Malignant progression in IPMN: a cohort analysis of patients initially selected for resection or observation

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

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

A pilot study of radiologic measures of abdominal adiposity: weighty contributors to early pancreatic carcinogenesis worth evaluating?

Objective:

Intra-abdominal fat is a risk factor for pancreatic cancer (PC), but little is known about its contribution to PC precursors known as intraductal papillary mucinous neoplasms (IPMNs). Our goal was to evaluate quantitative radiologic measures of abdominal/visceral obesity as possible diagnostic markers of IPMN severity/pathology.

Methods:

In a cohort of 34 surgically-resected, pathologically-confirmed IPMNs (17 benign; 17 malignant) with preoperative abdominal computed tomography (CT) images, we calculated body mass index (BMI) and four radiologic measures of obesity: total abdominal fat (TAF) area, visceral fat area (VFA), subcutaneous fat area (SFA), and visceral to subcutaneous fat ratio (V/S). Measures were compared between groups using Wilcoxon two-sample exact tests and other metrics.

Results:

Mean BMI for individuals with malignant IPMNs (28.9 kg/m²) was higher than mean BMI for those with benign IPMNs (25.8 kg/m²) (P=0.045). Mean VFA was higher for patients with malignant IPMNs (199.3 cm²) compared to benign IPMNs (120.4 cm²),P=0.092. V/S was significantly higher (P=0.013) for patients with malignant versus benign IPMNs (1.25vs. 0.69 cm²), especially among females. The accuracy, sensitivity, specificity, and positive and negative predictive value of V/S in predicting malignant IPMN pathology were 74%, 71%, 76%, 75%, and 72%, respectively.

Conclusions:

Preliminary findings suggest measures of visceral fat from routine medical images may help predict IPMN pathology, acting as potential noninvasive diagnostic adjuncts for management and targets for intervention that may be more biologically-relevant than BMI. Further investigation of gender-specific associations in larger, prospective IPMN cohorts is warranted to validate and expand upon these observations.

Surveillance for neoplasia in the pancreas

Despite its low incidence in the general population, pancreatic cancer is one of the leading causes of cancer-related mortality. Survival greatly depends on operability, but most patients present with unresectable disease. Therefore, there is great interest in the early detection of pancreatic cancer and its precursor lesions by surveillance. Worldwide, several programs have been initiated for individuals at high risk for pancreatic cancer. Their first results suggest that surveillance in high-risk individuals is feasible, but their effectiveness in decreasing mortality remains to be proven. This review will discuss which individuals are eligible for surveillance, which lesions are aimed to be detected, and which surveillance modalities are being used in current clinical practice. Furthermore, it addresses the management of abnormalities found during surveillance and topics for future research.

Survival Analysis and Risk for Progression of Intraductal Papillary Mucinous Neoplasia of the Pancreas (IPMN) Under Surveillance: A Single-Institution Experience

Purpose

While surveillance of the majority of patients with IPMN is considered best practice, consensus regarding the duration of follow-up is lacking. This study assessed the survival rate and risk for progression of IPMN under surveillance.

Methods

All patients diagnosed with and surveyed for IPMN between January 2008 and December 2013 were identified and assigned to two groups: patients without indication for surgery (Group 1), and patients whose IPMN required surgery but were inoperable for general reasons (Group 2). Disease progression and survival data were compared between both groups.

Results

In total 503 patients were identified, of whom 444 (88.3%) were followed up. Group 1 included 395 patients, and Group 2 had 49. In Group 1, IPMN-specific 1-, 5-, and 10-year survival rates were 100, 100, and 94.2%, respectively. Four patients died of associated or concomitant pancreatic cancer, and 230 patients (58.2%) experienced disease progression. The 1-, 4-, 10-year cumulative risk for progression and for surgery was 11.2, 70.6, 97.5, and 2.9, 26.2, 72.1%, respectively. In Group 2, the 1-, 5-, 10-year IPMN-specific survival rate was 90.7, 74.8, and 74.8%, respectively.

Conclusions

This study confirmed the safety of surveillance for patients with IPMN who do not require surgery. However, the risk for disease progression and for surgery increases significantly over time. The study results support International and European guidelines not to discontinue IPMN surveillance and validate the European recommendation to intensify follow-up after 5 years. The fairly good prognosis of patients whose IPMN requires surgery but cannot undergo resection suggests a relatively indolent disease biology.

Recurrence and Survival After Resection of Small Intraductal Papillary Mucinous Neoplasm-associated Carcinomas (≤20-mm Invasive Component): A Multi-institutional Analysis

BACKGROUND

Early invasive carcinoma may be encountered in association with intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. The natural history of these early invasive lesions is unknown.

METHODS

Pancreatic surgical databases from 4 high-volume centers were queried for IPMNs, with invasive components measuring 20 mm or less. All cases were reviewed by GI gastrointestinal pathologists, and pathologic features were analyzed to identify predictors of recurrence and survival.

RESULTS

A total of 70 small IPMN-associated invasive carcinomas (≤20-mm invasion) were identified, comprising 25% of resected IPMN-associated carcinomas (n = 280). Most of these small invasive cancers were multifocal (66%), less than 10 mm in size (73%), and arose in the setting of a main duct IPMN (96%). The most common adenocarcinoma subtypes were tubular (57%) and colloid (29%). Lymph node metastases were present in 19% of cases and 23% were T3 lesions. The overall recurrence rate was 24% (n = 17), and the median time to recurrence was 16 months (range: 4-132 months). Median and 5-year survival rates were 99 months and 59%. Recurrence patterns of invasive disease were local in 35%, distant in 47%, and both in 18%. Lymphatic spread and T3 stage were predictive of recurrence (univariate, P = 0.006), whereas tubular carcinoma type was the most predictive of poor overall survival (multivariate hazard ratio = 3.7, P = 0.04).

CONCLUSIONS

This study represents the largest multi-institutional experience of resected small IPMN-associated carcinoma. Although these malignancies may frequently be cured with resection, recurrence risk is significant. Lymphatic spread, increased T stage, and tubular type carcinoma were associated with the poorest outcome.

Predictive value of low serum pancreatic enzymes in invasive intraductal papillary mucinous neoplasms

BACKGROUND

Despite evidence suggesting a role of chronic pancreatitis in pancreatic carcinogenesis, its relationship with invasive intraductal papillary mucinous neoplasms (IPMN) remains unclear. Low levels of pancreatic enzymes are predictive markers of advanced chronic pancreatitis. We investigated whether low pancreatic enzyme levels were associated with a higher incidence of invasive IPMN.

METHODS

This study included 146 consecutive patients who underwent surgical resection of IPMN between April 2001 and October 2014. Multivariable logistic regression analysis was conducted to assess the association between serum pancreatic enzymes and the incidence of invasive IPMN, with adjustment for clinical characteristics including alcohol consumption. The association of serum pancreatic enzymes with pathological pancreatic atrophy and inflammation in areas adjacent to or distant from the tumor was also evaluated.

RESULTS

Low serum levels of pancreatic amylase and lipase were associated with a higher incidence of invasive IPMN (multivariable odds ratio [OR] = 9.6, 95% confidence interval [CI] = 2.99 to 35.1, P = 0.0001; OR = 14.2, 95% CI = 2.77 to 112, P = 0.001, respectively). Low serum pancreatic amylase and lipase levels were also associated with higher grade pancreatic atrophy in areas adjacent to the tumor (P = 0.011 and P = 0.017, respectively) and in areas distant from the tumor (P = 0.0002 and P = 0.001, respectively). Furthermore, low serum pancreatic amylase and lipase levels were associated with higher grade inflammation in areas distant from the tumor (P < 0.0001 and P = 0.001, respectively).

CONCLUSIONS

Low serum pancreatic enzymes may be a predictive marker of invasive IPMN. Excessive alcohol consumption did not influence the association of low pancreatic enzyme levels with invasive IPMN.

Clinical Impact of Structured Follow-up After Pancreatic Surgery

OBJECTIVES

Structured follow-up after surgery for pancreatic ductal adenocarcinoma (PDAC) remains controversial and is currently not recommended due to a supposed lack of therapeutic consequences. Furthermore, it is not clear whether noncancer patients after pancreas resection need to be seen in the clinic on a regular basis. The present study analyzed how follow-up after pancreatic surgery affected postoperative treatment and long-term outcomes.

METHODS

Data of all postoperative visits in a specialized outpatient clinic for pancreatic diseases were analyzed for a 1-year period with regard to symptoms, diagnostic procedures, and therapeutic consequences.

RESULTS

Six hundred eighteen patients underwent 940 postoperative follow-ups. Nearly half of them needed a change of medication due to altered pancreatic function. In 74 (40%) of 184 resected PDAC patients, recurrence (local or systemic) was detected during follow-up, although only 19 of these had shown associated symptoms (26%). In all patients with recurrence, a cancer-directed treatment was induced. Eleven (69%) of 16 patients with isolated local recurrence were referred for reresection.

CONCLUSIONS

Follow-up examinations are a substantial part of the clinical management after pancreas resections. Follow-up is particularly important for PDAC because recurrence is often asymptomatic, but its detection allows for therapeutic interventions and potentially improved prognosis. This should be implemented in future guidelines.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Tumor-associated Neutrophils and Malignant Progression in Intraductal Papillary Mucinous Neoplasms: An Opportunity for Identification of High-risk Disease

OBJECTIVES

To evaluate the association of tumor-associated neutrophils (TANs) with malignant progression in intraductal papillary mucinous neoplasms (IPMNs) and to study the cyst fluid from these lesions for biomarkers of the inflammation-carcinogenesis association.

BACKGROUND

There is a strong link between TANs and malignant progression. Inflammatory mediators released by these cells may be a measurable surrogate marker of this progression.

METHODS

We evaluated 78 resected IPMNs (2004-2013). Lesions were divided into the low-risk (low- and intermediate-grade dysplasia: n = 48) and high-risk (high-grade dysplasia and invasive carcinoma: n = 30) groups. TANs were assessed and categorized (negative, low, and high). A multiplexed assay was performed to evaluate 87 different cyst fluid proteins, including cyst fluid inflammatory markers (CFIMs), as possible surrogate markers for parenchymal inflammation.

RESULTS

Significant positive correlation between grade of dysplasia and TANs was found. High levels of TANs were identified in 2%, 33%, and 89% of the lesions when stratified by grade of dysplasia into low/intermediate-grade dysplasia, high-grade dysplasia, and invasive carcinoma, respectively (P < 0.001). Higher grades of dysplasia were also found to have positive correlation with 29 of the measured proteins, of which 23 (79%) were CFIMs. Higher levels of TANs correlated with higher levels of 18 CFIMs, of which 16 (89%) were also found to be associated with higher grades of dysplasia.

CONCLUSIONS

In this study, TANs were strongly associated with malignant progression in IPMNs. Measurement of CFIMs may be a surrogate marker for IPMN progression and allow for the identification of high-risk disease.

International consensus on the management of intraductal papillary mucinous neoplasm of the pancreas

International consensus guidelines for the management of intraductal papillary mucinous neoplasm (IPMN) of the pancreas revised in 2012 (Fukuoka consensus) seem to be accepted well worldwide. Division of various factors to predict malignant transformation into two categories, i.e., "high-risk stigmata" and "worrisome features", is also accepted as practically useful for stratifying the risk factors. Our current interest resides in the development of noninvasive and/or invasive pancreatic cancer in areas of the pancreas distinct from IPMN. Invasive pancreatic cancers derived from and concomitant with IPMN should be distinguished to clarify the incidence of each entity, although some more definitive method for differentiation has to be devised in some cases where histological distinction is obscure. IPMN is a clue to early detection of pancreatic cancer. The optimal surveillance protocol for IPMN on observation should be determined in consideration of both of these different pancreatic cancers.

Imaging patterns of intraductal papillary mucinous neoplasms of the pancreas: an illustrated discussion of the International Consensus Guidelines for the Management of IPMN

Intraductal papillary mucinous neoplasms (IPMN) are being diagnosed with increasing frequency, necessitating an algorithm to help stratify patients into low- and high-risk groups, for follow-up versus more invasive evaluation. New evidence concerning their natural history and overall risk of malignancy has emerged since the 2006 International Association of Pancreatology consensus guidelines, prompting an update in 2012, that distinguishes radiologic 'worrisome features' from 'high-risk stigmata'. The aim of this article is to illustrate, with case examples, the variable imaging patterns of IPMN and how their radiologic features, such as cyst size and mural nodules, are interpreted in the context of the new 2012 guidelines. The 2012 and 2006 guidelines will be compared and discussed with reference to additional studies that have since been published. Despite these guidelines, lingering uncertainty remains about the natural history of IPMN, a source of unease to both radiologists and referring clinicians alike, mandating further refinement of clinical and radiologic parameters predictive of malignancy. Emerging data regarding the risk of extrapancreatic malignancy, as well as synchronous or metachronous pancreatic ductal adenocarcinoma remote in location from a branch duct IPMN are also reviewed. With the expanding research and evolving understanding of this clinicopathologic entity across the globe, radiologists will continue to play an important role in the management of patients with IPMN.

Cystic Neoplasms of the Pancreas

Cystic neoplasms of the pancreas are being identified at an increasing frequency largely due to the increased use of abdominal cross-sectional imaging. These neoplasms represent a heterogeneous group of tumors with various genetic alterations, molecular features, and risks of malignancy. Despite the use of high-resolution radiographic studies, endoscopic evaluation, cyst fluid analysis, and novel molecular diagnostics, many of these lesions remain difficult to classify without operative resection. These diagnostic challenges are coupled with an improving but limited understanding of the natural history of these neoplasms. Treatment of pancreatic cystic neoplasms therefore remains controversial but consists largely of a selective tumor-specific approach to surgical resection. Future research remains necessary to better discriminate the biological behavior of these tumors in order to more appropriately select patients for operative intervention.

Intraductal Papillary Mucinous Neoplasms and the Risk of Diabetes Mellitus in Patients Undergoing Resection Versus Observation

OBJECTIVE

The aim of this study is to determine the prevalence of diabetes mellitus (DM) in patients with intraductal papillary mucinous neoplasm of the pancreas (IPMN) and compare rates of new/progressive DM between IPMN patients undergoing pancreatectomy versus observation.

METHODS

Patients diagnosed with IPMN were identified from institutional databases, divided into two groups based on treatment type, pancreatectomy versus clinical observation, and subsequently evaluated. Standard demographic and clinicopathologic variables, fasting glucose, diabetic status, and pancreatic volume data, were obtained and compared between groups.

RESULTS

One hundred thirty-four IPMN patients were identified; 103 (77 %) underwent pancreatectomy and 31 (23 %) were observed. Baseline DM rate was 18 % (24/134). This was not different between groups [17 % (17/103) resected vs. 23 % (7/31) observed, p = 0.51]. Median follow-up was 53 months and new/progressive DM occurred in 37 (28 %) patients with no difference between groups [29 (28 %) resected vs. 8 (26 %) observed, p = 0.74]. Among resected patients, degree of dysplasia was associated with increase risk of new/progressive DM [moderate dysplasia OR 5.76 (1.24-26.79) and severe dysplasia OR 9.43 (1.54-57.74), p = 0.04], while procedure type and remnant volume were not.

CONCLUSIONS

The incidence and prevalence of DM among patients with IPMN was high and did not differ between resected and observed groups. Degree of dysplasia, not the amount of resected pancreas, was associated with increased risk of DM, suggesting that the presence or development of DM may be a marker of malignant progression. Confirmatory studies are required.

Pancreatic adenocarcinoma pathology: changing "landscape"

Pancreatic cancer is a devastating disease. At time of diagnosis the disease is usually advanced and only a minority of patients are eligible for surgical resection. The overall 5-year survival is 6%. However, survival of patients with early stage pancreatic cancer is significantly better. To improve the prognosis of patients with pancreatic cancer, it is essential to diagnose and treat pancreatic cancer in the earliest stage. Prevention of pancreatic cancer by treating noninvasive precursor lesions just before they invade tissues can potentially lead to even better outcomes. Pancreatic carcinogenesis results from a stepwise progression in which accumulating genetic alterations drive neoplastic progression in well-defined precursor lesions, ultimately giving rise to an invasive adenocarcinoma. A thorough understanding of the genetic changes that drive pancreatic carcinogenesis can lead to identification of biomarkers for early detection and targets for therapy. Recent next-generation sequencing (NGS) studies have shed new light on our understanding of the natural history of pancreatic cancer and the precursor lesions that give rise to these cancers. Importantly, there is a significant window of opportunity for early detection and treatment between the first genetic alteration in a cell in the pancreas and development of full-blown pancreatic cancer. The current views on the pathology and genetics of pancreatic carcinogenesis that evolved from studies of pancreatic cancer and its precursor lesions are discussed in this review.

Intraductal Papillary Mucinous Neoplasm of Pancreas

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are neoplasms that are characterized by ductal dilation, intraductal papillary growth, and thick mucus secretion. This relatively recently defined pathology is evolving in terms of its etiopathogenesis, clinical features, diagnosis, management, and treatment guidelines. A PubMed database search was performed. All the relevant abstracts in English language were reviewed and the articles in which cases of IPMN could be identified were further scrutinized. Information of IPMN was derived, and duplication of information in several articles and those with areas of persisting uncertainties were excluded. The recent consensus guidelines were examined. The reported incidence of malignancy varies from 57% to 92% in the main duct-IPMN (MD-IPMN) and from 6% to 46% in the branch duct-IPMN (BD-IPMN). The features of high-risk malignant lesions that raise concern include obstructive jaundice in a patient with a cystic lesion in the pancreatic head, the findings on radiological imaging of a mass lesion of >30 mm, enhanced solid component, and the main pancreatic duct (MPD) of size ≥10 mm; while duct size 5-9 mm and cyst size <3 mm are considered as “worrisome features.” Magnetic resonance imaging (MRI) and endoscopic ultrasound (EUS) are primary investigations in diagnosing and following up on these patients. The role of pancreatoscopy and the analysis of aspirated cystic fluid for cytology and DNA analysis is still to be established. In general, resection is recommended for most MD-IPMN, mixed variant, and symptomatic BD-IPMN. The 5-year survival of patients after surgical resection for noninvasive IPMN is reported to be at 77-100%, while for those with invasive carcinoma, it is significantly lower at 27-60%. The follow-up of these patients could vary from 6 months to 1 year and would depend on the risk stratification for invasive malignancy and the pathology of the resected specimen. The understanding of IPMN has evolved over the years. The recent guidelines have played a role in this regard.

Risk factors for malignant progression of intraductal papillary mucinous neoplasms

BACKGROUND

Intraductal papillary mucinous neoplasms of the pancreas are increasingly diagnosed. Due to their malignant potential, greater understanding of their nature is required.

AIMS

Define risk factors for malignancy in intraductal papillary mucinous neoplasms.

METHODS

An international, multicentre study was performed in Europe and the United States. Clinical databases were reviewed for patients with intraductal papillary mucinous neoplasms diagnosis.

RESULTS

Of 1126 patients, 84 were diagnosed with invasive carcinoma/high-grade dysplasia and were compared to the rest of the cohort. Multivariate logistic analysis showed a statistically significant association between cancer/high-grade dysplasia and the variables smoking history (OR 1.9, 95% CI [1.1-3.1]), body mass index (OR 1.1, 95% CI [1-1.1]), symptoms (OR 3.4, 95% CI [1.9-6]), jaundice (OR 0.1, 95% CI [0-0.3]), and steatorrhea (OR 0.3, 95% CI [0.1-0.8]). Univariate analysis showed no association between malignancy and the cyst number/location (p=0.3 and p=0.5, respectively) although a strong association was shown for cyst size (p<0.001). The presence and size of nodules (p<0.01) and main duct involvement (p<0.001) were also strongly related with malignancy.

CONCLUSION

The presence of jaundice and steatorrhea, smoking, high body mass index, and imaging features such as cyst size, main duct involvement, and the presence and size of mural nodules are associated with high-grade neoplasia in intraductal papillary mucinous neoplasms.

Observational study of the incidence of pancreatic and extrapancreatic malignancies during surveillance of patients with branch-duct intraductal papillary mucinous neoplasm

OBJECTIVE

This observational analysis assessed the incidence of pancreatic and extrapancreatic malignancies in BD-IPMN patients.

BACKGROUND

Previous studies showed that progression to malignancy of pancreatic branch-duct (BD) intraductal papillary mucinous neoplasm (IPMN) is infrequent and that extrapancreatic malignancies (EPMs) occur with unusual frequency in IPMN patients.

METHODS

Patients observed from 2000 to 2012 and enrolled in a surveillance protocol according to the current guidelines were considered eligible for the study. Only patients with follow-up of more than 12 months were evaluated. The incidence of EPM was calculated only in patients who were free of them at the time of IPMN diagnosis. Data were compared with Italian cancer statistics. The standardized incidence ratios (SIRs) and the 5- and 10-year incidence rates were estimated.

RESULTS

The study population consisted of 569 patients. At a median follow-up of 56 months, 9 patients developed a pancreatic malignancy. Of these, 5 were unresectable. The SIR was 9.21 [95% confidence interval (CI), 1.85-26.91] in males, and 11.94 (95% CI, 4.36-26.0) in females, with a 5-year cumulative incidence of 1.4%. The EPM incidence analysis was performed in 456 patients. Thirty EPMs developed during the follow-up. The SIR was 1.40 (95% CI, 0.72-2.45) in males and 1.37 (95% CI, 0.81-2.16) in females. The 5-year rate of developing any EPM was 5.7%.

CONCLUSIONS

BD-IPMN patients are at risk of pancreatic carcinogenesis. Although the 5-year incidence rate was as low as 1.4%, the surveillance protocol based on the current guidelines failed to identify a small subset of patients who progressed to advanced disease. Patients with BD-IPMN are not at risk of extrapancreatic carcinogenesis.

Targeted screening of individuals at high risk for pancreatic cancer: results of a simulation model

PURPOSE

To identify when, from the standpoint of relative risk, magnetic resonance (MR) imaging-based screening may be effective in patients with a known or suspected genetic predisposition to pancreatic cancer.

MATERIALS AND METHODS

The authors developed a Markov model of pancreatic ductal adenocarcinoma (PDAC). The model was calibrated to National Cancer Institute Surveillance, Epidemiology, and End Results registry data and informed by the literature. A hypothetical screening strategy was evaluated in which all population individuals underwent one-time MR imaging screening at age 50 years. Screening outcomes for individuals with an average risk for PDAC ("base case") were compared with those for individuals at an increased risk to assess for differential benefits in populations with a known or suspected genetic predisposition. Effects of varying key inputs, including MR imaging performance, surgical mortality, and screening age, were evaluated with a sensitivity analysis. RESULTS In the base case, screening resulted in a small number of cancer deaths averted (39 of 100 000 men, 38 of 100 000 women) and a net decrease in life expectancy (-3 days for men, -4 days for women), which was driven by unnecessary pancreatic surgeries associated with false-positive results. Life expectancy gains were achieved if an individual's risk for PDAC exceeded 2.4 (men) or 2.7 (women) times that of the general population. When relative risk increased further, for example to 30 times that of the general population, averted cancer deaths and life expectancy gains increased substantially (1219 of 100 000 men, life expectancy gain: 65 days; 1204 of 100 000 women, life expectancy gain: 71 days). In addition, results were sensitive to MR imaging specificity and the surgical mortality rate.

CONCLUSION

Although PDAC screening with MR imaging for the entire population is not effective, individuals with even modestly increased risk may benefit.

Pancreatic intraductal papillary mucinous neoplasm in a patient with Lynch syndrome

Intraductal papillary mucinous neoplasm (IPMN) is a mucin-producing epithelial neoplasm that carries a risk of progression to invasive pancreatic ductal adenocarcinoma. Lynch syndrome is an autosomal dominant condition caused by germline mutations in mismatch repair genes such as MSH2 that lead to microsatellite instability and increased risk of tumor formation. Although families with Lynch syndrome have an increased risk of pancreatic cancer, a clear connection between Lynch syndrome and IPMN has not been drawn. We present a report of a 58 year-old Caucasian woman with multiple cancers and a germline mutation of MSH2 consistent with Lynch syndrome. A screening abdominal computed tomography scan revealed a dilated main pancreatic duct and cystic ductular structure in the uncinate process that were consistent with IPMN of the main pancreatic duct on excision. Immunohistochemistry and polymerase chain reaction of the patient’s pancreas specimen did not reveal microsatellite instability or mismatch repair gene loss of expression or function. Our findings may be explained by the fact that loss of mismatch repair function and microsatellite instability is a late event in neoplastic transformation. Given the relative rarity of main duct IPMN, its appearance in the setting of somatic MSH2 mutation suggests that IPMN may fit into the constellation of Lynch syndrome related malignancies.

Current recommendations for surveillance and surgery of intraductal papillary mucinous neoplasms may overlook some patients with cancer

BACKGROUND

The 2012 Sendai Criteria recommend that patients with 3 cm or larger branch duct intraductal papillary mucinous neoplasms (BD-IPMN) without any additional "worrisome features" or "high-risk stigmata" may undergo close observation. Furthermore, endoscopic ultrasound (EUS) is not recommended for BD-IPMN <2 cm. These changes have generated concern among physicians treating patients with pancreatic diseases. The purposes of this study were to (i) apply the new Sendai guidelines to our institution's surgically resected BD-IPMN and (ii) reevaluate cyst size cutoffs in identifying patients with lesions harboring high-grade dysplasia or invasive cancer.

METHODS

We retrospectively reviewed 150 patients at a university medical center with preoperatively diagnosed and pathologically confirmed IPMNs. Sixty-six patients had BD-IPMN. Pathologic grade was dichotomized into low-grade (low or intermediate grade dysplasia) or high-grade/invasive (high-grade dysplasia or invasive cancers). Fisher's exact test, chi-square test, student's t test, linear regression, and receiver operating characteristic (ROC) analyses were performed.

RESULTS

The median BD-IPMN size on imaging was 2.4 cm (interquartile range 1.5-3.0). Fifty-one (77 %) low-grade and 15 (23 %) high-grade/invasive BD-IPMN were identified. ROC analysis demonstrated that cyst size on preoperative imaging is a reasonable predictor of grade with an area under the curve of 0.691. Two-thirds of high-grade/invasive BD-IPMN were <3 cm (n = 10). Compared to a cutoff of 3, 2 cm was associated with higher sensitivity (73.3 vs. 33.3 %) and negative predictive value (83.3 vs. 80 %, NPV) for high-grade/invasive BD-IPMN. Mural nodules on endoscopic ultrasound (EUS) or atypical cells on endoscopic ultrasound-fine needle aspiration (EUS-FNA) were identified in all cysts <2 and only 50 % of those <3 cm. Forty percent of cysts >3 cm were removed based on size alone.

DISCUSSION/CONCLUSIONS

Our results suggest that "larger" size on noninvasive imaging can indicate high-grade/invasive cysts, and EUS-FNA may help identify "smaller" cysts with high-grade/invasive pathology.

Implications of imaging criteria for the management and treatment of intraductal papillary mucinous neoplasms - benign versus malignant findings

OBJECTIVES

Evaluation of computed tomography (CT) and magnetic resonance imaging (MRI) for differentiation of pancreatic intraductal papillary mucinous neoplasm (IPMN) subtypes based on objective imaging criteria.

METHODS

Fifty-eight patients with 60 histologically confirmed IPMNs were included in this retrospective study. Eighty-three imaging studies (CT,n = 42; MRI,n = 41) were analysed by three independent blinded observers (O1-O3), using established imaging criteria to assess likelihood of malignancy (-5, very likely benign; 5, very likely malignant) and histological subtype (i.e., low-grade (LGD), moderate-grade (MGD), high-grade dysplasia (HGD), early invasive carcinoma (IPMC), solid carcinoma (CA) arising from IPMN).

RESULTS

Forty-one benign (LGD IPMN,n = 20; MGD IPMN,n = 21) and 19 malignant (HGD IPMN,n = 3; IPMC,n = 6; solid CA,n = 10) IPMNs located in the main duct (n = 6), branch duct (n = 37), or both (n = 17) were evaluated. Overall accuracy of differentiation between benign and malignant IPMNs was 86/92 % (CT/MRI). Exclusion of overtly malignant cases (solid CA) resulted in overall accuracy of 83/90 % (CT/MRI). The presence of mural nodules and ductal lesion size ≥30 mm were significant indicators of malignancy (p = 0.02 and p < 0.001, respectively).

CONCLUSIONS

Invasive IPMN can be identified with high confidence and sensitivity using CT and MRI. The diagnostic problem that remains is the accurate radiological differentiation of premalignant and non-invasive subtypes.

KEY POINTS

• CT and MRI can differentiate benign from malignant forms of IPMN. • Identifying (pre)malignant histological IPMN subtypes by CT and MRI is difficult. • Overall, diagnostic performance with MRI was slightly (not significantly) superior to CT.

Intraductal papillary mucinous neoplasm: clinical surveillance and management decisions

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a relatively rare cystic neoplasm. Although most IPMNs appear to be benign and may be managed by surveillance, all IPMNs are considered premalignant lesions with malignant potential. As such, current efforts are focused on identifying those neoplasms that are at high risk for malignancy to optimize treatment strategy and outcome. IPMNs with invasive carcinoma have clinical outcomes that approach those of conventional pancreatic ductal adenocarcinoma. Management guidelines recommend surgical resection for IPMNs with high-risk imaging or cytologic features. The role of adjuvant therapy is unclear, and we review the evidence for chemoradiation here. Some studies suggest adjuvant chemoradiation may have the greatest impact in malignant IPMNs with adverse histologic features, that is, lymph node metastasis at the time of diagnosis or positive surgical margins. As more IPMNs are recognized and treated, more evidence will accumulate to guide clinicians regarding appropriate use of radiotherapy in the management of IPMN.

Single-operator pancreatoscopy is helpful in the evaluation of suspected intraductal papillary mucinous neoplasms (IPMN)

BACKGROUND AND OBJECTIVE

Even when advanced cross-sectional imaging modalities have been employed, endoscopic evaluation of intraductal papillary mucinous neoplasms (IPMN) is often required in order to assess the final character and extent of lesions. The current study addresses the use of SpyGlass single-operator peroral pancreatoscopy in suspected IPMN.

DESIGN

A prospective, non-randomized exploratory cohort study.

SETTING

Single-center.

PATIENTS AND INTERVENTION

A prospective study-cohort of 44 consecutive patients in a single tertiary referral center who underwent ERCP and peroral pancreatoscopy, was prospectively collected between July 2007 and March 2013 because of a radiological signs of IPMN. These IPMN-findings were discovered incidentally in 44% of the cases.

MAIN OUTCOME MEASUREMENTS

Diagnostic accuracy (specificity & sensitivity) and complications.

RESULTS

The targeted region of the pancreatic duct was reached with the SpyGlass system in 41 patients (median age 65 years, 41% female). Three patients were excluded from analysis because of failed deep cannulation of the pancreatic duct. Brush cytology was taken in 88% and direct biopsies in 41%. IPMN with intermediate or high-grade dysplasia was the main final diagnosis (76%) in 22 patients who had surgery. Out of the 17 patients with a final diagnosis of MD-IPMN, 76% were correctly identified by pancreatoscopy. Of the 9 patients with a final diagnosis of BD-IPMN, the pancreatoscopy identified 78% of the cases correctly.The incidence of post-ERCP pancreatitis was 17%. Pancreatoscopy was found to have provided additional diagnostic information in the vast majority of the cases and to affect clinical decision-making in 76%.

LIMITATIONS

Single-center study.

CONCLUSIONS

Single-operator peroral pancreatoscopy contributed to the clinical evaluation of IPMN lesions and influenced decision-making concerning their clinical management. The problem of post-procedural pancreatitis needs further attention.

Moving beyond morphology: new insights into the characterization and management of cystic pancreatic lesions

The frequency of detection of cystic pancreatic lesions with cross-sectional imaging, particularly with multidetector computed tomography, magnetic resonance (MR) imaging, and MR cholangiopancreatography, is increasing, and many of these cystic pancreatic lesions are being detected incidentally in asymptomatic patients. Because there is considerable overlap in the cross-sectional imaging findings of cystic pancreatic lesions, and because many of these lesions being detected are smaller than 3 cm in diameter and lack any specific cross-sectional imaging features, it has become difficult to make informed decisions about patient management when the precise diagnosis remains uncertain. This article presents the limitations of cross-sectional imaging in patients with cystic pancreatic lesions, details advances in knowledge of the genomic and epigenomic changes that lead to progression of carcinogenesis, outlines the current understanding of the natural history of mucinous cystic lesions, and includes the current use and future potential of novel tumor markers and molecular analysis to characterize cystic pancreatic lesions more precisely. The need to move beyond cross-sectional imaging morphology and toward the use of new techniques to diagnose these lesions accurately is emphasized. An algorithm that uses these techniques is proposed and will hopefully lead to improved patient management.

Pathological features and diagnosis of intraductal papillary mucinous neoplasm of the pancreas

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a noninvasive epithelial neoplasm of mucin-producing cells arising in the main duct (MD) and/or branch ducts (BD) of the pancreas. Involved ducts are dilated and filled with neoplastic papillae and mucus in variable intensity. IPMN lacks ovarian-type stroma, unlike mucinous cystic neoplasm, and is defined as a grossly visible entity (≥ 5 mm), unlike pancreatic intraepithelial neoplasm. With the use of high-resolution imaging techniques, very small IPMNs are increasingly being identified. Most IPMNs are solitary and located in the pancreatic head, although 20%-40% are multifocal. Macroscopic classification in MD type, BD type and mixed or combined type reflects biological differences with important prognostic and preoperative clinical management implications. Based on cytoarchitectural atypia, IPMN is classified into low-grade, intermediate-grade and high-grade dysplasia. Based on histological features and mucin (MUC) immunophenotype, IPMNs are classified into gastric, intestinal, pancreatobiliary and oncocytic types. These different phenotypes can be observed together, with the IPMN classified according to the predominant type. Two pathways have been suggested: gastric phenotype corresponds to less aggressive uncommitted cells (MUC1 -, MUC2 -, MUC5AC +, MUC6 +) with the capacity to evolve to intestinal phenotype (intestinal pathway) (MUC1 -, MUC2 +, MUC5AC +, MUC6 - or weak +) or pancreatobiliary /oncocytic phenotypes (pyloropancreatic pathway) (MUC1 +, MUC 2-, MUC5AC +, MUC 6 +) becoming more aggressive. Prognosis of IPMN is excellent but critically worsens when invasive carcinoma arises (about 40% of IPMNs), except in some cases of minimal invasion. The clinical challenge is to establish which IPMNs should be removed because of their higher risk of developing invasive cancer. Once resected, they must be extensively sampled or, much better, submitted in its entirety for microscopic study to completely rule out associated invasive carcinoma.

Early detection and prevention of pancreatic cancer: Is it really possible today?

Pancreatic cancer is the 4^th leading cause of cancer-related death in Western countries. Considering the low incidence of pancreatic cancer, population-based screening is not feasible. However, the existence of a group of individuals with an increased risk to develop pancreatic cancer has been well established. In particular, individuals suffering from a somatic or genetic condition associated with an increased relative risk of more than 5- to 10-fold seem to be suitable for enrollment in a surveillance program for prevention or early detection of pancreatic cancer. The aim of such a program is to reduce pancreatic cancer mortality through early or preemptive surgery. Considering the risk associated with pancreatic surgery, the concept of preemptive surgery cannot consist of a prophylactic removal of the pancreas in high-risk healthy individuals, but must instead aim at treating precancerous lesions such as intraductal papillary mucinous neoplasms or pancreatic intraepithelial neoplasms, or early cancer. Currently, results from clinical trials do not convincingly demonstrate the efficacy of this approach in terms of identification of precancerous lesions, nor do they define the outcome of the surgical treatment of these lesions. For this reason, surveillance programs for individuals at risk of pancreatic cancer are thus far generally limited to the setting of a clinical trial. However, the acquisition of a deeper understanding of this complex area, together with the increasing request for screening and treatment by individuals at risk, will usher pancreatologists into a new era of preemptive pancreatic surgery. Along with the growing demand to treat individuals with precancerous lesions, the need for low-risk investigation, low-morbidity operation and a minimally invasive approach becomes increasingly pressing. All of these considerations are reasons for preemptive pancreatic surgery programs to be undertaken in specialized centers only.

Disease-specific mortality among patients with intraductal papillary mucinous neoplasm of the pancreas

BACKGROUND & AIMS

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is associated with synchronous and metachronous pancreatic cancer. However, the risk factors for pancreatic cancer-specific mortality have not been determined. We evaluated disease-specific mortality among patients with IPMNs harboring high-risk stigmata.

METHODS

We analyzed data from 243 patients diagnosed with IPMN, with indications for surgery according to the consensus criteria, at the University of Tokyo Hospital from 1995 to January 2011. By using optimal matching and propensity scores based on 16 characteristics, we matched patients who underwent surgery at diagnosis with those who did not undergo surgery. A competing risk analysis was used to assess the risk of pancreatic cancer-specific mortality.

RESULTS

Fifty-nine patients underwent surgery after diagnosis and 184 did not. After adjustment with propensity scores, detection of a hypo-attenuating area by computed tomography, which indicates invasive carcinoma, was associated significantly with pancreatic cancer-specific mortality (adjusted hazard ratio, 16.75; 95% confidence interval, 2.72-103.3; P = .002). Cyst diameter, main pancreatic duct diameter, and the presence of a mural nodule were not associated significantly with pancreatic cancer-specific mortality. Surgical management was found to reduce pancreatic cancer-specific mortality, especially in patients with hypo-attenuating areas (P = .038).

CONCLUSIONS

Detection of a hypo-attenuating area by computed tomography significantly increases the risk for pancreatic cancer-specific mortality among IPMN patients with consensus indications for surgery. Surgical resection significantly reduces this risk.

Role of endoscopic ultrasonography in pancreatic cystic neoplasms: where do we stand and where will we go?

We increasingly encounter pancreatic cystic neoplasms (PCN) in clinical practice and the differential diagnoses vary widely from benign to malignant. There is no 'one and only' diagnostic procedure for PCN. Multiple modalities including computed tomography, magnetic resonance imaging, endoscopic retrograde cholangiopancreatography and endoscopic ultrasound (EUS) are widely used, but EUS has the advantage of anatomical proximity to the pancreas and upper gastrointestinal tract. In addition, EUS-guided fine-needle aspiration (EUS-FNA) provides both cytological evaluation and cyst fluid analysis. Although the role of EUS-FNA for PCN is established, the sensitivity of cytology is low and cyst fluid analysis is only useful for differentiation between mucinous and non-mucinous cysts. Recently, novel through-the-needle imaging under EUS-FNA, such as confocal laserendomicroscopy, is expected to attribute to a better diagnostic yield. Moreover, feasibility of cyst ablation has been reported and the role of EUS has expanded from diagnosis to treatment. However, clinical impact of cyst ablation in terms of safety, efficacy and cost-effectiveness should be validated further. In summary, EUS and EUS-guided intervention does and will play a central role in the management of PCN from surveillance to treatment, but many clinical questions remain unanswered, which warrants well-designed prospective clinical trials.

Dysplasia at the surgical margin is associated with recurrence after resection of non-invasive intraductal papillary mucinous neoplasms

BACKGROUND

The significance of a positive margin in resected non-invasive pancreatic intraductal papillary mucinous neoplasms (IPMN) remains controversial. The aim of this study was to determine recurrence rates when dysplasia was present at the final surgical margin.

METHODS

A prospectively maintained database identified 192 patients undergoing resection of non-invasive IPMN. Pathological, peri-operative and recurrence data were analysed.

RESULTS

Ductal dysplasia was identified at the final surgical margin in 86 patients (45%) and defined as IPMN or Pancreatic Intraepithelial Neoplasia PanIN in 38 (20%) and 54 (28%) patients, respectively. At a median follow-up of 46 months, 40 (21%) patients recurred with 31 developing radiographical evidence of new cysts, 6 re-resected for IPMN and 3 diagnosed with pancreatic cancer within the remnant. Of those with margin dysplasia, 31% developed recurrent disease compared with 13% in those without dysplasia (P = 0.002). On multivariate analysis, margin dysplasia was associated with a three-fold increased risk of recurrence (P = 0.02). No relationship between dysplasia and development of pancreatic cancer was found.

DISCUSSION

In this study, dysplasia at the margin after a pancreatectomy for non-invasive IPMN was associated with recurrence in the remnant gland, but not at the resection margin. While this finding may warrant closer follow-up, it does not identify a gland at higher risk for the subsequent development of invasive disease.

Predicting dysplasia and invasive carcinoma in intraductal papillary mucinous neoplasms of the pancreas: development of a preoperative nomogram

BACKGROUND

Clinical decision making for patients with intraductal papillary mucinous neoplasms (IPMN) of the pancreas is challenging. Even with strict criteria for resection, most resected lesions lack high-grade dysplasia (HGD) or invasive carcinoma.

METHODS

We evaluated patients who underwent resection of histologically confirmed IPMN and had preoperative imaging available for review. A hepatobiliary radiologist blinded to histopathologic subtype reviewed preoperative imaging and recorded cyst characteristics. Patients with mixed-type IPMN were grouped with main-duct lesions for this analysis. Based on an ordinal logistic regression model, we devised two independent nomograms to predict the findings of adenoma, high-grade dysplasia (HGD-CIS), and invasive carcinoma, separately in both main and branch-duct IPMN. Bootstrap validation was used to evaluate the performance of these models, and a concordance index was derived from this internal validation.

RESULTS

There were 219 patients who met criteria for this study. Branch-duct IPMN (bdIPMN) comprised 56 % of the resected lesions. The proportion of HGD-CIS was 15 % for bdIPMN and 33 % for main-duct lesions (mdIPMN); P = 0.003. Invasive carcinoma was identified in 15 % of bdIPMN and 41 % of main-duct lesions (P < 0.001). On multivariate regression, patient gender, history of prior malignancy, presence of solid component, and weight loss were found to be significantly associated with the ordinal outcome for patients with mdIPMN and built into the nomogram (concordance index 0.74). For patients with bdIPMN weight loss, solid component, and lesion diameter were associated with the outcome; (concordance index 0.74).

CONCLUSION

Based on the analysis of patients selected for resection, two nomograms were created that predict a patient's individual likelihood of harboring HGD or invasive malignancy in radiologically diagnosed IPMN. External validation is ongoing.

Is it necessary to follow patients after resection of a benign pancreatic intraductal papillary mucinous neoplasm?

BACKGROUND

Little is known about the risk of subsequently developing a new or progressive intraductal papillary mucinous neoplasm (IPMN) after partial pancreatic resection of a noninvasive IPMN.

STUDY DESIGN

One hundred thirty patients with more than 1 year of follow-up after resection were included in this analysis.

RESULTS

At a median follow-up of 38 months, 22 (17%) developed imaging evidence of a new or progressive IPMN. Eleven (8%) underwent completion resection. Three of the 11 patients had invasive adenocarcinoma. Two other patients developed metastatic pancreatic adenocarcinoma and did not undergo resection. All 5 patients (4%) with cancer had negative margins at initial operation. Sixteen of 100 patients (16%) with negative margins for IPMN at the initial operation developed a new IPMN vs 6 of 30 patients (20%) with margins positive for IPMN (p = ns). Five of 22 patients (23%) with a new IPMN had a family history of pancreatic cancer, while 8 of 108 patients (7%) without a new IPMN had a family history (p < 0.05). Overall, the chances of developing a new IPMN at 1, 5, and 10 years after the initial surgery were 4%, 25%, and 62%, respectively, and of requiring surgery were 1.6%, 14%, and 18%, respectively. The estimated chances of developing invasive pancreatic cancer were 0%, 7%, and 38% at 1, 5, and 10 years, respectively.

CONCLUSIONS

Patients who have undergone resection for noninvasive IPMN require indefinite close surveillance because of the risks of developing a new IPMN, of requiring surgery, and of developing cancer. A family history of pancreatic cancer, but not margin status or degree of dysplasia, is associated with a risk of development of a new or progressive IPMN.