Fracture of the patella involving inferior pole is associated with postoperative patella baja - A retrospective multicenter study.

BACKGROUND: The patella fracture involving of inferior pole fractures (IPF) may be associated with patella baja, However, the clinical impact of this condition remains unclear. This study aims to clarify 1) the incidence of patella baja following patellar fracture surgery, 2) the associated clinical outcomes with and without the presence of patella baja, and 3) the potential correlation between the detection of IPF on CT and the occurrence of patella baja. METHODS: We conducted a retrospective multicenter study involving 251 patients who underwent surgical treatment for patellar fractures. Patients were divided into the patella baja (PB; n = 49) group and patella norma (PN; n = 202) group. Data collected included demographics, radiographic findings, surgical details, and postoperative complications. We compared these items between PB group and PN group. Logistic regression analyses were used to identify risk factors for patella baja. RESULTS: Immediately following surgery, 36 (14.3%) patients presented with patella baja which increased to 49 cases (19.5%) at six months postoperatively. There is no statistically significant difference in the demographics, surgical details, clinical outcomes and complication between PB group and PN group. While, in the radiographical assessment, the prevalence of IPF on CT scan in the patella baja group was significantly higher than that in the patella norma group. By logistic regression analysis, IPFP on CT was identified as an independent risk factor for patella baja. (odds ratio 2.11, 95% confidence interval: 1.03-4.33, p = 0.042). CONCLUSION: In patients with patellar fractures, the incidence of patella baja increased from 14.3% immediately post-surgery to 19.5% at the six-month check-up. No significant differences were observed in clinical outcomes between the patella baja group and the norma group. The patella fracture involving IPF on CT emerged as a predictive factor for patella baja.

Feasibility of comprehensive genomic profiling using endoscopic ultrasound-guided tissue acquisition with a 22-gauge Franseen needle.

Aim: Comprehensive genomic profiling (CGP) test for solid tumors is now increasingly utilized in clinical practice, especially in pancreatobiliary cancer, and specimens obtained by endoscopic ultrasound-guided tissue acquisition (EUS-TA) are often submitted for tissue-based CGP test. In this study, we evaluated the feasibility of EUS-TA using a 22-gauge Franseen needle for the CGP test. Methods: Consecutive patients with solid tumors who underwent EUS-TA using a 22-gauge Franseen needle, and whose tissue samples were pre-checked for suitability for CGP test, were included in this single-center, retrospective analysis. The success rates of appropriate sample collection for CGP evaluated by pathologists (1st quality control) and CGP test (2nd quality control) were evaluated. In addition, The EUS-TA slides were evaluated for the tissue area and tumor area content, using the image software. Results: A total of 50 cases, with 78% of pancreatic cancer, were included in the analysis. A median of 3 passes of EUS-TA were performed with an adverse event rate of 4%. The success rates for 1st and 2nd quality control for CGP tests were 86% and 76%, respectively. The image analyses suggested EUS-TA specimen did not always fulfill CGP test criteria, with 18% of tissue area ≥16 mm2 and 38% of tumor area content ≥20%, even in cases with successful CGP tests. The suction method yielded a significantly larger amount of DNA but without a significant difference in the multivariate analysis. Conclusions: The present study demonstrated the feasibility of EUS-TA using a 22-gauge Franseen needle for CGP test.

Intraductal Papillary Mucinous Neoplasm Surveillance Leads to Early Diagnosis and Better Outcomes of Concomitant Cancer.

OBJECTIVE: To examine whether long-term surveillance of intraductal papillary mucinous neoplasms (IPMNs) leads to early diagnosis and better clinical outcomes of pancreatic ductal adenocarcinomas (PDACs) developing concomitantly with IPMNs. SUMMARY BACKGROUND DATA: Long-term image-based surveillance is recommended for patients with low-risk IPMNs. However, it is unknown whether the surveillance can improve surgical and survival outcomes of patients with concomitant PDACs. METHODS: Using a prospective single-institutional cohort of 4,620 patients with pancreatic cysts including 3,638 IPMN patients, we identified 63 patients who developed concomitant PDAC during long-term surveillance. We compared overall survival (OS) of 46 cases with concomitant PDAC to that of 460 matched cases diagnosed with non-IPMN-associated PDAC at the same institution. Multivariable hazard ratios and 95% confidence intervals (CIs) for overall mortality were computed using the Cox regression model with adjustment for potential confounders. RESULTS: Concomitant PDACs were identified at an earlier cancer stage compared to non-IPMN-associated PDACs with 67% and 38% cases identified at stage 2 or earlier, respectively (P<0.001) and 57% and 21% cases with R0 resection, respectively (P<0.001). Compared to non-IPMN-associated PDACs, concomitant PDACs were associated with longer OS (P=0.034) with a multivariable hazard ratio of 0.61 (95% CI, 0.39-0.96). The 5-year survival rate of patients with concomitant PDAC was higher compared to patients with non-IPMN-associated PDAC (34% vs. 18%, respectively; P=0.018). CONCLUSIONS: The surveillance for patients with IPMNs was associated with early identification of concomitant PDACs and longer survival of patients diagnosed with this malignancy.

Balloon endoscopy-assisted endoscopic retrograde cholangiopancreatography for hepatolithiasis in patients with hepaticojejunostomy.

BACKGROUND AND AIM: Balloon endoscopy-assisted endoscopic retrograde cholangiopancreatography (BE-ERCP) is an emerging procedure for pancreatobiliary diseases in patients with surgically altered anatomy. However, data on BE-ERCP for hepatolithiasis after hepaticojejunostomy (HJS) are still limited. METHODS: Stone removal success, adverse events and recurrence were retrospectively studied in consecutive patients who underwent BE-ERCP for hepatolithiasis after HJS between January 2011 and October 2022. Subgroup analysis was performed to compare clinical outcomes between patients who had undergone HJS over 10 years before (past HJS group) and within 10 years (recent HJS group). RESULTS: A total of 131 patients were included; 39% had undergone HJS for malignancy and 32% for congenital biliary dilation. Scope insertion and complete stone removal were successful in 89% and 73%, respectively. Early adverse events were observed in 9.9%. Four patients (3.1%) developed gastrointestinal perforation but could be managed conservatively. Hepatolithiasis recurrence rate was 17%, 20% and 31% in 1-year, 3-year, and 5-year after complete stone removal. The past HJS group was the only risk factor for failed stone removal (odds ratio 10.4, 95% confidence interval 2.99-36.5) in the multivariable analysis. Failed scope insertion (20%) and failed guidewire or device insertion to the bile duct (22%) were two major reasons for failed stone removal in the past HJS group. CONCLUSIONS: BE-ERCP for hepatolithiasis was effective and safe in cases with HJS but the complete stone removal rate was low in the past HJS group. Recurrent hepatolithiasis was common and careful follow up study is needed even after complete stone removal.

Skeletal muscle status and survival among patients with advanced biliary tract cancer.

BACKGROUND: Studies have demonstrated a prognostic role of sarcopenia (i.e., loss of skeletal muscle volume and functionality) in patients with various cancer types. In patients with biliary tract cancer, the quantity and quality of skeletal muscles and their serial changes have not been fully investigated in relation to survival outcomes. METHODS: We identified 386 patients with unresectable or recurrent biliary tract cancer and calculated skeletal muscle index (SMI) and skeletal muscle density (SMD) to estimate muscular quantity and quality, respectively, based on computed tomography images. Using the Cox regression model with adjustment for potential confounders, we calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for progression-free survival (PFS) and overall survival (OS) according to skeletal muscle status and its serial change. RESULTS: Compared to patients without sarcopenia, patients with sarcopenia were associated with shorter PFS (multivariable HR, 1.60; 95% CI, 1.15-2.22; P = 0.005), but not with OS (P = 0.027) at the adjusted α level of 0.013. SMD at baseline was associated with OS (multivariable HR comparing the extreme quartiles, 1.52; 95% CI, 1.07-2.14; Ptrend = 0.012), but not with PFS (Ptrend = 0.13). A reduction in SMI rather than that in SMD was associated with OS. Progressive disease was a risk factor for reductions in SMI and SMD. CONCLUSIONS: Skeletal muscle quantity and quality and their serial changes were associated with survival outcomes in patients with advanced biliary tract cancer. Our data highlight the importance of designing nutritional and physical interventions for improvements in skeletal muscle status.

Optimal age to discontinue long-term surveillance of intraductal papillary mucinous neoplasms: comparative cost-effectiveness of surveillance by age.

OBJECTIVE: Current guidelines recommend long-term image-based surveillance for patients with low-risk intraductal papillary mucinous neoplasms (IPMNs). This simulation study aimed to examine the comparative cost-effectiveness of continued versus discontinued surveillance at different ages and define the optimal age to stop surveillance. DESIGN: We constructed a Markov model with a lifetime horizon to simulate the clinical course of patients with IPMNs receiving imaging-based surveillance. We calculated incremental cost-effectiveness ratios (ICERs) for continued versus discontinued surveillance at different ages to stop surveillance, stratified by sex and IPMN types (branch-duct vs mixed-type). We determined the optimal age to stop surveillance as the lowest age at which the ICER exceeded the willingness-to-pay threshold of US$100 000 per quality-adjusted life year. To estimate model parameters, we used a clinical cohort of 3000 patients with IPMNs and a national database including 40 166 patients with pancreatic cancer receiving pancreatectomy as well as published data. RESULTS: In male patients, the optimal age to stop surveillance was 76-78 years irrespective of the IPMN types, compared with 70, 73, 81, and 84 years for female patients with branch-duct IPMNs <20 mm, =20-29 mm, ≥30 mm and mixed-type IPMNs, respectively. The suggested ages became younger according to an increasing level of comorbidities. In cases with high comorbidity burden, the ICERs were above the willingness-to-pay threshold irrespective of sex and the size of branch-duct IPMNs. CONCLUSIONS: The cost-effectiveness of long-term IPMN surveillance depended on sex, IPMN types, and comorbidity levels, suggesting the potential to personalise patient management from the health economic perspective.

Retrospective comparative study of new slim-delivery and conventional large-cell stents for stent-in-stent methods for hilar malignant biliary obstruction.

OBJECTIVES: Endoscopic management of unresectable hilar malignant biliary obstruction (HMBO) is technically challenging, and effectiveness of stent-in-stent using large-cell, metal stents was reported. A new, large-cell stent with a 6F tapered delivery system was recently developed. The aim of this study was to compare clinical outcomes of slim-delivery and conventional large-cell stents. METHODS: This was a multicenter retrospective comparative study of stent-in-stent methods using slim-delivery stents (Niti-S Large Cell SR Slim Delivery [LC slim-delivery]) and conventional stents (Niti-S large-cell D-type; LCD) for unresectable HMBO. RESULTS: Eighty-three patients with HMBO were included; 31 LC slim-delivery and 52 LCD. Overall technical and clinical success rates were 100% and 90% in LC slim-delivery group and 98% and 88% in LCD group. Use of the LC slim-delivery was associated with shorter stent placement time in the multiple regression analysis, with a stent placement time of 18 and 23 min in LC slim-delivery and LCD groups, respectively. The early adverse event (AE) rate of LC slim-delivery was 10%, with no cholangitis or cholecystitis as compared to 23% in the LCD group. Recurrent biliary obstruction (RBO) rates and time to RBO were comparable between the two groups: 35% and 44%, and 8.5 and 8.0 months in LC slim-delivery and LCD groups, respectively. The major cause of RBO was tumor ingrowth (82%) in the LC slim-delivery group and sludge (43%) and ingrowth (48%) in LCD group. CONCLUSION: Stent-in-stent methods using LC slim-delivery shortened stent placement time with low early AE rates and comparable time to RBO in patients with HMBO.

Development and external validation of a nomogram for prediction of post-endoscopic retrograde cholangiopancreatography pancreatitis.

BACKGROUND AND AIMS: Endoscopic retrograde cholangiopancreatography (ERCP) is widely performed for management of pancreatobiliary diseases; however, post-ERCP pancreatitis (PEP) remains as an unsolved problem. Although various risk factors for PEP have been reported, the prediction of PEP remains controversial. This study aimed to develop a predictive model for PEP. METHODS: Consecutive patients undergoing ERCP for biliary indications at two centers were retrospectively studied. Using data from a training cohort, we utilized a multivariable model to select five variables to construct a nomogram. The predictive model was internally and externally validated. Based on the nomogram, the patients were categorized into low-, moderate-, and high-risk groups. RESULTS: Using the data of 2224 patients in the training cohort, five variables were selected to generate a nomogram: 1) sex, 2) indication for ERCP, 3) difficult cannulation, 4) guidewire insertion into the pancreatic duct, and 5) endoscopic sphincterotomy or sphincteroplasty. The most significant risk factor was endoscopic papillary balloon dilation such as endoscopic sphincterotomy or sphincteroplasty. The bias-corrected concordance index was 0.72 in the training cohort and 0.72 in the validation cohort. Calibration curves for both cohorts demonstrated good agreement between the predicted and observed frequencies of the actual outcome. In the validation cohort, PEP developed in 5.0% and 14% of patients in the moderate- and high-risk groups, respectively. CONCLUSIONS: We successfully developed a good predictive model for PEP. The prevention of PEP in high risk patients should be investigated further.

Second Covered and Uncovered Self-Expandable Metal Stents for Recurrent Gastric Outlet Obstruction: A Retrospective Comparative Study.

Background: Endoscopic self-expandable metal stent (SEMS) placement is a current mainstay for malignant gastric outlet obstruction (GOO), but symptomatic recurrence due to initial SEMS dysfunction commonly occurs. We aimed to compare the safety and effectiveness of second SEMS for recurrent GOO (RGOO). Methods: Between April 2006 and December 2022, a total of 95 cases with malignant RGOO undergoing second endoscopic SEMS placement were enrolled. Technical and clinical success rates, RGOO, time to RGOO (TRGOO), stent patency rate, adverse events (AE), and overall survival (OS) were retrospectively compared between covered and uncovered SEMS (cSEMS/uSEMS) groups. Risk factors for TRGOO were also explored. Results: Baseline characteristics were well balanced between cSEMS (n = 48) and uSEMS (n = 47) groups, except for the causes of the initial SEMS dysfunction. High technical and clinical success rates with a similar incidence of AE (15% vs. 17%, p = 0.78) and OS (median of 101 vs. 102 days, p = 0.68) were achieved in both groups. There were no statistical differences in cumulative incidence of RGOO (19% vs. 13%, p = 0.58), TRGOO (median, not reached in both groups, p = 0.57), and stent patency rates at 1, 2, and 3 months between the groups (60%, 47% and 26%, respectively vs. 70%, 55% and 38%, respectively). However, TRGOO tended to be longer in cSEMS in cases with RGOO due to tumor ingrowth (median, not reached vs. 111 days, p = 0.19). A Cox regression analysis demonstrated that chemotherapy after second SEMS placement was significantly associated with an improved TRGOO (the hazard ratio of 0.27 [95% confidence interval, 0.08-0.93], p = 0.03). Conclusions: Regardless of the type of SEMS, second SEMS placement was similarly safe and effective for RGOO. The type of second SEMS might be considered based on the cause of initial SEMS dysfunction.

Clinical trajectory of intraductal papillary mucinous neoplasms progressing to pancreatic carcinomas during long-term surveillance: a prospective series of 100 carcinoma cases.

BACKGROUND: Trajectories of serological and morphological signatures have not been documented in pancreatic carcinogenesis related to intraductal papillary mucinous neoplasms (IPMNs). METHODS: Using a prospective cohort of 3437 IPMN patients, we identified 100 IPMN patients who developed pancreatic carcinomas during long-term surveillance. We examined serial changes of blood markers (carbohydrate antigen 19-9 [CA19-9], hemoglobin A1c [HbA1c], and pancreatic enzymes) and morphological features (worrisome features and high-risk stigmata) during the prediagnostic period of pancreatic carcinomas, overall and by carcinoma types (IPMN-derived vs. concomitant pancreatic carcinomas). RESULTS: CA19-9 elevation was observed in 39 patients and was associated with a metastatic stage. Compared to IPMN-derived carcinomas, concomitant carcinomas were more likely to represent CA19-9 elevation (60% vs. 30%, respectively; P = 0.005). HbA1c levels elevated only in 3 patients. Pancreatic enzyme elevation was observed in 18 patients with no differences in frequencies between the carcinoma types. All patients with elevated levels of blood markers had positive findings on cross-sectional imaging. High-risk stigmata or worrisome features were observed in all patients but one with concomitant carcinoma. The most common types of worrisome features were the main pancreatic duct dilatation and CA19-9 elevation in IPMN-derived and concomitant carcinomas, respectively. Compared to IPMN-derived carcinomas, concomitant carcinomas were less likely to harbor high-risk stigmata (16% vs. 86%, respectively; P < 0.001). CONCLUSIONS: The usefulness of currently available blood biomarkers was limited in early detection of pancreatic carcinomas related to IPMNs. Morphological alterations were well correlated with long-term risk of IPMN-derived carcinomas, but not with that of concomitant carcinomas.

Predictors of postoperative complications of tension band wiring techniques for patella fracture: A retrospective multicenter (TRON group) study.

OBJECTIVE: The relationship between postoperative complications and operative techniques of tension band wiring (TBW) is not well studied. We aimed to evaluate the incidence of implant breakage, implant migration, and loss of reduction in patellar fractures treated with TBW and identify radiographic factors associated with these postoperative complications. METHODS: This multicenter (named, TRON group) retrospective study included 224 patients who underwent open reduction and internal fixation of patella fractures using TBW from January 2016 to December 2020. Radiographic findings were evaluated by experienced orthopedic surgeons, and radiographic outcomes were assessed for K-wire migration, implant breakage, and loss of reduction. Logistic regression analysis was performed to identify radiographic factors associated with postoperative complications. RESULTS: Implant migration occurred in 44 cases (19.6%), with bending of a single K-wire end identified as a significant risk factor (OR: 12.90; 95% CI: 4.99-33.30; P < 0.001). Implant breakage occurred in 43 cases (19.2%), with a large patella-tension band ratio (OR: 291.0; 95% CI: 19.60-4330; P < 0.001) and a wide distance between K-wires (OR: 1.15; 95% CI: 1.060-1.250; P = 0.001) identified as significant risk factors. Loss of reduction occurred in 5 cases (2.0%), but no significant risk factors were identified. CONCLUSION: This study highlights the importance of bending both ends of the K-wires and proper placement of the tension band and K-wires in reducing postoperative complications in patellar fractures treated with TBW. Further research is needed to better understand the risk factors associated with loss of reduction.

Early skeletal muscle mass decline is a prognostic factor in patients receiving gemcitabine plus nab-paclitaxel for unresectable pancreatic cancer: a retrospective observational study.

PURPOSE: Patients with pancreatic cancer often have cancer cachexia at diagnosis. Recent studies suggested that loss of skeletal muscle mass was related to cancer cachexia, which hindered continuance of chemotherapy and could be one of prognostic factors in pancreatic cancer, however the association remains unclear in patients receiving gemcitabine and nab-paclitaxel (GnP). METHODS: We retrospectively studied 138 patients with unresectable pancreatic cancer receiving first-line GnP at the University of Tokyo from January 2015 to September 2020. We calculated body composition in CT images before chemotherapy and at initial evaluation, and evaluated the association of both body composition before chemotherapy and its changes at initial evaluation. RESULTS: Compared by skeletal muscle mass index (SMI) change rate between pre-chemotherapy and initial evaluation, there were statistically significantly differences in the median OS: 16.3 months (95%CI 12.3-22.7) and 10.3 months (95%CI 8.3-18.1) between SMI change rate ≥ -3.5% and < -3.5% groups (P = 0.01). By multivariate analysis for OS, CA19-9 (HR 3.34, 95%CI 2.00-5.57, P < 0.01), PLR (HR 1.68, 95%CI 1.01-2.78, P = 0.04), mGPS (HR 2.32, 95%CI 1.47-3.65, P < 0.01) and relative dose intensity (HR 2.21, 95%CI 1.42-3.46, P < 0.01) were significantly poor prognostic factors. SMI change rate (HR 1.47, 95%CI 0.95-2.28, P = 0.08) showed a trend to poor prognosis. Sarcopenia before chemotherapy was not significantly associated with PFS or OS. CONCLUSION: Early skeletal muscle mass decline was associated with poor OS. Further investigation is warranted whether the maintenance of skeletal muscle mass by nutritional support would improve prognosis.

Combination of serum human satellite RNA and miR-21-5p levels as a biomarker for pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis due to the difficulty of its diagnosis. Because human satellite II (HSATII) RNA, a satellite repeat RNA, is highly and specifically expressed in human PDAC, the serum HSATII RNA level may be a biomarker of PDAC. To measure the serum HSATII RNA level with high sensitivity and reproducibility, we previously developed a convenient method, tandem repeat amplification by nuclease protection (TRAP) combined with droplet digital PCR (ddPCR). Here, we refined the original method by simultaneously measuring the serum miR-21-5p level to enhance the detection of PDAC. The resulting PDAC-Index, constructed using serum HSATII RNA and miR-21-5p levels, discriminated patients with PDAC with high accuracy. We verified the clinical usefulness of the PDAC-Index as a supportive test in difficult-to-diagnose cases. The PDAC-Index has satisfactory diagnostic performance and may routinely be applied for detecting PDAC.

Clinical Outcomes of Intraductal Papillary Mucinous Neoplasms With Dilatation of the Main Pancreatic Duct.

BACKGROUND & AIMS: Dilatation of the main pancreatic duct (MPD) has been a surgical indication for intraductal papillary mucinous neoplasms (IPMNs). Few studies have investigated long-term outcomes of IPMNs with MPD dilatation. METHODS: Among 3610 patients diagnosed with pancreatic cysts between 1994 and 2021, we identified 2829 IPMN patients, including 282 patients with MPD ≥5 mm, and examined short-term (≤6 months) and long-term risks of pancreatic carcinoma. Utilizing competing risks proportional hazards models, we estimated subdistribution hazard ratios for incidence of pancreatic carcinoma with adjustment for potential confounders. RESULTS: In analyses of short-term outcomes of the 282 patients with MPD dilatation, 72 (26%) patients were diagnosed with pancreatic carcinoma based on surgical or nonsurgical exploration. During long-term follow-up of 168 patients, we documented 24 (14%) patients diagnosed with pancreatic carcinoma (18 with IPMN-derived carcinoma and 6 with concomitant ductal adenocarcinoma). The patients with the MPD = 5-9.9 mm had cumulative incidence rates of pancreatic carcinoma diagnosis of 8.1% (95% confidence interval [CI], 4.3%-13.5%) and 10.0% (95% CI, 5.5%-15.9%) at 2 and 5 years, respectively; and the patients with the MPD ≥10 mm had the corresponding rates of 16.0% (95% CI, 3.6-36.5%) and 33.3% (95% CI, 10.3%-58.8%). The multivariable subdistribution hazard ratios were 2.78 (95% CI, 1.57-4.90) and 7.00 (95% CI, 2.58-19.0) for the MPD = 5-9.9 mm and ≥10 mm (vs <5 mm), respectively. CONCLUSIONS: IPMNs with MPD dilatation at baseline were associated with higher prevalence and incidence of pancreatic carcinoma compared with IPMNs with no MPD dilatation.

Increased risk of biliary infection after biliary stent placement in users of proton pump inhibitors.

Objectives: Proton pump inhibitors (PPIs) are widely prescribed medications for gastric acid-induced diseases. Despite the effectiveness of PPIs, recent evidence suggested an increased risk of various bacterial infections in PPI users. The current study was conducted to evaluate the risk of biliary infection after endoscopic biliary stent placement in regular users of PPIs. Methods: Consecutive patients with a native papilla who underwent endoscopic retrograde cholangiopancreatography and stent placement for biliary stricture between January 2010 and August 2019 were included in this retrospective study. The cumulative incidences of biliary infection were compared between regular and non-regular PPI users. Results: During the study period, 270 regular PPI users and 146 non-regular PPI users were included in the analyses. Age, gender, and indication of endoscopic retrograde cholangiopancreatography were not different between the two groups. The incidences of biliary infection were 43% in regular PPI users and 36% in non-regular PPI users but the time to biliary infection was significantly shorter in regular PPI users than in non-regular users (28 vs. 87 days, p = 0.01). The cumulative incidence of biliary infection was significantly higher in regular PPI users compared with non-regular users (p = 0.008). The multivariable Cox regression analysis also showed a significantly higher hazard ratio of biliary infection in regular PPI users (1.62 [95% confidence interval 1.16-2.26; p = 0.005]). Conclusions: Regular PPI use was associated with a higher risk of biliary infection after endoscopic biliary drainage. Inappropriate PPI use should be avoided.

MNX1-HNF1B Axis Is Indispensable for Intraductal Papillary Mucinous Neoplasm Lineages.

BACKGROUND & AIMS: Chromatin architecture governs cell lineages by regulating the specific gene expression; however, its role in the diversity of cancer development remains unknown. Among pancreatic cancers, pancreatic ductal adenocarcinoma (PDAC) and intraductal papillary mucinous neoplasms (IPMN) with an associated invasive carcinoma (IPMNinv) arise from 2 distinct precursors, and their fundamental differences remain obscure. Here, we aimed to assess the difference of chromatin architecture regulating the transcriptional signatures or biological features in pancreatic cancers. METHODS: We established 28 human organoids from distinct subtypes of pancreatic tumors, including IPMN, IPMNinv, and PDAC. We performed exome sequencing (seq), RNA-seq, assay for transposase-accessible chromatin-seq, chromatin immunoprecipitation-seq, high-throughput chromosome conformation capture, and phenotypic analyses with short hairpin RNA or clustered regularly interspaced short palindromic repeats interference. RESULTS: Established organoids successfully reproduced the histology of primary tumors. IPMN and IPMNinv organoids harbored GNAS, RNF43, or KLF4 mutations and showed the distinct expression profiles compared with PDAC. Chromatin accessibility profiles revealed the gain of stomach-specific open regions in IPMN and the pattern of diverse gastrointestinal tissues in IPMNinv. In contrast, PDAC presented an impressive loss of accessible regions compared with normal pancreatic ducts. Transcription factor footprint analysis and functional assays identified that MNX1 and HNF1B were biologically indispensable for IPMN lineages. The upregulation of MNX1 was specifically marked in the human IPMN lineage tissues. The MNX1-HNF1B axis governed a set of genes, including MYC, SOX9, and OLFM4, which are known to be essential for gastrointestinal stem cells. High-throughput chromosome conformation capture analysis suggested the HNF1B target genes to be 3-dimensionally connected in the genome of IPMNinv. CONCLUSIONS: Our organoid analyses identified the MNX1-HNF1B axis to be biologically significant in IPMN lineages.

ABO Blood Group and Risk of Pancreatic Carcinogenesis in Intraductal Papillary Mucinous Neoplasms.

BACKGROUND: ABO blood group has been associated with risks of various malignancies, including pancreatic cancer. No study has evaluated the association of ABO blood group with incidence of pancreatic carcinogenesis during follow-up of patients with intraductal papillary mucinous neoplasms (IPMN). METHODS: Among 3,164 patients diagnosed with pancreatic cysts at the University of Tokyo (Tokyo, Japan) from 1994 through 2019, we identified 1,815 patients with IPMN with available data on ABO blood group. We studied the association of ABO blood group with incidence of pancreatic carcinoma, overall and by carcinoma types [IPMN-derived carcinoma or concomitant pancreatic ductal adenocarcinoma (PDAC)]. Utilizing competing-risks proportional hazards models, we estimated subdistribution hazard ratios (SHR) for incidence of pancreatic carcinoma with adjustment for potential confounders, including cyst characteristics. RESULTS: During 11,518 person-years of follow-up, we identified 97 patients diagnosed with pancreatic carcinoma (53 with IPMN-derived carcinoma and 44 with concomitant PDAC). Compared with patients with blood group O, patients with blood groups A, B, and AB had multivariable SHRs (95% confidence intervals) for pancreatic carcinoma of 2.25 (1.25-4.07; P = 0.007), 2.09 (1.08-4.05; P = 0.028), and 1.17 (0.43-3.19; P = 0.76), respectively. We observed no differential association of ABO blood group with pancreatic carcinoma incidence by carcinoma types. CONCLUSIONS: In this large long-term study, patients with IPMN with blood group A or B appeared to be at higher risk of pancreatic carcinoma compared with those with blood group O. IMPACT: ABO blood group can be a biomarker for pancreatic cancer risk among patients with IPMNs.