to define the risk factors for neoplastic potential of GBP. It remains difficult to precisely adapt the reported risk factors for the decision of surgery. Estimating the probability for neoplastic potential of GBP using a combination of several risk factors before surgical resection would be useful in patient consultation. STUDY: We collected data of patients confirmed as GBP through cholecystectomy at Samsung Medical Center between January 1997 and March 2015. Those with a definite evidence for malignancy, such as adjacent organ invasion, metastasis on preoperative imaging studies, polyp >15 mm, and absence of proper preoperative ultrasonographic imaging were excluded. A total of 1976 patients were enrolled. To make and validate the predictive model, we divided the cohort into the modeling group (n=979) and validation group (n=997). Clinical information, ultrasonographic findings, and blood tests were retrospectively analyzed. RESULTS: Clinical factors of older age, single lesion, sessile shape, and polyp size showed statistical significance for neoplastic potential of GBP in the modeling group. A predictive model for neoplastic potential of GBP was constructed utilizing the statistical outcome of the modeling group. Statistical validation was performed with the validation group to determine the optimal clinical sensitivity and specificity of the predictive model. Optimal cut-off value for neoplastic probability was 7.4%. CONCLUSIONS: The predictive model for neoplastic potential of GBP may support clinical decisions before cholecystectomy.

Long term outcome of EUS-based strategy for suspected choledocholithiasis but negative CT finding.

OBJECTIVES: The American Society for Gastrointestinal Endoscopy (ASGE) guidelines offered the risk-stratified approach in suspected choledocholithiasis. Previous studies have raised concern about the insufficient accuracy of the guideline, especially in high probability group. The purposes of this study were to authenticate the stratification and clinical predictors of the guidelines for suspected choledocholithiasis with no visible choledocholithiasis on computed tomography (CT) and to make clear the clinical strategy of endoscopic ultrasonography (EUS). MATERIALS AND METHODS: We carried out the retrospective single-center study of 156 patients with suspected choledocholithiasis but negative findings on CT who underwent EUS for about 8 years at Samsung Medical Center. We assessed the clinical predictors of the ASGE guidelines in predicting the presence of choledocholithiasis and the outcome of the EUS. RESULTS: Fifty-three of the 156 patients had positive findings on EUS that included choledocholithiasis (n = 43, 27.6%) or obstructive papillitis (n = 10, 6.4%). Among the 53 patients, 51 (96.2%) had choledocholithiasis or obstructive papillitis on ERCP. The 101 patients of 103 patients with negative finding on EUS did not show biliary events during follow-up period. EUS accuracy was 98.7% (sensitivity 100%; specificity 98.1%). Among the 49 patients with high probability, 21 (42.9%) had choledocholithiasis on ERCP. In 107 patients who were classified as intermediate probability, 30 (27.3%) had choledocholithiasis. There were no complications related to EUS. CONCLUSIONS: Not only intermediate probability group but also high probability group without definite acute cholangitis may require EUS. Application of EUS for suspected choledocholithiasis is highly accurate, safe and reduces unnecessary invasive ERCP in 57.1% of patients with high probability group.

Association between nonalcoholic fatty liver disease and bone mineral density in postmenopausal women.

OBJECTIVE: Growing evidence suggests that nonalcoholic fatty liver disease (NAFLD) is associated with reduced bone mineral density (BMD). This study examined the association between NAFLD and BMD in postmenopausal Korean women. METHODS: This retrospective cross-sectional study analyzed 3739 postmenopausal women aged 50-59 years who visited a health promotion center for a routine checkup from 2009 to 2014. Menopause was defined as absence of menstruation for ≥12 months and an elevated follicle-stimulating hormone serum level (>20 IU/L). Women were excluded if they had a history of disease or use of medication that might affect bone metabolism. NAFLD was diagnosed by ultrasonography; BMD was measured by dual-energy X-ray absorptiometry. BMDs were compared according to the presence of NAFLD, and associations between NAFLD and BMD were analyzed after adjustment. RESULTS: Among 3739 postmenopausal women, 605 (16.2%) had NAFLD. Mean BMD at the lumbar spine (P = 0.017) and femur neck (P < 0.0001) was significantly lower in women with NAFLD than in those without NAFLD. Associations between NAFLD and BMD were significantly negative at both sites after adjusting for potential clinical confounders and factors which were significantly associated with BMD. CONCLUSIONS: NAFLD is negatively associated with BMD in postmenopausal women. A longitudinal study is recommended.

22G versus 25G biopsy needles for EUS-guided tissue sampling of solid pancreatic masses: a randomized controlled study.

BACKGROUND/OBJECTIVES: No comparative study of 22-gauge biopsy needles (PC22) and 25-gauge biopsy needles (PC25) has been conducted. We prospectively compared the diagnostic accuracy of PC22 and PC25 in patients with pancreatic and peripancreatic solid masses. METHODS: We conducted a randomized noninferiority clinical study from January 2013 to May 2014 at Samsung Medical Center. A cytological and histological specimen of each pass was analyzed separately by an experienced pathologist. The primary outcome was to assess the diagnostic accuracy using the PC22 or PC25. Secondary outcomes included the optimal number of passes for adequate diagnosis, core specimen yield, sample adequacy, and complication rates. RESULTS: Diagnostic accuracy of combining cytology with histology in three cumulative passes was 97.1% (100/103) for the PC22 and 91.3% (94/103) for the PC25 group. Thus, noninferiority of PC25 to PC22 was not shown with a 10% noninferiority margin (difference, -5.8%; 95% CI, -12.1 to -0.5%). In a pairwise comparison with each needle type, two passes was non-inferior to three passes in the PC22 (96.1% vs. 97.1%; difference, -0.97%; 95% CI -6.63 to 4.69%) but noninferiority of two passes to three passes was not shown in the PC25 group (87.4% vs. 91.3%; difference, -3.88%; 95% CI, -13.5 to 5.7%). CONCLUSIONS: Non-inferiority of PC25 to PC22 diagnostic accuracy was not observed for solid pancreatic or peripancreatic masses without on-site cytology. PC22 may be a more ideal device because only two PC22 needle passes was sufficient to establish an adequate diagnosis, whereas PC25 required three or more needle passes.

SpyGlass cholangioscopy-assisted guidewire placement for post-LDLT biliary strictures: a case series.

BACKGROUND AND AIMS: Anastomotic biliary strictures are common in patients that undergo living donor liver transplantation. Although endoscopic management has the advantage over percutaneous approaches, the initial success rate for the endoscopic management is unsatisfactory. The SpyGlass system can be a useful device in patients with a severe anastomotic stricture. METHODS: The SpyGlass cholangioscopy-assisted guidewire placement was performed in 15 patients with a difficult guidewire placement in which the guidewire could not transverse the stricture with conventional methods for 10 min or more. RESULTS: The visualization rate of the stricture orifice was 93.3 % (14 of 15 patients). The total success rate of the SpyGlass cholangioscopy-assisted guidewire placement was 60 % (9 of 15 patients). No procedure-related complications occurred during or after the SpyGlass cholangioscopy-assisted guidewire placement. CONCLUSIONS: This series demonstrated that the SpyGlass cholangioscopy-assisted guidewire placement is a useful method when the guidewire passage of the strictures site is impossible by conventional methods.

Novel flower-type covered metal stent to prevent cholecystitis: experimental study in a pig model.

BACKGROUND: Covered self-expandable metal stent (CSEMS) has the risk of obstruction of the cystic duct, and the main and branch pancreatic ducts due to strong radial force and covering material, which results in cholecystitis and pancreatitis. A flower-type covered self-expandable metal stent (F-CSEMS) having a five-petal-shaped design with side grooves was constructed to prevent the obstruction of the cystic duct orifice. This study investigated the value of the F-CSEMS in protection for cholecystitis in a pig model. METHODS: Fourteen pigs randomly underwent endoscopic placement of either F-CSEMS or conventional CSEMS (C-CSEMS). The stent was placed across the cystic duct orifice to impede bile drainage from the gallbladder. Drainage was checked at 24, 48, 120 and 168 h after implantation. Blood was collected at baseline, on days 2 and 7 following implantation. The animals were killed for histologic evaluation on day 7. RESULTS: All stents were successfully inserted into bile duct without any procedure-related complications. At 48 h, the rate of contrast drainage from the gallbladder was higher in the F-CSEMS group than the C-CSEMS group without significant difference (71.4 vs. 28.6% p = 0.28). C-CSEMS was associated with higher levels of C-reactive protein (35.2 vs. 20.5 µg/dl, p = 0.03) and histologic inflammatory scores of gallbladder (score 4 vs. 2; p = 0.03). CONCLUSION: The F-CSEMS appears safe and helpful to prevent cholecystitis without disturbance of bile flow in a pig model.

Prolonged progression-free survival achieved by gemcitabine, cisplatin, and albumin-bound paclitaxel for the treatment of advanced biliary tract cancers.

Background: A regimen of gemcitabine, cisplatin, and nab-paclitaxel (GPA) has shown promising results in patients with advanced biliary tract cancer (aBTC). Objectives: This study aimed to evaluate the benefit of GPA compared to a regimen of gemcitabine plus cisplatin (GP) in patients with aBTC. Design: Retrospective study. Methods: Patients with aBTC who received first-line chemotherapy with GPA or GP regimen at the Samsung Medical Center between July 2020 and June 2022 were included. The primary endpoint was progression-free survival (PFS). Results: In all, 37 patients were treated with GPA and 43 patients with GP. The GPA group showed significantly longer median PFS [12.0 months (95% CI, 7.2-16.8)] compared to the GP group [5.5 months (95% CI, 3.7-7.4; p = 0.007)]. The median overall survival (OS) was also longer in the GPA group [18.7 months (95% CI, 13.7-23.7)] than in the GP group [10.7 months (95% CI, 1.5-19.9); p = 0.021]. First-line chemotherapy with GPA was associated with longer PFS, while metastatic disease at initial diagnosis and post-treatment increase in CA 19-9 level were associated with worse PFS. Conclusion: The GPA regimen improved the PFS of patients with aBTC compared to the GP regimen but showed no significant benefit in terms of OS after adjusting for confounding variables. Further large-scale studies are required to establish optimal indications for GPA.

Comparing new and standard chemotherapy treatments for advanced biliary tract cancer: a study of effectiveness and survival In this study, researchers at Samsung Medical Center investigated the effectiveness of two chemotherapy regimens for advanced biliary tract cancer (aBTC) from July 2020 to June 2022. The study compared a new treatment combination, gemcitabine, cisplatin, and nab-paclitaxel (GPA), against the standard treatment of gemcitabine and cisplatin (GP). The main focus was on progression-free survival (PFS) ­ the time patients lived without their cancer worsening, and overall survival (OS) ­ the total lifespan after treatment. A total of 37 patients received the GPA treatment, while 43 received the GP treatment. The results showed that patients on the GPA regimen had a longer median PFS of 12.0 months, compared to 5.5 months for those on the GP regimen. This significant difference suggested that GPA might be more effective in slowing cancer progression. Moreover, the median OS was also longer for patients treated with GPA (18.7 months) than for those with the GP regimen (10.7 months). These findings indicated that GPA not only delayed the progression of cancer but also potentially increased the overall survival time of patients. However, when accounting for other factors that could influence the results, the advantage of GPA in terms of overall survival became less clear. This suggests that while GPA is effective in delaying disease progression, its impact on extending the overall life expectancy of patients with aBTC is not definitive. Despite these promising findings, the researchers cautioned that the benefits of the GPA regimen in extending overall survival need further investigation. The study underscores the potential of GPA in improving outcomes for aBTC patients but also highlights the necessity for more comprehensive studies. These future studies are needed to confirm the optimal treatment for this challenging cancer type. This research is a step towards better understanding and managing aBTC, a cancer that currently has limited treatment options.

Aggressive hydration with lactated Ringer's solution versus plasma solution for the prevention of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (ALPS study): protocol for a multicentre, double-blind, randomised controlled trial.

INTRODUCTION: Endoscopic retrograde cholangiopancreatography (ERCP) plays an indispensable role in treating pancreato-biliary diseases but carries a risk of post-ERCP pancreatitis (PEP). Despite advances in the prevention strategies, prevention of PEP remains imperfect, necessitating more refined hydration methods. This study investigates the effectiveness of lactated Ringer's solution versus plasma solution in preventing PEP. METHOD AND ANALYSIS: This multicentre, double-blind, randomised controlled trial, will be initiated by the investigator-sponsor, and conducted in three tertiary centres in South Korea. The aim of this study is to assess the effectiveness of hydration in preventing PEP in patients with naïve papillae. It will target patients with naïve papillae, focusing on those at medium to high risk of PEP. Patients aged ≤18 years and those with serious comorbidities, acute/chronic pancreatitis and various other medical conditions will be excluded. Eligible participants will be randomly assigned into two arms in equal numbers: (1) PEP prevention using lactated Ringer's solution and (2) PEP prevention using plasma solution. The primary outcome of this study will be the occurrence of PEP, and secondary outcomes will be additional risk factors and potential adverse events related to ERCP. With a total enrolment of 844 patients, the study will be able to detect significant differences between the intervention arms. ETHICS AND DISSEMINATION: Ethical approval is obtained from each institution (Asan Medical Centre, 2023-0382; Seoul National University Hospital, H-2302-05-1404; Samsung Medical Centre, SMC 2023-02-001-009). All participants provided informed consent following clear explanation of the study procedures. The results of the study will be disseminated in peer-reviewed journals and research conferences. TRIAL REGISTRATION NUMBER: NCT05832047. PROTOCOL VERSION: Ver 4.1 (2023).

Diagnosis and Treatment of Perihilar Cholangiocarcinoma: A National Survey from the Korean Pancreatobiliary Association.

Background/Aims: Based on their anatomy, cholangiocarcinomas (CCAs) are classified into intrahepatic, hilar, and distal CCAs. Although the diagnosis and treatment of each type of CCA are thought to be different, real-world data studies on the current practice are limited. Therefore, this study was designed to capture the current practice of diagnosing and treating perihilar CCA in Korea. Methods: We conducted a survey using an online platform. The questionnaire consisted of 18 questions designed to evaluate the current practice of diagnosing and treating perihilar CCA in Korea. The targets of this survey were biliary endoscopists who are members of the Korean Pancreatobiliary Association. Results: In total, 119 biliary endoscopists completed the survey. Of the respondents, 89.9% thought that the use of the International Classification of Diseases, 11th Revision (ICD-11) system is necessary to classify CCA. Approximately half of the respondents would recommend surgery or chemotherapy until patients were 80 years of age. For the pathological diagnosis of CCA, endoscopic retrograde cholangiopancreatography with biopsy was the most preferred modality. Routine preoperative biliary drainage was performed by 44.5% of the respondents. For operable CCAs, 64.7% of the respondents preferred endoscopic biliary drainage using plastic stents. For palliative biliary drainage, 69.7% of the respondents used plastic stents. For palliative endoscopic biliary drainage using metal stents, 63% of the respondents preferred the stent-in-stent method. Conclusions: A new coding system using the ICD-11 is needed for classifying CCAs. Guidelines for diagnosing and treating CCA based on the clinical situation in Korea are needed.

Outcomes of Palliative Chemotherapy for Ampulla of Vater Adenocarcinoma: A Multicenter Cohort Study.

Background/Aims: : Palliative chemotherapy (PC) is not standardized for patients with advanced ampulla of Vater adenocarcinoma (AA). This multicenter, retrospective study evaluated first-line PC outcomes in patients with AA. Methods: : Patients diagnosed with AA between January 2010 and December 2020 who underwent PC were enrolled from 10 institutions. Overall survival (OS) and progression-free survival (PFS) according to the chemotherapy regimen were analyzed. Results: : Of 255 patients (mean age, 64.0±10.0 years; male, 57.6%), 14 (5.5%) had locally advanced AA and 241 (94.5%) had metastatic AA. Gemcitabine plus cisplatin (GP) was administered as first-line chemotherapy to 192 patients (75.3%), whereas capecitabine plus oxaliplatin (CAPOX) was administered to 39 patients (15.3%). The median OS of all patients was 19.8 months (95% confidence interval [CI], 17.3 to 22.3), and that of patients who received GP and CAPOX was 20.4 months (95% CI, 17.2 to 23.6) and 16.0 months (95% CI, 11.2 to 20.7), respectively. The median PFS of GP and CAPOX patients were 8.4 months (95% CI, 7.1 to 9.7) and 5.1 months (95% CI, 2.5 to 7.8), respectively. PC for AA demonstrated improved median outcomes in both OS and PFS compared to conventional bile duct cancers that included AA. Conclusions: : While previous studies have shown mixed prognostic outcomes when AA was analyzed together with other biliary tract cancers, our study unveils a distinct clinical prognosis specific to AA on a large scale with systemic anticancer therapy. These findings suggest that AA is a distinct type of tumor, different from other biliary tract cancers, and AA itself could be expected to have a favorable response to PC.

The predictive value of PD-L1 expression in response to anti-PD-1/PD-L1 therapy for biliary tract cancer: a systematic review and meta-analysis.

Background: Recently, anti-programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) immunotherapy offers promising results for advanced biliary tract cancer (BTC). However, patients show highly heterogeneous responses to treatment, and predictive biomarkers are lacking. We performed a systematic review and meta-analysis to assess the potential of PD-L1 expression as a biomarker for treatment response and survival in patients with BTC undergoing anti-PD-1/PD-L1 therapy. Methods: We conducted a comprehensive systematic literature search through June 2023, utilizing the PubMed, EMBASE, and Cochrane Library databases. The outcomes of interest included objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) according to PD-L1 expression. Subgroup analyses and meta-regression were performed to identify possible sources of heterogeneity. Results: A total of 30 studies was included in the final analysis. Pooled analysis showed no significant differences in ORR (odds ratio [OR], 1.56; 95% confidence intervals [CIs], 0.94-2.56) and DCR (OR, 1.84; 95% CIs, 0.88-3.82) between PD-L1 (+) and PD-L1 (-) patients. In contrast, survival analysis showed improved PFS (hazard ratio [HR], 0.54, 95% CIs, 0.41-0.71) and OS (HR, 0.58; 95% CI, 0.47-0.72) among PD-L1 (+) patients compared to PD-L1 (-) patients. Sensitivity analysis excluding retrospective studies showed no significant differences with the primary results. Furthermore, meta-regression demonstrated that drug target (PD-1 vs. PD-L1), presence of additional intervention (monotherapy vs. combination therapy), and PD-L1 cut-off level (1% vs. ≥5%) significantly affected the predictive value of PD-L1 expression. Conclusion: PD-L1 expression might be a helpful biomarker for predicting PFS and OS in patients with BTC undergoing anti-PD-1/PD-L1 therapy. The predictive value of PD-L1 expression can be significantly influenced by diagnostic or treatment variables. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO, identifier CRD42023434114.