International Intraductal Papillary Mucinous Neoplasms Registry: Long-Term Results Based on the New Guidelines

Comparison of intra- and inter-reader agreement of abbreviated versus comprehensive MRCP for pancreatic cyst surveillance

OBJECTIVE

To retrospectively compare inter- and intra-reader agreement of abbreviated MRCP (aMRCP) with comprehensive MRI (cMRCP) protocol for detection of worrisome features, high-risk stigmata, and concomitant pancreatic cancer in pancreatic cyst surveillance.

METHODS

151 patients (104 women, mean age: 69[10] years) with baseline and follow-up contrast-enhanced MRIs were included. This comprised 138 patients under cyst surveillance with 5-year follow-up showing no pancreatic ductal adenocarcinoma (PDAC), 6 with pancreatic cystic lesion-derived malignancy, and 7 with concomitant PDAC. The aMRCP protocol used four sequences (axial and coronal Half-Fourier Single-shot Turbo-spin-Echo, axial T1 fat-saturated pre-contrast, and 3D-MRCP), while cMRCP included all standard sequences, including post-contrast. Three blinded abdominal radiologists assessed baseline cyst characteristics, worrisome features, high-risk stigmata, and PDAC signs using both aMRCP and cMRCP, with a 2-week washout period. Intra- and inter-reader agreement were calculated using Fleiss' multi-rater kappa and Intra-class Correlation Coefficient (ICC). 95% confidence intervals (CI) were calculated.

RESULTS

Cyst size, growth, and abrupt main pancreatic duct transition had strong intra- and inter-reader agreement. Intra-reader agreement was ICC = 0.93-0.99 for cyst size, ICC = 0.71-1.00 for cyst growth, and kappa = 0.83-1.00 for abrupt duct transition. Inter-reader agreement for cyst size was ICC = 0.86 (aMRCP) and ICC = 0.83 (cMRCP), and for abrupt duct transition was kappa = 0.84 (aMRCP) and kappa = 0.69 (cMRCP). Thickened cyst wall, mural nodule and cyst-duct communication demonstrated varying intra-reader agreements and poor inter-reader agreements.

CONCLUSION

aMRCP showed high intra- and inter-reader agreement for most pancreatic cyst parameters that highly rely on T2-weighted sequences.

Imaging for Early Detection of Pancreatic Ductal Adenocarcinoma: Updates and Challenges in the Implementation of Screening and Surveillance Programs

Pancreatic ductal adenocarcinoma (PDA) is one of the most aggressive cancers. It has a poor 5-year survival rate of 12%, partly because most cases are diagnosed at advanced stages, precluding curative surgical resection. Early-stage PDA has significantly better prognoses due to increased potential for curative interventions, making early detection of PDA critically important to improved patient outcomes. We examine current and evolving early detection concepts, screening strategies, diagnostic yields among high-risk individuals, controversies, and limitations of standard-of-care imaging.

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.

Intraductal papillary mucinous neoplasms of the pancreas: Uncommon imaging presentation, evolution and comparison of guidelines

Pancreatic cystic lesions are often asymptomatic, incidentally detected and include a range of entities with varying degrees of concern for malignancy. Among these, intraductal papillary mucinous neoplasms (IPMN) are considered premalignant pancreatic lesions, with a broad pathological spectrum ranging from lesions without dysplasia, which can be managed conservatively, to malignant lesions that require surgical resection. The increasing use of CT and MRI has led to increased recognition of this entity incidentally, with branch-duct IPMN representing the most common subtype and the most challenging lesions in terms of patient management. The main imaging modality involved in diagnosis and surveillance of IPMN is MRI. Radiologists play an important role in the management of patients with IPMN, including lesion detection, characterization, follow-up and prognostication, allowing early MRI identification of features that are concerning for malignancy. The main aim of this pictorial review is to illustrate MRI features of IPMN and to discuss risk stratification scores based on different guidelines, with a main focus on branch-duct IPMN. The secondary aims include the presentation of common and uncommon imaging evolution of BD-IPMN as well as the discussion on current controversies on the appropriate management of IPMN.

Surveillance of Pancreatic Cystic Neoplasms

Pancreatic cystic neoplasms (PCNs) are increasingly detected because of the widespread use of cross-sectional imaging and overall aging population. While the majority of these cysts are benign, some can progress to advanced neoplasia (defined as high-grade dysplasia and invasive cancer). As the only widely accepted treatment for PCNs with advanced neoplasia is surgical resection, accurate preoperative diagnosis, and stratification of malignant potential for deciding about surgery, surveillance or doing nothing remains a clinical challenge. Surveillance strategies for pancreatic cysts (PCNs) combine clinical evaluation and imaging to assess changes in cyst morphology and symptoms that may indicate advanced neoplasia. PCN surveillance heavily relies on various consensus clinical guidelines that focus on high-risk morphology, surgical indications, and surveillance intervals and modalities. This review will focus on current concepts in the surveillance of newly diagnosed PCNs, especially on low-risk presumed intraductal papillary mucinous neoplasms (those without worrisome features and high-risk stigmata), and appraise current clinical surveillance guidelines.

Benefit of Extended Surveillance of Low-Risk Pancreatic Cysts After 5-Year Stability: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Low-risk branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) lacking worrisome features (WF) and high-risk stigmata (HRS) warrant surveillance. However, their optimal duration, especially among cysts with initial 5 years of size stability, warrants further investigation. We systematically reviewed the surveillance of low-risk BD-IPMNs and investigated the incidence of WF/HRS and advanced neoplasia, high-grade dysplasia, and pancreatic cancer during the initial (<5 years) and extended surveillance period (>5-years).

METHODS

A systematic search (CRD42020117120) identified studies investigating long-term IPMN surveillance outcomes of low-risk IPMN among the Cochrane Library, Embase, Google Scholar, Ovid Medline, PubMed, Scopus, and Web of Science, from inception until July 9, 2021. The outcomes included the incidence of WF/HRS and advanced neoplasia, disease-specific mortality, and surveillance-related harm (expressed as percentage per patient-years). The meta-analysis relied on time-to-event plots and used a random-effects model.

RESULTS

Forty-one eligible studies underwent systematic review, and 18 studies were meta-analyzed. The pooled incidence of WF/HRS among low-risk BD-IPMNs during initial and extended surveillance was 2.2% (95% CI, 1.0%-3.7%) and 2.9% (95% CI, 1.0%-5.7%) patient-years, respectively, whereas the incidence of advanced neoplasia was 0.6% (95% CI, 0.2%-1.00%) and 1.0% (95% CI, 0.6%-1.5%) patient-years, respectively. The pooled incidence of disease-specific mortality during initial and extended surveillance was 0.3% (95% CI, 0.1%-0.6%) and 0.6% (95% CI, 0.0%-1.6%) patient-years, respectively. Among BD-IPMNs with initial size stability, extended surveillance had a WF/HRS and advanced neoplasia incidence of 1.9% (95% CI, 1.2%-2.8%) and 0.2% (95% CI, 0.1%-0.5%) patient-years, respectively.

CONCLUSIONS

A lower incidence of advanced neoplasia during extended surveillance among low-risk, stable-sized BD-IPMNs was a key finding of this study. However, the survival benefit of surveillance among this population warrants further exploration through high-quality studies before recommending surveillance cessation with certainty.

Systematic review and meta-analysis of observational studies on BD-IPMNS progression to malignancy

BACKGROUND

The vast majority of presumed branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) of the pancreas are referred to a surveillance program due to the relatively low risk of malignancy. We aim to evaluate all available data from observational studies focused on the risks of BD-IPMN progression and malignancy to provide vital insights into its management in clinical practice.

METHODS

A comprehensive search was conducted at PubMed, Cochrane, Web of Science and Embase for observational studies published before January 1st, 2020. The progression of BD-IPMN was defined as the development of worrisome features (WFs) or high-risk stigmata (HRS) during surveillance. Overall malignancy was defined as all malignancies, such as malignant IPMN, concomitant pancreatic ductal adenocarcinoma (PDAC) and other malignancies, including BD-IPMN with high-grade sec. Baltimore consensus 2015 or BD-IPMN with high-grade dysplasia (carcinoma in situ) sec. WHO 2010. A meta-analysis was performed to investigate the presence of a mural nodule as a possible predictor of malignancy.

RESULTS

Twenty-four studies were included, with a total of 8941 patients with a presumed BD-IPMN. The progression rate was 20.2%, and 11.8% underwent surgery, 29.5% of whom showed malignancy at the final pathology. Of those, 78% had malignant IPMNs, and 22% had concomitant pancreatic cancer. Overall, 0.5% had distant metastasis. The meta-analysis showed that the risk of malignancy in the presence of a mural nodule >5 mm had a RR of 5.457 (95% CI 1.404-21.353), while a nonenhancing mural nodule or an enhancing mural nodule < 5 mm had a RR of 5.286 (95% CI 1.805-15.481) of harboring malignancy.

CONCLUSION

Most presumed BD-IPMNs entering surveillance do not become malignant. Of those submitted to surgery, concomitant PDAC adds to the overall risk of detecting malignancy.

Pancreatic cancer with ovarian metastases: A case report and review of the literature

BACKGROUND

Pancreatic cancer with ovarian metastases is rare and easily misdiagnosed. Most patients are first diagnosed with ovarian cancer. We report a rare case of ovarian metastases secondary to pancreatic adenocarcinoma. We also review the literature to analyze the clinical characteristics of, diagnostic methods for, and perioperative management strategies for this rare malignancy.

CASE SUMMARY

A 48-year-old woman with an abdominal mass presented to our hospital. Computed tomography revealed lesions in the pancreas and lower abdomen. Radiological examination and histological investigation of biopsy specimens revealed either an ovarian metastasis from a pancreatic neoplasm or two primary tumors, with metastasis strongly suspected. The patient simultaneously underwent distal pancreatectomy plus splenectomy by a general surgeon and salpingo-oophorectomy with hysterectomy by a gynecologist. Histological examination of the surgical specimen revealed a pancreatic adenocarcinoma (intermediate differentiation, mucinous) and a metastatic mucinous adenocarci-noma in the ovary.

CONCLUSION

For this rare tumor, surgical resection is the most effective treatment, and the final diagnosis depends on tumor pathology.

Possibility of detecting intraductal papillary mucinous neoplasms using metabolite biomarkers for pancreatic cancer

Aim: The aim of this study was to identify whether metabolite biomarker candidates for pancreatic cancer (PC) could aid detection of intraductal papillary mucinous neoplasms (IPMN), recognized as high-risk factors for PC. Materials & methods: The 12 metabolite biomarker candidates, which were found to be useful to detect PC in our previous study, were evaluated for plasma samples from patients with PC (n = 44) or IPMN (n = 24) or healthy volunteers (n = 46). Results: Regarding the performance of individual biomarkers of PC and PC high-risk IPMN, lysine exhibited the best performance (sensitivity: 67.8%; specificity: 86.9%). The multiple logistic regression analysis-based detection model displayed high sensitivity and specificity values of 92.5 and 90.6%, respectively. Conclusion: Metabolite biomarker candidates for PC are useful for detecting high-risk IPMN, which can progress to PC.

Testing for Verification Bias in Reported Malignancy Risks for Side-Branch Intraductal Papillary Mucinous Neoplasms: A Simulation Modeling Approach

OBJECTIVE

The objective of our study was to test for the possibility that published malignancy risks for side-branch intraductal papillary mucinous neoplasms (IPMNs) are overestimates, likely due to verification bias.

MATERIALS AND METHODS

We tested for possible verification bias using simulation modeling techniques. First, in age-defined hypothetical cohorts of 10 million persons, we projected the frequency of pancreatic ductal adenocarcinoma (PDAC) arising from side-branch IPMNs over 5 years using published estimates of their prevalence (4.4%) and rate of malignant transformation (1.9%). Second, we projected the total number of PDAC cases in corresponding cohorts over the same time horizon using national cancer registry data. For each cohort, we determined whether the percentage of all PDAC cases that arose from side-branch IPMNs (i.e., side-branch IPMN-associated PDAC cases) was clinically plausible using an upper limit of 10% to define plausibility, as estimated from the literature. Model assumptions and parameter uncertainty were evaluated in sensitivity analysis.

RESULTS

Across all cohorts, percentages of side-branch IPMN-associated PDACs greatly exceeded 10%. In the base case (mean age = 55.7 years), 80% of PDAC cases arose from side-branch IPMNs (7877/9786). In the oldest cohort evaluated (mean age = 75 years), this estimate was 76% (14,227/18,714). In a secondary analysis, we found that if an upper limit threshold of 10% for side-branch IPMN-associated PDAC was imposed, the model-predicted rate of malignancy for side-branch IPMNs would be less than 0.24% over a 5-year time horizon, substantially lower than most literature-based estimates.

CONCLUSION

Our results suggest that reported malignancy risks associated with side-branch IPMNs are likely to be overestimates and imply the presence of verification bias.

Clinical Management and Surgical Decision-Making of IPMN of the Pancreas

Intraductal papillary mucinous neoplasm (IPMN) is the most common pancreatic cystic neoplasm (PCN). The increased attention to IPMN is due to its unique features of malignant progression, being different between main duct IPMN and branch duct IPMN, and increased de novo development of conventional pancreatic ductal adenocarcinoma elsewhere in the pancreas. The increased interest in IPMN led to publication of many guidelines on its clinical management. This chapter aims to summarize and compare characteristics of nine guidelines on the clinical management of IPMN and other PCNs published in the English literature and further to show a current strategy for surgical decision making in the management of IPMN.

Systematic review and meta-analysis: Prevalence of incidentally detected pancreatic cystic lesions in asymptomatic individuals

BACKGROUND & AIMS

Pancreatic cystic lesions (PCLs) are frequent incidental findings. As most PCLs require costly diagnostic evaluation and active surveillance, it is important to clarify their prevalence in asymptomatic individuals. We therefore aimed at performing a systematic review and meta-analysis to determine it.

METHODS

a systematic search was conducted and studies meeting inclusion criteria were included. The prevalence of PCLs was pooled across studies. A random effect model was used with assessment of heterogeneity.

RESULTS

17 studies, with 48,860 patients, were included. Only 3 were prospective; 5 studies were conducted in the US, 7 in Europe, 4 in Asia and 1 in Brazil. The pooled prevalence of PCLs was 8% (95% CI 4-14) with considerable heterogeneity (I² = 99.5%). This prevalence was higher in studies of higher quality, examining older subjects, smaller cohorts, and employing MRCP (24.8% vs 2.7% with CT-scan). The pooled rate of PCLs was four times higher in studies conducted in the US than in Asia (12.6% vs 3.1%). 7 studies reported the prevalence of mucinous lesions, with a pooled rate of 4.3% (95% CI 2-10; I² = 99.2%), but of 0.7% only for worrisome features or high risk stigmata.

CONCLUSION

The rate of incidentally detected PCLs is of 8%. Mucinous lesions are the most common incidentally detected PCLs, although they rarely present with potential indication for surgery. The observed different rates in the US and other geographic Areas suggest that different protocols might be necessary to help balancing costs and effectiveness of follow-up investigations in asymptomatic subjects.

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.

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.

Pancreatectomy for pancreatic incidentaloma: What are the risks?

BACKGROUND

Pancreatic incidentalomas (PI) are nowadays common but the benefit-risk balance of surgery remains difficult to determine.

METHODS

Monocentric retrospective study of 881 pancreatectomies comparing resected PI with symptomatic lesion. Univariate and multivariate (MV) analyses were done to identify risk factors of malignancy in PI undergoing surgery.

RESULTS

Overall, 32% of pancreatectomies were performed for PI. Median size of PI was 30 mm (vs 28 mm; p = 0.15) and 49% were cystic (vs 42%; p = 0.197). Resected PI were mostly located in distal pancreas (61% vs 34%; p < 0.001), less frequently malignant (49% vs 59%; p = 0.004). PNETs were more frequent in PI (50% vs 21%; p < 0.001). Distal pancreatectomy (36% vs 23%; p < 0.001) or parenchyma-sparing surgery (34% vs 13%; p < 0.001) were more frequently performed for PI. Overall mortality (1.1% vs 1.2%) and morbidity (70% vs 68%) were not significantly different between both groups. Severe morbidity was lower for PI (15% vs 22%; p = 0.007). In multivariate analysis, age>55 years (HR 6.14; p < 0.001), size >20 mm (HR:26.7; p < 0.001) and biliary dilatation (HR 29.9; p = 0.027) were independent risk factors of malignancy and, when associated, the likelihood of malignancy was above 90%.

CONCLUSIONS

PI represent about 30% of indications for pancreatectomy and when resected after careful selection are malignant in 50% of cases.

Intraductal papillary mucinous neoplasm of the pancreas - epidemiology, risk factors, diagnosis, and management

Intraductal papillary mucinous neoplasm (IPMN) is one of the most common cystic neoplasms of the pancreas. It is a heterogeneous disease and can be divided into ductal types and morphological subtypes. The incidence of IPMN is increasing, likely due to the widespread use of cross-sectional imaging and a growing elderly population. IPMN poses an increasing demand on the health care system. Current guidelines provide indications for surgery and recommendations for surveillance, but management of IPMN is still challenging in routine clinical practice. In this article, we review current knowledge about IPMN and provide future directions for improving diagnosis and management.

Revisions of international consensus Fukuoka guidelines for the management of IPMN of the pancreas

The management of intraductal papillary mucinous neoplasm (IPMN) continues to evolve. In particular, the indications for resection of branch duct IPMN have changed from early resection to more deliberate observation as proposed by the international consensus guidelines of 2006 and 2012. Another guideline proposed by the American Gastroenterological Association in 2015 restricted indications for surgery more stringently and recommended physicians to stop surveillance if no significant change had occurred in a pancreatic cyst after five years of surveillance, or if a patient underwent resection and a non-malignant IPMN was found. Whether or not it is safe to do so, as well as the method and interval of surveillance, has generated substantial debate. Based on a consensus symposium held during the meeting of the International Association of Pancreatology in Sendai, Japan, in 2016, the working group has revised the guidelines regarding prediction of invasive carcinoma and high-grade dysplasia, surveillance, and postoperative follow-up of IPMN. As the working group did not recognize the need for major revisions of the guidelines, we made only minor revisions and added most recent articles where appropriate. The present guidelines include updated information and recommendations based on our current understanding, and highlight issues that remain controversial or where further research is required.

Management of Incidental Pancreatic Cysts: A White Paper of the ACR Incidental Findings Committee

The ACR Incidental Findings Committee (IFC) presents recommendations for managing pancreatic cysts that are incidentally detected on CT or MRI. These recommendations represent an update from the pancreatic component of the JACR 2010 white paper on managing incidental findings in the adrenal glands, kidneys, liver, and pancreas. The Pancreas Subcommittee-which included abdominal radiologists, a gastroenterologist, and a pancreatic surgeon-developed this algorithm. The recommendations draw from published evidence and expert opinion, and were finalized by informal iterative consensus. Algorithm branches successively categorize pancreatic cysts based on patient characteristics and imaging features. They terminate with an ascertainment of benignity and/or indolence (sufficient to discontinue follow-up), or a management recommendation. The algorithm addresses most, but not all, pathologies and clinical scenarios. Our goal is to improve quality of care by providing guidance on how to manage incidentally detected pancreatic cysts.