Linear-array EUS improves detection of pancreatic lesions in high-risk individuals: a randomized tandem study

Advancements in Early Detection and Screening Strategies for Pancreatic Cancer: From Genetic Susceptibility to Novel Biomarkers

Pancreatic cancer is a rare but lethal cancer due to its biologically aggressive nature, advanced stage at the time of diagnosis, and poor response to oncologic therapies. The risk of pancreatic cancer is significantly higher to 5% in certain high-risk individuals with inherited genetic susceptibility. Screening for pancreatic cancer in these individuals from high-risk groups can help with the early detection of pancreatic cancer as well as the detection of precursor lesions leading to early surgical resection and improved overall outcomes. The advancements in radiological imaging as well as advanced endoscopic procedures has made a significant impact on the early diagnosis, surveillance, and staging of pancreatic cancer. There is also a significant advancement in the development of biomarkers for the early detection of pancreatic cancer, which has also led to the development of liquid biopsy, allowing for microRNA detection in serum and circulating tumor cells. Various societies and organizations have provided guidelines for pancreatic cancer screening and surveillance in high-risk individuals. In this review, we aim to discuss the hereditary risk factors for developing pancreatic cancer, summarize the screening recommendations by different societies, and discuss the development of novel biomarkers and areas for future research in pancreatic cancer screening for high-risk individuals.

Chronic jetlag accelerates pancreatic neoplasia in conditional Kras-mutant mice

Misalignment of the circadian clock compared to environmental cues causes circadian desynchrony, which is pervasive in humans. Clock misalignment can lead to various pathologies including obesity and diabetes, both of which are associated with pancreatic ductal adenocarcinoma - a devastating cancer with an 80% five-year mortality rate. Although circadian desynchrony is associated with an increased risk of several solid-organ cancers, the correlation between clock misalignment and pancreas cancer is unclear. Using a chronic jetlag model, we investigated the impact of clock misalignment on pancreas cancer initiation in mice harboring a pancreas-specific activated Kras mutation. We found that chronic jetlag accelerated the development of pancreatic cancer precursor lesions, with a concomitant increase in precursor lesion grade. Cell-autonomous knock-out of the clock in pancreatic epithelial cells of Kras-mutant mice demonstrated no acceleration of precursor lesion formation, indicating non-cell-autonomous clock dysfunction was responsible for the expedited tumor development. Therefore, we applied single-cell RNA sequencing over time and identified fibroblasts as the cell population manifesting the greatest clock-dependent changes, with enrichment of specific cancer-associated fibroblast pathways due to circadian misalignment.

Pancreatic duct imaging during aging

As part of the aging process, fibrotic changes, fatty infiltration, and parenchymal atrophy develop in the pancreas. The pancreatic duct also becomes wider with age. This article provides an overview of the diameter of the pancreatic duct in different age groups and different examination methods. Knowledge of these data is useful to avoid misinterpretations regarding the differential diagnosis of chronic pancreatitis, obstructive tumors, and intraductal papillary mucinous neoplasia (IPMN).

Detection rate of endoscopic ultrasound and computed tomography in diagnosing pancreatic neuroendocrine neoplasms including small lesions: a multicenter study

BACKGROUND/PURPOSE

The detection ability and role of different imaging modalities to detect pancreatic neuroendocrine neoplasms (PNENs) including small lesions is unclear. This study aimed to compare the ability of endoscopic ultrasound (EUS) and computed tomography (CT) to detect PNENs.

METHODS

Data of patients who underwent EUS and contrast-enhanced CT and were diagnosed with PNENs were analyzed. The detection rates of pancreatic lesions with EUS and CT based on tumor size and influencing factors were investigated.

RESULTS

For 256 PNEN lesions, the detection rate of EUS was better than that of CT (94.5% vs. 86.3%; p < 0.001). EUS was significantly superior to CT for PNENs ≤ 5 mm (58.3% vs 16.7%; p = 0.006) and 5-10 mm (97.7% vs 79.5%; p = 0.008). There was no significant difference in the detection rate between EUS and CT for PNENs > 10 mm (98.4% vs 96.4%; p = 0.375). Size (≤ 5 mm) and insulinoma were independent factors associated with poor EUS and CT detection rates.

CONCLUSIONS

EUS exhibited better detection ability than CT, with an excellent detection rate for PNENs > 5 mm, except for insulinomas. CT could detect PNENs > 10 mm, which are amenable to treatment.

Standardization of EUS imaging and reporting in high-risk individuals of pancreatic adenocarcinoma: consensus statement of the Pancreatic Cancer Early Detection Consortium

BACKGROUND AND AIMS

Pancreatic ductal adenocarcinoma is an aggressive disease most often diagnosed after local progression or metastatic dissemination, precluding resection and resulting in a high mortality rate. For individuals with elevated personal risk of the development of pancreatic cancer, EUS is a frequently used advanced imaging and diagnostic modality. However, variability in the expertise and definition of EUS findings exists among gastroenterologists, as well as a lack of standardized reporting of relevant findings at the time of examination. Adoption of standardized EUS reporting, using a universally accepted and agreed on terminology, is needed.

METHODS

A consensus statement designed to create a standardized reporting template was authored by a multidisciplinary group of experts in pancreatic diseases that includes gastroenterologists, radiologists, surgeons, oncologists, and geneticists. This statement was developed using a modified Delphi process as part of the Pancreatic Cancer Early Detection Consortium, and >75% agreement was required to reach consensus.

RESULTS

We identified reporting elements and present standardized reporting templates for EUS indications, procedural data, EUS image capture, and descriptors of findings, tissue sampling, and postprocedural assessment of adequacy.

CONCLUSIONS

Adoption of this standardized EUS reporting template should improve consistency in clinical decision-making for individuals with elevated risk of pancreatic cancer by providing complete and accurate reporting of pancreatic abnormalities. Standardization will also help to facilitate research and clinical trial design by using clearly defined and consistent imaging descriptions, thus allowing for comparison of results across different centers.

Curriculum for ERCP and endoscopic ultrasound training in Europe: European Society of Gastrointestinal Endoscopy (ESGE) Position Statement

The European Society of Gastrointestinal Endoscopy (ESGE) has recognized the need to formalize and enhance training in endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS). This manuscript represents the outcome of a formal Delphi process resulting in an official Position Statement of the ESGE and provides a framework to develop and maintain skills in ERCP and EUS. This curriculum is set out in terms of the prerequisites prior to training; recommended steps of training to a defined syllabus; the quality of training; and how competence should be defined and evidenced before independent practice. 1: Trainees should be competent in gastroscopy prior to commencing training. Formal training courses and the use of simulation in training are recommended. 2: Trainees should keep a contemporaneous logbook of their procedures, including key performance indicators and the degree of independence. Structured formative assessment is encouraged to enhance feedback. There should be a summative assessment process prior to commencing independent practice to ensure there is robust evidence of competence. This evidence should include a review of a trainee's procedure volume and current performance measures. A period of mentoring is strongly recommended in the early stages of independent practice. 3: Specifically for ERCP, all trainees should be competent up to Schutz level 2 complexity (management of distal biliary strictures and stones > 10 mm), with advanced ERCP requiring a further period of training. Prior to independent practice, ESGE recommends that a trainee can evidence a procedure volume of > 300 cases, a native papilla cannulation rate of ≥ 80 % (90 % after a period of mentored independent practice), complete stones clearance of ≥ 85 %, and successful stenting of distal biliary strictures of ≥ 90 % (90 % and 95 % respectively after a mentored period of independent practice). 4: The progression of EUS training and competence attainment should start from diagnostic EUS and then proceed to basic therapeutic EUS, and finally to advanced therapeutic EUS. Before independent practice, ESGE recommends that a trainee can evidence a procedure volume of > 250 cases (75 fine-needle aspirations/biopsies [FNA/FNBs]), satisfactory visualization of key anatomical landmarks in ≥ 90 % of cases, and an FNA/FNB accuracy rate of ≥ 85 %. ESGE recognizes the often inadequate quality of the evidence and the need for further studies pertaining to training in advanced endoscopy, particularly in relation to therapeutic EUS.

Screening for pancreatic cancer: a review for general clinicians

Pancreatic cancer (PC) is an exceptionally lethal malignancy with increasing incidence and mortality worldwide. One of the principal challenges in the treatment of PC is that the diagnosis is usually made at a late stage when potentially curative surgical resection is no longer an option. General clinicians including internists and family physicians are well positioned to identify high-risk individuals and refer them to centers with expertise in PC screening and treatment where screening modalities can be employed. Here, we provide an up-to-date review of PC precursor lesions, epidemiology, and risk factors to empower the general clinician to recognize high-risk patients and employ risk reduction strategies. We also review current screening guidelines and modalities and preview progress that is being made to improve screening tests and biomarkers. It is our hope that this review article will empower the general clinician to understand which patients need to be screened for PC, strategies that may be used to reduce PC risk, and which screening modalities are available in order to diminish the lethality of PC.

Comparison of the Diagnostic Efficiency of Radial- and Convex-Arrayed Echoendoscopes for Indirect Findings of Pancreatic Cancer: A Retrospective Comparative Study Using Propensity Score Method

Simple Summary

Pancreatic cancer (PC) has a poor prognosis; however, diagnosing PC at an earlier stage could improve long-term patient outcomes. Endoscopic ultrasonography (EUS) plays an important role in PC detection, and the indirect findings (caliber change, retention cysts, and dilatation of the branch duct) that are detected by EUS are especially important for the early detection of PC. The aim of this retrospective study was to compare the diagnostic efficacy of radial- and convex-arrayed echoendoscope for the detection rate of indirect findings. As a result, the radial-arrayed echoendoscope was found to be an independent detection factor of indirect findings by multivariate analysis. The radial-arrayed echoendoscope is useful for the detection of indirect findings.

Abstract

Endoscopic ultrasonography (EUS) is useful for detecting early-stage pancreatic cancer. Because the detection of small lesions is difficult, it is important to detect indirect findings, namely caliber change, retention cysts, and dilatation of the branch duct, during the procedure. Although two types of EUS endoscopes are frequently used, there is no comparative study on their efficacy for detecting indirect findings. Therefore, we aimed to compare the diagnostic efficacy of these two types for indirect findings. We retrospectively analyzed 316 consecutive patients who had undergone EUS for pancreaticobiliary disease at a single center between January 2017 and December 2018. The main outcome was the detection rate of indirect findings and its comparison between the two echoendoscope types. This outcome was achieved using the inverse probability of treatment weighting (IPTW) analysis. The detection rate of indirect findings was higher for the radial-arrayed endoscope than for the convex-arrayed echoendoscope (9.2% vs. 2.3% (p = 0.02)). The univariate analysis also revealed that the radial-arrayed echoendoscope was significantly superior to the convex-arrayed echoendoscope in terms of the detection of indirect findings (odds ratio, 5.94; 95% confidence interval, 1.68–21.10; p = 0.01) after IPTW. After adjustment for magnetic resonance imaging (MRI) and computed tomography (CT), radial-arrayed echoendoscope remained an independent factor for indirect finding detection (odds ratio, 6.04; 95% confidence interval, 1.74–21.00; p = 0.01). Finally, five patients who had indirect EUS findings were diagnosed with pancreatic cancer. Our results indicate that the radial-arrayed echoendoscope is useful for the detection of indirect findings.

Value of endoscopic ultrasonography in the observation of the remnant pancreas after pancreatectomy

BACKGROUND

Endoscopic ultrasonography (EUS) is proven to be a more specific and sensitive method for detecting pancreatic lesions. However, usefulness of EUS after pancreatectomy has not been reported. This study aimed to evaluate the observational capability of EUS for the remnant pancreas (RP) after pancreatectomy.

PATIENT AND METHODS

This single-center, retrospective study enrolled 395 patients who underwent pancreatectomy at Onomichi General Hospital between December 2002 and March 2016, 45 patients who underwent EUS for RP were included for analysis. We evaluated the usefulness of EUS for RP using logistic regression analysis.

RESULTS

Complete observation of the RP was done in 42 patients (93%). In the initial surgical procedure, 21 patients underwent pancreaticoduodenectomy (PD), and 24 patients underwent distal pancreatectomy (DP). PD and DP were observed in 85% (18/21) and 100% (24/24) cases, respectively. A comparison of the detection capability of EUS and contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) showed that EUS was significantly superior to contrast-enhanced CT or MRI (p < 0.01). Eight of the 45 patients showed recurrence lesions in the RP. The median recurrence period was 33 months. Predictive factors for recurrence in the univariate and multivariate analyses were significantly different in space occupying lesion with EUS findings (p < 0.01) and elevated CA19-9(p < 0.01).

CONCLUSIONS

EUS was able to observe the RP in almost all cases. In addition, the detection capability of EUS was significantly superior to those of CT or MRI. We recommend that all patients with RP should undergo EUS, and a longer follow-up must be performed.

Main Duct Dilatation Is the Best Predictor of High-grade Dysplasia or Invasion in Intraductal Papillary Mucinous Neoplasms of the Pancreas

OBJECTIVE

The purpose of this study is to determine preoperative factors that are predictive of malignancy in patients undergoing pancreatic resection for intraductal papillary mucinous neoplasms (IPMN).

SUMMARY BACKGROUND DATA

IPMN of the pancreas may be precursor lesions to pancreatic cancer (PC) and represent a target for early diagnosis or prevention. While there has been much effort to define preoperative risk factors for malignant pathology, guidelines are ever-changing and controversy remains surrounding which patients would benefit most from resection.

METHODS

We performed a retrospective analysis of 901 consecutive patients obtained from two tertiary referral centers who underwent pancreatic resection for histologically proven IPMN between 2004 and 2017. Collected data included patient demographic characteristics, preoperative symptoms, radiological findings, and laboratory data.

RESULTS

Main pancreatic duct (MPD) dilatation was the only variable that was significantly associated with increased probability of malignancy (defined high-dysplasia or invasion) on both univariate and multivariate analysis. Even middle-range MPD dilatation from 5 mm to 9.9 mm (n = 286) was associated with increased odds of HG-IPMN (OR = 2.74; 95% CI = 1.80-4.16) and invasion (OR = 4.42; 95% CI = 2.55-7.66). MPD dilatation >10 mm (n = 150) had even greater odds of HG-IPMN (OR = 6.57; 95% CI = 3.94-10.98) and invasion (OR = 15.07; 95% CI = 8.21-27.65). A cutoff of 5 to 7 mm MPD diameter was determined to be the best predictor to discriminate between malignant and benign lesions.

CONCLUSIONS

In agreement with current IPMN management guidelines, we found MPD dilatation, even low levels from 5 mm to 9.9 mm, to be the single best predictor of HG-IPMN or invasion, highlighting the critical role that MPD plays in the selection of surgical candidates.

Linear-array EUS improves the accuracy of predicting deep submucosal invasion in non-pedunculated rectal polyps compared with radial EUS: a prospective observational study

BACKGROUND

Radial endoscopic ultrasound (EUS) is typically used to estimate the depth of rectal polyp invasion, however, there are no data on linear EUS in this setting and its relative accuracy compared to radial EUS.

METHODS

In this prospective cohort study, 89 patients with non-pedunculated rectal polyp who underwent linear EUS or radial EUS were prospectively enrolled. The invasion depth was measured for each polyp and categorized as mucosal to shallow submucosal(SM_s) or deep submucosal(SM_d) invasion. Invasion measurements were compared with the final diagnosis on histopathology.

RESULTS

A total of 58 patients underwent radial EUS and 31 patients underwent linear EUS examination. There were 38 lesions correctly diagnosed in the radial EUS group and 29 correctly diagnosed lesions in the linear EUS group. The diagnostic accuracy of SM_d invasion for linear EUS was significantly higher than radial EUS (0.936 vs. 0.655, p = 0.003). A significant difference was also noted for specificity between the two groups (0.963 vs. 0.659, p = 0.003). Univariate analysis showed radial EUS type (OR 0.131, 95% CI 0.028-0.606, p = 0.009) to be an independent predictor for incorrect diagnosis. The area under the receiver operating curve (ROC) was 0.856 and 0.651 for linear EUS and radial EUS, respectively. It was noted that four patients underwent unnecessary surgery for radial EUS while there were no such patients in the linear EUS group.

CONCLUSIONS

Linear EUS was more accurate for determining SM_d invasion and contributed to the selection of appropriate treatment modalities in patients with non-pedunculated rectal polyp.

Linear-array endoscopic ultrasound improves the accuracy of preoperative submucosal invasion prediction in suspected early gastric cancer compared with radial endoscopic ultrasound: A prospective cohort study

BACKGROUND AND AIM

There is a lack of literature comparing linear endoscopic ultrasound (EUS) and radial EUS for the prediction of the depth of invasion in early gastric cancer (EGC). The aim of this study is to evaluate the accuracy of linear EUS for the diagnosis of submucosal (SM) invasion and compare linear EUS with radial EUS in suspected EGC patients.

METHODS

Seventy-two consecutive patients with suspected EGC who underwent a preoperative assessment using linear EUS or radial EUS were prospectively enrolled. The depth of invasion was categorized into mucosal to SM (< T1b) and SM or deeper (≥ T1b), and the EUS-determined diagnosis was compared with postoperative histopathological findings.

RESULTS

Thirty-nine patients underwent radial EUS, and 33 patients underwent linear EUS examination. The baseline characteristics between the groups were well balanced. The diagnostic accuracy was much higher for patients who underwent linear EUS compared with radial EUS (90.9% vs 69.2%, P = 0.024). The sensitivity was 92.3% (95% confidence interval [CI] 66.7-98.6%) for linear EUS and 90.9% (95% CI 62.3-98.4%) for radial EUS. The specificity was 90.0% (95% CI 69.9-97.2%) in the linear EUS group, while the specificity was 60.7% (95% CI 42.4-76.4%) in the radial EUS group. Univariate analysis showed that EUS type (odds ratio 0.225, 95% CI 0.057-0.884, P = 0.033) was an associated risk factor of incorrect T1b staging in EGC patients. The area under the receiver operating curve was 0.912 and 0.758 for linear and radial EUS, respectively.

CONCLUSION

Linear EUS was more accurate for determining SM invasion and therapeutic strategy in suspected EGC patients compared with radial EUS.

Role of endoscopic ultrasound in the screening and follow-up of high-risk individuals for familial pancreatic cancer

Managing familial pancreatic cancer (FPC) is challenging for gastroenterologists, surgeons and oncologists. High-risk individuals (HRI) for pancreatic cancer (PC) (FPC or with germline mutations) are a heterogeneous group of subjects with a theoretical lifetime cumulative risk of PC over 5%. Screening is mainly based on annual magnetic resonance imaging (MRI) and endoscopic ultrasound (EUS). The goal of screening is to identify early-stage operable cancers or high-risk precancerous lesions (pancreatic intraepithelial neoplasia or intraductal papillary mucinous neoplasms with high-grade dysplasia). In the literature, target lesions are identified in 2%-5% of HRI who undergo screening. EUS appears to provide better identification of small solid lesions (0%-46% of HRI) and chronic-pancreatitis-like parenchymal changes (14%-77% of HRI), while MRI is probably the best modality to identify small cystic lesions (13%-49% of HRI). There are no specific studies in HRI on the use of contrast-enhanced harmonic EUS. EUS can also be used to obtain tissue samples. Nevertheless, there is still limited evidence on the accuracy of imaging procedures used for screening or agreement on which patients to treat. The cost-effectiveness of screening is also unclear. Certain new EUS-related techniques, such as searching for DNA abnormalities or protein markers in pancreatic fluid, appear to be promising.

Screening for Pancreatic Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Pancreatic adenocarcinoma is the third most common cause of cancer death among men and women in the United States.

OBJECTIVE

To systematically review benefits and harms of screening for pancreatic adenocarcinoma to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed, and the Cochrane Collaboration Registry of Controlled Trials, from January 2002 through April 27, 2018; surveillance through March 22, 2019.

STUDY SELECTION

Studies of adults with or without risk factors for pancreatic adenocarcinoma (eg, family history of pancreatic cancer, personal history of new-onset diabetes) undergoing imaging-based screening; studies of treatment for adults with screen-detected or asymptomatic pancreatic adenocarcinoma. Included study designs were randomized clinical trials, nonrandomized controlled intervention studies, diagnostic accuracy studies with a reference standard, cohort studies, and case-control studies (for evaluation of harms only). Studies consisting entirely of populations with known genetic syndromes associated with pancreatic cancer were excluded.

DATA EXTRACTION AND SYNTHESIS

Two investigators independently reviewed abstracts and full-text articles and rated included studies for quality; data were quantitatively analyzed to calculate a pooled diagnostic yield and narratively synthesized.

MAIN OUTCOMES AND MEASURES

Mortality, morbidity, or quality of life; diagnostic accuracy of screening tests; any harm of screening or treatment.

RESULTS

Thirteen fair-quality prospective cohort screening studies (N = 1317) conducted predominantly in populations at high familial risk for pancreatic adenocarcinoma were included. No studies reported on the effect of screening on morbidity or mortality or on the effectiveness of treatment for screen-detected pancreatic adenocarcinoma. Although no studies evaluated the diagnostic accuracy of screening tests, all 13 studies reported the diagnostic yield. Yields ranged from 0 to 75 cases per 1000 persons in studies using endoscopic ultrasound, magnetic resonance imaging, and/or computed tomography-based screening. In total, 18 cases of pancreatic adenocarcinoma were detected in 1156 adults at increased familial risk and 0 cases were detected in 161 average-risk adults. In 8 studies (n = 675) assessing procedural harms of screening, no serious harms from initial screening were reported. Two studies (n = 271) found no evidence of psychosocial harms related to screening. Evidence of surgical harms was limited.

CONCLUSIONS AND RELEVANCE

Imaging-based screening in groups at high familial risk can detect pancreatic adenocarcinoma with limited evidence of minimal harms. However, the effect of screening on morbidity and mortality in groups at high familial risk has not been studied, and no data are available in average-risk populations. There is limited evidence to assess benefits or harms of surgical intervention for screen-detected pancreatic adenocarcinoma.

Screening for Pancreatic Cancer: US Preventive Services Task Force Reaffirmation Recommendation Statement

IMPORTANCE

Pancreatic cancer is an uncommon cancer with an age-adjusted annual incidence of 12.9 cases per 100 000 person-years. However, the death rate is 11.0 deaths per 100 000 person-years because the prognosis of pancreatic cancer is poor. Although its incidence is low, pancreatic cancer is the third most common cause of cancer death in the United States. Because of the increasing incidence of pancreatic cancer, along with improvements in early detection and treatment of other types of cancer, it is estimated that pancreatic cancer may soon become the second-leading cause of cancer death in the United States.

OBJECTIVE

To update the 2004 US Preventive Services Task Force (USPSTF) recommendation on screening for pancreatic cancer.

EVIDENCE REVIEW

The USPSTF reviewed the evidence on the benefits and harms of screening for pancreatic cancer, the diagnostic accuracy of screening tests for pancreatic cancer, and the benefits and harms of treatment of screen-detected or asymptomatic pancreatic cancer.

FINDINGS

The USPSTF found no evidence that screening for pancreatic cancer or treatment of screen-detected pancreatic cancer improves disease-specific morbidity or mortality, or all-cause mortality. The USPSTF found adequate evidence that the magnitude of the benefits of screening for pancreatic cancer in asymptomatic adults can be bounded as no greater than small. The USPSTF found adequate evidence that the magnitude of the harms of screening for pancreatic cancer and treatment of screen-detected pancreatic cancer can be bounded as at least moderate. The USPSTF reaffirms its previous conclusion that the potential benefits of screening for pancreatic cancer in asymptomatic adults do not outweigh the potential harms.

CONCLUSIONS AND RECOMMENDATION

The USPSTF recommends against screening for pancreatic cancer in asymptomatic adults. (D recommendation).

BIRC5 is a target for molecular imaging and detection of human pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a major cause of cancer mortality with a dismal overall survival rate and an urgent need for detection of minute tumors. Current diagnostic modalities have high sensitivity and specificity for larger tumors, but not for minute PDAC. In this study, we test the feasibility of a precision diagnostic platform for detecting and localizing minute human PDAC in mice. This platform includes: 1) defining BIRC5 as an early PDAC-upregulated gene and utilizing an enhanced BIRC5 super-promoter to drive expression of dual Gaussia luciferase (GLuc) and sr39 thymidine kinase (sr39TK) reporter genes exponentially and specifically in PDAC; 2) utilizing a genetically-engineered AAV₂^RGD to ensure targeted delivery of GLuc and sr39TK specifically to PDAC; 3) using serologic GLuc and sr39TK microPET/CT imaging to detect and localize minute human PDAC in mice. The study demonstrates feasibility of a precision diagnostic platform using an integrated technology through a multiple-stage amplification strategy of dual reporter genes to enhance the specificity and sensitivity of detection and localization of minute PDAC tumors and currently undetectable disease.

Evaluation of a new slim radial echoendoscope: A better option for an aging population

Background and Objectives:

The radial echoendoscope is still widely used for the investigation of abnormalities in the gastrointestinal wall and for stone detection in the extrahepatic biliary tree. Due to aging patient population, EUS is frequently performed in fragile and elderly individuals. We aimed to compare the maneuverability and image quality of a new thin radial echoendoscope to the current one.

Patients and Methods:

This evaluation was conducted at a referral academic EUS center. The new radial echoendoscope has a thinner shaft and distal tube and a shorter bending section compared to the previous one. Patients referred for diagnostic EUS with a radial echoendoscope were enrolled. Indications included pancreaticobiliary disease, esophagogastric abnormalities, and neoplasms and rectal cancer staging.

Results:

We enrolled 177 patients (122 pancreaticobiliary, 48 esophagogastric, and 7 rectal cases). Overall, the new echoendoscope performed better than the previous model in terms of maneuverability during esophageal intubation and transition from the duodenal bulb to the second portion. On the other hand, pylorus traversing was comparable to the current radial echoendoscope. No loss in image quality was appreciated at predefined stations (esophagus, stomach, and duodenum) compared to the current model. On the other hand, image penetration depth in tissue harmonic mode was significantly improved with the new echoendoscope.

Conclusions:

A new thinner radial echoendoscope showed improved maneuverability compared to the existing version. Image quality was also improved thanks to increased penetration depth in the tissue harmonic mode. We speculate that this new echoendoscope may allow for safer and faster EUS examination, which may prove useful in an aging patient population.

What should be known prior to performing EUS?

Direct referral of patients for EUS – instead of preprocedural consultation with the endosonographer – has become standard practice (like for other endoscopic procedures) as it is time- and cost-effective. To ensure appropriate indications and safe examinations, the endosonographer should carefully consider what information is needed before accepting the referral. This includes important clinical data regarding relevant comorbidities, the fitness of the patient to consent and undergo the procedure, and the anticoagulation status. In addition, relevant findings from other imaging methods to clarify the clinical question may be necessary. Appropriate knowledge and management of the patients’ anticoagulation and antiplatelet therapy, antibiotic prophylaxis, and sedation issues can avoid unnecessary delays and unsafe procedures. Insisting on optimal preparation, appropriate indications, and clear clinical referral questions will increase the quality of the outcomes of EUS. In this paper, important practical issues regarding EUS preparations are raised and discussed from different points of view.

Diagnostic Yield From Screening Asymptomatic Individuals at High Risk for Pancreatic Cancer: A Meta-analysis of Cohort Studies

BACKGROUND & AIMS

There have been few studies of abdominal imaging screening of individuals at high risk for pancreatic cancer (based on family history or genetic variants). We performed a meta-analysis of prospective cohort studies to determine the diagnostic yield and outcomes of abdominal imaging screening for asymptomatic individuals at high risk.

METHODS

Through a systematic review of multiple electronic databases and conference proceedings through July 2017, we identified prospective cohort studies (>20 patients) of asymptomatic adults determined to be at high-risk of pancreatic cancer (lifetime risk >5%, including specific genetic-associated conditions) who were screened by endoscopic ultrasound (EUS) and/or magnetic resonance imaging (MRI) to detect pancreatic lesions. Our primary outcome was identification of high-risk pancreatic lesions (high-grade pancreatic intraepithelial neoplasia, high-grade dysplasia, or adenocarcinoma) at initial screening, and overall incidence during follow up. Summary estimates were reported as incidence rates per 100 patient-years.

RESULTS

We identified 19 studies comprising 7085 individuals at high risk for pancreatic cancer; of these, 1660 patients were evaluated by EUS and/or MRI. Fifty-nine high-risk lesions were identified (43 adenocarcinomas: 28 during the initial exam and 15 during follow-up surveillance) and 257 patients underwent pancreatic surgery. Based on our meta-analysis, the overall diagnostic yield screening for high-risk pancreatic lesions was 0.74 (95% CI, 0.33-1.14), with moderate heterogeneity among studies. The number needed to screen to identify 1 patient with a high-risk lesion was 135 (95% CI, 88-303). The diagnostic yield was similar for patients with different genetic features that increased risk, and whether patients were screened by EUS or MRI.

CONCLUSIONS

Based on meta-analysis, 135 patients at high-risk for pancreatic cancer must be screened to identify 1 patient with a high-risk pancreatic lesion. Further studies are needed to determine whether screening reduces mortality and is cost effectiveness for individuals at high-risk of pancreatic cancer.

What should be known prior to performing EUS exams? (Part II)

In “What should be known prior to performing EUS exams, Part I,” the authors discussed the need for clinical information and whether other imaging modalities are required before embarking EUS examinations. Herewith, we present part II which addresses some (technical) controversies how EUS is performed and discuss from different points of view providing the relevant evidence as available. (1) Does equipment design influence the complication rate? (2) Should we have a standardized screen orientation? (3) Radial EUS versus longitudinal (linear) EUS. (4) Should we search for incidental findings using EUS?

Diagnosis and Detection of Pancreatic Cancer

Computed tomography is the first-line imaging modality for suspected pancreatic cancer. Magnetic resonance cholangiopancreatography is a second-line modality for suspected pancreatic cancer and is usually reserved for equivocal cases. Both computed tomography and MR are highly sensitive in the detection of pancreatic cancer, with up to 96% and 93.5% sensitivity, respectively. Computed tomography is superior to MR in the assessment of tumor resectability, with accuracy rates of up to 86.8% and 78.9%, respectively. Close attention to secondary signs of pancreatic cancer, such as pancreatic duct dilatation, abrupt pancreatic duct caliber change, and parenchymal atrophy, are critical in the diagnosis of pancreatic cancer. Emerging techniques such as radiomics and molecular imaging have the potential of identifying malignant precursors and lead to earlier disease diagnosis. The results of these promising techniques need to be validated in larger clinical studies.

Pancreatic cancer screening in high-risk individuals with germline genetic mutations

BACKGROUND AND AIMS

Pancreatic cancer (PC) is a deadly disease that is most commonly diagnosed at an incurable stage. Different high-risk genetic variants and cancer syndromes increase the lifetime risk of developing PC. This study aims to assess the yield of initial PC screening in patients with high-risk germline mutations.

METHODS

Asymptomatic adults underwent PC screening by EUS, magnetic resonance imaging, or CT during a 10-year period and were retrospectively identified. High-risk individuals were defined as carrying germline mutations in BRCA1, BRCA2, p53 (Li-Fraumeni), STK11 (Peutz-Jeghers), MSH2 (Lynch), ATM (ataxia-telangiectasia), or APC (familial adenomatous polyposis). Patients without germline mutations were excluded.

RESULTS

In total, 86 patients met the study criteria. The median age was 48.5 years (interquartile range, 40-58), 79.1% (68) were women, and 43.0% (37) had a family history of PC. The genetic mutations were BRCA2 (50, 58.1%), BRCA1 (14, 16.3%), p53 (12, 14.0%), STK11 (5, 5.8%), MSH2 (3, 3.5%), ATM (1, 1.2%), and APC (1, 1.2%). Screening detected a pancreatic abnormality (PA) in 26.7% (23/86), including cysts (11, 47.8%), hyperechoic strands and foci (10, 43.5%), and mild pancreatic duct dilation (2, 8.7%). Patients older than 60 years were more likely to have a PA detected (P = .043). EUS detected more PAs than magnetic resonance imaging or CT. No cases of PC were diagnosed by screening or during follow-up (median, 29.8 months; interquartile range, 21.7-43.5).

CONCLUSIONS

Unless indicated otherwise by family or personal history, PC screening under the age of 50 is low yield. Linear EUS may be the preferred modality for initial PC screening.

Results of surveillance in individuals at high-risk of pancreatic cancer: A systematic review and meta-analysis

Background

Data on surveillance for pancreatic ductal adenocarcinoma (PDAC) in high-risk individuals (HRIs) with "familial pancreatic cancer" (FPC) and specific syndromes are limited and heterogeneous.

Objective

We conducted a systematic review and meta-analysis of PDAC surveillance studies in HRIs.

Methods

Prevalence of solid/cystic pancreatic lesions and of lesions considered a successful target of surveillance (proven resectable PDAC and high-grade precursors) was pooled across studies. The rate of lesions diagnosed by endoscopic ultrasonography (EUS)/magnetic resonance imaging (MRI) and across different HRI groups was calculated.

Results

Sixteen studies incorporating 1588 HRIs were included. The pooled prevalence of pancreatic solid and cystic lesions was 5.8% and 20.2%, respectively. The pooled prevalence of patients with lesions considered a successful target of surveillance was 3.3%, being similar to EUS or MRI and varying across subgroups, being 3% in FPC, 4% in hereditary pancreatitis, 5% in familial melanoma, 6.3% in hereditary breast/ovarian cancer, and 12.2% in Peutz-Jeghers syndrome. The pooled estimated rate of lesions considered a successful target of surveillance during follow-up was 5/1000 person-years.

Conclusion

Surveillance programs identify successful target lesions in 3.3% of HRIs with a similar yield of EUS and MRI and an annual risk of 0.5%. A higher rate of target lesions was reported in HRIs with specific DNA mutations.

Prevalence of incidental pancreatic cyst on upper endoscopic ultrasound

Background:

This study aimed to determine the prevalence of incidental pancreatic cysts in patients undergoing upper endoscopic ultrasound without a known pancreatic abnormality.

Methods:

This prospective study was conducted in two hospitals in Spain and enrolled consecutive patients referred for upper endoscopic ultrasound for a condition unrelated to the pancreas. Patients with a previous pancreatic anomaly, history of acute or chronic pancreatitis, evidence of acute pancreatitis, previous upper gastrointestinal surgery, or chronic abdominal pain suggestive of pancreatic origin were excluded. Univariate logistic regression was performed to evaluate individual covariates and the incidental pancreatic cyst risk.

Results:

A total of 298 patients were included, of whom 64 had pancreatic cysts (21.5%; 16.9-26.6%). The mean size of the cysts was 6.3±3.7 (range 3-25) mm. Six cysts (2%) were >10 mm and 16 (5.4%) were compatible with branch duct intraductal papillary mucinous neoplasm. The pancreatic cyst prevalence was similar in the two hospitals and increased significantly with age.

Conclusion:

The prevalence of incidental pancreatic cysts during endoscopic ultrasound was very high in our study population.

Pancreatic Cancer Screening

PURPOSE OF REVIEW

This review describes the rationale for pancreatic cancer screening, outlines groups that are at elevated risk for pancreatic cancer, and summarizes the relative risk in each setting. We also review the methods available for performing pancreatic cancer screening and the recommended screening intervals.

RECENT FINDINGS

Several genetic mutations have been identified that increase the risk for pancreatic cancer. Most are rare, however, and at-risk individuals are most often those with a strong family history of pancreatic cancer (with multiple family members affected) but no identifiable genetic mutation. Known genetic syndromes that increase the risk for pancreatic cancer include hereditary pancreatitis, familial atypical mole and multiple melanoma, Peutz-Jeghers syndrome, Lynch syndrome, BRCA mutations, and Li-Fraumeni syndrome. Genetic testing should be performed in conjunction with genetic counseling, and testing of an affected family member is preferred if possible.The goal of pancreatic cancer screening is to identify pancreatic cancer at an early, curable stage or, ideally, to identify precancerous lesions that can be resected to prevent the development of cancer. Imaging can be performed with either endoscopic ultrasound (EUS) or magnetic resonance cholangiopancreatography (MRCP). These techniques are generally considered to be complementary, although an advantage of EUS is that cysts or solid lesions can be sampled at the time of the procedure. Published results of small cohorts of high-risk patients in pancreatic cancer screening programs have demonstrated a high prevalence of small cystic lesions identified on EUS or MRCP, which often represent side-branch intraductal papillary mucinous neoplasms (IPMN). Knowledge of conditions and syndromes that increase pancreatic cancer risk allows one to identify those patients that may benefit from pancreatic cancer screening. As we gather evidence from large, international, multicenter cohorts of patients at high-risk for pancreatic cancer who are undergoing screening and as our understanding of the genetic underpinnings of pancreatic cancer improve, recommendations on screening will continue to be refined.

A Clinical Prediction Model to Assess Risk for Pancreatic Cancer Among Patients With New-Onset Diabetes

BACKGROUND & AIMS

Approximately 50% of all patients with pancreatic ductal adenocarcinoma (PDA) develop diabetes mellitus before their cancer diagnosis. Screening individuals with new-onset diabetes might allow earlier diagnosis of PDA. We sought to develop and validate a PDA risk prediction model to identify high-risk individuals among those with new-onset diabetes.

METHODS

We conducted a retrospective cohort study in a population representative database from the United Kingdom. Individuals with incident diabetes after the age of 35 years and 3 or more years of follow-up after diagnosis of diabetes were eligible for inclusion. Candidate predictors consisted of epidemiologic and clinical characteristics available at the time of diabetes diagnosis. Variables with P values <.25 in the univariable analyses were evaluated using backward stepwise approach. Model discrimination was assessed using receiver operating characteristic curve analysis. Calibration was evaluated using the Hosmer-Lemeshow test. Results were internally validated using a bootstrapping procedure.

RESULTS

We analyzed data from 109,385 patients with new-onset diabetes. Among them, 390 (0.4%) were diagnosed with PDA within 3 years. The final model (area under the curve, 0.82; 95% confidence interval, 0.75-0.89) included age, body mass index, change in body mass index, smoking, use of proton pump inhibitors, and anti-diabetic medications, as well as levels of hemoglobin A1C, cholesterol, hemoglobin, creatinine, and alkaline phosphatase. Bootstrapping validation showed negligible optimism. If the predicted risk threshold for definitive PDA screening was set at 1% over 3 years, only 6.19% of the new-onset diabetes population would undergo definitive screening, which would identify patients with PDA with 44.7% sensitivity, 94.0% specificity, and a positive predictive value of 2.6%.

CONCLUSIONS

We developed a risk model based on widely available clinical parameters to help identify patients with new-onset diabetes who might benefit from PDA screening.

New strategies for the early detection of pancreatic cancer

Pancreatic cancer (PC) remains a deadly disease and early detection through screening is likely to be our best hope to improve survival. Considering the low incidence of PC, population-based screening is not feasible, but is advisable for high-risk patients. Screening individuals at high risk for developing PC leads to the detection of premalignant lesions. High-grade pancreatic intraepithelial neoplasia and intraductal papillary mucinous neoplasm are the targets for early detection of PC. Endoscopic ultrasound (EUS) and magnetic resonance imaging are considered the most accurate techniques for pancreatic imaging; in particular EUS has emerged as a promising imaging test given its potential for tissue sampling to obtain diagnosis and to provide material for molecular profiling of PC. At the moment, screening should be performed within research protocols at experienced centers with a specific clinical and research interest, where a multidisciplinary team of specialists is available.

Pancreatic cancer

Pancreatic cancer is a major cause of cancer-associated mortality, with a dismal overall prognosis that has remained virtually unchanged for many decades. Currently, prevention or early diagnosis at a curable stage is exceedingly difficult; patients rarely exhibit symptoms and tumours do not display sensitive and specific markers to aid detection. Pancreatic cancers also have few prevalent genetic mutations; the most commonly mutated genes are KRAS, CDKN2A (encoding p16), TP53 and SMAD4 - none of which are currently druggable. Indeed, therapeutic options are limited and progress in drug development is impeded because most pancreatic cancers are complex at the genomic, epigenetic and metabolic levels, with multiple activated pathways and crosstalk evident. Furthermore, the multilayered interplay between neoplastic and stromal cells in the tumour microenvironment challenges medical treatment. Fewer than 20% of patients have surgically resectable disease; however, neoadjuvant therapies might shift tumours towards resectability. Although newer drug combinations and multimodal regimens in this setting, as well as the adjuvant setting, appreciably extend survival, ∼80% of patients will relapse after surgery and ultimately die of their disease. Thus, consideration of quality of life and overall survival is important. In this Primer, we summarize the current understanding of the salient pathophysiological, molecular, translational and clinical aspects of this disease. In addition, we present an outline of potential future directions for pancreatic cancer research and patient management.