Prediction of malignancy in cystic neoplasms of the pancreas: a population-based cohort study

Should All Pancreatic Cystic Lesions with Worrisome or High-Risk Features Be Resected? A Clinical and Radiological Machine Learning Model May Help to Answer

RATIONALE AND OBJECTIVES

According to current guidelines, pancreatic cystic lesions (PCLs) with worrisome or high-risk features may have overtreatment. The purpose of this study was to build a clinical and radiological based machine-learning (ML) model to identify malignant PCLs for surgery among preoperative PCLs with worrisome or high-risk features.

MATERIALS AND METHODS

Clinical and radiological details of 317 pathologically confirmed PCLs with worrisome or high-risk features were retrospectively analyzed and applied to ML models including Support Vector Machine, Logistic Regression (LR), Decision Tree, Bernoulli NB, Gaussian NB, K Nearest Neighbors and Linear Discriminant Analysis. The diagnostic ability for malignancy of the optimal model with the highest diagnostic AUC in the cross-validation procedure was further evaluated in internal (n = 77) and external (n = 50) testing cohorts, and was compared to two published guidelines in internal mucinous cyst cohort.

RESULTS

Ten clinical and radiological feature-based LR model was the optimal model with the highest AUC (0.951) in the cross-validation procedure. In the internal testing cohort, LR model reached an AUC, accuracy, sensitivity, and specificity of 0.927, 0.909, 0.914, and 0.905; in the external testing cohort, LR model reached 0.948, 0.900, 0.963, and 0.826. When compared to the European guidelines and the ACG guidelines, LR model demonstrated significantly better accuracy and specificity in identifying malignancy, while maintaining the same high sensitivity.

CONCLUSION

Clinical- and radiological-based LR model can accurately identify malignant PCLs in patients with worrisome or high-risk features, possessing diagnostic performance better than the European guidelines as well as ACG guidelines.

Quantitative Radiomic Features From Computed Tomography Can Predict Pancreatic Cancer up to 36 Months Before Diagnosis

INTRODUCTION

Pancreatic cancer is the third leading cause of cancer deaths among men and women in the United States. We aimed to detect early changes on computed tomography (CT) images associated with pancreatic ductal adenocarcinoma (PDAC) based on quantitative imaging features (QIFs) for patients with and without chronic pancreatitis (CP).

METHODS

Adults 18 years and older diagnosed with PDAC in 2008-2018 were identified. Their CT scans 3 months-3 years before the diagnosis date were matched to up to 2 scans of controls. The pancreas was automatically segmented using a previously developed algorithm. One hundred eleven QIFs were extracted. The data set was randomly split for training/validation. Neighborhood and principal component analyses were applied to select the most important features. A conditional support vector machine was used to develop prediction algorithms separately for patients with and without CP. The computer labels were compared with manually reviewed CT images 2-3 years before the index date in 19 cases and 19 controls.

RESULTS

Two hundred twenty-seven of 554 scans of non-CP cancer cases/controls and 70 of 140 scans of CP cancer cases/controls were included (average age 71 and 68 years, 51% and 44% females for non-CP patients and patients with CP, respectively). The QIF-based algorithms varied based on CP status. For non-CP patients, accuracy measures were 94%-95% and area under the curve (AUC) measures were 0.98-0.99. Sensitivity, specificity, positive predictive value, and negative predictive value were in the ranges of 88%-91%, 96%-98%, 91%-95%, and 94%-96%, respectively. QIFs on CT examinations within 2-3 years before the index date also had very high predictive accuracy (accuracy 95%-98%; AUC 0.99-1.00). The QIF-based algorithm outperformed manual rereview of images for determination of PDAC risk. For patients with CP, the algorithms predicted PDAC perfectly (accuracy 100% and AUC 1.00).

DISCUSSION

QIFs can accurately predict PDAC for both non-CP patients and patients with CP on CT imaging and represent promising biomarkers for early detection of pancreatic cancer.

Advances in the Diagnosis of Pancreatic Cystic Lesions

Pancreatic cystic lesions (PCLs) are a heterogenous group of lesions ranging from benign to malignant. There has been an increase in PCLs prevalence in recent years, mostly due to advances in imaging techniques, increased awareness of their existence and population aging. Reliable discrimination between neoplastic and non-neoplastic cystic lesions is paramount to ensuring adequate treatment and follow-up. Although conventional diagnostic techniques such as ultrasound (US), magnetic resonance imaging (MRI) and computer tomography (CT) can easily identify these lesions, assessing the risk of malignancy is limited. Endoscopic ultrasound (EUS) is superior to cross-sectional imaging in identifying potentially malignant lesions due to its high resolution and better imaging characteristics, and the advantage of allowing for cyst fluid sampling via fine-needle aspiration (FNA). More complex testing, such as cytological and histopathological analysis and biochemical and molecular testing of the aspirated fluid, can ensure an accurate diagnosis.

Clinical significance of pancreatic calcifications: a 15-year single-center observational study

Objectives

Pancreatic calcifications (PC) are considered specific for chronic pancreatitis (CP), but PC may also be present in non-CP diseases. The aims are to understand the pattern of calcifications in different diseases and to determine they were related to malignant diseases.

Methods

A retrospective study was performed including patients with PC or CP undergoing surgery in the Department of General Surgery of Ruijin Hospital from January 2003 to June 2018.

Results

PC were observed in 168 (4.5%) of the 3755 patients with pancreatic lesions treated during the study period. The majority of patients with PC had three kinds of CP (73.2%) while 26.8% had other five kinds of non-CP diseases. In patients with non-CP diseases, the incidence of PC in malignant intraductal papillary mucinous neoplasm (IPMN) was significantly higher than benign IPMN (8.3% vs. 0.7%, p = 0.004). In patients of CP with pancreatic mass (n = 81), PC (Odds ratio = 28.6, p = 0.000), advanced age (> 55 years) and parenchymal atrophy were independent predictors for malignancy. In patients of CP without pancreatic mass (n = 110), there were 82 cases (74.5%) with PC and 5 cases (4.5%) with pancreatic ductal adenocarcinoma. The regression model of risk factors was not successful.

Conclusions

The disease spectrum with PC was very diverse. PC may be related to malignant IPMN in non-CP diseases and is related to malignancy in the patients of CP with pancreatic mass and indications for resection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40001-022-00725-9.

Pancreas Cancer Incidence and Pancreas Cancer-Associated Mortality Are Low in National Cohort of 7211 Pancreas Cyst Patients

BACKGROUND AND AIMS

Pancreatic cancer incidence and mortality among patients with pancreas cysts are unclear. The aims of this study are to evaluate incidence of pancreatic cancer and cause-specific mortality among patients with pancreatic cysts using a large national cohort over a long follow-up period.

METHODS

We conducted a retrospective cohort study of US Veterans diagnosed with a pancreatic cyst 1999-2013, based on International Classification of Diseases, 9th edition (ICD9) coding within national Department of Veterans Affairs (VA) data. Pancreatic cancer incidence was ascertained using VA cancer registry data, ICD-9 codes, and the National Death Index, a national centralized database of death records, including cause-specific mortality.

RESULTS

Among 7211 Veterans with pancreatic cysts contributing 31,501 person-years of follow-up (median follow-up 4.4 years), 79 (1.1%) developed pancreatic cancer. A total of 1982 patients (27.5%) died during the study follow-up period. Sixty-three patients (3.2% of deaths; 0.9% of pancreas cyst cohort) died from pancreatic cancer, but the leading causes of death in the cohort were non-pancreatic cancer (n = 498, 25% of deaths) and cardiovascular disease (n = 398, 20% of deaths).

CONCLUSIONS

Pancreas cancer incidence and pancreatic cancer-associated mortality are very low in a large national cohort of VA pancreatic cyst patients with long-term follow-up. Most deaths were from non-pancreas cancers and cardiovascular causes, and only a minority (3.2%) were attributable to pancreas cancer. Given death from pancreas cancer is rare, future research should focus on identifying criteria for selecting individuals at high risk for death from pancreatic cancer for pancreatic cyst surveillance.

Opportunistic Detection for Pancreatic Cystic Lesions During Chest Multidetector CT Scans for Lung Cancer Screening

Purpose

The purpose of this study was to analyze the prevalence of and risk factors for incidental pancreatic cystic lesions (PCLs) in the Chinese general population. Furthermore, the association between baseline imaging findings and PCL progression was also investigated.

Patients and Methods

A total of 9826 individuals who underwent computed tomography (CT) examinations for lung cancer screening between January 1, 2018 and January 1, 2019 were included in this study. The participants’ CT imaging findings and biochemical biomarker levels were reviewed and analyzed. PCLs detected during the screening were followed up for 12 months. Associations between imaging findings and clinical factors with PCL progression were explored.

Results

PCLs were observed in 172 of the 9826 participants. The crude prevalence of PCLs in total population was 1.75%. In subjects aged >60 years, the prevalence of PCLs was 3.2% (102/3151). The occurrence of PCLs was significantly increased with an increase of age in both men and women (p < 0.001). High-risk PCLsL commonly located in pancreatic head showed extrapancreatic growth, and had high urea levels (p = 0.005, p = 0.015, p = 0.002, respectively) compared with low-risk PCLs. Location in the pancreatic head (odds ratio (OR) = 6.286, 95% confidence interval (CI): 1.842–21.452) and extrapancreatic growth (OR = 4.049, 95% CI: 1.235–13.333) were risk factors for PCL progression.

Conclusion

PCLs are not uncommon in the Chinese general population. Location in the pancreatic head and extrapancreatic growth are the independent predictors of high-risk of PCLs and PCL progression.

Transabdominal Ultrasound for Follow-Up of Incidentally Detected Low-Risk Pancreatic Cysts: A Prospective Multicenter Study

OBJECTIVE. The purpose of this study is to investigate the detection rate of transabdominal ultrasound (TAUS) for pancreatic cysts incidentally detected on CT or MRI as well as the factors that influence detection rates. SUBJECTS AND METHODS. Fifty-seven patients with low-risk pancreatic cysts (n = 77; cyst size, 5 mm to 3 cm) that were incidentally detected on CT or MRI were prospectively enrolled at five institutions. At each institution, TAUS was independently performed by two radiologists who assessed detection of cysts, cyst location and size, and the diameter of the main pancreatic duct (MPD). Cyst detection rates based on cyst size, location, and multiplicity and the body mass index of the patient were compared using the Mann-Whitney test. Kappa statistics and the interclass correlation coefficient were used to evaluate interobserver agreement regarding cyst detection and consistency of cyst size and the diameter of the MPD on TAUS versus prior CT or MRI. RESULTS. The detection rate for known low-risk pancreatic cysts was 81.8% (63/77) and 83.1% (64/77) for TAUS conducted by each of the two radiologists. The detection rate for larger (≥ 10 mm) cysts was significantly higher than that for smaller cysts (89.0% vs 63.6% for TAUS performed and interpreted by radiologist 1 [TAUS 1] and 89.0% vs 68.2% for TAUS conducted and interpreted by radiologist 2 [TAUS 2]; p < .05). A higher detection rate was noted for cysts located outside the tail of the pancreas compared with those located in the tail (89.5% vs 65.0% for TAUS 2; p = .01), and the detection rate was also significantly higher for single cysts than for multiple cysts (90.9% vs 69.7% for TAUS 1; p = .02). However, no significant difference was observed for body mass index. Interobserver agreement was excellent regarding the size of the detected cysts (inter-class correlation coefficient: 0.964 [95% CI, 0.940-0.979] for CT, TAUS 1, and TAUS 2 and 0.965 [95% CI. 0.924-986] for MRI, TAUS 1, and TAUS 2) and the diameter of the MPD (interclass correlation coefficient, 0.934; 95% CI, 0.898-0.959). CONCLUSION. TAUS could be a useful alternative imaging tool for surveillance of known low-risk pancreatic cysts, especially single pancreatic cysts and those that are of larger size (≥ 1 cm) or are located outside the tail.

A Review of the Diagnosis and Management of Premalignant Pancreatic Cystic Lesions

Pancreatic cystic lesions are an increasingly common clinical finding. They represent a heterogeneous group of lesions that include two of the three known precursors of pancreatic cancer, intraductal papillary mucinous neoplasms (IPMN) and mucinous cystic neoplasms (MCN). Given that approximately 8% of pancreatic cancers arise from these lesions, careful surveillance and timely surgery offers an opportunity for early curative resection in a disease with a dismal prognosis. This review summarizes the current evidence and guidelines for the diagnosis and management of IPMN/MCN. Current pre-operative diagnostic tests in pancreatic cysts are imperfect and a proportion of patients continue to undergo unnecessary surgical resection annually. Balancing cancer prevention while preventing surgical overtreatment, continues to be challenging when managing pancreatic cysts. Cyst fluid molecular markers, such as KRAS, GNAS, VHL, PIK3CA, SMAD4 and TP53, as well as emerging endoscopic technologies such as needle-based confocal laser endomicroscopy and through the needle microbiopsy forceps demonstrate improved diagnostic accuracy. Differences in management and areas of uncertainty between the guidelines are also discussed, including indications for surgery, surveillance protocols and if and when surveillance can be discontinued.

Endoscopic Ultrasound-Guided Ablation of Focal Pancreatic Lesions: The GRUPUGE Perspective

Focal pancreatic lesions include a heterogeneous group of solid and cystic lesions, with different natures and variable clinical, imagiological, and pathological characteristics. Several endoscopic ultrasound (EUS)-guided ablative techniques have been tested during the last decade for the treatment of these pancreatic lesions, mostly consisting of the injection of ablative agents and, more recently, radiofrequency ablation. The most encouraging EUS-guided ablation outcomes are being reached in the treatment of some pancreatic cystic neoplasms and small (≤2 cm) pancreatic neuroendocrine tumours (pNETs). Data supporting a potential role of ablative therapies in the treatment of pancreatic ductal adenocarcinoma is still lacking. In this article, GRUPUGE presents an updated perspective of the potential role of EUS-guided ablation for the treatment of pancreatic cystic neoplasms and pNETs, addressing the selection criteria and technical issues of different techniques and analysing recent data on their safety and efficacy.

Pancreatic Diseases and Microbiota: A Literature Review and Future Perspectives

Gut microbiota represent an interesting worldwide research area. Several studies confirm that microbiota has a key role in human diseases, both intestinal (such as inflammatory bowel disease, celiac disease, intestinal infectious diseases, irritable bowel syndrome) and extra intestinal disorders (such as autism, multiple sclerosis, rheumatologic diseases). Nowadays, it is possible to manipulate microbiota by administering prebiotics, probiotics or synbiotics, through fecal microbiota transplantation in selected cases. In this scenario, pancreatic disorders might be influenced by gut microbiota and this relationship could be an innovative and inspiring field of research. However, data are still scarce and controversial. Microbiota manipulation could represent an important therapeutic strategy in the pancreatic diseases, in addition to standard therapies. In this review, we analyze current knowledge about correlation between gut microbiota and pancreatic diseases, by discussing on the one hand existing data and on the other hand future possible perspectives.

Prediction of Pancreatic Cancer Based on Imaging Features in Patients With Duct Abnormalities

OBJECTIVES

Abnormalities of the main pancreatic duct may be an early indicator of pancreatic ductal adenocarcinoma (PDAC). We develop and validate algorithms that predict the risk of PDAC using features identified on cross-sectional imaging and other clinical characteristics collected through electronic medical records.

METHODS

Adult patients with abdominal computed tomography or magnetic resonance imaging in January 2006 to June 2016 demonstrating dilatation of main pancreatic duct were identified. Pancreas-related morphologic features were extracted from radiology reports using natural language processing. The cumulative incidence of PDAC with death as a competing risk was estimated using multistate models. Model discrimination was assessed using c-index. The models were internally validated using bootstrapping.

RESULTS

The cohort consisted of 7819 patients (mean age, 71 years; 65% female). A total of 781 patients (10%) developed PDAC within 3 years after the first eligible imaging study. The final models achieved reasonable discrimination (c-index, 0.825-0.833). The 3-year average risk of PDAC in the top 5% of the total eligible patients was 56.0%, more than 20 times of the average risk among the bottom 50% of patients.

CONCLUSIONS

Prediction models combining imaging features and clinical measures can be used to further stratify the risk of pancreatic cancer among patients with pancreas ductal dilatation.

Clinical and radiological features that predict malignant transformation in cystic lesions of the pancreas: a retrospective case note review

Background: Pancreatic cystic lesions (PCL) are being detected with increasing frequency. Current methods of stratifying risk of malignant transformation are imperfect. This study aimed to determine the frequency of pancreatic malignancy in patients with PCL and define clinical and radiological features that predict malignant transformation in patients managed by surgery and/or surveillance.

Methods: A retrospective cohort of adults who were evaluated in a tertiary hepatopancreaticobiliary centre between January 2000 - December 2013 with a confirmed PCL and followed up for at least 5 years. All cystic lesions were discussed at a weekly multidisciplinary meeting.

Results: Of the 1,090 patients diagnosed with a PCL, 768 patients were included in the study: 141 patients were referred for immediate pancreatic resection, 570 entered surveillance while 57 had a malignant PCL which was unresectable at diagnosis (n=47) or were unfit for surgery (n=10). In those who were resected following presentation, malignancy was present in 38%. During follow-up 2% of those entering a surveillance programme underwent malignant transformation. Clinical and radiological features associated with a high-risk PCL included older age, symptoms, associated solid component or dilated main pancreatic duct. In intraductal papillary mucinous neoplasms, larger size was not a feature of malignant transformation (benign vs. malignant 30mm vs. 23mm; P= 0.012).

Conclusion: The sensitivity of standard diagnostic tests leading to immediate surgery for high-risk PCL (malignant or mucinous) was 92% but with a specificity of just 5%. Surveillance of PCL without high-risk features within a multidisciplinary meeting was associated with a low incidence of cancer development, supporting the use of worrisome clinical and radiological features in the initial stratification of PCL.

Pancreatic Cysts and Intraductal Papillary Mucinous Neoplasm in Autosomal Dominant Polycystic Kidney Disease

OBJECTIVES

Pancreatic lesions in autosomal dominant polycystic kidney disease (ADPKD) are primarily cysts. They are increasingly recognized, with isolated reports of intraductal papillary mucinous neoplasia (IPMN).

METHODS

Retrospective study to determine prevalence, number, size, and location of pancreatic abnormalities using abdominal magnetic resonance imaging (MRI) of genotyped ADPKD patients (seen February 1998 to October 2013) and compared with age- and sex-matched non-ADPKD controls. We evaluated presentation, investigation, and management of all IPMNs among individuals with ADPKD (January 1997 to December 2016).

RESULTS

Abdominal MRIs were examined for 271 genotyped ADPKD patients. A pancreatic cyst lesion (PCL) was detected in 52 patients (19%; 95% confidence interval, 15%-23%). Thirty-seven (71%) had a solitary PCL; 15 (28%) had multiple. Pancreatic cyst lesion prevalence did not differ by genotype. Intraductal papillary mucinous neoplasia was detected in 1% of ADPKD cases. Among 12 IPMN patients (7 branch duct; 5 main duct or mixed type) monitored for about 140 months, 2 with main duct IPMNs required Whipple resection, and 1 patient died of complications from small-bowel obstruction after declining surgical intervention.

CONCLUSIONS

With MRI, PCLs were detected in 19% and IPMNs in 1% of 271 ADPKD patients with proven mutations, without difference across genotypes. Pancreatic cyst lesions were asymptomatic and remained stable in size.

Risk of malignancy in resected pancreatic mucinous cystic neoplasms

BACKGROUND

Pancreatic mucinous cystic neoplasms (MCNs) are rare mucin-producing cystic tumours defined by the presence of ovarian-type stroma. MCNs have a malignant potential and thus surgery is frequently performed. The aim of this cohort study was to define better the criteria for surgical resection in patients with MCN.

METHODS

This multicentre retrospective study included all resected MCNs between 2003 and 2015 in participating centres. Lesions without ovarian-type stroma were excluded. Patient characteristics, preoperative findings, histopathology findings and follow-up data were recorded.

RESULTS

The study included 211 patients; their median age was 53 (range 18-82) years, and 202 (95·7 per cent) were women. Median preoperative tumour size was 55 (range 12-230) mm. Thirty-four of the 211 (16·1 per cent) were malignant, and high-grade dysplasia (HGD) was found in a further 13 (6·2 per cent). One-third of MCNs in men were associated with invasive cancer, compared with 15·3 per cent in women. Five cases of malignant transformation occurred in MCNs smaller than 4 cm. All cases of malignancy or HGD were associated with symptoms or features of concern on preoperative cross-sectional imaging. In multivariable analysis, raised carbohydrate antigen 19-9 (odds ratio (OR) 10·54, 95 per cent c.i. 2·85 to 218·23; P < 0·001), tumour size (OR 4·23, 3·02 to 11·03; P = 0·001), mural nodules (OR 3·55, 1·31 to 20·55; P = 0·002) and weight loss (OR 3·40, 2·34 to 12·34; P = 0·034) were independent factors predictive of malignant transformation.

CONCLUSIONS

Small indeterminate MCNs with no symptoms or features of concern may safely be observed as they have a low risk of malignant transformation.

Endoscopic ultrasound-through-the-needle biopsy in pancreatic cystic lesions: A multicenter study

BACKGROUND AND AIM

Tissue acquisition in pancreatic cystic lesions (PCL) is the ideal method for diagnosis and risk stratification for malignancy of these lesions. Direct sampling from the walls of PCL with different devices has shown better results than cytology from cystic fluid. We carried out a retrospective, multicenter study to evaluate the feasibility, safety, and diagnostic yield of a micro-forceps, specifically designed to be used through a 19-gauge needle after endoscopic ultrasonography (EUS)-guided puncture of PCL.

METHODS

We retrospectively collected data from patients who underwent EUS-through-the-needle biopsy (EUS-TTNB) in PCL at six referral centers.

RESULTS

The sampling procedure was carried out in 56 patients (mean age 57.5 ± 13.1 years, M:F 17:39), and was technically successful in all of them (100%; 95% confidence interval [CI], 94-100%). Adverse events occurred in 9/56 (16.1%; 95% CI, 8-28%) patients, with self-limited intracystic hemorrhage the most common (7/56, 12.5%; 95% CI, 5-24%). All adverse events were mild, and resolved without any specific intervention. Specimens were considered adequate for histological diagnosis in 47/56 (83.9%; 95% CI, 72-92%). In two of these patients, despite the histological adequacy, a diagnosis could not be reached. In two other cases, a specimen sufficient for a cytological diagnosis was obtained. Overall diagnostic yield by combining cytological and histological samples was 47/56 (83.9%; 95% CI, 72-92%).

CONCLUSION

EUS-TTNB with micro-forceps in PCL is feasible, safe, and has a high diagnostic yield. Future prospective studies are needed to better assess the clinical impact of EUS-TTNB on the management of PCL.

High Growth Rate of Pancreatic Ductal Adenocarcinoma in CDKN2A-p16-Leiden Mutation Carriers

CDKN2A-p16-Leiden mutation carriers have a 20% to 25% risk of developing pancreatic ductal adenocarcinoma (PDAC). Better understanding of the natural course of PDAC might allow the surveillance protocol to be improved. The aims of the study were to evaluate the role of cystic precursor lesions in the development of PDAC and to assess the growth rate. In 2000, a surveillance program was initiated, consisting of annual MRI in carriers of a CDKN2A-p16-Leiden mutation. The study cohort included 204 (42% male) patients. Cystic precursor lesions were found in 52 (25%) of 204 mutation carriers. Five (9.7%) of 52 mutation carriers with cystic lesions and 8 (7.0%) of 114 mutation carriers without cystic lesions developed PDAC (P = 0.56). Three of 6 patients with a cystic lesion of ≥10 mm developed PDAC. The median size of all incident PDAC detected between 9 and 12 months since the previous normal MRI was 15 mm, suggesting an annual growth rate of about 15 mm/year. In conclusion, our findings show that patients with and without a cystic lesions have a similar risk of PDAC. However, cystic precursor lesions between 10 and 20 mm increase the risk of PDAC substantially. In view of the large size of the screen-detected tumors, a shorter interval of screening might be recommended for all patients. Cancer Prev Res; 11(9); 551-6. ©2018 AACR.

Clinical outcomes of endoscopic ultrasound-guided ethanol ablation for pancreatic cystic lesions compared with the natural course: a propensity score matching analysis

BACKGROUND

Endoscopic ultrasound-guided ethanol ablation (EUS-EA) is a recently introduced treatment for pancreatic cystic lesions (PCLs). However, clinical benefits such as survival gain and maintenance of quality of life (QOL) have not been fully established. The aim of this study was to evaluate the clinical benefits of EUS-EA compared with the natural course (NC) of PCLs.

METHODS

This retrospective comparative study of patients with PCLs investigated an EUS-EA group (n = 118) and an NC group (n = 428). Propensity score matching (PSM) analysis was applied to minimize the effects of selection bias. The overall survival as the primary outcome and the surgical resection rate and complete remission (CR) rate as the secondary outcomes were evaluated.

RESULTS

Between 84 matched pairs of both groups, there were no significant differences in the baseline clinical characteristics and the mean follow-up duration (78.88 ± 38.86, 75.90 ± 57.46 months, p = 0.694). Overall survival did not differ significantly (194.12 ± 5.60, 247.54 ± 12.70 months, p = 0.235). The surgical resection rate (4.8% versus 26.2%, p < 0.001) was significantly lower in the EUS-EA group. CR was observed only in the EUS-EA group and the CR rate was 32.1%.

CONCLUSIONS

EUS-EA for PCLs with low risk of malignancy might not be able to obtain a survival benefit, but showed maintenance of QOL by avoidance of unnecessary surgery, and a certain level of CR when compared to the NC. EUS-EA could be considered a useful treatment option for these, but careful application is needed because of the limited effects in some types of PCLs.

Pancreatic cyst fluid harbors a unique microbiome

BACKGROUND

It is clear that specific intestinal bacteria are involved in the development of different premalignant conditions along the gastrointestinal tract. An analysis of the microbial constituents in the context of pancreatic cystic lesions has, however, as yet not been performed. This consideration prompted us to explore whether endoscopically obtained pancreatic cyst fluids (PCF) contain bacterial DNA and to determine the genera of bacteria present in such material.

METHODS

Total DNA was isolated from 69 PCF samples. Bacterial 16S rRNA gene-specific PCR was performed followed by Sanger sequencing and de novo deep sequencing for the V3-V4 variable region of 16S rRNA gene.

RESULTS

We observed that 98.2% of the samples were positive in conventional PCR, and that 100% of selected PCF samples (n = 33) were positive for bacterial microbiota as determined by next generation sequencing (NGS). Comprehensive NGS data analysis of PCF showed the presence of 408 genera of bacteria, of which 17 bacterial genera were uniquely abundant to PCF, when compared to the Human Microbiome Project (HMP) database and 15 bacterial microbiota were uniquely abundant in HMP only. Bacteroides spp., Escherichia/Shigella spp., and Acidaminococcus spp. which were predominant in PCF, while also a substantial Staphylococcus spp. and Fusobacterium spp. component was detected.

CONCLUSION

These results reveal and characterize an apparently specific bacterial ecosystem in pancreatic cyst fluid samples and may reflect the local microbiota in the pancreas. Some taxa with potential deleterious functions are present in the bacterial abundance profiles, suggesting that the unique microbiome in this specific niche may contribute to neoplastic processes in the pancreas. Further studies are needed to explore the intricate relationship between pathophysiological status in the host pancreas and its microbiota.

Does next-generation sequencing of cyst fluid improve management of pancreatic cystic neoplasms?

Pancreatic cystic lesions represent a heterogeneous group of diseases ranging from benign to malignant lesions. They are increasingly being detected due to the widespread use of cross-sectional imaging. Their management is a challenge because it is often not possible to reliably discriminate between malignant and nonmalignant lesions using current imaging technology. Next-generation sequencing (NGS) has the ability of both whole genome and targeted sequencing at a low cost and from a limited amount of DNA. NGS of cyst fluid aspired by endoscopic ultrasonography-guided fine-needle aspiration provides a valuable tool in biomarker research and may in the future help improve diagnosis and management of pancreatic cystic lesions.

Endoscopic Ultrasound Imaging for Diagnosing and Treating Pancreatic Cysts

Cystic pancreatic lesions are increasingly diagnosed owing to the abundant use of cross-sectional imaging. Given their malignant potential, true pancreatic cysts should be considered for resection or periodic follow-up. Cystic lesions of the pancreas (CLPs) require further evaluation and management. Therefore, it is important to establish a solid diagnosis at the time of detection. Endoscopic ultrasound examination is the imaging modality of choice. Fine needle aspiration provides fluid for cytologic, biochemical, and molecular assays to classify lesions and predict biological behavior. This review provides an overview of the diagnosis and management of various types of commonly encountered true CLPs.

Fukuoka criteria accurately predict risk for adverse outcomes during follow-up of pancreatic cysts presumed to be intraductal papillary mucinous neoplasms

OBJECTIVE

Fukuoka consensus guidelines classify pancreatic cystic lesions (PCLs) presumed to be intraductal papillary mucinous neoplasms (IPMNs) into Fukuoka positive (FP) (subgroups of high-risk (HR) and worrisome features (WFs)) and Fukuoka negative (FN) (non-HR feature/WF cysts). We retrospectively estimated 5-year risk of pancreatic cancer (PC) in FN, WF and HR cysts of patients with PCL-IPMN.

DESIGN

From Mayo Clinic databases, we randomly selected 2000 patients reported to have a PCL; we excluded inflammatory or suspected non-IPMN cysts and those without imaging follow-up. We re-reviewed cross-sectional imaging and abstracted clinical and follow-up data on PCL-IPMNs. The study contained 802 patients with FN cysts and 358 with FP cysts.

RESULTS

Patients with PCL-IPMN had median (IQR) follow-up of 4.2 (1.8-7.1) years. Among FN cysts, 5-year PC risk was low (2-3%) regardless of cyst size (p=0.67). After excluding events in the first 6 months, 5-year PC risk remained low (0-2%) regardless of cyst size (p=0.61). Among FP cysts, HR cysts (n=66) had greater 5-year PC risk than WF cysts (n=292) (49.7% vs 4.1%; p<0.001). In HR cysts, 3-year PC risk was greatest for obstructive jaundice versus enhancing solid component or main pancreatic duct >10 mm (79.8% vs 37.3% vs 39.4%, respectively; p=0.01).

CONCLUSIONS

Fukuoka guidelines accurately stratify PCL-IPMNs for PC risk, with FN cysts having lowest and HR cysts having greatest risk. After 6-month follow-up, WF and FN cysts had a low 5-year PC risk. Surveillance strategies should be tailored appropriately.

Incidental, Small (< 3 cm), Unilocular, Pancreatic Cysts: Factors That Predict Lesion Progression during Imaging Surveillance

OBJECTIVE

To explore the features that predict size increase and development of potential malignant features in incidentally detected, unilocular cystic pancreatic lesions (CPLs) less than 3 cm in diameter, during subsequent follow-up.

MATERIALS AND METHODS

We retrieved data of patients diagnosed with unilocular CPLs less than 3 cm in diameter during the period from November 2003 through December 2014, using a computerized search. All serial CT and MR images were analyzed to identify the number, size, and location of CPLs; dilatation of the main pancreatic duct; and occurrence of worrisome features and high-risk stigmata of malignancy in the lesion. The characteristics of CPLs were compared between the increase (i.e., size increase during subsequent follow-up) and no-increase groups. For CPLs in the increase group, subgroup analysis was performed according to the lesion size at the last follow-up (< 3 cm vs. ≥ 3 cm).

RESULTS

Among 553 eligible patients, 132 (23.9%) had CPLs that increased in size, and 421 (76.1%) had CPLs that did not, during follow-up. Of the 132, 12 (9.1%) CPLs increased to diameters ≥ 3 cm at the final follow-up. Among the various factors, follow-up duration was a significant independent factor for an interval size increase of CPLs (p < 0.001). In the increase group, initial cyst size was a significant independent factor to predict later size increase to or beyond 3 cm in diameter (p < 0.001), and the initial cyst diameter ≥ 1.5 cm predicted such a growth with a sensitivity and specificity of 83% and 72%, respectively. No significant factors to predict the development of potential malignant features were identified.

CONCLUSION

Follow-up duration was associated with an interval size increase of CPLs. Among the growing CPLs, initial cyst size was associated with future lesion growth to and beyond 3 cm.

Appropriate Interval for Imaging Follow-up of Small Simple Pancreatic Cysts

CONTEXT

The frequency at which patients should undergo follow-up imaging of small pancreatic cysts is problematic because different medical societies have different follow-up guidelines.

OBJECTIVE

To determine whether short-term follow-up of small pancreatic cysts is necessary to detect pancreatic cancer or cystic neoplasia.

DESIGN

We retrospectively reviewed all abdominal magnetic resonance imaging (MRI) studies obtained in a geographically isolated health maintenance organization between January 1, 2012, and December 31, 2014, looking for pancreatic cysts. For each patient with one or more simple cysts, we recorded the size of the largest cyst. For patients with cysts, all their other computed tomography and MRI studies were reviewed to determine any change in size or morphology. The electronic medical record of every patient who underwent MRI was reviewed to determine development of pancreatic cancer.

MAIN OUTCOME MEASURES

Change in cyst size on images.

RESULTS

Of 1946 patients, 342 were found to have at least 1 pancreatic cyst. A total of 228 patients had additional imaging from which to determine rates of change. The mean rate (standard deviation) of change for these cysts was 0.1 ± 2.0 mm/y. None of those cysts measuring 2 cm or smaller on MRI grew more than 5 mm in 2 years.

CONCLUSION

Our data validate the clinical efficacy of obtaining follow-up imaging no sooner than 24 months after the initial detection of a simple pancreatic cyst 2 cm or smaller. Patients with cysts are more likely to have pancreatic cancer, but earlier follow-up imaging would not change their diagnosis of pancreatic cancer.

Competing Risks for Mortality in Patients With Asymptomatic Pancreatic Cystic Neoplasms: Implications for Clinical Management

OBJECTIVES

Pancreatic cystic neoplasms (PCNs) are being detected with increased frequency. Current clinical practice guidelines emphasize management based on cyst-related features. We aimed to evaluate the impact of comorbidity on mortality in PCN patients via competing risk analysis.

METHODS

We analyzed a retrospective cohort of patients diagnosed between 2005-2010, with follow-up through 2015, for overall and cause-specific mortality. Comorbidities were classified by the Charlson comorbidity index. We used Cox proportional hazards regression to evaluate the independent effect of cyst features, age, gender, and comorbidities on cause-specific mortality. Subgroup analysis was performed to determine the cause-specific mortality based on four a priori clinical profiles-healthy patients with low- or high-risk cysts, and high-comorbidity patients with low- or high-risk cysts.

RESULTS

A total of 1,800 patients with PCNs comprised the study cohort (median follow-up 5.7 years). A total of 402 deaths (22.3%) occurred during the study period: 43 pancreatic cancer and 359 non-pancreatic cancer deaths. Compared to healthy patients without any high-risk cyst features (reference group), patients with high comorbidity as well as high-risk cyst features had an increased risk of overall mortality (Cox hazard ratio 6.30, 95% confidence interval (CI) 4.71, 8.42, P<0.01), pancreatic cancer mortality (subdistribution hazard ratio (SHR) 51.13, 95% CI 6.35, 411.29, P<0.01), as well as non-pancreatic cancer mortality (SHR 5.24, 95% CI 3.85, 7.12, P<0.01). Meanwhile, low-risk patients with a high-risk cyst were more likely to experience pancreatic cancer mortality (SHR 68.14, 95% CI 9.27, 501.01, P<0.01) rather than non-pancreatic cancer mortality (SHR 1.22, 95% CI 0.88, 1.71, P=0.23), compared to the reference group. Similarly, compared to the reference group, high-risk patients with a low-risk cyst were more likely to experience non-pancreatic cancer mortality (SHR 3.96, 95% CI 2.98, 5.26, P<0.01) rather than pancreatic cancer mortality (SHR 2.35, 95% CI 0.14, 38.82, P=0.55).

CONCLUSIONS

Most of the deaths in the study were unrelated to pancreatic cancer. This has implications for clinical management. By applying patient-related factors in conjunction with cyst features, we defined commonly encountered patient profiles to help guide PCN clinical management.

Clinical Approach to Incidental Pancreatic Cystic Neoplasm in Outpatient Clinics

Cystic lesions of the pancreas are increasingly observed due to increased use of abdominal images. The malignant rate of pancreas cystic lesion varies widely between various types. Identification of malignant or high-risk lesions is important when determining the appropriate course of management. Using these image findings, including cyst size, presence of solid components, and pancreatic duct involvement, the 2012 International Association of Pancreatology (IAP) and the 2015 American Gastroenterological Association (AGA) guidelines provide a rationale in identifying higher risk patients requiring further workups using an endoscopic ultrasound (EUS). EUS with fine needle aspiration and cytology allows confirmation of the cyst type and determines the risk of malignancy. Small cysts with no suspicious features may undergo the regular imaging study for regular surveillance due to low risk for malignancy. In this review, the differences between the 2012 IAP and 2015 AGA guidelines are presented, In addition to possible recommendations for management and surveillance.

Natural History of Pancreatic Cysts

Pancreatic cystic neoplasms are discovered with increasing frequency. Accurate knowledge of the natural history of cystic neoplasms is crucial to develop useful and cost-effective strategies for surveillance and surgical resection. To date, the natural history of cystic neoplasms is still incomplete due to lack of adequate diagnostic accuracy in the absence of surgical pathology. Nevertheless, current evidence points to risk factors for malignant transformation to help clinical management. New biomarkers that accurately distinguish cyst neoplasms and those most likely to progress to cancer would help clarify the natural history of cystic neoplasms.

Imaging modalities for characterising focal pancreatic lesions

BACKGROUND

Increasing numbers of incidental pancreatic lesions are being detected each year. Accurate characterisation of pancreatic lesions into benign, precancerous, and cancer masses is crucial in deciding whether to use treatment or surveillance. Distinguishing benign lesions from precancerous and cancerous lesions can prevent patients from undergoing unnecessary major surgery. Despite the importance of accurately classifying pancreatic lesions, there is no clear algorithm for management of focal pancreatic lesions.

OBJECTIVES

To determine and compare the diagnostic accuracy of various imaging modalities in detecting cancerous and precancerous lesions in people with focal pancreatic lesions.

SEARCH METHODS

We searched the CENTRAL, MEDLINE, Embase, and Science Citation Index until 19 July 2016. We searched the references of included studies to identify further studies. We did not restrict studies based on language or publication status, or whether data were collected prospectively or retrospectively.

SELECTION CRITERIA

We planned to include studies reporting cross-sectional information on the index test (CT (computed tomography), MRI (magnetic resonance imaging), PET (positron emission tomography), EUS (endoscopic ultrasound), EUS elastography, and EUS-guided biopsy or FNA (fine-needle aspiration)) and reference standard (confirmation of the nature of the lesion was obtained by histopathological examination of the entire lesion by surgical excision, or histopathological examination for confirmation of precancer or cancer by biopsy and clinical follow-up of at least six months in people with negative index tests) in people with pancreatic lesions irrespective of language or publication status or whether the data were collected prospectively or retrospectively.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched the references to identify relevant studies and extracted the data. We planned to use the bivariate analysis to calculate the summary sensitivity and specificity with their 95% confidence intervals and the hierarchical summary receiver operating characteristic (HSROC) to compare the tests and assess heterogeneity, but used simpler models (such as univariate random-effects model and univariate fixed-effect model) for combining studies when appropriate because of the sparse data. We were unable to compare the diagnostic performance of the tests using formal statistical methods because of sparse data.

MAIN RESULTS

We included 54 studies involving a total of 3,196 participants evaluating the diagnostic accuracy of various index tests. In these 54 studies, eight different target conditions were identified with different final diagnoses constituting benign, precancerous, and cancerous lesions. None of the studies was of high methodological quality. None of the comparisons in which single studies were included was of sufficiently high methodological quality to warrant highlighting of the results. For differentiation of cancerous lesions from benign or precancerous lesions, we identified only one study per index test. The second analysis, of studies differentiating cancerous versus benign lesions, provided three tests in which meta-analysis could be performed. The sensitivities and specificities for diagnosing cancer were: EUS-FNA: sensitivity 0.79 (95% confidence interval (CI) 0.07 to 1.00), specificity 1.00 (95% CI 0.91 to 1.00); EUS: sensitivity 0.95 (95% CI 0.84 to 0.99), specificity 0.53 (95% CI 0.31 to 0.74); PET: sensitivity 0.92 (95% CI 0.80 to 0.97), specificity 0.65 (95% CI 0.39 to 0.84). The third analysis, of studies differentiating precancerous or cancerous lesions from benign lesions, only provided one test (EUS-FNA) in which meta-analysis was performed. EUS-FNA had moderate sensitivity for diagnosing precancerous or cancerous lesions (sensitivity 0.73 (95% CI 0.01 to 1.00) and high specificity 0.94 (95% CI 0.15 to 1.00), the extremely wide confidence intervals reflecting the heterogeneity between the studies). The fourth analysis, of studies differentiating cancerous (invasive carcinoma) from precancerous (dysplasia) provided three tests in which meta-analysis was performed. The sensitivities and specificities for diagnosing invasive carcinoma were: CT: sensitivity 0.72 (95% CI 0.50 to 0.87), specificity 0.92 (95% CI 0.81 to 0.97); EUS: sensitivity 0.78 (95% CI 0.44 to 0.94), specificity 0.91 (95% CI 0.61 to 0.98); EUS-FNA: sensitivity 0.66 (95% CI 0.03 to 0.99), specificity 0.92 (95% CI 0.73 to 0.98). The fifth analysis, of studies differentiating cancerous (high-grade dysplasia or invasive carcinoma) versus precancerous (low- or intermediate-grade dysplasia) provided six tests in which meta-analysis was performed. The sensitivities and specificities for diagnosing cancer (high-grade dysplasia or invasive carcinoma) were: CT: sensitivity 0.87 (95% CI 0.00 to 1.00), specificity 0.96 (95% CI 0.00 to 1.00); EUS: sensitivity 0.86 (95% CI 0.74 to 0.92), specificity 0.91 (95% CI 0.83 to 0.96); EUS-FNA: sensitivity 0.47 (95% CI 0.24 to 0.70), specificity 0.91 (95% CI 0.32 to 1.00); EUS-FNA carcinoembryonic antigen 200 ng/mL: sensitivity 0.58 (95% CI 0.28 to 0.83), specificity 0.51 (95% CI 0.19 to 0.81); MRI: sensitivity 0.69 (95% CI 0.44 to 0.86), specificity 0.93 (95% CI 0.43 to 1.00); PET: sensitivity 0.90 (95% CI 0.79 to 0.96), specificity 0.94 (95% CI 0.81 to 0.99). The sixth analysis, of studies differentiating cancerous (invasive carcinoma) from precancerous (low-grade dysplasia) provided no tests in which meta-analysis was performed. The seventh analysis, of studies differentiating precancerous or cancerous (intermediate- or high-grade dysplasia or invasive carcinoma) from precancerous (low-grade dysplasia) provided two tests in which meta-analysis was performed. The sensitivity and specificity for diagnosing cancer were: CT: sensitivity 0.83 (95% CI 0.68 to 0.92), specificity 0.83 (95% CI 0.64 to 0.93) and MRI: sensitivity 0.80 (95% CI 0.58 to 0.92), specificity 0.81 (95% CI 0.53 to 0.95), respectively. The eighth analysis, of studies differentiating precancerous or cancerous (intermediate- or high-grade dysplasia or invasive carcinoma) from precancerous (low-grade dysplasia) or benign lesions provided no test in which meta-analysis was performed.There were no major alterations in the subgroup analysis of cystic pancreatic focal lesions (42 studies; 2086 participants). None of the included studies evaluated EUS elastography or sequential testing.

AUTHORS' CONCLUSIONS

We were unable to arrive at any firm conclusions because of the differences in the way that study authors classified focal pancreatic lesions into cancerous, precancerous, and benign lesions; the inclusion of few studies with wide confidence intervals for each comparison; poor methodological quality in the studies; and heterogeneity in the estimates within comparisons.

Patient Preferences for Management of Cystic Neoplasms of the Pancreas: A Cross-Sectional Survey Study

OBJECTIVE

The aim of this study was to determine how patient anxiety, knowledge, and cancer worry influence preferences for management of pancreatic cysts.

METHODS

We performed a prospective, cross-sectional study using a disease-specific survey instrument. We included patients older than 18 years who were diagnosed with a pancreatic cyst. A telephone survey instrument was developed to assess baseline anxiety using the Hospital Anxiety and Depression Scale (HADS), knowledge regarding pancreatic cysts, cancer worry, and patient preferences using a standard gamble.

RESULTS

Of the 100 studied participants (median age, 65 years; 72% women), median Hospital Anxiety and Depression Scale score was 4 (normal range). In terms of knowledge, 96% of the patients were not aware of their specific cyst type, and 58% were unaware of the possibility of any cyst-related malignancy. Overall, 8% of respondents had some degree of cancer worry. Respondents were more willing to undergo magnetic resonance imaging surveillance compared with endoscopic ultrasound or surgery. Knowledge of cyst type was a significant predictor of willingness to undergo invasive testing.

CONCLUSIONS

There is a significant gap in patient knowledge with respect to pancreatic cysts. Greater emphasis on patient education can help patients make informed decisions regarding cyst management.

Intraductal papillary mucinous neoplasms and mucinous cystadenomas: current status and recommendations

The real prevalence of pancreatic cystic lesions remains unknown. The malignant potential of some of these lesions remains a cause for significant concern. Thus, it is mandatory to develop a strategy to clearly discriminate those cysts with a potential for malignant transformation from those that do not carry any significant risk. Intraductal papillary mucinous neoplasms and mucinous cystadenomas are mucinous cystic neoplasms with a known malignant potential that have gained greater recognition in recent years. However, despite the numerous studies that have been carried out, their differential diagnosis among other cysts subtypes and their therapeutic approach continue to be a challenge for clinicians. This review contains a critical approach of the current recommendations and management strategies regarding intraductal papillary mucinous neoplasms and mucinous cystadenomas, as well as highlighting the limitations exposed in current guidelines.

Management of Patients With Pancreatic Cysts: Analysis of Possible False-Negative Cases of Malignancy

GOALS

To examine the utility of integrated molecular pathology (IMP) in managing surveillance of pancreatic cysts based on outcomes and analysis of false negatives (FNs) from a previously published cohort (n=492).

BACKGROUND

In endoscopic ultrasound with fine-needle aspiration (EUS-FNA) of cyst fluid lacking malignant cytology, IMP demonstrated better risk stratification for malignancy at approximately 3 years' follow-up than International Consensus Guideline (Fukuoka) 2012 management recommendations in such cases.

STUDY

Patient outcomes and clinical features of Fukuoka and IMP FN cases were reviewed. Practical guidance for appropriate surveillance intervals and surgery decisions using IMP were derived from follow-up data, considering EUS-FNA sampling limitations and high-risk clinical circumstances observed. Surveillance intervals for patients based on IMP predictive value were compared with those of Fukuoka.

RESULTS

Outcomes at follow-up for IMP low-risk diagnoses supported surveillance every 2 to 3 years, independent of cyst size, when EUS-FNA sampling limitations or high-risk clinical circumstances were absent. In 10 of 11 patients with FN IMP diagnoses (2% of cohort), EUS-FNA sampling limitations existed; Fukuoka identified high risk in 9 of 11 cases. In 4 of 6 FN cases by Fukuoka (1% of cohort), IMP identified high risk. Overall, 55% of cases had possible sampling limitations and 37% had high-risk clinical circumstances. Outcomes support more cautious management in such cases when using IMP.

CONCLUSIONS

Adjunct use of IMP can provide evidence for relaxed surveillance of patients with benign cysts that meet Fukuoka criteria for closer observation or surgery. Although infrequent, FN results with IMP can be associated with EUS-FNA sampling limitations or high-risk clinical circumstances.

Long-term follow-up of neoplastic pancreatic cysts without high-risk stigmata: how often do we change treatment strategy because of malignant transformation?

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OBJECTIVE

Patients with potentially premalignant neoplastic pancreatic cysts without high-risk stigmata usually enter a surveillance program. Data on outcomes of such surveillance programs are scarce. We aimed to evaluate the resection rate and malignancy rate during follow-up.

MATERIAL AND METHODS

From our prospective database (2006-2015) of patients with pancreatic cysts, we analyzed patients with pancreatic cysts without high-risk stigmata with at least six months follow-up.

RESULTS

In total, 146 patients were followed for a median of 29 months (IQR 13.5-50 months). In 124 patients (84.9%), no changes in clinical or imaging characteristics occurred during follow-up. Thirteen patients (8.9%) developed an indication for surgery after a median follow-up of 25 months (IQR 12-42 months). Two patients did not undergo surgery because of comorbidity, 11 patients (7.5%) underwent resection. Indications for surgery were symptoms (n = 2), development of a pancreatic mass (n = 1), a new nodule (n = 2), thickened cyst wall (n = 1), pancreatic duct dilation (n = 3), and/or suspicion of mucinous cystic neoplasm (MCN) (n = 3). Postoperative histology showed one pancreatic malignancy not originating from the cyst, three mixed type-intraductal papillary mucinous neoplasm (IPMN), one side branch-IPMN, two MCN, one neuroendocrine tumor, one serous cystadenoma, one inflammatory cyst, and one lymphangioma. The highest grade of cyst dysplasia was borderline dysplasia.

CONCLUSIONS

Most neoplastic pancreatic cysts without high-risk stigmata at initial presentation show no substantial change during 1-4-year follow-up. Only 7.5% of patients underwent surgery and less than 1% of patients developed pancreatic malignancy. This indicates that additional markers are needed to tailor treatment of pancreatic cysts.

Routine Cyst Fluid Cytology Is Not Indicated in the Evaluation of Pancreatic Cystic Lesions

BACKGROUND

The work-up of cystic lesions of the pancreas often involves endoscopic ultrasound (EUS) with fine needle aspiration (FNA). In addition to CEA and amylase measurement, fluid is routinely sent for cytologic examination. We evaluated the utility of cytologic findings in clinical decision-making.

MATERIALS AND METHODS

Records of patients who underwent EUS-guided pancreatic cyst aspiration were reviewed. Findings from axial imaging and EUS were compared to cyst fluid cytology as well as fluid amylase and CEA. All results were then compared to final diagnosis, determined by clinical analysis for those patients not resected, and surgical pathology report for those who underwent resection.

RESULTS

A total of 167 patients were reviewed. Of 48 patients with suspicious findings on imaging, cytology yielded diagnostic information in 89.6 % of cases (43 patients). However, in the 119 patients where no suspicious components were revealed on imaging, fluid cytology yielded no significant diagnostic results in any case. In all cases where mucin was noted on cytologic review, thick fluid was also seen at the time of aspiration.

DISCUSSION

In our cohort of patients with cystic pancreatic lesions, cytologic analysis of pancreatic cyst fluid yielded no diagnostic benefit over radiologic findings alone. In such cases where fluid is to be aspirated, specimens that would otherwise be sent for cytologic evaluation would be better served for other purposes, such as molecular analysis or banking for future research.

Requirement of a single high-risk feature as an indication for EUS for the diagnosis of asymptomatic pancreatic cysts

BACKGROUND AND AIMS

Endoscopic ultrasound (EUS) is widely used to evaluate pancreatic cysts. Recent American Gastroenterological Association (AGA) guideline limits EUS for evaluation of cysts with at-least two high-risk features (size ≥ 3 cm, dilated main pancreatic duct or presence of a solid component). We have investigated the impact of this guideline on sensitivity of EUS for pancreatic cancer and the reduction of EUS procedures for pancreas cysts.

METHODS

EUS procedures performed between 2004 and 2015 and related patient records were retrospectively reviewed to determine the presence or absence of high-risk features, and for the results of fine needle aspiration cytology.

RESULTS

Two hundred ten patients (108 males) underwent EUS for diagnostic evaluation of pancreatic cysts. Four patients (1.9%), all with at-least one high-risk feature, were diagnosed with cytologically-proven pancreatic cancer. Only 2 patients with cancer had at-least two high-risk features that would have warranted EUS examination based on the new AGA guideline. The requirement for at-least two high-risk features would have decreased the number of EUS procedures by 91%, but reduced the sensitivity for pancreatic malignancy to 50%. If only one high-risk feature was required, EUS procedures would have been decreased by 67%, with a sensitivity of 100%.

CONCLUSION

Limiting EUS to patients with pancreatic cysts with 2 or more high-risk features may substantially reduce the sensitivity for pancreatic malignancy. Performing EUS in patients with at least one high-risk feature may substantially decrease the need of invasive procedures without reducing sensitivity for detecting malignancy.

Risk of pancreatic cancer in patients with pancreatic cyst

BACKGROUND AND AIMS

Certain pancreatic cysts (mucinous cystic neoplasm and side branch intraductal papillary mucinous neoplasm [IPMN]) have malignant potential and require surveillance. However, whether patients with pancreatic cysts have a higher long-term risk of pancreatic cancer (PaCa) has still not been established.

METHODS

This was a retrospective study of Veterans Administration patients. Patients noted to have pancreatic cysts on CT/magnetic resonance imaging (n = 1050) were identified using International Classification of Diseases, Ninth Revision, Clinical Modification codes. Patients aged <15 years (n = 425), patients with <1 year of follow-up (n = 13,259), and patients diagnosed to have PaCa within 1 year of identification of a pancreatic cyst (n = 102) or within 1 year of follow-up in the remaining patients in the database (n = 200) were excluded. Patients with pancreatic cystic lesions (group A, n = 755) and the remaining patients in the database without cysts (group B, n = 520,215) were followed from 1998 to 2007.

RESULTS

During the study period, in group A and B PaCa was diagnosed in 17 and 1206 patients, respectively, and the incidence rate of PaCa was 5.08 and .32 per 1000 patient-years, respectively. The hazard ratio of PaCa in all patients with cysts was 19.64 (95% CI, 12.12-31.82; P < .0001) when compared with the rest of the patients without cysts. In the subset of patients with cysts, without a history of acute or chronic pancreatitis (n = 241), the hazard ratio of PaCa (n = 5) was 18.80 (95% CI, 7.80-45.31; P < .0001).

CONCLUSION

Patients with pancreatic cysts have a significantly higher overall risk of PaCa. The etiologic distribution of cysts in our study patients is not available. Patients with mucinous cystic neoplasm and side branch IPMN are likely to have a higher risk of PaCa than our estimation of risk based on all etiologies.

Risk of pancreatic malignancy and mortality in branch-duct IPMNs undergoing surveillance: A systematic review and meta-analysis

BACKGROUND

Safety of non-operative management for low-risk branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) is debated.

AIM

To perform a systematic review/meta-analysis to determine their risk of developing pancreatic malignancy and of pancreatic malignancy-related deaths.

METHODS

A MEDLINE search was performed and methodology was based on PRISMA statement. Incidence rates of overall pancreatic malignancy, malignant BD-IPMN, IPMN-distinct PDAC, and of pancreatic malignancy-related death rates were calculated by dividing the total number of events by the total number of person-years (pyrs) of follow-up. Heterogeneity was determined by I(2) statistic.

RESULTS

20 studies including 2177 patients were included. Mean follow-up ranged from 29.3 to 76.7 months. Overall, 82 patients (3.7%) developed a pancreatic malignancy with a pooled estimate rate of 0.007/pyrs (I(2)=32.8%). The pooled estimate rate of malignant IPMN was 0.004/pyrs (I(2)=40.8%), and the pooled estimate rate of distinct PDAC 0.002/pyrs (I(2)=0%). The rate of death due to pancreatic malignancy during follow-up was 0.9%, with an overall pooled estimate rate of death of 0.002/pyrs (I(2)=0%).

CONCLUSION

Non-operative management of low-risk BD-IPMN is safe, with a very low risk of malignant transformation of IPMN and of distinct PDAC. The rate of pancreatic malignancy-related mortality is low, particularly when compared with the mortality of pancreatic surgery.

What is the reasonable option for elderly patients with incidental pancreatic cystic neoplasms? Follow-up observation versus surgical resection

AIMS

Pancreatic cystic neoplasms (PCN) with malignant potential are thought to be less aggressive than ordinary ductal adenocarcinoma, even in the setting of malignant transformation. Therefore, deciding whether or not to carry out surgery is very difficult, especially in elderly and asymptomatic patients, because of the high risk of perioperative morbidities. The aim of the present study was to examine clinical outcomes of PCN patients aged 65 years or older.

METHODS

This retrospective analysis included patients with incidentally detected PCN with follow-up durations >1 year. Patients diagnosed with obvious simple cysts, pseudocysts or pancreatic cancer and patients with a history of pancreatic disease were excluded from the study.

RESULTS

The present study included 201 patients (older group 104 patients ≥65 years; younger group 97 patients <65 years). Surgical resections were carried out for 27 patients in the older group and 41 patients in the younger group. There were 133 patients who were followed up without surgery (mean follow-up duration 41 months). Postoperative morbidity occurred in 22.2% of the patients in the older group and 21.9% of the patients in the younger group. Malignancy occurred in one patient in the older group and in two patients in the younger group. The PCN diameter increased in 20 patients during follow up: 16.9% of the older group and 12.5% of the younger group.

CONCLUSIONS

The malignancy rate was very low in incidental PCN patients irrespective of age. Follow-up observation without surgery appears to be a safe option in older patients with morbidity. Geriatr Gerontol Int 2017; 17: 256-261.

Influence of integrated molecular pathology test results on real-world management decisions for patients with pancreatic cysts: analysis of data from a national registry cohort

BACKGROUND

Integrated molecular pathology (IMP) approaches based on DNA mutational profiling accurately determine pancreatic cyst malignancy risk in patients lacking definitive diagnoses following endoscopic ultrasound imaging with fine-needle aspiration of fluid for cytology. In such cases, IMP 'low-risk' and 'high-risk' diagnoses reliably predict benign and malignant disease, respectively, and provide improved risk stratification for malignancy than a model of the 2012 International Consensus Guideline (ICG) recommendations. Our objective was to determine if initial adjunctive IMP testing influenced future real-world pancreatic cyst management decisions for intervention or surveillance relative to ICG recommendations, and if this benefitted patient outcomes.

METHODS

Analysis of data from the previously described National Pancreatic Cyst Registry. Associations between real-world decisions (intervention vs. surveillance), ICG model recommendations (surgery vs. surveillance) and IMP diagnoses (high-risk vs. low-risk) were evaluated using 2 × 2 tables. Kaplan Meier and hazard ratio analyses were used to assess time to malignancy. Odds ratios (OR) for surgery decision were determined using logistic regression.

RESULTS

Of 491 patients, 206 received clinical intervention at follow-up (183 surgery, 4 chemotherapy, 19 presumed by malignant cytology). Overall, 13 % (66/491) of patients had a malignant outcome and 87 % (425/491) had a benign outcome at 2.9 years' follow-up. When ICG and IMP were concordant for surveillance/surgery recommendations, 83 % and 88 % actually underwent surveillance or surgery, respectively. However, when discordant, IMP diagnoses were predictive of real-world decisions, with 88 % of patients having an intervention when ICG recommended surveillance but IMP indicated high risk, and 55 % undergoing surveillance when ICG recommended surgery but IMP indicated low risk. These IMP-associated management decisions benefitted patient outcomes in these subgroups, as 57 % had malignant and 99 % had benign outcomes at a median 2.9 years' follow-up. IMP was also more predictive of real-world decisions than ICG by multivariate analysis: OR 11.4 (95 % CI 6.0 - 23.7) versus 3.7 (2.4 - 5.8), respectively.

CONCLUSIONS

DNA-based IMP diagnoses were predictive of real-world management decisions. Importantly, when ICG and IMP were discordant, IMP influence benefitted patients by increasing confidence in surveillance and surgery decisions and reducing the number of unnecessary surgeries in patients with benign disease.

A MicroRNA Panel in Pancreatic Cyst Fluid for the Risk Stratification of Pancreatic Cysts in a Prospective Cohort

A subset of pancreatic cystic neoplasms are regarded as precursor lesions of pancreatic cancer, but only a minority of all pancreatic cystic neoplasms will undergo malignant transformation. MicroRNAs are increasingly recognized as molecular targets in carcinogenesis. Previously, a 9-microRNA (miR) signature was suggested to discriminate between high risk and low risk pancreatic cystic neoplasm. In this study, we aimed to validate this 9-miR panel in a prospective cohort. Total miR was isolated from pancreatic cyst fluid and expression of miR18a, miR24, miR30a-3p, miR92a, miR99b, miR106b, miR142-3p, miR342-3p, and miR532-3p was analyzed by singleplex Taqman MicroRNA Assay. A total of 62 patient samples were analyzed. During follow-up, 24 (38.7%) patients underwent resection, of which 6 (9.7%) patients showed at least high grade dysplasia. A logistic regression model presented a “predicted risk” score which significantly differed between low and high risk cysts, either including all patients or only those with histological confirmation of diagnosis. Using a set cut-off of 50%, the sensitivity of the model for the total cohort was 10.0%, specificity 100.0%, positive predicted value 100.0%, negative predicted value 85.2%, and diagnostic accuracy of 85.5%. Thus, while observing a significant difference between low and high risk cysts, clinical implementation of this biomarker panel is as yet unlikely to be beneficial in the management of pancreatic cysts.

Predictors for Surgical Referral in Patients With Pancreatic Cystic Lesions Undergoing Endoscopic Ultrasound: Results From a Large Multicenter Cohort Study

OBJECTIVE

Endoscopic ultrasound (EUS) plays an integral role in the evaluation of pancreatic cysts lesions (PCLs). The aim of the study was to determine predictors of surgical referral in patients with PCLs undergoing EUS.

METHODS

We performed a multicenter retrospective study of patients undergoing EUS for evaluation of PCLs. Demographics, EUS characteristics, and fine-needle aspiration results were recorded. Patients were categorized into surgery or surveillance groups on the basis of post-EUS recommendations. Univariate and multivariate analyses were performed to identify predictors of surgical referral.

RESULTS

1804 patients were included. 1301 patients were recommended to undergo surveillance and 503 patients were referred for surgical evaluation, of which 360 patients underwent surgery. Multivariate analysis revealed the following 5 independent predictors of surgical referral: symptoms of weight loss on presentation (odds ratio [OR], 2.69; 95% confidence interval [CI], 1.44-5.03), EUS findings of associated solid mass (OR, 7.34; 95% CI, 3.81-14.16), main duct communication (OR, 4.13; 95% CI, 1.71-9.98), multilocular macrocystic morphology (OR, 2.79; 95% CI, 1.78-4.38), and fine-needle aspiration findings of mucin on cytology (OR, 3.06; 95% CI, 1.94-4.82).

CONCLUSIONS

This study identifies factors associated with surgical referral in patients with PCLs undergoing EUS. Future studies should focus on creation of risk stratification models to determine the need for surgery or enrollment in surveillance programs.

Features associated with progression of small pancreatic cystic lesions: A retrospective study

AIM: To investigate the progression rate of small pancreatic cystic lesions and identify characteristics associated with their progression.

METHODS: Patients with pancreatic cystic lesions with at least 1-year of follow-up were evaluated retrospectively. We excluded patients with cysts larger than 3 cm or with features that were a concern for malignancy. In total, 135 patients were evaluated. The interval progression of the cysts was examined. Characteristics were compared between patients with and without progression.

RESULTS: The pancreatic cysts ranged from 3 to 29 mm. The mean follow-up period was 4.5 ± 2.3 years and the mean progression rate was 1.0 ± 1.3 mm/year. Ninety patients showed interval progression and were divided into two groups; the minimal-change group (n = 41), who had cyst progression at less than 1 mm/year, and the progression group (n = 49), who had a progression rate of more than 1 mm/year. Compared with the cysts without progression, the lesions of the progression group were more frequently associated with tubular cyst, septation or a prominent pancreatic duct (P < 0.05). The odds ratio for progression was 5.318 for septation and 4.582 for tubular cysts.

CONCLUSION: Small pancreatic cysts progress slowly. Lesions with tubular shape, septa, or prominent pancreatic duct were more likely to progress, and required further diagnostic intervention or shorter surveillance interval.

Role of emerging molecular markers in pancreatic cyst fluid

Cystic lesions of the pancreas (CLPs) are increasingly diagnosed due to the growing utilization of cross-sectional imaging modalities. The differentiation between true cysts (epithelial tumors) and nonepithelial lesions (such as pseudocysts) relies on clinical and imaging characteristics, but more reliably obtained by endoscopic ultrasound (EUS) fine-needle aspiration. Due to their malignant potential, some of the true pancreatic cysts require further assessment and periodic follow-up. Therefore, it is important to establish a solid diagnosis at the time of detection of the various types of pancreatic cysts. Due to the limitations of cytology and biochemical markers in accurately classifying cyst pathology, the search for specific molecular markers associated with each type of cyst is ongoing. In this chapter, we will review some of the emerging molecular markers in pancreatic cystic fluid and their potential impact on endosonography and pancreatic cyst management.

Suboptimal accuracy of carcinoembryonic antigen in differentiation of mucinous and nonmucinous pancreatic cysts: results of a large multicenter study

BACKGROUND AND AIMS

The exact cutoff value at which pancreatic cyst fluid carcinoembryonic antigen (CEA) level distinguishes pancreatic mucinous cystic neoplasms (MCNs) from pancreatic nonmucinous cystic neoplasms (NMCNs) is unclear. The aim of this multicenter retrospective study was to evaluate the diagnostic accuracy of cyst fluid CEA levels in differentiating between MCNs and NMCNs.

METHODS

Consecutive patients who underwent EUS with FNA at 3 tertiary care centers were identified. Patients with histologic confirmation of cyst type based on surgical specimens served as the criterion standard for this analysis. Demographic characteristics, EUS morphology, FNA fluid, and cytology results were recorded. Multivariate logistic regression analysis to identify predictors of MCNs was performed. Receiver-operating characteristic (ROC) curves were generated for CEA levels.

RESULTS

A total of 226 patients underwent surgery (mean age, 61 years, 96% white patients, 39% female patients) of whom 88% underwent Whipple's procedure or distal pancreatectomy. Based on surgical histopathology, there were 150 MCNs and 76 NMCNs cases. The median CEA level was 165 ng/mL. The area under the ROC curve for CEA levels in differentiating between MCNs and NMCNs was 0.77 (95% confidence interval, 0.71-0.84, P < .01) with a cutoff of 105 ng/mL, demonstrating a sensitivity and specificity of 70% and 63%, respectively. The cutoff value of 192 ng/mL yielded a sensitivity of 61% and a specificity of 77% and would misdiagnose 39% of MCN cases.

CONCLUSIONS

Cyst fluid CEA levels have a clinically suboptimal accuracy level in differentiating MCNs from NMCNs. Future studies should focus on novel cyst fluid markers to improve risk stratification of pancreatic cystic neoplasms.

Endoscopic ultrasound-guided fine-needle aspiration for the diagnosis of pancreatic cysts by combined cytopathology and cystic content analysis

Recent advances in imaging technology have resulted in an increase in incidental discoveries of pancreatic cystic lesions. Pancreatic cysts comprise a wide variety of lesions and include non-neoplastic cysts and neoplastic cysts. Because some pancreatic cysts have more of a malignant potential than others, it is absolutely essential that an accurate diagnosis is rendered so that effective care can be given to each patient. In many centers, endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) has emerged as the modality of choice that enables one to distinguish between mucinous and non-mucinous lesion, diagnose malignancy and collect cyst fluid for further diagnostic studies, such as pancreatic enzyme levels, molecular analysis and other tumor biomarkers. The current review will focus on EUS-guided FNA and the cytological diagnosis for pancreatic cysts.

Early detection of pancreatic cancer

Pancreatic adenocarcinoma is a low-incident but highly mortal disease. It accounts for only 3% of estimated new cancer cases each year but is currently the fourth common cause of cancer mortality. By 2030, it is expected to be the 2(nd) leading cause of cancer death. There is a clear need to diagnose and classify pancreatic cancer at earlier stages in order to give patients the best chance at a definitive cure through surgery. Three precursor lesions that distinctly lead to pancreatic adenocarcinoma have been identified, and we have increasing understanding the non-genetic and genetic risk factors for the disease. With increased understanding about the risk factors, the familial patters, and associated accumulation of genetic mutations involved in pancreatic cancer, we know that there are mutations that occur early in the development of pancreatic cancer and that improved genetic risk-based strategies in screening for pancreatic cancer may be possible and successful at saving or prolonging lives. The remaining challenge is that current standards for diagnosing pancreatic cancer remain too invasive and too costly for widespread screening for pancreatic cancer. Furthermore, the promises of noninvasive methods of detection such as blood, saliva, and stool remain underdeveloped or lack robust testing. However, significant progress has been made, and we are drawing closer to a strategy for the screening and early detection of pancreatic cancer.