Rapid Growth Rates of Suspected Pancreatic Cyst Branch Duct Intraductal Papillary Mucinous Neoplasms Predict Malignancy

Endoscopic ultrasound is useful for the risk stratification of mucinous pancreatic cystic lesions: A long-term prospective study

OBJECTIVES

The aims of this prospective observational study were to test worrisome features on endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) as a stratification tool in patients with mucinous pancreatic cystic lesions (PCLs), and to assess these patients' long-term risk of adenocarcinoma and mortality.

METHODS

Patients with suspected PCLs on cross-sectional imaging who underwent EUS-FNA at Sahlgrenska University Hospital between February 2007 and February 2018 were consecutively enrolled. The main inclusion criterion was the final diagnosis of a mucinous PCL. The results from EUS-FNA were analyzed in the context of outcome gathered from medical records of follow-up until February 2021.

RESULTS

Of 334 patients undergoing EUS-FNA, 171 (51 %) had a final diagnosis of a mucinous PCL. 29/171 (17 %) patients were diagnosed with HGD or adenocarcinoma <6 months after EUS-FNA, with 28/29 (97 %) patients having at least one worrisome feature on EUS-FNA. A solid component in mucinous PCLs on EUS was independently associated with the presence of HGD or adenocarcinoma (OR 23.6, 95 % CI 6.1-91.6, p < .001). A total of 4/142 (3 %) patients developed adenocarcinoma during the follow-up period (median = 61.4 months). Overall, in 80/82 (98 %) of the patients without worrisome features on EUS-FNA, HGD or adenocarcinoma was not detected. Six of the 21 (29 %) patients with HGD or adenocarcinoma who underwent surgery as initial management died from pancreatic cancer during follow-up.

CONCLUSIONS

EUS-FNA is useful for the risk stratification of mucinous PCLs. The low incidence of adenocarcinoma over time after a negative EUS-FNA may allow for a less resource intensive surveillance strategy.

Long-term clinical outcomes of pancreatic cystic lesions in liver transplant patients

BACKGROUND

Pancreatic cystic lesions (PCL) are often incidentally diagnosed in transplant patients, although long-term impact in this chronically immunosuppressed population remains unclear. This study examines long-term malignant potential and outcomes of PCL in orthotopic liver transplant (OLT) patients.

METHODS

A retrospective study of 1110 patients who underwent OLT from 2011 to 2017 at a tertiary referral center was performed. Demographic, imaging, and outcomes data were examined.

RESULTS

86 OLT patients with 148 PCL were identified. Median follow up after PCL identification was 7.6 years (IQR 5.7-9.7). Most cysts decreased in size (45%) or remained stable (30.2%). Only 24% of PCL increased in size, with average growth of 2.7 mm/year. Based on American College of Gastroenterology (ACG) 2018 guidelines, 20 patients (23%) developed high-risk imaging characteristics. Of 16 endoscopic ultrasounds (EUS) performed, 1 patient was diagnosed with pancreatic adenocarcinoma. There were no pancreas-specific causes of death and no survival differences in OLT patients with and without PCL on multivariate analysis.

CONCLUSION

There is a low incidence of malignant transformation of PCL in OLT patients and no survival disadvantage at long-term follow up despite immunosuppression. PCL in OLT patients should be managed under similar guidelines as immunocompetent patients.

Risk factors for pancreatic cancer in individuals with intraductal papillary mucinous neoplasms and no high-risk stigmata during up to 5 years of surveillance: a prospective longitudinal cohort study

BACKGROUND

Cyst size, its growth rate, and diameter of the main pancreatic duct (MPD) are all associated with pancreatic carcinoma prevalence in intraductal papillary mucinous neoplasms (IPMNs).

OBJECTIVE

To examine the above factors in relation to future risk of incident pancreatic carcinoma in individuals with IPMNs harbouring no high-risk stigmata.

DESIGN

In a prospective longitudinal cohort, we analysed 2549 patients with IPMNs. A multivariable cause-specific Cox proportional hazards regression model was built to estimate HRs for incident pancreatic carcinoma.

RESULTS

IPMN size at baseline and its annual growth rate over 2 years of follow-up were associated with incident pancreatic carcinoma (ptrend<0.001). The multivariable cause-specific HR per 10 mm increase in IPMN size was 1.28 (95% CI 1.10 to 1.50). The annual growth rates of 1.5-2.4 mm/year and ≥2.5 mm/year over 2 years were associated with multivariable cause-specific HRs of 1.91 (95% CI 0.78 to 4.67) and 4.52 (95% CI 2.28 to 8.98), respectively (vs <1.5 mm/year). Neither IPMN size at 5 years nor its maximum growth rate during 5 years was associated with incident pancreatic carcinoma (ptrend>0.07). MPD diameter at 5 years was associated with incident pancreatic carcinoma (multivariable cause-specific HR per 2 mm increase, 2.12; 95% CI 1.72 to 2.63). A predictive nomogram was generated for calculating the risk of incident pancreatic carcinoma.

CONCLUSION

IPMN size and its growth rate predict future pancreatic carcinoma risk only during first 5 years of follow-up. MPD diameter at 5 years may identify patients who still harbour a high risk for pancreatic carcinoma.

Systematic review on surveillance for non-resected branch-duct intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND

The management of branch-duct type intraductal papillary mucinous neoplasms (BD-IPMN) varies in existing guidelines. This study investigated the optimal surveillance protocol and safe discontinuation of surveillance considering natural history in non-resected IPMN, by systematically reviewing the published literature.

METHODS

This review was guided by PRISMA. Research questions were framed in PICO format "CQ1-1: Is size criteria helpful to determine surveillance period? CQ1-2: How often should surveillance be carried out? CQ1-3: When should surveillance be discontinued? CQ1-4: Is nomogram predicting malignancy useful during surveillance?". PubMed was searched from January-April 2022.

RESULTS

The search generated 2373 citations. After screening, 83 articles were included. Among them, 33 studies were identified for CQ1-1, 19 for CQ1-2, 26 for CQ1-3 and 12 for CQ1-4. Cysts <1.5 or 2 cm without worrisome features (WF) were described as more indolent, and most studies advised an initial period of surveillance. The median growth rate of cysts <2 cm ranged from 0.23 to 0.6 mm/year. Patients with cysts <2 cm showing no morphological changes and no WF after 5-years of surveillance have minimal malignancy risk of 0-2%. Two nomograms created with over 1000 patients had AUCs of around 0.8 and appear to be feasible in a real-world practice.

CONCLUSIONS

For patients with suspected BD-IPMN <2 cm and no other WF, less frequent surveillance is recommended. Surveillance may be discontinued for cysts that remain stable during 5-year surveillance, with consideration of patient condition and life expectancy. With this updated surveillance strategy, patients with non-worrisome BD-IPMN should expect more streamlined management and decreased healthcare utilization.

International evidence-based Kyoto guidelines for the management of intraductal papillary mucinous neoplasm of the pancreas

This study group aimed to revise the 2017 international consensus guidelines for the management of intraductal papillary mucinous neoplasm (IPMN) of the pancreas, and mainly focused on five topics; the revision of high-risk stigmata (HRS) and worrisome features (WF), surveillance of non-resected IPMN, surveillance after resection of IPMN, revision of pathological aspects, and investigation of molecular markers in cyst fluid. A new development from the prior guidelines is that systematic reviews were performed for each one of these topics, and published separately to provide evidence-based recommendations. One of the highlights of these new "evidence-based guidelines" is to propose a new management algorithm, and one major revision is to include into the assessment of HRS and WF the imaging findings from endoscopic ultrasound (EUS) and the results of cytological analysis from EUS-guided fine needle aspiration technique, when this is performed. Another key element of the current guidelines is to clarify whether lifetime surveillance for small IPMNs is required, and recommends two options, "stop surveillance" or "continue surveillance for possible development of concomitant pancreatic ductal adenocarcinoma", for small unchanged BD-IPMN after 5 years surveillance. Several other points are also discussed, including identifying high-risk features for recurrence in patients who underwent resection of non-invasive IPMN with negative surgical margin, summaries of the recent observations in the pathology of IPMN. In addition, the emerging role of cyst fluid markers that can aid in distinguishing IPMN from other pancreatic cysts and identify those IPMNs that harbor high-grade dysplasia or invasive carcinoma is discussed.

Association of high-risk stigmata and worrisome features with advanced neoplasia in intraductal papillary mucinous neoplasms (IPMN): A systematic review

BACKGROUND

This systematic review aimed to assess the diagnostic accuracy of the International Consensus Fukuoka Guidelines (ICG2017) in identifying high-risk lesions of Intraductal Papillary Mucinous Neoplasms (IPMNs).

METHODS

The ICG2017 revision committee conducted a comprehensive literature review to establish evidence-based statements on IPMNs. The review focused on articles examining the diagnostic value of imaging features (e.g., cyst or main pancreatic duct diameter), clinical symptoms associated with IPMN, and serum biomarkers. Five clinical questions regarding high-risk stigmata (HRS) and worrisome features (WF) in the ICG2017 guidelines were addressed.

RESULTS

A total of 210 articles were reviewed. The findings revealed a significant association between the presence of mural nodules ≥5 mm in diameter or solid components with contrast enhancement and the diagnosis of high-grade dysplasia or invasive carcinoma. Contrast-enhanced diagnostic tools, such as CT, MRI, or EUS, demonstrated the highest prediction rate and were recommended. Positive cytology was identified as an HRS, while symptoms like acute pancreatitis and cyst diameter growth ≥2.5 mm per year were considered WFs. The use of nomograms and multiple diagnostic factors was recommended for optimal IPMN management.

CONCLUSIONS

This systematic review provides evidence supporting the improved diagnostic accuracy of ICG2017 in identifying high-risk lesions of IPMN. The multidisciplinary incorporation of HRS and WF based on imaging findings and clinical symptoms is crucial. These findings should inform the revision of ICG2017, enhancing the evaluation and management of IPMN patients. By implementing these recommendations, clinicians can make more informed decisions, leading to better diagnosis and treatment outcomes for high-risk IPMN cases.

Tracking incidentally discovered pancreatic cysts smaller than 30 mm: Natural course and predictors of malignancy

BACKGROUND AND AIMS

The aim of this study was to assess the natural course and predictors of malignancy in incidentally detected small pancreatic cysts (PCs).

METHOD

We retrospectively included patients with PCs smaller than 30 mm followed up with the same cross-sectional imaging modality at least 12 months apart between January 2010 and December 2019 in three academic institutions. Cyst growth, pancreatic cancer incidence, and associated factors associated with pancreatic cancer were analyzed.

RESULTS

A total of 1109 patients were followed up for a median of 34 months (range, 12‒118 months). Cyst growth and rapid cyst growth (≥ 5 mm/2 years) during follow-up were observed in 20.7% and 8.3%, respectively, both with higher rates for 15‒30 mm sized PCs. Eight patients were diagnosed with pancreatic cancer. The standardized incidence ratio for pancreatic cancer in small PCs was calculated as 5.2 [95% Confidence interval (CI): 1.3‒20.5].  The development of pancreatic cancer was associated with rapid growth [hazard ratio (HR): 8.1, 95% CI: 1.5‒43.4, p = 0.015] and newly developed worrisome features (HR: 11.7, 95% CI: 1.7‒79.6, p = 0.012) in competing risk analysis.

CONCLUSIONS

One-fifth of small incidentally detected PCs increased in size. Rapid growth and newly developed worrisome features were predictors of malignancy.

Intraductal Papillary Mucinous Neoplasms in High-Risk Individuals: Incidence, Growth Rate, and Malignancy Risk

BACKGROUND AND AIMS

In high-risk individuals (HRIs), we aimed to assess the cumulative incidence of intraductal papillary mucinous neoplasms (IPMNs) and compare IPMN growth, neoplastic progression rate, and the value of growth as predictor for neoplastic progression to these in sporadic IPMNs.

METHODS

We performed annual surveillance of Dutch HRIs, involving carriers of germline pathogenic variants (PVs) and PV-negative familial pancreatic cancer kindreds. HRIs with IPMNs were compared with Italian individuals without familial risk under surveillance for sporadic IPMNs.

RESULTS

A total of 457 HRIs were followed for 48 (range 2-172) months; the estimated cumulative IPMN incidence was 46% (95% confidence interval, 28%-64%). In comparison with 442 control individuals, IPMNs in HRIs were more likely to grow ≥2.5 mm/y (31% vs 7%; P < .001) and develop worrisome features (32% vs 19%; P = .010). PV carriers with IPMNs more often displayed neoplastic progression (n = 3 [11%] vs n = 6 [1%]; P = .011), while familial pancreatic cancer kindreds did not (n = 0 [0%]; P = 1.000). The malignancy risk in a PV carrier with an IPMN was 23% for growth rates ≥2.5 mm/y (n = 13), 30% for ≥5 mm/y (n = 10), and 60% for ≥10 mm/y (n = 5).

CONCLUSIONS

The cumulative incidence of IPMNs in HRIs is higher than previously reported in the general population. Compared with sporadic IPMNs, they have an increased growth rate. PV carriers with IPMNs are suggested to be at a higher malignancy risk. Intensive follow-up should be considered for PV carriers with an IPMN growing ≥2.5 mm/y, and surgical resection for those growing ≥5 mm/y.

Pancreatic Cyst Size Measurement on Magnetic Resonance Imaging Compared to Pathology

BACKGROUND

While multiple cyst features are evaluated for stratifying pancreatic intraductal papillary mucinous neoplasms (IPMN), cyst size is an important factor that can influence treatment strategies. When magnetic resonance imaging (MRI) is used to evaluate IPMNs, no universally accepted sequence provides optimal size measurements. T2-weighted coronal/axial have been suggested as primary measurement sequences; however, it remains unknown how well these and maximum all-sequence diameter measurements correlate with pathology size. This study aims to compare agreement and bias between IPMN long-axis measurements on seven commonly obtained MRI sequences with pathologic size measurements.

METHODS

This retrospective cohort included surgically resected IPMN cases with preoperative MRI exams. Long-axis diameter tumor measurements and the presence of worrisome features and/orhigh-risk stigmata were noted on all seven MRI sequences. MRI size and pathology agreement and MRI inter-observer agreement involved concordance correlation coefficient (CCC) and intraclass correlation coefficient (ICC), respectively. The presence of worrisome features and high-risk stigmata were compared to the tumor grade using kappa analysis. The Bland-Altman analysis assessed the systematic bias between MRI-size and pathology.

RESULTS

In 52 patients (age 68 ± 13 years, 22 males), MRI sequences produced mean long-axis tumor measurements from 2.45-2.65 cm. The maximum MRI lesion size had a strong agreement with pathology (CCC = 0.82 (95% CI: 0.71-0.89)). The maximum IPMN size was typically observed on the axial T1 arterial post-contrast and MRCP coronal series and overestimated size versus pathology with bias +0.34 cm. The radiologist interobserver agreement reached ICCs 0.74 to 0.91 on the MRI sequences.

CONCLUSION

The maximum MRI IPMN size strongly correlated with but tended to overestimate the length compared to the pathology, potentially related to formalin tissue shrinkage during tissue processing.

Pancreatic Cysts: Radiology

This article reviews the types of pancreatic cysts encountered in Radiologic practice. It summarizes the malignancy risk of each of the following: serous cystadenoma, mucinous cystic tumor, intraductal papillary mucinous neoplasm main duct and side branch, and some miscellaneous cysts such as neuroendocrine tumor and solid pseudopapillary epithelial neoplasm. Specific reporting recommendations are given. The choice between radiology follow-up versus endoscopic analysis is discussed.

Cystic pancreatic neoplasms in a tertiary gastroenterologic referral center: Evaluation of the diagnostic accuracy of endoscopic ultrasound, progression rate and malignancy rate in a large unicentric cohort

INTRODUCTION

Cystic pancreatic neoplasms (CPN) are frequently diagnosed due to better diagnostic techniques and patients becoming older. However, diagnostic accuracy of endoscopic ultrasound (EUS) and value of follow-up are still unclear.

MATERIAL AND METHODS

The aim of our retrospective study was to investigate the frequency of different cystic pancreatic neoplasms (intraductal papillary mucinous neoplasm [IPMN], serous and mucinous cystadenoma, solid pseudopapillary neoplasia), diagnostic accuracy, size progression, and rate of malignancy using EUS in a tertiary reference center in Germany. Between January 1, 2012 and December 31, 2018, 455 patients were diagnosed with cystic pancreatic lesions (798 EUS examinations).

RESULTS

Endoscopic ultrasound diagnosed 223 patients with cystic pancreatic neoplasms, including 138 (61.9%) patients with branch duct IPMN, 16 (7.2%) with main duct IPMN, and five (2.2%) with mixed-type IPMN. In the largest subgroup of branch duct IPMN, cysts were size progressive in 20 patients (38.5%). Fine needle aspiration (FNA) was performed in 21 patients, and confirmed the suspected diagnosis in 12/21 patients. 28 surgical resections were performed, in 7/28 patients (25%), high-grade dysplasia or cancer was diagnosed. Endoscopic ultrasound diagnosis of serous and mucinous cystic pancreatic neoplasms was correct in 68.4%.

CONCLUSIONS

Endoscopic ultrasound differential diagnosis of CPNs is challenging. Even in a tertiary expert center, differentiation of serous and mucinous cystic neoplasia is not guaranteed. Relevant size progression of CPN, however, is rare, as is the rate of malignancy. The data of this study suggest that morphologic criteria to assess pancreatic cysts alone are not sufficient to allow a clear diagnosis. Hence, for the improved assessment of pancreatic cysts, EUS should be combined with additional tests and techniques such as MRT/MRCP, contrast-enhanced EUS, and/or FNA/fine needle biopsy including fluid analysis. The combination and correlation of imaging studies with EUS findings is mandatory.

A model for predicting degree of malignancy in patients with intraductal papillary mucinous neoplasm

Background/Objectives

There is no predictive model available to address early stage malignant intraductal papillary mucinous neoplasm (IPMN) including high grade dysplasia (HGD) and pT1a (invasive component≤0.5 cm). The aim of this study was to establish an objective and sufficient model to predict the degree of malignancy in patients with IPMN, which can be easily applied in daily practice and adopted for any type of lesion.

Methods

A retrospective cohort study of 309 patients who underwent surgical resection for IPMN was performed. Members of the cohort were randomly allocated to the training or testing set. A detection tree model and random forest model were used for a 3-class classification to distinguish low grade dysplasia (LGD), HGD/pT1a IPMN, and invasive intraductal papillary mucinous cancer (I-IPMC) beyond pT1a.

Results

Of the 309 patients, 54 (17.4%) had early stage malignancy (19 HGD, 35 pT1a), 49 (15.9%) had I-IPMC beyond pT1a, and 206 (66.7%) had LGD IPMN. We proposed a 3-class classification model using a random forest algorithm, and the model had an accuracy of 99.5% with the training set, and displayed an accuracy of 96.0% with the testing set. We used SHAP for interpretation of the model and showed the top five factors (mural nodule size, main pancreatic duct diameter, CA19-9 levels, lesion edge and common bile duct dilation) were most likely to influence the 3-class classification results in terms of interpretation of the random forest model.

Conclusions

This predictive model will help assess an individual's risk for different stages of IPMN malignancy and may help identify patients with IPMN who require surgery.

Standardization of MRI Screening and Reporting in Individuals With Elevated Risk of Pancreatic Ductal Adenocarcinoma: Consensus Statement of the PRECEDE Consortium

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies, with a dismal survival rate. Screening the general population for early detection of PDAC is not recommended, but because early detection improves survival, high-risk individuals, defined as those meeting criteria based on a family history of PDAC and/or the presence of known pathogenic germline variant genes with PDAC risk, are recommended to undergo screening with MRI and/or endoscopic ultrasound at regular intervals. The Pancreatic Cancer Early Detection (PRECEDE) Consortium was formed in 2018 and is composed of gastroenterologists, geneticists, pancreatic surgeons, radiologists, statisticians, and researchers from 40 sites in North America, Europe, and Asia. The overarching goal of the PRECEDE Consortium is to facilitate earlier diagnosis of PDAC for high-risk individuals to increase survival of the disease. A standardized MRI protocol and reporting template are needed to enhance the quality of screening examinations, improve consistency of clinical management, and facilitate multiinstitutional research. We present a consensus statement to standardize MRI screening and reporting for individuals with elevated risk of pancreatic cancer.

Pancreatic Cystic Lesions on MRI: What Is The Likelihood of a Present or Future Diagnosis of Pancreatic Carcinoma?

BACKGROUND

Pancreatic cystic lesions (PCLs) are followed for years due to older and likely biased works demonstrating a strong association with pancreatic carcinoma; more recent data are needed clarifying this relationship.

PURPOSE

To determine the association between PCLs on MRI and a synchronous or future diagnosis of pancreatic carcinoma.

STUDY TYPE

Single-center retrospective cohort.

POPULATION

A total of 192 patients (111 female, 58%) with median age 66 years (range 26-87 years) with PCLs on abdominal MRI from 2011 to 2016.

FIELD STRENGTH/SEQUENCES

1.5 T and 3 T, including T₂ WI, T₁ WI, diffusion weighted imaging and contrast-enhanced T₁ WI.

ASSESSMENT

Each PCL was reviewed independently by 2 of 10 fellowship-trained abdominal radiologists. Fukuoka guideline worrisome features and high-risk stigmata were evaluated. Follow-up imaging and clinical notes were reviewed within a system that captures pancreatic carcinoma for the region, for a median follow-up of 67 months (interquartile range: 43-88 months).

STATISTICAL TESTS

Pancreatic carcinoma prevalence and incidence rate for future carcinoma with 95% confidence intervals (95% CI). Fisher exact test, logistic regression with odds ratios (OR) and the Wilcoxon rank-sum test were used to assess PCL morphologic features with the Kolmogorov-Smirnov test used to assess for normality. P < 0.05 defined statistical significance.

RESULTS

The prevalence of pancreatic carcinoma on initial MRI showing a PCL was 2.4% (95% CI: 0.9%, 5.2%). Thickened/enhancing cyst wall was associated with pancreatic carcinoma, OR 52 (95% CI: 4.5, 1203). Of 189 patients with a PCL but without pancreatic carcinoma at the time of initial MRI, one developed high-grade dysplasia and none developed invasive carcinoma for an incidence rate of 0.97 (95% CI: 0.02, 5.43) and 0 (95% CI: 0, 3.59) cases per 1000 person-years, respectively.

DATA CONCLUSION

A low percentage of patients with a PCL on MRI had a pancreatic carcinoma at the time of initial evaluation and none developed carcinoma over a median 67 months of follow-up.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: 5.

Computed tomography nomogram to predict a high-risk intraductal papillary mucinous neoplasm of the pancreas

OBJECTIVE

The intraductal papillary mucinous neoplasm (IPMN) of the pancreas is regarded as a precursor to pancreatic cancer; this study aimed to develop and validate a model based on CT characteristics for the non-invasive prediction of the high-risk IPMN of the pancreas.

MATERIALS AND METHODS

In this retrospective study, all patients underwent multidetector CT and surgical resection. A prediction model was developed based on a training set consisting of 136 patients with low-risk IPMN and 85 patients with high-risk IPMN between October 2012 and April 2019, and a multivariable logistic regression model was adopted to establish a nomogram. The nomogram performance was determined by its discrimination, calibration, and clinical usefulness. The model was validated in 80 consecutive patients between May 2019 and April 2020, of which 47 and 33 patients had low-risk and high-risk IPMNs, respectively.

RESULTS

The multivariable logistic regression model of CT characteristics included the enhancing mural nodule size, the main pancreatic duct (MPD) diameter, the abrupt change in caliber of the MPD with distal pancreatic atrophy, cyst size, thickened enhancing cyst wall, and the presence of lymphadenopathy. The individualized prediction nomogram using these predictors of the high-risk IPMN achieved an area under the curve (AUC) of 0.92 (95% CI 0.88-0.95) in the training set and 0.87 (95% CI 0.79-0.95) in the validation set. The decision curve analysis demonstrated that the nomogram was clinically useful.

CONCLUSION

The CT nomogram, which is a non-invasive predictive tool, can preoperatively predict the risk of malignant IPMN and help identify patients who require a surgical procedure.

Risk of the Watch-and-Wait Concept in Surgical Treatment of Intraductal Papillary Mucinous Neoplasm

Importance

The natural history of intraductal papillary mucinous neoplasms (IPMNs) remains uncertain. The inconsistencies among published guidelines preclude accurate decision-making. The outcomes and potential risks of a conservative watch-and-wait approach vs a surgical approach must be compared.

Objective

To provide an overview of the surgical management of IPMNs, focusing on the time of resection.

Design, Setting, and Participants

This cohort study was conducted in a single referral center; all patients with pathologically proven IPMN who received a pancreatic resection at the institution between October 2001 and December 2019 were analyzed. Preoperatively obtained images and the medical history were scrutinized for signs of progression and/or malignant features. The timeliness of resection was stratified into too early (adenoma and low-grade dysplasia), timely (intermediate-grade dysplasia and in situ carcinoma), and too late (invasive cancer). The perioperative characteristics and outcomes were compared between these groups.

Exposures

Timeliness of resection according to the final pathological findings.

Main Outcomes and Measures

The risk of malignant transformation at the final pathology.

Results

Of 1439 patients, 438 (30.4%) were assigned to the too early group, 504 (35.1%) to the timely group, and 497 (34.5%) to the too late group. Radiological criteria for malignant conditions were detected in 53 of 382 patients (13.9%), 149 of 432 patients (34.5%), and 341 of 385 patients (88.6%) in the too early, timely, and too late groups, respectively (P < .001). Patients in the too early group underwent more parenchyma-sparing resections (too early group, 123 of 438 [28.1%]; timely group, 40 of 504 [7.9%]; too late group, 5 of 497 [1.0%]; P < .001), while morbidity (too early group, 112 of 438 [25.6%]; timely group, 117 of 504 [23.2%]; too late group, 158 of 497 [31.8%]; P = .002) and mortality (too early group, 4 patients [0.9%]; timely, 4 [0.8%]; too late, 13 [2.6%]; P = .03) were highest in the too late group. Of the 497 patients in the too late group, 124 (24.9%) had a previous history of watch-and-wait care.

Conclusions and Relevance

Until the biology and progression patterns of IPMN are clarified and accurate guidelines established, a watch-and-wait policy should be applied with caution, especially in IPMN bearing a main-duct component. One-third of IPMNs reach the cancer stage before resection. At specialized referral centers, the risks of surgical morbidity and mortality are justifiable.

Pancreatic cyst characterization: maximum axial diameter does not measure up

BACKGROUND

Unidimensional size is commonly used to risk stratify pancreatic cysts (PCs) despite inconsistent performance. The current study aimed to determine if unidimensional size, demonstrated by maximum axial diameter (MAD), is an appropriate surrogate measurement for volume and surface area.

METHODS

Patients with cross-sectional imaging of PCs from 2012 to 2013 were identified. Cyst MAD, volume, and surface area were measured using quantitative imaging software. Non-pseudocystic PCs >1 cm were selected for inclusion to assess MAD correlation with volume and surface area. Cysts imaged twice >1 year apart were selected to evaluate volumetric growth rate.

RESULTS

In total, 195 cysts were included. Overall, MAD was strongly correlated with volume (r = 0.83) and surface area (r = 0.93). However, cysts 1-2 cm and 2-3 cm were weakly correlated with volume and surface area: r = 0.78, 0.57 and 0.82, 0.61, respectively. Cyst volumes and surface areas varied widely within unidimensional size groups with 51% and 40% of volumes and surface areas overlapping unidimensional size groups, respectively. Estimated changes in volume poorly predicted measured changes in volume with 42% of cysts having >100% absolute percent difference.

CONCLUSIONS

Pancreatic cyst volume and surface area may be useful adjunct measurements to risk stratify patients and surveil cyst changes and deserves further study.

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas: recommendations for Standardized Imaging and Reporting from the Society of Abdominal Radiology IPMN disease focused panel

There have been many publications detailing imaging features of malignant transformation of intraductal papillary mucinous neoplasms (IPMN), management and recommendations for imaging follow-up of diagnosed or presumed IPMN. However, there is no consensus on several practical aspects of imaging IPMN that could serve as a clinical guide for radiologists and enable future data mining for research. These aspects include how to measure IPMN, define reporting terminology, standardize reporting and unify guidelines for surveillance. The Society of Abdominal Radiology (SAR) created multiple Disease-Focused Panels (DFP) comprised multidisciplinary panel members who focus on a particular disease, with the goal to develop ways for radiologists to improve patient care, education, and research. DFP members met to identify the current controversies and limitations of imaging pancreatic IPMN. This paper aims to provide a practical review of the key imaging characteristics of IPMN for trainees and practicing radiologists, to guide uniformity of performance and interpretation of surveillance imaging studies, and to improve communication with clinicians by providing a lexicon and reporting template based on the experience of the SAR-DFP panel members.

Predictive Factors for Pancreatic Cancer and Its Early Detection Using Special Pancreatic Ultrasonography in High-Risk Individuals

Because pancreatic cancer has a dismal prognosis, a strategy for early diagnosis is required. This study aimed to identify predictive factors of neoplastic progression in patients at high risk for pancreatic cancer and examined the efficiency of surveillance using transabdominal special ultrasonography focusing on the pancreas (special pancreatic US). Patients with slight main pancreatic duct (MPD) dilatation (≥2.5 mm) and/or pancreatic cysts (≥5 mm) were enrolled in a prospective surveillance study with special pancreatic US in a Japanese cancer referral center. A total of 498 patients undergoing surveillance for ≥3 years were included. During the median follow-up of 5.9 years, neoplastic progression developed in 11 patients (2.2%), including 9 patients who underwent pancreatectomy. Eight patients (72.7%) were diagnosed with stage 0/I disease, with an overall survival duration of 8.8 years. Findings of both MPD dilatation and pancreatic cysts at initial surveillance, MPD growth (≥0.2 mm/year) and cyst growth (≥2 mm/year) during surveillance were identified as independent risk factors for neoplastic progression. In summary, surveillance with special pancreatic US for high-risk individuals contributed to earlier detection of neoplastic progression, leading to a favorable prognosis. During surveillance, attention should be paid to MPD growth as well as to cyst growth.

Long-term follow-up of branch-duct intraductal papillary mucinous neoplasms with No change in first 5 Years of diagnosis

BACKGROUND

Discontinuation of branch-duct intraductal papillary mucinous neoplasm (BD-IPMN) surveillance after 5 years of no change remains controversial. Long-term outcomes of BD-IPMN without significant changes in the first 5 years were evaluated.

METHODS

We performed a multi-center retrospective analysis of patients with BD-IPMN diagnosis from 2005 to 2011 (follow-up until 2017). Significant changes were defined as pancreatic cancer (PC), pancreatectomy, high-risk stigmata (HRS), worrisome features (WF) and worrisome EUS features (WEUS).

RESULTS

Of 982 patients who had no significant changes, 5 (0.5%), 7 (0.7%), 99 (10.1%), 4 (0.4%) patients developed PC, HRS, WF, WEUS, respectively, post-5 years. PC and HRS/WF/WEUS incidences at 12 years were 1.0% and 29.0%, respectively. Patients that developed HRS/WF/WEUS had larger cyst size in first 5 years compared to those that did not [16 (12-23) vs. 12 (9-17) mm, p = 0.0001], cyst size of >15 mm having higher cumulative incidence of HRS/WF/WEUS. PC mortality was 0.8%; all-cause mortality was 32%. Incidence of mortality due to PC was higher in HRS/WF/WEUS group, p < 0.0001. The mortality rate at 12 years for ACCI (age-adjusted Charlson Comorbidity Index) of ≤3, 4-6, and ≥7 were 3.5%, 19.9%, and 57.6% (p < 0.0001), respectively.

CONCLUSIONS

Incidence of PC in patients with BD-IPMN without significant changes in first 5 years of diagnosis remains low at 1.0%. Incidence of HRS/WF/WEUS was higher at 29.0%. PC-related mortality was higher in HRS/WF/WEUS group. These risks should be weighed against patients' overall mortality (utilizing scoring systems such as ACCI) when making surveillance decision of BD-IPMN beyond 5 years.

The European evidence-based guidelines on pancreatic cystic neoplasms (PCN) in clinical practice: The development of relative and absolute indications for surgery during prospective IPMN surveillance

INTRODUCTION

The European evidence-based guidelines on PCN recommend surveillance for IPMN patients who are fit for surgery but who have no indication for immediate surgery. Our aim was to demonstrate the feasibility of the new guidelines in clinical practice.

METHODS

This is a prospective cohort study of patients included in the IPMN register in Tampere University Hospital, Finland. IPMN was diagnosed from January 1, 2013 to December 31, 2018. Patients were analyzed for surveillance and indications for surgery according to the European guidelines on PCN.

RESULTS

Out of 128 patients in register 23 was decided to operate upfront and 105 patients were included in the surveillance programme. Invasive carcinoma was found in 4/23 of operated patients. Median follow-up time was 26 months (6-69). Median size of the cyst at the beginning and end of the surveillance was 16 mm (4-58 mm). During surveillance 0/105 (0.0%) patients had or developed an absolute indication for surgery. Relative indication for surgery was present in 8/105 (7.6%) patients in the beginning surveillance and 9/105 (8.6%) patients developed at least one relative indication for surgery during surveillance. From the surveillance cohort 2/105 patients were operated. Surveillance was abandoned in 15/105 (14.1%) patients all due to poor general condition or other medical conditions.

CONCLUSIONS

In clinical practice, surveillance of IPMN according to the European guidelines on PCN is feasible. Among our patients 16% were detected to have relative indications for surgery during the median 26 (range 3-135) months of surveillance. Nearly 15% became surgically unfit during surveillance period.

Risk of malignancy in small pancreatic cysts decreases over time

BACKGROUND

Pancreatic cysts <15 mm without worrisome features have practically no risk of malignancy at the time of diagnosis but this can change over time. Optimal duration of follow-up is a matter of debate. We evaluated predictors of malignancy and attempted to identify a time to safely discontinue surveillance.

METHODS

Bi-centric study utilizing prospectively collected databases of patients with pancreatic cysts measuring <15 mm and without worrisome features who underwent surveillance at the Massachusetts General Hospital (1988-2017) and at the University of Verona Hospital Trust (2000-2016). The risk of malignant transformation was assessed using the Kaplan-Meier method and parametric survival models, and predictors of malignancy were evaluated using Cox regression.

RESULTS

806 patients were identified. Median follow-up was 58 months (6-347). Over time, 58 (7.2%) cysts were resected and of those, 11 had high grade dysplasia (HGD) or invasive cancer. Three additional patients had unresectable cancer for a total rate of malignancy of 1.7%. Predictors of development of malignancy included an increase in size ≥2.5 mm/year (HR = 29.54, 95% CI: 9.39-92.91, P < 0.001) and the development of worrisome features (HR = 9.17, 95% CI: 2.99-28.10, P = 0.001). Comparison of parametric survival models suggested that the risk of malignancy decreased after three years of surveillance and was lower than 0.2% after five years.

CONCLUSIONS

Pancreatic cysts <15  mm at the time of diagnosis have a very low risk of malignant transformation. Our findings indicate the risk decreases over time. Size increase of ≥2.5 mm/year is the strongest predictor of malignancy.

Value of repeated cytology for intraductal papillary mucinous neoplasms of the pancreas with high risk potential of malignancy: Is it a promising method for monitoring a malignant transformation?

OBJECTIVES

The efficacy of and indications for cytological reexamination to detect malignant changes in branch duct type intraductal papillary mucinous neoplasms (BD-IPMNs) have not been studied in detail. We conducted a retrospective study to evaluate the efficacy and indications of cytological reexamination by using pancreatic juice (repeated cytology) for BD-IPMNs.

METHODS

Forty-five patients who underwent repeated cytology after a diagnosis of benignancy by using initial cytology were recruited for this study.

RESULTS

Thirty-eight patients, excluding 7 patients with lack of surveillance period after the final cytology, were classified into Malignancy (n = 13) and Benignancy groups (n = 25) on the bases of the findings from resected specimens or changes in BD-IPMNs after repeated cytology. The sensitivity and specificity to detect malignant changes in BD-IPMNs by using repeated cytology were 62% and 100%, respectively. For the 12 patients with mural nodules (MNs) ≥ 5 mm (67% of them were malignant), the sensitivity was 50%, whereas, for the 26 patients without MNs ≥ 5 mm (19% of them were malignant), it was 80%. In addition, malignant changes in BD-IPMNs after initial cytology occurred in 62% of the patients with changes in the MNs and 27% of the patients with an increase in the cyst size.

CONCLUSION

Repeated cytology can play a role in the determination for surgery even after a diagnosis of benignancy by using initial cytology, especially for BD-IPMNs without MNs ≥5 mm. In addition, changes in the MNs or cyst size may be appropriate indications for repeated cytology.

Magnetic resonance morphologic features predict progression of incidental pancreatic cystic lesions during follow-up

PURPOSE

We aimed to evaluate which morphologic features on magnetic resonance imaging (MRI) could predict the progression of pancreatic cystic lesions (PCLs) that are suitable for follow-up.

METHODS

A total of 2176 MRI findings of PCLs were retrospectively reviewed between January 2009 and December 2016. The study population was composed of 223 patients. Clinical data and morphologic features of PCLs were recorded. We divided the individuals into two sub-groups according to the final features on MRI. Univariable and multivariable regression analyses were performed to identify independent risk factors for progression of PCLs.

RESULTS

A total of 84 PCLs (37.7%) progressed during follow-up, while 139 PCLs (62.3%) were stable. Age (odds ratio [OR], 1.042; P = 0.017), number of lesions (OR, 0.491; P = 0.048), communication to pancreatic duct (PD) (OR, 2.425; P = 0.007) and presence of septa (OR, 6.105; P < 0.001) were significant independent factors for progression of PCLs. Among 84 lesions that progressed, 23 lesions (27.4%) increased to ≥ 30 mm in diameter or showed worrisome imaging features at the end of follow-up that needed clinical intervention. The initial size and communication to PD were independent factors for progression of PCLs necessitating clinical intervention (P < 0.001 and P = 0.011, respectively).

CONCLUSION

Age, number of the lesions, communication to PD and presence of septa were independent risk factors for the progression of PCLs, and the initial size and communication to PD could potentially predict PCLs needing clinical interventions.

Importance of each high-risk stigmata and worrisome features as a predictor of high-grade dysplasia in intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND

High-risk stigmata (HRS) and 'worrisome features' (WFs) are defined as predictive factors for malignancies of intraductal papillary mucinous neoplasms (IPMNs). We performed this study to determine the importance and odds ratio (OR) of each HRS and WFs as predictors for high-grade dysplasia (HGD).

METHODS

We analyzed 295 patients who underwent pancreatectomy for branch duct and mixed-type IPMN, and evaluated the association between HRS and WFs (as defined by the '2017 Fukuoka Consensus Guidelines') and HGD.

RESULTS

The proportions of patients with low-grade dysplasia (LGD), HGD, and invasive carcinoma were 47%, 28%, and 25%, respectively. Multivariate analysis comparing patients with LGD and HGD using all HRS and WFs revealed that an enhancing mural nodule ≥5 mm (OR: 4.1), pancreatitis (OR: 2.2), and thickened/enhancing cyst walls (OR: 2.2) were independent predictive factors for HGD. Based on the OR (the former factor is two points and the latter two factors are each one point), the incidence of HGD in patients with none (n = 43), one (n = 82), two (n = 25), three (n = 52), and four (n = 19) of these predictive factors were 9%, 26%, 52%, 62%, and 63%, respectively. Assuming a score of one or higher as a surgical indication, the sensitivity, specificity, positive predict value, and negative predict value of HGD were 95, 38, 44, and 91%.

CONCLUSIONS

Our derived scoring system using more important factors in HRS and WFs may be useful for predicting HGD and determining surgical indications of IPMN.

[Indications for the Surgical Management of Pancreatic Cystic Lesions]

A steady improvement in modern imaging as well as increasing age in society have led to an increasing number of cystic pancreatic tumours being detected. Pancreatic cysts are a clinically challenging entity because they span a broad biological spectrum and their differentiation is often difficult, especially in small tumours. Therefore, they require a differentiated indication for indication of surgery. To determine recommendations for the surgical indication in cystic tumours of the pancreas, a quality committee for pancreatic diseases of the German Society for General and Visceral Surgery performed a systematic literature search and created this review. Based on the current evidence, signs of malignancy and high-risk criteria (icterus due to cystic pancreatic duct obstruction in the bile duct, enhancing mural nodules ≥ 5 mm or solid components in the cyst or pancreatic duct ≥ 10 mm), as well as symptoms, are a surgical indication, independently of the cyst entity (except pseudocysts). If the entity of the pancreatic cyst is detectable by diagnostic imaging, all main duct IPMN and IPMN of the mixed type, all MCN > 4 cm and all SPN should be resected. SCN and branch-duct IPMN without worrisome features do not constitute an indication for surgery. The indication of operation in branch-duct IPMN with relative risk criteria and MCN < 4 cm is the subject of current discussions and should be individualised. By defining indication recommendations, the present work aims to improve the indication quality in cystic pancreatic tumours. However, the surgical indication should always be individualised, taking into account age, comorbidities and the patient's wishes.

Comparison of imaging modalities for measuring the diameter of intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMNs) are pre-malignant pancreatic cysts detected by imaging. Cyst size is one of many features evaluated on computed tomography (CT), magnetic resonance imaging (MRI), or endoscopic ultrasonography (EUS) to help guide IPMN management. Our objective was to determine which imaging modality best predicts pathological cyst size.

METHODS

We analyzed records for 57 IPMN cases surgically treated at Moffitt Cancer Center from 2008 to 2016 for whom pre-operative CT, MRI, and EUS IPMN cyst size and post-operative pathological cyst size values were available. Long axis cyst diameter measurements were compared to each other and corresponding pathological cyst measurements using within-subjects ANOVA, Bland-Altman analysis, and linear regression. Consensus measurements were also performed on CT and MRI images.

RESULTS

Cyst size measured via CT and MRI overestimated pathological size by 0.33 cm and 0.27 cm, respectively, whereas EUS underestimated pathological size by 0.05 cm and had the narrowest 95% limit of agreement (LOA). Among pathologically-confirmed cysts <3 cm, MRI overestimated pathological size by 0.30 cm (P = 0.049) and had the widest LOA, followed by EUS and CT. Among cysts ≥3 cm, EUS underestimated pathological size by 0.35 cm (P = 0.059) and MRI and CT overestimated pathological size by 0.23 cm and 0.51 cm, respectively.

CONCLUSIONS

In this small retrospective study, EUS cyst size measurements correlated best with pathologic specimens compared to CT and MRI, especially for cysts < 3 cm. Larger prospective studies are needed to determine which imaging modalities are best to risk-stratify IPMNs and guide surgical versus. Non-surgical management.

Determining Malignant Potential of Intraductal Papillary Mucinous Neoplasm of the Pancreas: CT versus MRI by Using Revised 2017 International Consensus Guidelines

Background Several changes have been made to the revised 2017 international consensus guidelines for management of pancreatic intraductal papillary mucinous neoplasms (IPMNs). However, the diagnostic performance is yet to be verified. Purpose To evaluate the revised guidelines for predicting malignant potential of pancreatic IPMNs and to compare diagnostic performance and intermodality agreement between contrast material-enhanced CT and MRI. Materials and Methods In this retrospective study, two radiologists analyzed the preoperative contrast-enhanced CT and MRI of patients with surgically resected pancreatic IPMNs from January 2007 to December 2017. The diagnostic performance of CT and MRI were analyzed by using receiver operating curve analysis. Intermodality agreement was assessed by using weighted κ and intraclass correlation coefficient values. Results A total of 86 patients (mean age, 67.6 years ± 8.9 [standard deviation]; 47 men and 39 women) with pancreatic IPMNs (benign, 58; malignant, 28) were included. At both CT and MRI, enhancing mural nodule (P < .001), abrupt main pancreatic duct caliber change (P < .001), lymphadenopathy (P = .006), larger main pancreatic duct size (P = .003), and faster cyst growth rate (P = .04) were more common in malignant than benign IPMNs. Irrespective of the modality, enhancing mural nodule of 5 mm or greater had the highest odds ratio (25 at CT vs 29 at MRI). The diagnostic performance of CT (area under the receiver operating characteristic curve, 0.83 [95% confidence interval: 0.75, 0.92]) and MRI (area under the receiver operating characteristic curve, 0.86 [95% confidence interval: 0.77, 0.95]) for predicting malignant IPMNs were comparable (P = .43), with good intermodality agreement (κ = 0.70). Conclusion Among revised features, enhancing mural nodule of 5 mm or greater had the strongest association with malignant intraductal papillary mucinous neoplasm (IPMN), and diagnostic performance for prediction of malignant IPMNs were comparable between contrast-enhanced CT and MRI with good intermodality agreement. © RSNA, 2019 Online supplemental material is available for this article.

Follow-up of Incidentally Detected Pancreatic Cystic Neoplasms: Do Baseline MRI and CT Features Predict Cyst Growth?

Background Incidental detection of pancreatic cystic neoplasm (PCN) has increased. Since a small percentage of PCNs possess malignant potential, management is challenging. The recently revised American College of Radiology (ACR) recommendations define PCN measurement and growth for different categories based on baseline cyst size. However, no data are available regarding PCN growth rate under the ACR-defined size categories. Purpose To assess growth of incidentally detected PCNs on long-term imaging follow-up using revised ACR recommendations and to evaluate the association between baseline imaging features and growth. Materials and Methods This retrospective study included PCNs with baseline imaging performed between January 2002 and May 2017, with two or more cross-sectional imaging studies performed at least 12 months apart. PCN assessment was based on ACR 2017 recommendations. Cyst features, including location, septations, and mural nodules and multiplicity, were noted. Time to cyst progression (growth by ACR criteria) was examined by using baseline PCN size, among other factors. Results A total of 646 cysts in 390 patients were followed up for a median of 50 months (range, 12-186 months). A total of 184 (28.5%) cysts increased in size, 52 (8.1%) decreased in size, and 410 (63.4%) remained stable. For groups in which baseline PCN size was smaller than 5 mm, 5-14 mm, 15-25 mm, and larger than 25 mm, growth was noted in seven (13.2%), 106 (28.9%), 49 (32.2%), and 22 (29.7%) cysts, respectively. ACR baseline size categories (subhazard ratio: 2.8 [5-14-mm PCN group], 3.4 [15-25-mm PCN group], and 2.7 [>25 mm group], as compared with the <5 mm PCN group; P < .05 for each) demonstrated association with growth. Presence of mural nodules, septations, or lesion multiplicity failed to demonstrate association with growth. Among PCNs smaller than 5 mm at baseline, 100% of PCNs at 3-year follow-up and 94.2% of PCNs at 5-year follow-up were likely to remain stable. Conclusion American College of Radiology baseline size category of 15-25-mm pancreatic cystic neoplasms (PCNs) demonstrated the highest (3.1 times) likelihood of growth, as compared with the category of PCNs smaller than 5 mm. PCNs smaller than 5 mm at baseline did not demonstrate growth at 3-year imaging follow-up. © RSNA, 2019 Online supplemental material is available for this article.

Clinical validation of the 2017 international consensus guidelines on intraductal papillary mucinous neoplasm of the pancreas

Purpose

The 2017 international consensus guidelines (ICG) for intraductal papillary mucinous neoplasm (IPMN) of the pancreas were recently released. Important changes included the addition of worrisome features such as elevated serum CA 19-9 and rapid cyst growth (>5 mm over 2 years). We aimed to clinically validate the 2017 ICG and compare the diagnostic performance between the 2017 and 2012 ICG.

Methods

This was a retrospective cohort study. During January 2000–January 2017, patients who underwent complete surgical resection and had pathologic confirmation of branch-duct or mixed-type IPMN were included. To evaluate diagnostic performance, the areas under the receiver operating curves (AUCs) were evaluated.

Results

A total of 448 patients were included. The presence of mural nodule (hazard ratio [HR], 9.12; 95% confidence interval [CI], 4.60–18.09; P = 0.001), main pancreatic duct dilatation (>5 mm) (HR, 5.32; 95% CI, 2.67–10.60; P = 0.001), thickened cystic wall (HR, 3.40; 95% CI, 1.51–7.63; P = 0.003), and elevated CA 19-9 level (>37 unit/mL) (HR, 5.25; 95% CI, 2.05–13.42; P = 0.001) were significantly associated with malignant IPMN. Malignant lesions showed a cyst growth rate >5 mm over 2 years more frequently than benign lesions (60.9% vs. 29.7%, P = 0.012). The AUC was higher for the 2017 ICG than the 2012 ICG (0.784 vs. 0.746).

Conclusion

The new 2017 ICG for IPMN is clinically valid, with a superior diagnostic performance to the 2012 ICG. The inclusion of elevated serum CA 19-9 level and cyst growth rate to the 2017 ICG is appropriate.

Clinical criteria for integrated molecular pathology in intraductal papillary mucinous neoplasm: less is more

BACKGROUND

For pancreatic cysts with negative cytology, Integrated Molecular Pathology (IMP) is a malignancy risk score integrating clinical criteria with pancreatic cyst fluid DNA profiling. Aside from main pancreatic duct (MPD) diameter, integrated clinical criteria are not International Consensus Guidelines High-Risk Stigmata. We predicted exclusion of clinical criteria except MPD diameter could simplify the IMP and better distinguish invasive/malignant disease.

METHODS

Records of >1100 patients with IPMN were reviewed retrospectively. Sensitivity, specificity, and accuracy of conventional IMP for invasive/malignant disease was compared to DNA profile including only MPD ≥10mm (IMP-10.) Invasive outcomes were invasive-IPMN/adenocarcinoma on surgical pathology, pathologic or radiographic evidence of invasive/metastatic disease during surveillance. Malignant outcomes included high grade dysplastic IPMN (HGD-IPMN).

RESULTS

225 patients who met study criteria underwent 283 IMP evaluations: 98 followed by surgery, 185 followed by ≥ 23 months surveillance. IMP-10 had greater specificity (90.1% vs. 73.7%) and accuracy (89.8% vs. 74.2%) for invasive disease compared to IMP in surgery + surveillance patients, but lower sensitivity (77.8% vs. 88.9%). Trends were similar in surgery patients alone and malignant outcome analyses.

CONCLUSION

IMP-10 excludes less-reliable clinical factors resulting in greater accuracy in predicting invasive/malignant disease and fewer patients with benign disease being recommended for surgery.

Impact of endoscopic ultrasound on diagnosis and management of presumed mucinous neoplasms when done for pancreatic cyst morphology change on non-invasive surveillance imaging

Background and study aims  Guidelines for management of presumed neoplastic pancreatic cysts have encouraged noninvasive imaging for low-risk surveillance, while reserving endoscopic ultrasound for worrisome features including morphologic change. We aim to study the impact of endoscopic ultrasound on diagnosis and management compared with non-invasive imaging. Patients and methods  A single-institution pancreatic cyst database was retrospectively queried for patients who underwent endoscopic ultrasound for the indication of change in cyst morphology. Diagnoses were classified as presumed mucinous neoplasm with or without worrisome features or high-risk stigmata and non-mucinous lesions. Management decisions were defined a priori as surgical evaluation for patients with high-risk stigmata, positive cytology or mural nodule, or continued surveillance for all others. Results  Between January 2013 and October 2016, 709 pancreas cyst endoscopic ultrasounds were performed of which 89 were for cyst morphology change seen on noninvasive imaging including 10 presumed pseudocysts, nine presumed serous cystadenomas, and 70 presumed mucinous cystic neoplasms. Cyst morphologic changes included increase in caliber of the main pancreatic duct (7 cases), increase in cyst size (68 cases), cyst ≥ 30 mm (10 cases), and presence of a solid nodule (1 case). Median cyst size increase was 5 mm with interquartile range of 4 mm over 2.1 ± 1.9 years. Endoscopic ultrasound done for morphologic change resulted in a change in diagnosis and management in 16 % and 13 % of cases, respectively. Conclusion  Endoscopic ultrasound has a modest but clinically significant role in impacting diagnosis and management for presumed mucinous cystic neoplasms when performed for the indication of cyst morphology change.

Growth rate of serous pancreatic neoplasms in vivo: a retrospective, observational study

BACKGROUND

Determining the growth rate of pancreatic cystic lesions on follow-up imaging is important in managing patients with these lesions. However, the growth rates of serous pancreatic neoplasms (SPNs) have been reported to vary among studies.

PURPOSE

To determine the in vivo growth rate of SPNs.

MATERIAL AND METHODS

This retrospective, single-institutional study included patients diagnosed with SPNs during 2006-2015. The diagnosis of SPNs was based on the results of surgery, endoscopic ultrasonography (EUS)-guided fine needle aspiration (FNA) or core needle biopsy (CNB), or typical radiologic features of SPN. A linear mixed-effects model was utilized to determine whether the diagnostic intervention was associated with tumor growth rate in all patients. The in vivo growth rate of SPNs was estimated from patients without or before diagnostic intervention. SPN growth rates were compared before and after diagnostic intervention.

RESULTS

SPN growth rates in the overall patient cohort (n = 304) differed significantly between patients who did and did not undergo diagnostic interventions. The in vivo SPN growth rate in 204 patients without or before diagnostic intervention was 1.9 mm/year (95% confidence interval [CI] = 1.6-2.2). In the 130 patients who underwent diagnostic intervention, the SPN growth rate was significantly greater before than after diagnostic intervention (1.8 vs. 0.2 mm/year).

CONCLUSIONS

In the absence of diagnostic intervention, the in vivo growth rate of SPNs was 1.9 mm/year (95% CI = 1.6-2.2). EUS-guided FNA or CNB may affect the growth rate of SPNs.

Diagnosis and Surveillance of Incidental Pancreatic Cystic Lesions: 2017 Consensus Recommendations of the Korean Society of Abdominal Radiology

The occurrence of incidentally detected pancreatic cystic lesions (PCLs) is continuously increasing. Radiologic examinations including computed tomography and magnetic resonance imaging with magnetic resonance cholangiopancreatography have been widely used as the main diagnostic and surveillance methods for patients with incidental PCLs. Although most incidentally detected PCLs are considered benign, they have the potential to become malignant. Currently, we have several guidelines for the management of incidental PCLs. However, there is still debate over proper management, in terms of accurate diagnosis, optimal follow-up interval, and imaging tools. Because imaging studies play a crucial role in the management of incidental PCLs, the 2017 consensus recommendations of the Korean Society of Abdominal Radiology for the diagnosis and surveillance of incidental PCLs approved 11 out of 16 recommendations. Although several challenges remain in terms of optimization and standardization, these consensus recommendations might serve as useful tools to provide a more standardized approach and to optimize care of patients with incidental PCLs.

Current Approaches to Pancreatic Cancer Screening

Pancreatic ductal adenocarcinoma (PDAC) has a 5-year survival rate of only 8% and is estimated to be the second leading cause of cancer-related deaths by 2021. Prior convention held that screening for PDAC would not be beneficial; however, a deeper understanding of the carcinogenesis pathway supports a potential window of opportunity among the target population. Screening for PDAC is not a standard practice among the general population because of its low incidence. However, screening may be beneficial for individuals with familial history, chronic diseases with genetic predispositions, or inherited cancer syndromes, such as hereditary breast ovarian cancer syndrome, hereditary pancreatitis, Peutz-Jeghers syndrome, familial atypical multiple mole melanoma, Lynch syndrome (hereditary nonpolyposis colorectal cancer), ataxia telangiectasia, and Li-Fraumeni syndrome, all of which have been associated with an increased risk of developing PDAC. The screening strategies among these high-risk individuals are targeted to identify precursor lesions and PDAC at an early resectable stage. This review describes the risk factors for pancreatic cancer, especially the genetic risk factors in high-risk individuals and current screening strategies available for PDAC.

Rapid growth speed of cysts can predict malignant intraductal mucinous papillary neoplasms

BACKGROUND

Branch duct intraductal papillary mucinous neoplasm (BD-IPMN) has the potential for malignant transformation. Current risk factors used to predict malignant transformation, such as mural nodules and cyst size > 30 mm, are insufficient. Therefore, we aimed to investigate the predictive significance of cyst growth speed.

MATERIALS AND METHODS

Between 2006 and 2017, 102 patients underwent pancreatectomy for IPMN. Of these, 50 patients with pathologically diagnosed BD-IPMN were selected for cyst growth analysis. Cyst growth speed, total cyst growth, and cyst growth rate were calculated retrospectively using the maximum diameter of the cyst at the first diagnosis and images taken preoperatively.

RESULTS

Of the 50 BD-IPMN cases, 33 were diagnosed as benign (low to intermediate dysplasia) and 17 were malignant (10 high-grade dysplasias and seven invasive carcinomas). While no significant differences were observed in the presence of enhancing mural nodules or cyst size, malignant IPMN grew at a significantly faster speed (5.7 versus 1.6 mm/y; P < 0.001), greater amount of cyst diameter (10.1 versus 3.1 mm; P = 0.015), and greater percentage of cyst diameter (28.5% versus 9.5%; P = 0.006) than those of benign IPMN. Receiver operator characteristic curve analysis indicated that cyst growth speed had the greatest predictive performance among these three factors. Cyst growth speed > 3.5 mm/y was demonstrated to predict malignant IPMN with a sensitivity of 88% and specificity of 91%.

CONCLUSIONS

Cyst growth speed > 3.5 mm/y may be a good predictor for malignant IPMN. It can improve the diagnostic accuracy and optimize surgery for BD-IPMN.

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.

Current Guideline Controversies in the Management of Pancreatic Cystic Neoplasms

Pancreatic cystic lesions are a common clinical entity. The majority are neoplastic and have the potential for malignant transformation. To assist with patient management, a number of clinical guidelines have been developed over the past decade. However, controversies exist in regards to the various guidelines and treatment strategies they offer. This article will review the various clinical guidelines for management of pancreatic cysts, describe the limitations of these guidelines, and present future directions for improvement in clinical decision making for patients diagnosed with a pancreatic cystic neoplasm.

Management of Intraductal Papillary Mucinous Neoplasms: Controversies in Guidelines and Future Perspectives

Purpose of review

Management of intraductal papillary mucinous neoplasm (IPMN) is currently based on consensus, in the absence of evidence-based guidelines. In recent years, several consensus guidelines have been published, with distinct management strategies. In this review, we will discuss these discrepancies, in order to guide treating physicians in clinical management.

Recent findings

The detection rate of pancreatic cysts has increased substantially with the expanded use of high-quality imaging techniques to up to 45%. Of these cysts, 24–82% are IPMNs, which harbour a malignant potential. Timely detection of high-risk lesions is therefore of great importance. Surgical management is based on the presence of clinical and morphological high-risk features, yet the majority of resected specimens appear to be low risk.

Summary

International collaboration and incentive large-scale prospective registries of individuals undergoing cyst surveillance are needed to accumulate unbiased data and develop evidence-based guidelines. Additionally, development of non-invasive, accurate diagnostic tools (e.g. biomarkers) is needed to differentiate between neoplastic and non-neoplastic pancreatic cysts and detect malignant transformation at an early stage (i.e. high-grade dysplasia).

Risk of Neoplastic Progression in Individuals at High Risk for Pancreatic Cancer Undergoing Long-term Surveillance

BACKGROUND & AIMS

Screening of individuals who have a high risk of pancreatic ductal adenocarcinoma (PDAC), because of genetic factors, frequently leads to identification of pancreatic lesions. We investigated the incidence of PDAC and risk factors for neoplastic progression in individuals at high risk for PDAC enrolled in a long-term screening study.

METHODS

We analyzed data from 354 individuals at high risk for PDAC (based on genetic factors of family history), enrolled in Cancer of the Pancreas Screening cohort studies at tertiary care academic centers from 1998 through 2014 (median follow-up time, 5.6 years). All subjects were evaluated at study entry (baseline) by endoscopic ultrasonography and underwent surveillance with endoscopic ultrasonography, magnetic resonance imaging, and/or computed tomography. The primary endpoint was the cumulative incidence of PDAC, pancreatic intraepithelial neoplasia grade 3, or intraductal papillary mucinous neoplasm with high-grade dysplasia (HGD) after baseline. We performed multivariate Cox regression and Kaplan-Meier analyses.

RESULTS

During the follow-up period, pancreatic lesions with worrisome features (solid mass, multiple cysts, cyst size > 3 cm, thickened/enhancing walls, mural nodule, dilated main pancreatic duct > 5 mm, or abrupt change in duct caliber) or rapid cyst growth (>4 mm/year) were detected in 68 patients (19%). Overall, 24 of 354 patients (7%) had neoplastic progression (14 PDACs and 10 HGDs) over a 16-year period; the rate of progression was 1.6%/year, and 93% had detectable lesions with worrisome features before diagnosis of the PDAC or HGD. Nine of the 10 PDACs detected during routine surveillance were resectable; a significantly higher proportion of patients with resectable PDACs survived 3 years (85%) compared with the 4 subjects with symptomatic, unresectable PDACs (25%), which developed outside surveillance (log rank P < .0001). Neoplastic progression occurred at a median age of 67 years; the median time from baseline screening until PDAC diagnosis was 4.8 years (interquartile range, 1.6-6.9 years).

CONCLUSIONS

In a long-term (16-year) follow-up study of individuals at high-risk for PDAC, we found most PDACs detected during surveillance (9/10) to be resectable, and 85% of these patients survived for 3 years. We identified radiologic features associated with neoplastic progression.

Higher Growth Rate of Branch Duct Intraductal Papillary Mucinous Neoplasms Associates With Worrisome Features

BACKGROUND & AIMS

For patients with branch duct intraductal papillary mucinous neoplasms (BD-IPMNs, cysts), it is a challenge to identify those at high risk for malignant lesions. We sought to identify factors associated with development of pancreatic cancer, focusing on neoplasm growth rate.

METHODS

We performed a retrospective study of 189 patients with BD-IPMNs who underwent at least 2 contrast-enhanced cross-sectional imaging studies, 1 year or more apart, at a tertiary referral center from January 2003 through 2013. Patients with cysts that had Fukuoka worrisome or high-risk features were excluded. Two radiologists reviewed all images. Cyst size was recorded at the initial and final imaging studies and growth rate was calculated. We collected patient demographic data, cyst characteristics, and clinical outcomes; univariate logistic regression models were used to determine the odds of developing worrisome features. The primary outcomes were to determine growth rate of low-risk BD-IPMNs and to assess whether cyst growth rate correlates high-risk features of IPMNs.

RESULTS

Based on image analyses, cysts were initially a median 11 mm (range, 3-31 mm) and their final size was 12.5 mm (range, 3-42 mm). After a median follow-up time of 56 months (range, 12-163 months), the median cyst growth rate was 0.29 mm/year. Twelve patients developed worrisome features, no patients developed high-risk features, 4 patients had surgical resection, and no cancers developed. The rate of BD-IPMN growth was greater in patients who developed worrisome features than those who did not (2.84 mm/year vs 0.23 mm/year; P < .001). The odds of developing worrisome features increased for each unit (mm) increase in cyst size (odds ratio, 1.149; 95% CI, 1.035-1.276, P = .009).

CONCLUSION

In a retrospective analysis of images from patients with BD-IPMN, we found low-risk BD-IPMNs to grow at an extremely low rate (less than 0.3 mm/year). BD-IPMNs in only about 6% of patients developed worrisome features, and none developed high-risk features or invasive cancers. BD-IPMNs that developed worrisome features were associated with a significantly higher rate of growth than lesions with low-risk features. Low risk BD-IPMNs that grow more than 2.5 mm/year might require surveillance.

Does cyst growth predict malignancy in branch duct intraductal papillary mucinous neoplasms? Results of a large multicenter experience

BACKGROUND

Cyst growth of BD-IPMNs on follow-up imaging remains a concerning sign.

AIMS

To describe cyst size changes over time in BD-IPMNs, and determine whether cyst growth rate is associated with increased risk of malignancy.

METHODS

This is a retrospective study performed at two high volume tertiary centers. Mean cyst size at baseline (MCSB) and mean growth rate percentage (MGRP) were calculated. Rapid cyst growth was defined as MGRP ≥30%/year. Patient and cyst related characteristics were studied.

RESULTS

160 patients were followed for a median of 27.4 (12-114.5) months. MCSB was 15.1 ± 8.0 mm. During follow-up, 73 (45.6%) showed any cyst size increase, of which 15 cysts (9.4%) exhibited MGRP ≥30%/year. Rapid cyst growth was not associated with patient or cyst characteristics. Cyst fluid molecular analysis from 101 cysts showed KRAS mutation in 26. Compared to KRAS-negative cysts, neither MCSB (16.0 mm vs. 17.7 mm; p = 0.3) nor MGRP (3.9%/year vs. 5.8%/year; p = 0.7) was significantly different. Eighteen patients underwent surgery; 15 (83%) had LGD, and 3 had advanced neoplasia. Two cysts with LGD and one cyst with advanced neoplasia had MGRP ≥30%/year.

CONCLUSION

Increase in BD-IPMNs size was not associated with the known high risk patient or cyst-related characteristics. Rapid growth of BD-IPMNs was not associated with advanced neoplasia on surgical pathology.

The European Study Group on Cystic Tumours of the Pancreas. European evidence-based guidelines on pancreatic cystic neoplasms

Evidence-based guidelines on the management of pancreatic cystic neoplasms (PCN) are lacking. This guideline is a joint initiative of the European Study Group on Cystic Tumours of the Pancreas, United European Gastroenterology, European Pancreatic Club, European-African Hepato-Pancreato-Biliary Association, European Digestive Surgery, and the European Society of Gastrointestinal Endoscopy. It replaces the 2013 European consensus statement guidelines on PCN. European and non-European experts performed systematic reviews and used GRADE methodology to answer relevant clinical questions on nine topics (biomarkers, radiology, endoscopy, intraductal papillary mucinous neoplasm (IPMN), mucinous cystic neoplasm (MCN), serous cystic neoplasm, rare cysts, (neo)adjuvant treatment, and pathology). Recommendations include conservative management, relative and absolute indications for surgery. A conservative approach is recommended for asymptomatic MCN and IPMN measuring <40 mm without an enhancing nodule. Relative indications for surgery in IPMN include a main pancreatic duct (MPD) diameter between 5 and 9.9 mm or a cyst diameter ≥40 mm. Absolute indications for surgery in IPMN, due to the high-risk of malignant transformation, include jaundice, an enhancing mural nodule >5 mm, and MPD diameter >10 mm. Lifelong follow-up of IPMN is recommended in patients who are fit for surgery. The European evidence-based guidelines on PCN aim to improve the diagnosis and management of PCN.

ACG Clinical Guideline: Diagnosis and Management of Pancreatic Cysts

Pancreatic cysts are very common with the majority incidentally identified. There are several types of pancreatic cysts; some types can contain cancer or have malignant potential, whereas others are benign. However, even the types of cysts with malignant potential rarely progress to cancer. At the present time, the only viable treatment for pancreatic cysts is surgical excision, which is associated with a high morbidity and occasional mortality. The small risk of malignant transformation, the high risks of surgical treatment, and the lack of high-quality prospective studies have led to contradictory recommendations for their immediate management and for their surveillance. This guideline will provide a practical approach to pancreatic cyst management and recommendations for cyst surveillance for the general gastroenterologist.

Predictors of Progression Among Low-Risk Intraductal Papillary Mucinous Neoplasms in a Multicenter Surveillance Cohort

OBJECTIVES

Our aim was to identify baseline characteristics associated with disease progression and malignant transformation in low-risk suspected intraductal papillary mucinous neoplasms (IPMNs).

METHODS

This is a retrospective cohort study of prospectively maintained databases of pancreatic cysts at 3 international, academic institutions. Five hundred fifty-nine adult patients with clinically suspected asymptomatic IPMN evaluated by radiologic studies or endoscopic ultrasound between 2003 and 2013 without worrisome features and under surveillance for 12 months or longer were included. We evaluated the relationship of baseline demographics and cyst features to disease progression (size increase, development of worrisome features, or high-grade dysplasia/cancer).

RESULTS

After a median of 44 months follow-up, 269 (48%) patients experienced cyst size increase, 68 (12%) developed worrisome features, and 11 (2%) developed high-grade dysplasia/cancer. In multivariable Cox-regression analysis, no baseline characteristics were associated with size increase. An initial cyst size of 2 cm or greater, multifocality, history of prostate cancer, and smoking were the strongest predictors of development of new worrisome features. Univariable analysis found male sex, diabetes, and recent weight loss associated with development of high-grade dysplasia/cancer.

CONCLUSIONS

Our study demonstrates that low-risk suspected IPMNs carry a small but clinically relevant risk of disease progression and provides data on baseline characteristics that may help in risk stratification.

Meta-analysis of mortality in patients with high-risk intraductal papillary mucinous neoplasms under observation

BACKGROUND

Although consensus guidelines suggest that patients with high-risk intraductal papillary mucinous neoplasms (IPMNs) should have surgery, a non-operative strategy is often selected in patients who are poor surgical candidates. The aim was to determine the risk of disease-related death from IPMN in patients with worrisome features or high-risk stigmata who were kept under observation.

METHODS

A PubMed literature search was undertaken of articles published from August 1992 to June 2016 (updated October 2017). The methodology was developed from PRISMA and MOOSE checklists. Incidence proportions and rates of overall and IPMN-related deaths were calculated, with subgroup analyses for main-duct/mixed-type and branch-duct IPMNs. Quality of the studies, publication bias and heterogeneity were explored.

RESULTS

Six studies reported data on overall mortality and eight described disease-specific mortality for 556 patients during follow-up ranging from 24·9 to 60·0 months. Pooled rates of overall and IPMN-related mortality were 30·9 (95 per cent c.i. 19·6 to 45·1) and 11·6 (6·0 to 21·2) per cent respectively. The pooled incidence rate for overall mortality was substantially higher than that for IPMN-related mortality: 78 (95 per cent c.i. 44 to 111) and 23 (9 to 37) per 1000 patient-years respectively. The pooled incidence rate for disease-specific mortality was considerably lower for branch-duct than for main-duct or mixed-type IPMNs: 5 (0 to 10) and 32 (12 to 52) per 1000 patient-years respectively.

CONCLUSION

In patients unfit for surgery, IPMN-related mortality among patients with worrisome features and high-risk stigmata is low, and the risk of death from other causes much higher.

Predictive performance of factors associated with malignancy in intraductal papillary mucinous neoplasia of the pancreas

Background

Estimation of the risk of malignancy in intraductal papillary mucinous neoplasia (IPMN) of the pancreas is a clinical challenge. Several routinely used clinical factors form the basis of the current consensus guidelines. This study aimed to determine the predictive values of the most commonly assessed risk factors.

Methods

A meta-analysis of individual risk factors of malignancy in IPMN was performed. Contingency tables were derived from these data, and sensitivity, specificity, negative and positive predictive values, and diagnostic odds ratios (DOR) were determined. Hierarchical summary receiver operating characteristic (HSROC) curves for each factor were calculated and the respective area under the curve (AUC) was assessed.

Results

A total of 3443 studies were screened initially. Analysis of recent literature revealed 60 studies with 13 relevant risk factors including clinical, serological and radiological parameters. The largest area under the HSROC curve was found for weight loss (0·84) and jaundice/raised bilirubin level (0·80), followed by increased carcinoembryonic antigen (CEA) (0·79) or carbohydrate antigen (CA) 19-9 (0·78) levels. The most sensitive factors were patient age (71 per cent) and mural nodules (65 per cent), and jaundice/raised bilirubin level (97 per cent) and increased CEA level (95 per cent) were most specific. None of the analysed factors reached a positive or negative level of prediction beyond 90 per cent.

Conclusion

None of the established criteria safely distinguishes malignant from non-malignant lesions.