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.

Diagnostic Performance of Endoscopic Ultrasound Elastography for Differential Diagnosis of Gallbladder Polyp.

BACKGROUND AND AIMS: It is difficult to differentiate between neoplastic and non-neoplastic gallbladder (GB) polyps before surgery. Endoscopic ultrasound-elastography (EUS-EG) is a non-invasive complementary diagnostic method. The utility of EUS-EG in the differential diagnosis of GB polyps has not been investigated. We aimed to investigate the diagnostic performance of EUS-EG for the differential diagnosis of GB polyps. METHODS: Patients with GB polyps were prospectively enrolled from June 2020 until November 2022. EUS-EG and semi-quantitative evaluation of the strain ratio (SR) were performed for differential diagnosis of GB polyps. Fifty-three eligible patients were divided into two groups based on the final diagnosis after surgery. Patient demographics, EUS characteristics, and SR values were compared. Receiver-operating characteristic (ROC) curve analysis was performed to determine the optimal cutoff SR value that discriminates between neoplastic and non-neoplastic GB polyps. RESULTS: The median SR value for neoplastic polyps (32.93 [interquartile range: 22.37-69.02]) was significantly higher than for non-neoplastic polyps (5.40 [2.36-14.44]; p<0.001). There were significant differences in SR values between non-neoplastic, benign neoplastic (23.38 [13.62-39.04]), and malignant polyps (49.25 [27.90-82.00]). The optimal cut-off SR value to differentiate between neoplastic and non-neoplastic polyps was 18.4. In multivariable logistic regression, SR value >18.4 (odds ratio 33.604, 95% confidence interval 2.588-436.292) was an independent predictor of neoplastic polyps. CONCLUSIONS: EUS-EG and SR values can be used as a supplementary method for evaluating GB polyps.

Application of plasma circulating KRAS mutations as a predictive biomarker for targeted treatment of pancreatic cancer.

Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations in circulating tumor deoxyribonucleic acid (ctDNA) have been reported as representative noninvasive prognostic markers for pancreatic ductal adenocarcinoma (PDAC). Here, we aimed to evaluate single KRAS mutations as prognostic and predictive biomarkers, with an emphasis on potential therapeutic approaches to PDAC. A total of 128 patients were analyzed for multiple or single KRAS mutations (G12A, G12C, G12D, G12R, G12S, G12V, and G13D) in their tumors and plasma using droplet digital polymerase chain reaction (ddPCR). Overall, KRAS mutations were detected by multiplex ddPCR in 119 (93%) of tumor DNA and 68 (53.1%) of ctDNA, with a concordance rate of 80% between plasma ctDNA and tumor DNA in the metastatic stage, which was higher than the 44% in the resectable stage. Moreover, the prognostic prediction of both overall survival (OS) and progression-free survival (PFS) was more relevant using plasma ctDNA than tumor DNA. Further, we evaluated the selective tumor-suppressive efficacy of the KRAS G12C inhibitor sotorasib in a patient-derived organoid (PDO) from a KRAS G12C-mutated patient using a patient-derived xenograft (PDX) model. Sotorasib showed selective inhibition in vitro and in vivo with altered tumor microenvironment, including fibroblasts and macrophages. Collectively, screening for KRAS single mutations in plasma ctDNA and the use of preclinical models of PDO and PDX with genetic mutations would impact precision medicine in the context of PDAC.

Annotation-Efficient Deep Learning Model for Pancreatic Cancer Diagnosis and Classification Using CT Images: A Retrospective Diagnostic Study.

The aim of this study was to develop a novel deep learning (DL) model without requiring large-annotated training datasets for detecting pancreatic cancer (PC) using computed tomography (CT) images. This retrospective diagnostic study was conducted using CT images collected from 2004 and 2019 from 4287 patients diagnosed with PC. We proposed a self-supervised learning algorithm (pseudo-lesion segmentation (PS)) for PC classification, which was trained with and without PS and validated on randomly divided training and validation sets. We further performed cross-racial external validation using open-access CT images from 361 patients. For internal validation, the accuracy and sensitivity for PC classification were 94.3% (92.8-95.4%) and 92.5% (90.0-94.4%), and 95.7% (94.5-96.7%) and 99.3 (98.4-99.7%) for the convolutional neural network (CNN) and transformer-based DL models (both with PS), respectively. Implementing PS on a small-sized training dataset (randomly sampled 10%) increased accuracy by 20.5% and sensitivity by 37.0%. For external validation, the accuracy and sensitivity were 82.5% (78.3-86.1%) and 81.7% (77.3-85.4%) and 87.8% (84.0-90.8%) and 86.5% (82.3-89.8%) for the CNN and transformer-based DL models (both with PS), respectively. PS self-supervised learning can increase DL-based PC classification performance, reliability, and robustness of the model for unseen, and even small, datasets. The proposed DL model is potentially useful for PC diagnosis.

Establishment of Patient-Derived Organoids Using Ascitic or Pleural Fluid from Cancer Patients.

PURPOSE: Patient-derived tumor cells can be a powerful resource for studying pathophysiological mechanisms and developing robust strategies for precision medicine. However, establishing organoids from patient-derived cells is challenging because of limited access to tissue specimens. Therefore, we aimed to establish organoids from malignant ascites and pleural effusions. MATERIALS AND METHODS: Ascitic or pleural fluid from pancreatic, gastric, and breast cancer patients was collected and concentrated to culture tumor cells ex vivo. Organoids were considered to be successfully cultured when maintained for five or more passages. Immunohistochemical staining was performed to compare the molecular features, and drug sensitivity was assayed to analyze the clinical responses of original patients. RESULTS: We collected 70 fluid samples from 58 patients (pancreatic cancer, n=39; gastric cancer, n=21; and breast cancer, n=10). The overall success rate was 40%; however, it differed with types of malignancy, with pancreatic, gastric, and breast cancers showing 48.7%, 33.3%, and 20%, respectively. Cytopathological results significantly differed between successful and failed cases (p=0.014). Immunohistochemical staining of breast cancer organoids showed molecular features identical to those of tumor tissues. In drug sensitivity assays, pancreatic cancer organoids recapitulated the clinical responses of the original patients. CONCLUSION: Tumor organoids established from malignant ascites or pleural effusion of pancreatic, gastric, and breast cancers reflect the molecular characteristics and drug sensitivity profiles. Our organoid platform could be used as a testbed for patients with pleural and peritoneal metastases to guide precision oncology and drug discovery.

Prevalence and Risk Factors of Germline Pathogenic Variants in Pancreatic Ductal Adenocarcinoma.

PURPOSE: The genetic attribution for pancreatic ductal adenocarcinoma (PDAC) has been reported as 5%-10%. However, the incidence of germline pathogenic variants (PVs) in Korean PDAC patients has not been thoroughly investigated. Therefore, we studied to identify the risk factors and prevalence of PV for future treatment strategies in PDAC. MATERIALS AND METHODS: Total of 300 (155 male) patients with a median age of 65 years (range, 33 to 90 years) were enrolled in National Cancer Center in Korea. Cancer predisposition genes, clinicopathologic characteristics, and family history of cancer were analyzed. RESULTS: PVs were detected in 20 patients (6.7%, median age 65) in ATM (n=7, 31.8%), BRCA1 (n=3, 13.6%), BRCA2 (n=3), and RAD51D (n=3). Each one patient showed TP53, PALB2, PMS2, RAD50, MSH3, and SPINK1 PV. Among them, two likely PVs were in ATM and RAD51D, respectively. Family history of various types of cancer including pancreatic cancer (n=4) were found in 12 patients. Three patients with ATM PVs and a patient with three germline PVs (BRCA2, MSH3, and RAD51D) had first-degree relatives with pancreatic cancer. Familial pancreatic cancer history and PVs detection had a significant association (4/20, 20% vs. 16/264, 5.7%; p=0.035). CONCLUSION: Our study demonstrated that germline PVs in ATM, BRCA1, BRCA2, and RAD51D are most frequent in Korean PDAC patients and it is comparable to those of different ethnic groups. Although this study did not show guidelines for germline predisposition gene testing in patients with PDAC in Korea, it would be emphasized the need for germline testing for all PDAC patients.

Prolonged patency of fully covered self-expandable metal stents with an externally anchored plastic stent in distal malignant biliary obstruction.

BACKGROUND : Fully covered self-expandable metal stents (FCSEMSs) are widely used for endoscopic treatment of distal malignant biliary obstruction (dMBO). We aimed to assess the efficacy of anchoring an external plastic stent to an FCSEMS in dMBO. METHODS : A multicenter retrospective cohort study was performed in patients with dMBO to compare stent patency between FCSEMSs and FCSEMSs with an externally anchored plastic stent (EPS). For external anchoring, a 7-Fr double-pigtail plastic stent (DPPS) was placed first in the bile duct, then an FCSEMS was deployed side-by-side. RESULTS : Among a total of 185 patients, 65 had an FCSEMS alone and 120 had an FCSEMS with an EPS. The median stent patency was significantly longer in the FCSEMS with an EPS group than in the FCSEMS only group (342 vs. 240 days; P = 0.04). The rate of stent migration was significantly lower in the FCSEMS with an EPS group than in the FCSEMS only group (10.8 % vs. 27.7 %; P = 0.01). There were no significant differences in the rates of stent occlusion and adverse events between the two groups. CONCLUSIONS : A novel and simple technique of anchoring an external plastic stent may decrease the risk of FCSEMS migration and prolong stent patency, without significantly increasing the adverse events rate in dMBO.

Usefulness of Liquid-Based Cytology in Diagnosing Biliary Tract Cancer Compared to Conventional Smear and Forceps Biopsy.

BACKGROUND/AIMS: Liquid-based cytology (LBC) has been shown to improve the diagnostic efficacy of brush cytology for thyroid, cervical and pancreatic cancer. To evaluate the diagnostic performance of LBC for biliary tract cancer, we compared it with conventional smears and forceps biopsies. METHODS: A retrospective study was conducted of all consecutive patients who underwent brush cytology under ERCP from January 2010 to April 2020. The primary outcome was the diagnostic efficacy of conventional smears and LBC. The difference between the two groups was corrected using inverse probability weighting (IPW). The secondary outcome was the sensitivity and specificity of brush cytology and forceps biopsy. The secondary outcome was evaluated in patients who underwent both methods. RESULTS: Among 162 patients, conventional smears were performed in 70 patients and LBC was performed in 92 patients. In the primary analysis using IPW, the sensitivity of conventional smears and LBC was 56.00% and 78.26% respectively (P = 0.009). The specificity was 100% for both methods. The accuracy was 66.15% for conventional smears and 83.33% for LBC (P = 0.012). In the secondary analysis, the sensitivity of conventional smears versus forceps biopsies was 62.16% versus 78.38% (P = 0.034) and 81.16% for both LBC and forceps biopsies. The specificity of both cytological examination and forceps biopsies was 100%. CONCLUSIONS: Liquid-based cytology demonstrated better sensitivity and accuracy than conventional smears. Moreover, its diagnostic performance was close to that of forceps biopsies.

Clinical Efficacy of Hypofractionated Proton Beam Therapy for Intrahepatic Cholangiocarcinoma.

Forty-seven patients with intrahepatic cholangiocarcinoma (IHCC) who received proton beam therapy (PBT) were analyzed to evaluate the clinical efficacy and safety of hypofractionated PBT in patients with inoperable or recurrent IHCC. The median prescribed dose of PBT was 63.3 GyE (range: 45-80 GyE) in 10 fractions, and the median duration of follow-up in all the patients was 18.3 months (range: 2.4-89.9 months). Disease progression occurred in 35 of the 47 (74.5%) patients; local, intrahepatic, and extrahepatic progression occurred in 5 (10.6%), 20 (42.6%), and 29 (61.7%) patients, respectively. The 2-year freedom from local progression (FFLP), progression-free survival (PFS), overall survival (OS) rates, and median time of OS were 86.9% (95% confidence interval [CI], 74.4-99.4%), 16.8% (95% CI, 4.3-29.3%), 42.7% (95% CI, 28.0-57.4%), and 21.9 months (95% CI, 16.2-28.3 months), respectively; grade ≥ 3 adverse events were observed in four (8.5%) patients. In selected patients with localized disease (no viable tumors outside of the PBT sites), the median time of OS was 33.8 months (95% CI, 5.4-62.3). These findings suggest that hypofractionated PBT is safe and could offer a high rate of FFLP and promising OS in patients with inoperable or recurrent IHCC.

Capecitabine and temozolomide for metastatic intermediate to high-grade pancreatic neuroendocrine neoplasm: a single center experience.

BACKGROUND/AIMS: The combination of capecitabine and temozolomide (CAPTEM) is one of the treatment options for metastatic pancreatic neuroendocrine neoplasms (pNENs). This study aims to evaluate the efficacy of CAPTEM in patients with metastatic intermediate to high-grade pancreatic neuroendocrine tumor (pNET) or carcinoma (pNEC). METHODS: This study was conducted retrospectively in a single center. Patients were treated for intermediate to high-grade tumor with 750 mg/m² of capecitabine twice daily from day 1 to 14 and 200 mg/m² of temozolomide once daily from day 10 to 14, repeating twice in a cycle of 28 days. The primary outcomes were durations of overall survival (OS) and progression-free survival (PFS). The secondary outcomes consisted of objective response rate and disease control rate. RESULTS: A total of 12 patients (grade 2 NET in six, grade 3 NET in three, NEC in three patients) who received CAPTEM were included in this study. Patients received a median of five cycles (range, 2 to 46) of CAPTEM. The median dose combined 1,150 mg of capecitabine and 300 mg of temozolomide. The median OS and PFS were 41.2 months (range, 3.2 to 167) and 39.7 months (range, 2.1 to 100), respectively. Patients with NET had longer OS and PFS compared to those of patients with NEC (p = 0.002 and p = 0.028). High Ki-67 proliferative index (> 50%) was significantly associated with poor survival outcomes. CONCLUSION: CAPTEM showed favorable survival outcomes in patients with metastatic intermediate to high-grade pNENs. Our study supports that CAPTEM may be an effective treatment option for metastatic pNENs.

A real-world analysis of nanoliposomal-irinotecan with 5-fluorouracil and folinic acid as third- or later-line therapy in patients with metastatic pancreatic adenocarcinoma.

Background: Nanoliposomal encapsulation of irinotecan (nal-IRI) with 5-fluorouracil and leucovorin (5-FU/LV) has shown a survival benefit for gemcitabine-pretreated patients with metastatic pancreatic adenocarcinoma (mPAC). The aim of this study was to evaluate the effectiveness and safety of nal-IRI with 5-FU/LV for use beyond second-line treatment after standard frontline therapy for mPAC. Method: This multicenter, retrospective, non-comparative observational study included mPAC patients who received nal-IRI plus 5-FU/LV as third- or later-line therapy after disease progression on first-line FOLFIRINOX (FFX) or gemcitabine plus nab-paclitaxel. Results: In all, 128 patients who received nal-IRI plus 5-FU/LV beyond second-line treatment between October 2017 and July 2021 were analyzed. Most patients (82%) received nal-IRI plus 5-FU/LV as a third-line treatment. The median overall survival (OS) was 4.9 months and the median progression-free survival (PFS) was 2.4 months. Patients with better Eastern Cooperative Oncology Group (ECOG) performance status experienced significantly longer OS (ECOG 0, 8.7 months; ECOG 1, 4.8 months; ECOG 2, 2.9 months; p < 0.001) and PFS (3.9 months; 2.1 months; 1.5 months; p = 0.019). Patients who had not been previously treated with FFX or had a time to progression of 7 months or more on FFX experienced longer OS and PFS than those who did not (6.1 months and 5.6 versus 4.1 months, p = 0.053; 3.6 months and 2.4 versus 2.1 months, p = 0.002). The most common adverse events were neutropenia (56%) and anemia (51%). Conclusion: Our real-world data indicated that nal-IRI plus 5-FU/LV can be effective not only as second-line therapy, but also as third-line or later-line treatment in selected patients. Nal-IRI plus 5-FU/LV may be particularly beneficial for the survival of patients that maintain good general condition or those with favorable prior experience to irinotecan.

Proton Beam Therapy for Treatment-Naïve Hepatocellular Carcinoma and Prognostic Significance of Albumin-Bilirubin (ALBI) Grade.

To evaluate the efficacy of proton beam therapy (PBT) as an initial treatment in treatment-naïve hepatocellular carcinoma (HCC) patients and to assess the prognostic significance of albumin-bilirubin (ALBI) grade, 46 treatment-naïve HCC patients treated with PBT were analyzed. The ALBI grade distribution was grade 1 in 11 (23.9%) patients, grade 2 in 34 (73.9%) patients, and grade 3 in 1 (2.2%) patient. The median duration of follow-up was 56.5 months (95% confidence interval [CI], 48.2−64.7). Among the 46 patients, disease progression was observed in 23 (50%) patients: local progression in 3 (6.5%) patients; intrahepatic progression in 22 (47.8%); and extrahepatic progression in 5 (10.9%). The 5-year freedom from local progression (FFLP), progression-free survival (PFS), and overall survival (OS) rates were 92.7% (95% CI, 84.7−100.7), 43.3% (95% CI, 28.2−58.4), and 69.2% (95% CI, 54.9−83.5), respectively. In multivariate analysis, there were no independent factors for FFLP (p > 0.05 each), but tumor stage and ALBI grade were independent factors for PFS and OS (p < 0.05 each). PBT could result in comparable OS in treatment-naïve HCC patients to other recommended first-line treatments, and ALBI grade, in addition to tumor stage, could be useful for predicting OS.

The effect of nafamostat mesilate infusion after ERCP for post-ERCP pancreatitis.

BACKGROUND: Nafamostat mesilate decreases the incidence of pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP). However, no studies have administered nafamostat mesilate after ERCP. So we investigated if the infusion of nafamostat mesilate after ERCP can affect the post-ERCP pancreatitis (PEP) in high-risk patients. METHODS: In a tertiary hospital, 350 high-risk patients of PEP were reviewed retrospectively. Among them, 201 patients received nafamostat mesilate after ERCP. Patient-related and procedure-related risk factors for PEP were collected. We performed a propensity score matching to adjust for the significant different baseline characteristics. The incidence and severity of PEP were evaluated according to the infusion of nafamostat mesilate. The risk factors of PEP were also analyzed by multivariate logistic regression. RESULTS: The baseline characteristics were not different after the matching. The PEP rate (17.4% vs. 10.3%, P = 0.141) was insignificant. Among the PEP patients, mild PEP was significantly higher in the nafamostat mesilate group (85.7% vs. 45.5%, P = 0.021). Only one patient in the nafamostat mesilate group developed severe PEP. Although young age (odds ratio [OR] 3.60, 95% CI 1.09-11.85, P = 0.035) was a risk factor, nafamostat mesilate (odds ratio [OR] 0.30, 95% CI 0.09-0.98, P = 0.047) was a protective factor for moderate to severe PEP. CONCLUSIONS: The administration of nafamostat mesilate after ERCP in high-risk patients was not effective in preventing PEP, but may attenuate the severity of PEP.

[Liver Graft Failure after Plastic Stent Removal of an Anastomotic Biliary Stricture].

A biliary anastomotic stricture developed 13 months after living donor liver transplantation in a 19-year-old male with congenital hepatic fibrosis. Endoscopic management with balloon dilation followed by the placement of a 7F plastic stent was performed for the anastomotic stricture. After 6 months of indwelling of the stent, the plastic stent was removed because the stenosis and cholestasis were improved. One month after stent removal, he was admitted for acute liver graft failure owing to cholestatic hepatitis, and required retransplantation secondary to graft loss.

A remnant choledochal cyst after choledochal cyst excision treated with a lumen-apposing metal stent: a case report.

A lumen-apposing metal stent (LAMS) is a saddle-shaped stent with large flanges at both ends, thereby preventing stent migration and helping with approximation of the adjacent structures. We report the case of a 25-year-old female with remnant choledochal cyst which was successfully treated with LAMS after initial treatment failure with a plastic stent. Although complete excision of the cyst is the definite treatment of choledochal cysts, endoscopic ultrasonography-guided cystoduodenostomy can be considered in cases wherein surgery is not feasible and dysplasia is not present. LAMS may be preferred to plastic stents for effective resolution of remnant choledochal cyst and prevention of ascending infection.

Acetylsalicylic acid for metal stent in malignant distal common bile duct obstruction: A randomized controlled trial.

BACKGROUND: Endoscopic biliary drainage is the treatment of choice for patients with malignant distal common bile duct obstruction. Self-expandable metal stents have clinical advantages including an increased duration of patency that may be prolonged by acetylsalicylic acid (ASA) use. The aim of this study was to investigate whether ASA had a positive effect on the patency of self-expandable metal stents compared with placebo. METHODS: This prospective, multicenter, double-blinded, and randomized placebo-controlled trial was conducted from October 2017 to May 2020 in Korea. Patients who underwent palliative endoscopic biliary drainage with self-expandable metal stents for malignant distal bile duct obstruction were enrolled, and allocated to ASA treatment or placebo. The study outcomes were the rate of stent dysfunction at 6 months, duration of stent patency, risk factors for stent dysfunction, and any adverse events. RESULTS: Interim analysis included 24 and 28 patients in the ASA and placebo groups, respectively. There was no significant difference between the ASA and placebo groups in stent dysfunction (25.0% vs. 20.7%, P = 0.761) or the duration of stent patency (150.97 ± 10.55 vs. 158.07 ± 8.70 days, P = 0.497). Six patients experienced suspected ASA-related adverse events, and there was one lethal case. CONCLUSIONS: ASA did not prolong stent patency. This study was terminated early because of the possibility of serious adverse events related to ASA treatment of these patients receiving palliative care.

Establishment of Patient-Derived Pancreatic Cancer Organoids from Endoscopic Ultrasound-Guided Fine-Needle Aspiration Biopsies.

Background/Aims: Three-dimensional cultures of human pancreatic cancer tissue also known as "organoids" have largely been developed from surgical specimens. Given that most patients present with locally advanced and/or metastatic disease, such organoids are not representative of the majority of patients. Therefore, we used endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) to collect pancreatic cancer tissues from patients with advanced pancreatic cancer to create organoids, and evaluated their utility in pancreatic cancer research. Methods: Single-pass EUS-FNA samplings were employed to obtain the tissue for organoid generation. After establishment of the organoid, we compared the core biopsy tissues with organoids using hematoxylin and eosin staining, and performed whole exome sequencing (WES) to detect mutational variants. Furthermore, we compared patient outcome with the organoid drug response to determine the potential utility of the clinical application of such organoid-based assays. Results: Organoids were successfully generated in 14 of 20 tumors (70%) and were able to be passaged greater than 5 times in 12 of 20 tumors (60%). Among them, we selected eight pairs of organoid and core biopsy tissues for detailed analyses. They showed similar patterns in hematoxylin and eosin staining. WES revealed mutations in KRAS, TP53, CDKN2A, SMAD4, BRCA1, and BRCA2 which were 93% homologous, and the mean nonreference discordance rate was 5.47%. We observed moderate drug response correlations between the organoids and clinical outcomes in patients who underwent FOLFIRINOX chemotherapy. Conclusions: The established organoids from EUS-FNA core biopsies can be used for a suitable model system for pancreatic cancer research.

RRM1 Expression as a Prognostic Biomarker for Unresectable or Recurrent Biliary Tract Cancer Treated with Gemcitabine plus Cisplatin.

The combination of gemcitabine plus cisplatin (GP) is regarded as a first-line treatment for patients with unresectable or recurrent biliary tract cancer (BTC). Several proteins including human equilibrative nucleoside transporter-1 (hENT1), deoxycytidine kinase (DCK), cytidine deaminase (CDA), and ribonucleotide reductase subunit 1 (RRM1) are known to be involved in gemcitabine uptake and metabolism. This study was aimed to identify the predictive and prognostic values of these biomarkers in patients who treated with GP for advanced BTC. Tumor samples were obtained from 34 patients with unresectable or recurrent BTC who were treated with GP between August 2015 and February 2018. Intratumoral expression of hENT1, DCK, CDA and RRM1 was determined by immunohistochemistry and analyzed for association with chemotherapy response, progression-free survival (PFS) and overall survival (OS). Median OS was significantly longer in the RRM1-negative group than in the RRM1-positive (9.9 months vs. 5.9 months, p = 0.037). Multivariate adjustment analyses also demonstrated RRM1 expression as an independent prognostic factor for OS in patients treated with GP chemotherapy. Increased intratumoral expression of RRM1 on immunohistochemical staining may be a biomarker predicting poor survival in patients with GP chemotherapy for advanced BTC. Large-scale well-predefined prospective research is needed to validate the utility of biomarkers in clinical practice.

Comparison between FOLFIRINOX and gemcitabine plus nab-paclitaxel including sequential treatment for metastatic pancreatic cancer: a propensity score matching approach.

BACKGROUND: FOLFIRINOX (FFX) and Gemcitabine plus nab-paclitaxel (GnP) have been recommended as the first-line chemotherapy for metastatic pancreatic cancer (mPC). However, the evidence is lacking comparing not only two regimens, but also sequential treatment (FFX-GnP vs. GnP-FFX). METHODS: Data of 528 patients (FFX, n = 371; GnP, n = 157) with mPC were collected retrospectively. Propensity score matching was conducted to alleviate imbalance of the two groups. Overall survival (OS), progression free survival (PFS), and toxicity of patients were analyzed. RESULTS: In the whole population, OS (12.5 months vs. 10.3 months, P = 0.05) and PFS (7.1 months vs. 5.8 months, P = 0.02) were longer in the FFX group before matching and after matching (OS: 11.8 months vs. 10.3 months, P = 0.02; PFS: 7.2 months vs. 5.8 months, P <  0.01). For sequential treatment, OS and PFS showed no significant difference. Interruptions of chemotherapy due to toxicities were more frequent (6.8 vs. 29.3%, P <  0.001) in the GnP group, and cessation of chemotherapy showed a significant association with mortality (z = - 1.94, P = 0.03). CONCLUSIONS: FFX achieved a longer overall survival than GnP in mPC, but not in the comparison for sequential treatment. More frequent adverse events followed by treatment interruptions during GnP might lead to a poor survival outcome. Therefore, FFX would be a better first-line treatment option than GnP for mPC.

Optimal timing of endoscopic retrograde cholangiopancreatography for acute cholangitis associated with distal malignant biliary obstruction.

BACKGROUND: There is a lack of studies regarding the optimal timing for endoscopic retrograde cholangiopancreatography (ERCP) in patients with cholangitis caused by distal malignant biliary obstruction (MBO). This study aims to investigate the optimal timing of ERCP in patients with acute cholangitis associated with distal MBO with a naïve papilla. METHODS: A total of 421 patients with acute cholangitis, associated with distal MBO, were enrolled for this study. An urgent ERCP was defined as being an ERCP performed within 24 h following emergency room (ER) arrival, and early ERCP was defined as an ERCP performed between 24 and 48 h following ER arrival. We evaluated both 30-day and 180-day mortality as primary outcomes, according to the timing of the ERCP. RESULTS: The urgent ERCP group showed the lowest 30-day mortality rate (2.2%), as compared to the early and delayed ERCP groups (4.3% and 13.5%) (P < 0.001). The 180-day mortality rate was lowest in the urgent ERCP group, followed by early ERCP and delayed ERCP groups (39.4%, 44.8%, 60.8%; P = 0.006). A subgroup analysis showed that in both the primary distal MBO group, as well as in the moderate-to-severe cholangitis group, the urgent ERCP had significantly improved in both 30-day and 180-day mortality rates. However, in the secondary MBO and mild cholangitis groups, the difference in mortality rate between urgent, early, and delayed ERCP groups was not significant. CONCLUSIONS: In patients with acute cholangitis associated with distal MBO, urgent ERCP might be helpful in improving the prognosis, especially in patients with primary distal MBO or moderate-to-severe cholangitis.