Intraductal papillary mucinous neoplasms of the pancreas: an increasingly recognized clinicopathologic entity

Rare tumours of the pancreas: monocentric study

PURPOSE

The biology of rare pancreatic tumours, which differs from that of ductal pancreatic cancer, requires increased attention. Although the majority of rare pancreatic tumours are benign, it is difficult to decide whether an invasive component exists without complete removal of the lesion, despite considerable progress in diagnosis. We are investigating a large cohort of patients with histologically confirmed epithelial non-ductal non-neuroendocrine neoplasms of the pancreas.

METHODS

Here we analyze long-term survival from patients, who underwent resection of histologically confirmed epithelial non-ductal non-neuroendocrine neoplasms of the pancreas. At our department between Jan 1st, 1999, and Dec 31st, 2019. The median follow-up was 61 (range 0-168) month. All statistical analyses were performed using SPSS 26.0 (IBM, Chicago, IL, USA) software.

RESULTS

46 patients (48%) were followed up for more than 5 years, 18 patients (19%) for more than 10 years. The 5-year and 10-year survival rates for rare non-invasive pancreatic tumours were 72% and 55% respectively. The proportion of rare tumour entities (non-ductal and non-neuroendocrine) increased continuously and statistically significantly (p = 0.004) from 4.2 to 12.3% in our clinic between 1999 and 2019. If there is no invasive growth yet, there is a varying risk of malignant degeneration in the course of the disease. Therefore, the indication for pancreatic resection is still the subject of discussion.

CONCLUSION

The long-term prognosis of rare epithelial pancreatic tumours after R0 resection-even if they are already malignant-is much better than that of ductal pancreatic cancer.

Long-Term Outcomes and Risk of Pancreatic Cancer in Intraductal Papillary Mucinous Neoplasms

Importance

Intraductal papillary mucinous neoplasms (IPMNs) are pancreatic cysts that can give rise to pancreatic cancer (PC). Limited population data exist on their prevalence, natural history, or risk of malignant transformation (IPMN-PC).

Objective

To fill knowledge gaps in epidemiology of IPMNs and associated PC risk by estimating population prevalence of IPMNs, associated PC risk, and proportion of IPMN-PC.

Design, Setting, and Participants

: This retrospective cohort study was conducted in Olmsted County, Minnesota. Using the Rochester Epidemiology Project (REP), patients aged 50 years and older with abdominal computed tomography (CT) scans between 2000 and 2015 were randomly selected (CT cohort). All patients from the REP with PC between 2000 and 2019 were also selected (PC cohort). Data were analyzed from November 2021 through August 2023.

Main outcomes and Measures

CIs for PC incidence estimates were calculated using exact methods with the Poisson distribution. Cox models were used to estimate age, sex, and stage-adjusted hazard ratios for time-to-event end points.

Results

The CT cohort included 2114 patients (1140 females [53.9%]; mean [SD] age, 68.6 [12.1] years). IPMNs were identified in 231 patients (10.9%; 95% CI, 9.7%-12.3%), most of which were branch duct (210 branch-duct [90.9%], 16 main-duct [6.9%], and 5 mixed [2.2%] IPMNs). There were 5 Fukuoka high-risk (F-HR) IPMNs (2.2%), 39 worrisome (F-W) IPMNs (16.9%), and 187 negative (F-N) IPMNs (81.0%). After a median (IQR) follow-up of 12.0 (8.1-15.3) years, 4 patients developed PC (2 patients in F-HR and 2 patients in F-N groups). The PC incidence rate per 100 person years for F-HR IPMNs was 34.06 incidents (95% CI, 4.12-123.02 incidents) and not significantly different for patients with F-N IPMNs compared with patients without IPMNs (0.16 patients; 95% CI, 0.02-0.57 patients vs 0.11 patients; 95% CI, 0.06-0.17 patients; P = .62). The PC cohort included 320 patients (155 females [48.4%]; mean [SD] age, 72.0 [12.3] years), and 9.8% (95% CI, 7.0%-13.7%) had IPMN-PC. Compared with 284 patients with non-IPMN PC, 31 patients with IPMN-PC were older (mean [SD] age, 76.9 [9.2] vs 71.3 [12.5] years; P = .02) and more likely to undergo surgical resection (14 patients [45.2%] vs 60 patients [21.1%]; P = .003) and more-frequently had nonmetastatic PC at diagnosis (20 patients [64.5%] vs 130 patients [46.8%]; P = .047). Patients with IPMN-PC had better survival (adjusted hazard ratio, 0.62; 95% CI, 0.40-0.94; P = .03) than patients with non-IPMN PC.

Conclusions and Relevance

In this study, CTs identified IPMNs in approximately 10% of patients aged 50 years or older. PC risk in patients with F-N IPMNs was low and not different compared with patients without IPMNs; approximately 10% of patients with PC had IPMN-PC, and they had better survival compared with patients with non-IPMN PC.

Uncinate Duct Dilatation Predicts Additional Risk for High-Grade Dysplasia or Invasive Carcinoma Among Fukuoka-Positive Intraductal Papillary Mucinous Neoplasms

OBJECTIVE

To determine whether uncinate duct dilatation (UDD) increases the risk of high-grade dysplasia or invasive carcinoma (HGD/IC) in Fukuoka-positive intraductal papillary mucinous neoplasms (IPMNs).

BACKGROUND

Though classified as a branch duct, the uncinate duct is the primary duct of the pancreatic ventral anlage. We hypothesized that UDD, like main duct dilatation, confers additional risk for HGD/IC.

METHODS

A total of 467 patients met inclusion criteria in a retrospective cohort study of surgically resected IPMNs at the Massachusetts General Hospital. We used multivariable logistic regression to analyze the association between UDD (defined as ≥4 mm) and HGD/IC, controlling for Fukuoka risk criteria. In a secondary analysis, the modeling was repeated in the 194 patients with dorsal branch duct IPMNs (BD-IPMNs) in the pancreatic neck, body, or tail.

RESULTS

Mean age at surgery was 70, and 229 (49%) patients were female. In total, 267 (57%) patients had only worrisome features and 200 (43%) had at least 1 high-risk feature. UDD was present in 164 (35%) patients, of whom 118 (73%) had HGD/IC. On multivariable analysis, UDD increased the odds of HGD/IC by 2.8-fold, even while controlling for Fukuoka risk factors (95% CI: 1.8-4.4, P <0.001). Prevalence of HGD/IC in all patients with UDD was 73%, compared with 74% in patients with high-risk stigmata and 73% in patients with main duct IPMNs. In the secondary analysis, UDD increased the odds of HGD/IC by 3.2-fold in patients with dorsal BD-IPMNs (95% CI: 1.3-7.7, P =0.010).

CONCLUSIONS

UDD confers additional risk for HGD/IC unaccounted for by current Fukuoka criteria. Further research can extend this study to Fukuoka-negative patients, including unresected patients.

Pancreatic cancer: Advances and challenges

Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest cancers. Significant efforts have largely defined major genetic factors driving PDAC pathogenesis and progression. Pancreatic tumors are characterized by a complex microenvironment that orchestrates metabolic alterations and supports a milieu of interactions among various cell types within this niche. In this review, we highlight the foundational studies that have driven our understanding of these processes. We further discuss the recent technological advances that continue to expand our understanding of PDAC complexity. We posit that the clinical translation of these research endeavors will enhance the currently dismal survival rate of this recalcitrant disease.

The effectiveness of endoscopic ultrasonography findings to distinguish benign and malignant intraductal papillary mucinous neoplasm

BACKGROUND AND AIMS

Accurate evaluation of intraductal papillary mucinous neoplasm (IPMN) is necessary to inform clinical decision-making. But it is still difficult to distinguish benign and malignant IPMN preoperatively. This study aims to evaluate the utility of EUS to predict the pathology of IPMN.

METHODS

Patients with IPMN who underwent endoscopic ultrasound within 3 months before surgery were collected from six centers. Logistic regression model and random forest model were used to determine risk factors associated with malignant IPMN. In both models, 70% and 30% of patients were randomly assigned to the exploratory group and validation group, respectively. Sensitivity, specificity, and ROC were used in model assessment.

RESULTS

Of the 115 patients, 56 (48.7%) had low-grade dysplasia (LGD), 25 (21.7%) had high-grade dysplasia (HGD), and 34 (29.6%) had invasive cancer (IC). Smoking history (OR = 6.95, 95%CI: 1.98-24.44, p = 0.002), lymphadenopathy (OR = 7.91, 95%CI: 1.60-39.07, p = 0.011), MPD > 7 mm (OR = 4.75, 95%CI: 1.56-14.47, p = 0.006) and mural nodules > 5 mm (OR = 8.79, 95%CI: 2.40-32.24, p = 0.001) were independent risk factors predicting malignant IPMN according to the logistic regression model. The sensitivity, specificity, and AUC were 0.895, 0.571, and 0.795 in the validation group. In the random forest model, the sensitivity, specificity, and AUC were 0.722, 0.823, and 0.773, respectively. In patients with mural nodules, random forest model could reach a sensitivity of 0.905 and a specificity of 0.900.

CONCLUSIONS

Using random forest model based on EUS data is effective to differentiate benign and malignant IPMN in this cohort, especially in patients with mural nodules.

Long-term outcomes of patients with multifocal intraductal papillary mucinous neoplasm following pancreatectomy

BACKGROUND

The decision to perform surgery is complicated by the presence of multifocal (MF) intraductal papillary mucinous neoplasms (IPMNs), which are characterized by two or more cysts located in different areas of the pancreas.

OBJECTIVES

We aimed to establish a suitable treatment strategy and surgical indications in patients with MF-IPMNs.

METHODS

This single-center retrospective study included patients with IPMNs who underwent pancreatic resection from 2006 to 2020. Patients with distant metastasis and patients with IPMNs of the main pancreatic duct were excluded from the analysis.

RESULTS

After excluding 22 patients, 194 patients were included. One hundred thirteen patients (58.2%) had unifocal IPMNs, while 81 patients (41.8%) had MF-IPMNs. There were no significant differences in the 5-year disease-specific survival (DSS) rate (92.3% vs. 92.4%, p = 0.976) and the 5-year disease-free survival rate (88.6% vs. 86.5%, p = 0.461). The multivariate analysis identified high-risk stigmata, invasive carcinoma, and lymph node metastasis as independent predictors of DSS. The presence of cystic lesions in the pancreatic remnant was not a predictor of survival. Even in the MF-IPMN group, there were no significant differences in DSS when stratified by procedure (total pancreatectomy vs. segmental pancreatectomy, p = 0.268) or presence of cystic lesions in the pancreatic remnant (p = 0.476). The multivariate analysis identified lymph node metastasis as an independent predictor of DSS in the MF-IPMN group.

CONCLUSIONS

In patients with MF-IPMNs, each cyst should be evaluated individually for the presence of features associated with malignancy.

One hundred most cited article related to pancreaticoduodenectomy surgery: A bibliometric analysis

BACKGROUND

In light of the challenges associated with pancreaticoduodenectomy (PD) and recent key improvements, this bibliometric analysis aimed to analyze the 100 top-cited (T100) articles related to PD surgery to widen the awareness of relevant research on this procedure.

METHODS

The term "pancreaticoduodenectomy" was used to retrieve articles from the Web of Science Core Collection database. The 100 most cited manuscripts in the English language were identified and further analyzed by their countries of origin, publication journals, authors, and themes.

RESULTS

A thorough literature search was performed on the Web of Science until April 2020. The total number of citations for the T100 articles ranged from 227 to 3029. The T100 articles came from 18 different countries, with the USA accounting for the plurality (n = 72). Professor J.L. Cameron from Johns Hopkins Medicine USA published the most articles (n = 22), including one as the first author and two as a co-author. Furthermore, Johns Hopkins Medicine, USA, published the most articles on PD surgery (n = 24), with a total citation count of 14,151. The journal Annals of Surgery published 40 of the T100 articles, with 15,847 citations and an average citation count of 396. Among the T100 articles, the citation frequency following the year of publication showed a parabolic trend, with citations peaking in the 9th year following publication.

CONCLUSION

Our study identified and analyzed the T100 articles in PD surgery. The USA was the dominant country regarding articles, researchers, and institutions. The citations of the articles peaked in the 9th year after publication.

Survival comparison of invasive intraductal papillary mucinous neoplasm versus pancreatic ductal adenocarcinoma

BACKGROUND

The aim of this study was to assess the relevance of highlighting T1a invasive intraductal papillary mucinous carcinoma as a separate subcategory and to compare the tumor biology between invasive intraductal papillary mucinous carcinoma and pancreatic ductal adenocarcinoma.

METHODS

A total of 144 and 328 consecutive patients with intraductal papillary mucinous neoplasms and pancreatic ductal adenocarcinoma, respectively, were analyzed.

RESULTS

Patients with T1a invasive intraductal papillary mucinous carcinoma comprised 25% (11/44) of the overall subject population with invasive intraductal papillary mucinous carcinoma with 5-year disease-specific survival rate being 100%. None of the patients with pancreatic ductal adenocarcinoma were classified as having T1a disease. When patients with invasive intraductal papillary mucinous carcinoma and pancreatic ductal adenocarcinoma were compared after excluding patients with T1a invasive intraductal papillary mucinous carcinoma, the 5-year disease-specific survival rates were 63% vs 40% in node-negative status (P = .018); and they were 20% vs 13% in node-positive status (P = .385). Subsequent analyses revealed that this survival superiority was limited to patients without evidence of lymphatic invasion.

CONCLUSION

T1a invasive intraductal papillary mucinous carcinoma is a clinical entity specifically observed in patients with intraductal papillary mucinous carcinoma, but not in patients with pancreatic ductal adenocarcinoma, and is associated with excellent postoperative survival outcomes. In the survival comparison after exclusion of patients with T1a tumors, when the analysis was limited to patients without lymphatic invasion or lymph node metastasis, the disease-specific survival rate remained higher in patients with invasive intraductal papillary mucinous carcinoma compared with those with pancreatic ductal adenocarcinoma, and this difference was considered as being attributable to the intrinsic indolent biological behavior of invasive intraductal papillary mucinous carcinoma. However, this survival advantage was lost once lymphatic invasion occurred.

Pancreatic ductal adenocarcinoma and invasive intraductal papillary mucinous tumor: Different prognostic factors for different overall survival

BACKGROUND

It is unclear whether invasive intraductal papillary mucinous neoplasm (IPMN) has different clinical and prognostic characteristics, beyond histological factors, when compared to pancreatic ductal adenocarcinoma (PDAC).

AIMS

compare prognostic features of resected PDAC and invasive IPMN METHODS: A retrospective study of patients resected for PDAC or invasive IPMN realized at Humanitas Cancer Center's Pancreatic Surgery Unit, Milan, Italy, between 2010 and 2016. Data recorded included patient demographics, onset symptoms, preoperative health status, tumor features, histology and surgical characteristics. Overall survival was estimated using Kaplan-Meier and prognostic factors for survival were assessed by multivariate Cox regression.

RESULTS

A total of 332 patients were included (PDAC, n = 289; invasive IPMN, n = 43). Patients with invasive IPMN had better overall survival than PDAC patients (median: 76.6 versus 25.6 months; 5-year OS rate: 65.4% vs. 14.2%; p < 0.001). PDAC histology was associated with a significantly higher risk of death than IPMN (hazard ratio 1.815, 95% CI: 1.02, 3.24; p = 0.044). Survival was also worse with PDAC in early-stage disease (IA-IB-IIA, N0). In multivariate analysis, independent predictors of worse survival included perineural invasion, preoperative ASA physical status ≥3 and pain at diagnosis.

CONCLUSIONS

Patients with IPMN had a better prognosis than PDAC patients, regardless of disease stage.

Current Pathology Model of Pancreatic Cancer

Pancreatic cancer (PC) is one of the most aggressive and lethal malignant neoplasms, ranking in seventh place in the world in terms of the incidence of death, with overall 5-year survival rates still below 10%. The knowledge about PC pathomechanisms is rapidly expanding. Daily reports reveal new aspects of tumor biology, including its molecular and morphological heterogeneity, explain complicated "cross-talk" that happens between the cancer cells and tumor stroma, or the nature of the PC-associated neural remodeling (PANR). Staying up-to-date is hard and crucial at the same time. In this review, we are focusing on a comprehensive summary of PC aspects that are important in pathologic reporting, impact patients' outcomes, and bring meaningful information for clinicians. Finally, we show promising new trends in diagnostic technologies that might bring a difference in PC early diagnosis.

Intraductal Papillary Mucinous Carcinoma Versus Conventional Pancreatic Ductal Adenocarcinoma: A Comprehensive Review of Clinical-Pathological Features, Outcomes, and Molecular Insights

Intraductal papillary mucinous neoplasms (IPMN) are common and one of the main precursor lesions of pancreatic ductal adenocarcinoma (PDAC). PDAC derived from an IPMN is called intraductal papillary mucinous carcinoma (IPMC) and defines a subgroup of patients with ill-defined specificities. As compared to conventional PDAC, IPMCs have been associated to clinical particularities and favorable pathological features, as well as debated outcomes. However, IPMNs and IPMCs include distinct subtypes of precursor (gastric, pancreato-biliary, intestinal) and invasive (tubular, colloid) lesions, also associated to specific characteristics. Notably, consistent data have shown intestinal IPMNs and associated colloid carcinomas, defining the “intestinal pathway”, to be associated with less aggressive features. Genomic specificities have also been uncovered, such as mutations of the GNAS gene, and recent data provide more insights into the mechanisms involved in IPMCs carcinogenesis. This review synthetizes available data on clinical-pathological features and outcomes associated with IPMCs and their subtypes. We also describe known genomic hallmarks of these lesions and summarize the latest data about molecular processes involved in IPMNs initiation and progression to IPMCs. Finally, potential implications for clinical practice and future research strategies are discussed.

Differentiating benign from malignant pancreatic cysts on computed tomography

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CT can distinguish between benign and premalignant or malignant pancreatic cysts.

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Solid component and septation were the only CT features that could differentiate benign from malignant cysts.

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Cyst wall enhancements on CT were more commonly observed in premalignant or malignant cysts than in benign cysts.

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CT is a necessary diagnostic modality to preoperatively detect and characterize pancreatic lesions.

Purpose

It is important to identify features on computed tomography (CT) that can distinguish between benign and premalignant or malignant pancreatic cysts to avoid unnecessary surgeries. This study investigated the preoperative diagnostic evaluation of cystic pancreatic lesions to determine how advanced imaging and clinical factors should guide management.

Methods

In total, 53 patients with 27 benign and 26 premalignant or malignant cysts were enrolled. CT features of the cysts were compared using univariate and multivariate analyses.

Results

On univariate analysis, a solid component (p < 0.01), septation (p < 0.01), location (p < 0.01), border (p < 0.01), wall enhancement (p = 0.01), lesion margins (p < 0.01), pancreatic atrophy (p = 0.04), and a cystic wall (p < 0.01) were all significantly different between benign and premalignant or malignant cysts. On multivariate analysis, only a solid component (p < 0.01) and septation (p < 0.01) were significant.

Conclusion

A thin cystic wall, uniform homogeneity, a clear border, the presence of septation, pancreatic atrophy, and the absence of both wall enhancements and solid components were more frequently seen in benign cysts. A thick wall, lack of homogeneity, the presence of wall enhancements and solid components, absence of septation, only a small degree of pancreatic atrophy, and unclear borders were more frequent among premalignant or malignant cysts. The only CT features to differentiate benign from premalignant or malignant cysts were a solid component and septation.

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas: clinicopathological features and long-term outcomes following a pancreatectomy

OBJECTIVE

the objective of this study was to analyze the anatomical and clinical features and long-term oncologic outcomes of 25 patients that underwent surgery due to intraductal papillary mucinous neoplasm of the pancreas.

MATERIAL AND METHODS

patients undergoing surgery for intraductal papillary mucinous neoplasm of the pancreas were identified from a prospective database of pancreatic resections. Demographic data, symptoms, type of surgery and type of lesion (branch type, main duct or mixed) were recorded. The lesions were classified into invasive (high grade dysplasia and carcinoma) and noninvasive (low- or intermediate-grade dysplasia). Postoperative complications were analyzed as well as the pattern of recurrence and disease-free survival at five and ten years.

RESULTS

the most common symptoms in the 25 patients (14 males and eleven females) were abdominal pain and weight loss. Eight (32%) cases were diagnosed incidentally. Twelve (48%) of the lesions were of the branch type, three affected the main duct and ten (40%) were mixed. Twelve cephalic duodenopancreatectomies and seven total pancreatectomies were performed; three were central; two, distal; and one, enucleation. Seven cases (32%) had an invasive phenotype. Three patients had locoregional and distant recurrence at six, 16 and 46 months after surgery with a median follow-up of 7.7 years. Disease-free survival at five and ten years for the noninvasive type was 94% and 57% for invasive phenotypes (p < 0.05).

CONCLUSIONS

intraductal papillary mucinous neoplasm is a heterogeneous entity with well differentiated phenotypes, which requires a tailored strategy and treatment, as established in the current consensus guidelines due to its malignant potential.

Analyzing Intraductal Papillary Mucinous Neoplasms Using Artificial Neural Network Methodologic Triangulation

Intraductal papillary mucinous neoplasms (IPMN) are a type of mucinous pancreatic cyst. IPMN have been shown to be pre-malignant precursors to pancreatic cancer, which has an extremely high mortality rate with average survival less than 1 year. The purpose of this analysis is to utilize methodological triangulation using artificial neural networks and regression to examine the impact and effectiveness of a collection of variables believed to be predictive of malignant IPMN pathology. Results indicate that the triangulation is effective in both finding a new predictive variable and possibly reducing the number of variables needed for predicting if an IPMN is malignant or benign.

Genomic analysis of pancreatic juice DNA assesses malignant risk of intraductal papillary mucinous neoplasm of pancreas

Intraductal papillary mucinous neoplasm (IPMN) of pancreas has a high risk to develop into invasive cancer or co‐occur with malignant lesion. Therefore, it is important to assess its malignant risk by less‐invasive approach. Pancreatic juice cell‐free DNA (PJD) would be an ideal material in this purpose, but genetic biomarkers for predicting malignant risk from PJD are not yet established. We here performed deep exome sequencing analysis of PJD from 39 IPMN patients with or without malignant lesion. Somatic alterations and copy number alterations (CNAs) detected in PJD were compared with the histologic grade of IPMN to evaluate their potential as a malignancy marker. Somatic mutations of KRAS, GNAS, TP53, and RNF43 were commonly detected in PJD of IPMNs, but no association with the histologic grades of IPMN was found. Instead, mutation burden was positively correlated with the histologic grade (r = 0.427, P = 0.015). We also observed frequent copy number deletions in 17p13 (TP53) and amplifications in 7q21 and 8q24 (MYC) in PJDs. The amplifications in 7q21 and 8q24 were positively correlated with the histologic grade and most prevalent in the cases of invasive carcinoma (P = 0.002 and 7/11; P = 0.011 and 6/11, respectively). We concluded that mutation burden and CNAs detected in PJD may have potential to assess the malignant progression risk of IPMNs.

Diagnostic Accuracy of Preoperative Imaging for Differentiation of Branch Duct Versus Mixed Duct Intraductal Papillary Mucinous Neoplasms

OBJECTIVE

The aim of this study is to determine the diagnostic accuracy of preoperative evaluation to detect main pancreatic duct involvement in pancreatic cystic lesions thus differentiating mixed intraductal papillary mucinous neoplasm (IPMN) from branch duct (BD)-IPMN.

METHODS

The pathology database of pancreatic resections from 2000 to 2014 was reviewed. Main pancreatic duct-IPMNs and IPMNs with intracystic mass/nodules were excluded. The preoperative test characteristics were analyzed using surgical histopathology as the "gold standard."

RESULTS

Sixty BD-IPMNs and 23 mixed-IPMNs were identified. Mixed-IPMNs were larger (mean [standard deviation], 4.14 [2.9] vs 2.74 [1.9] mm; P = 0.03) and demonstrated frequent high-grade dysplasia/adenocarcinoma (43% vs 12%, P = 0.004) than BD-IPMNs. Endoscopic ultrasound (EUS) (sensitivity, 80%; specificity, 78%; accuracy, 79%) had the best diagnostic accuracy, whereas magnetic resonance imaging (MRI) (sensitivity, 83%; specificity, 63%; accuracy, 68%) had the highest sensitivity for the diagnosis of mixed-IPMN. A combination of EUS and MRI reached maximum sensitivity but with decreased accuracy (sensitivity, 100%; specificity, 64%; accuracy, 67%). The area under the curve for receiver operation curve was 0.71 whereas the optimal cyst size to detect main duct involvement was 3 cm.

CONCLUSIONS

For preoperative evaluation of pancreatic cystic lesions without evidence of intracystic nodules, a combination of MRI and EUS should be considered for improved detection of main duct involvement.

Natural History of Patients Followed Radiographically with Mucinous Cysts of the Pancreas

OBJECTIVE

The aim of this study was to evaluate the outcome of patients presumed to have mucinous cysts of the pancreas who were initially selected for radiographic surveillance.

METHODS

Patients with a pancreatic cyst and a measured cyst fluid carcinoembryonic antigen (CEA) ≥192 ng/mL were included. Patients were stratified by those who underwent initial resection and those who were recommended for radiographic surveillance. The natural history of these two groups was examined.

RESULTS

From 1999 to 2014, 227 patients were identified who had a cyst fluid CEA ≥192 ng/mL (median 961, range 192-300,000 ng/mL). Immediate resection was performed on 63 patients (28%). Initial radiographic surveillance was recommended for 164 patients; 87% did not have main pancreatic duct dilation, and 87% met consensus criteria for radiographic surveillance. After a median follow-up of 56 months, 48 of the 164 patients (29%) had undergone resection. Ultimately, there were three cases (2%) of high-grade dysplasia and two cases of invasive carcinoma (1%) within these 164 patients selected for observation. Three of the five cases of either high-grade dysplasia or invasive carcinoma were among the 22 patients followed outside of consensus guidelines.

CONCLUSIONS

Appropriately selected patients with mucinous pancreatic cysts can be safely followed with serial surveillance with a low risk of malignant progression.

Long-Term Surveillance and Timeline of Progression of Presumed Low-Risk Intraductal Papillary Mucinous Neoplasms

OBJECTIVE

The purpose of this study was to assess risk of progression and rate of growth of presumed low-risk branch duct intraductal papillary mucinous neoplasms surveyed for more than 4 years.

MATERIALS AND METHODS

A keyword search of electronic medical charts was performed for the years 2001-2013. Cystic lesions that met the criteria for clinical branch duct intraductal papillary mucinous neoplasm, lacked baseline high-risk or worrisome features, and had more than 4 years of surveillance were included in this study. Two radiologists performed cyst size measurements to assess interreader variability. Cyst progression was defined either as 2-mm or greater or 20% or greater increase in diameter or as development of worrisome features. Kaplan-Meier curves were generated to evaluate cyst progression time and linear mixed models to evaluate growth rates.

RESULTS

The search revealed 2423 patients with cystic pancreatic lesions. Among these patients 228 had imaging follow-up for 4 or more years, and 131 met the clinical criteria for branch duct intraductal papillary mucinous neoplasms. Among the 131 cysts, 73 (55.7%) progressed: 61 (46.6%) increased in size, 10 (7.6%) increased in size and developed worrisome features, and two (1.5%) developed worrisome features only. Of the 71 cysts that increased in size, 50 (70.4%) did so within the first 5 years, and 21 (29.6%) grew after 5 years. No patient had adenocarcinoma. There was no significant difference in growth rate based on cyst size within the first 50 months. After 50 months, cysts larger than 20 mm continued to increase in size (p < 0.05) and had faster growth rates.

CONCLUSION

Among presumed low-risk branch duct intraductal papillary mucinous neoplasms, most increased in size, approximately 30% after 5 years. Cysts with baseline size larger than 20 mm continued to grow beyond 5 years at a faster rate.

Surgical treatments of cystic neoplasms of the pancreas: an Asian university hospital experience

Background

Premalignant and malignant cystic neoplasms of the pancreas are relatively rare, but absolute indications for surgical resection. Modern imaging modalities have increased recognition of asymptomatic cysts resulting in therapeutic dilemmas of whether surgery or observation is appropriate.

Objectives

To examine our surgical experience with cystic neoplasms of the pancreas.

Methods

A retrospective study of patients who had cystic neoplasms of the pancreas and underwent surgical resections from June 2000 to April 2013. Presenting symptoms, surgical procedures, pathological diagnoses, and postoperative complications were analyzed.

Results

Data from 16 patients were examined. Two patients had asymptomatic cystic neoplasms. Fourteen had symptoms ranging from 2 days to 6 years before diagnosis and surgery. Six patients underwent pylorus preserving pancreaticoduodenectomy, 4 underwent distal pancreatectomy with splenectomy, 2 underwent splenic preserving distal pancreatectomy, and 1 each underwent a classical Whipple operation, total pancreatectomy, distal pancreatectomy with splenectomy with partial resection of the posterior gastric wall, and distal pancreatectomy with splenectomy with left colectomy. The operative time ranged from 150 to 450 minutes. Operative blood transfusion ranged from 0 to 5 units. Four patients had mucinous cystadenoma, 4 had intraductal papillary mucinous neoplasia with varying degree of dysplasia and carcinomatous changes, 6 had other malignancies, and 2 had other benign cysts. Postoperative complications occurred in 3 patients. There was no perioperative mortality.

Conclusion

Any suspicion of malignant changes in asymptomatic cysts should have them considered for surgical resection. Meticulous surgical techniques are important for pancreatic resection to minimize the occurrence of postoperative complications.

Therapeutic Approach to Cystic Neoplasms of the Pancreas

Management of cystic neoplasms of the pancreas is challenging as it relies on radiologic and cyst fluid markers to discriminate between benign and pre-cancerous lesions, however their ability to predict malignancy is limited. While asymptomatic serous cystadenomas can be managed conservatively, mucinous cystic neoplasms and intraductal papillary mucinous neoplasms are more difficult to manage. A selective approach, based on the preoperative likelihood of high-grade dysplasia or invasive disease, is the standard of care. Research is focusing on the development of pre-operative markers for identifying high risk lesions, which will spare patients with low-risk or benign lesions the risks of pancreatectomy.

Stromal Fibrosis and Expression of Matricellular Proteins Correlate With Histological Grade of Intraductal Papillary Mucinous Neoplasm of the Pancreas

OBJECTIVE

The aim of the study was to clarify the correlation between the microenvironmental factors and histological grade in intraductal papillary mucinous neoplasm (IPMN).

METHODS

We investigated 65 IPMNs resected at Yamagata University Hospital between 2000 and 2011, and all cases were categorized to low-inter (including low- and intermediate-grade dysplasia) and high-inv (including high-grade dysplasia and IPMN with an associated invasive carcinoma) groups. We compared between the 2 groups pathologically with regard to fibrosis and the expression of alpha-smooth muscle actin (α-SMA), periostin, and galectin-1 in the periductal stroma of IPMN.

RESULTS

There were 41 low-inter and 24 high-inv. The subtype was categorized as 22 main duct type (MD-IPMN) and 43 branch duct type (BD-IPMN). The degree of fibrosis and the expression of α-SMA, periostin, and galectin-1 were significantly higher in high-inv than in low-inter within BD-IPMNs. Multivariate logistic regression analysis indicated that high expression of α-SMA (odds ratio, 13.802; 95% confidence interval, 1.108-171.893; P = 0.0414) was a significant independent related factor of high-inv in BD-IPMN.

CONCLUSIONS

Stromal fibrosis and expression of α-SMA, periostin, and galectin-1 are more marked in high-inv than in low-inter within BD-IPMNs, and they could become new markers for determining the indications for surgery in BD-IPMN.

Intraductal papillary mucinous neoplasm (IPMN) with high-grade dysplasia is a risk factor for the subsequent development of pancreatic ductal adenocarcinoma

BACKGROUND

Non-invasive intraductal papillary mucinous neoplasm (IPMN) with high-grade dysplasia and IPMN-associated invasive pancreatic ductal adenocarcinoma (PDAC) are frequently included under the term "malignancy". The goal of this study is to clarify the difference between these two entities.

METHODS

From 1996 to 2013, data of 616 patients who underwent pancreatic resection for an IPMN were reviewed.

RESULTS

The median overall survival for patients with IPMN with high-grade dysplasia (92 months) was similar to survival for patients with IPMN with low/intermediate-grade dysplasia (118 months, p = 0.081), and superior to that of patients with IPMN-associated PDAC (29 months, p < 0.001). IPMN-associated PDAC had lymph node metastasis in 53%, perineural invasion in 58%, and vascular invasion in 33%. In contrast, no lymph node metastasis, perineural or vascular invasion was observed with high-grade dysplasia. None of the patients with IPMN with high-grade dysplasia developed recurrence outside the remnant pancreas. In stark contrast 58% of patients with IPMN-associated PDAC recurred outside the remnant pancreas. The rate of progression within the remnant pancreas was significant in patients with IPMN with high-grade (24%) and with low/intermediate dysplasia (22%, p = 0.816).

CONCLUSION

Non-invasive IPMN with high-grade dysplasia should not be considered a malignant entity. Compared to patients with IPMN with low/intermediate-grade dysplasia, those with high-grade dysplasia have an increased risk of subsequent development of PDAC in the remnant pancreas.

Cystic micropapillary neoplasm of peribiliary glands with concomitant perihilar cholangiocarcinoma

We report a case of a 75-year-old man with cystic micropapillary neoplasm of peribiliary glands detected preoperatively by radiologic examination. Enhanced computed tomography showed a low-density mass 2.2 cm in diameter in the right hepatic hilum and a cystic lesion around the common hepatic duct. Under a diagnosis of perihilar cholangiocarcinoma, right hepatectomy with caudate lobectomy and bile duct resection were performed. Pathological examination revealed perihilar cholangiocarcinoma mainly involving the right hepatic duct. The cystic lesion was multilocular and covered by columnar lining epithelia exhibiting increased proliferative activity and p53 nuclear expression; it also contained foci of micropapillary and glandular proliferation. Therefore, the lesion was diagnosed as a cystic micropapillary neoplasm of peribiliary glands and resembled flat branch-type intraductal papillary mucinous neoplasm of the pancreas. Histological examination showed the lesion was discontinuous with the perihilar cholangiocarcinoma. Immunohistochemistry showed the cystic neoplasm was strongly positive for MUC6 and that the cholangiocarcinoma was strongly positive for MUC5AC and S100P. These results suggest these two lesions have different origins. This case warrants further study on whether this type of neoplasm is associated with concomitant cholangiocarcinoma as observed in pancreatic intraductal papillary mucinous neoplasm with concomitant pancreatic duct adenocarcinoma.

Positive surgical margins in surgically treated unifocal and multifocal IPMN

INTRODUCTION

Although treatment methods for the positive margins of surgically treated intraductal papillary mucinous neoplasms (IPMNs) are established, the significance of the positive surgical margins remains unclear. We aimed to clarify the risk factors of the positive margins and their impact on the recurrence of cystic lesions.

METHODS

Fifty-five surgically treated IPMN cases occurring at the Ogaki Municipal Hospital from 2004 to 2013 were analyzed retrospectively.

RESULTS

Out of the 55 IPMN patients who underwent pancreatectomy, positive surgical margins were found in 16 cases. Most of the positive surgical margin cases were found to be a multifocal IPMN; specifically, 9 out of 19 were a multifocal IPMN case, and 7 out of 36 were a unifocal IPMN case (47.4% and 19.4%, respectively, p = 0.030). Recurrences of cystic lesions in the remnant pancreases were found in 7 cases; 4 out of 16 cases were in the positive margin group, and 3 out of 39 were in the negative margin group (25.0% and 7.7%, respectively, p = 0.080). While a positive margin was a significant risk factor in unifocal IPMN (p = 0.031), it was not in multifocal IPMN (p = 0.90).

CONCLUSION

Positive surgical margins are frequently found in multifocal IPMNs and might include false positive margins.

The Neutrophil-to-Lymphocyte Ratio Predicts Malignant Potential in Intraductal Papillary Mucinous Neoplasms

BACKGROUND

Accurately identifying malignant components in patients with pancreatic intraductal papillary mucinous neoplasms (IPMN) remains challenging. Preoperative neutrophil-to-lymphocyte ratio (NLR) is a marker of poor prognosis in patients with several types of malignancy. This study assessed whether NLR was predictive of intraductal papillary mucinous carcinoma (IPMC) in patients with IPMN.

METHOD

This study retrospectively assessed 76 patients who underwent curative resection for IPMN from 1995 to 2015. The correlation between the presence of malignant components and preoperative NLR was analyzed.

RESULTS

Preoperative NLR in IPMC was significantly higher in patients with in IPMC (2.51 ± 0.84) than in patients with intraductal papillary mucinous adenoma (2.01 ± 0.71, P = 0.0079) and healthy volunteers (1.37 ± 0.33, P < 0.0001). NLR was significantly reduced after curative tumor resection. The main duct type (P = 0.0231) and NLR >2.074 (P = 0.0329) were independent predictors of IPMC in all patients. Combined criteria including international consensus guidelines, CA19-9 >37 IU/ml, and NLR >2.074 shows a high positive predictive value of 78 % and high specificity of 96 %.

CONCLUSIONS

Preoperative NLR is a useful supportive marker to predict IPMC in patients with IPMN.

Assessment of Malignant Potential in Intraductal Papillary Mucinous Neoplasms of the Pancreas: Comparison between Multidetector CT and MR Imaging with MR Cholangiopancreatography

PURPOSE

To compare the diagnostic performance of multidetector computed tomography (CT) and magnetic resonance (MR) imaging with MR cholangiopancreatography (MRCP) in identifying the malignant potential of pancreatic intraductal papillary neoplasms (IPMNs) and evaluate their intermodality agreement.

MATERIALS AND METHODS

Institutional review board approval was obtained, and the requirement for informed consent was waived for this retrospective study. In 129 patients with pathologically proved pancreatic IPMNs, three reviewers independently evaluated their preoperative CT and MR imaging with MRCP findings. Intermodality agreement between multidetector CT and MR imaging with MRCP, as well as interobserver agreement of each imaging modality, for depicting high-risk stigmata and worrisome features were assessed. Diagnostic values of other signs of overt malignancy, including the presence of a parenchymal mass and local-regional extension, were analyzed. Diagnostic performance and intermodality agreement were assessed by using receiver operating characteristics (ROC) curve analysis and weighted κ statistics.

RESULTS

Overall, multidetector CT and MR imaging with MRCP were similar in their ability to depict signs suspicious or indicative of malignancy in patients with IPMN (area under the ROC curve [AUC] = 0.82 for both), with good intermodality agreement (κ = 0.75) and moderate interobserver agreement (κ = 0.47-0.59) when high-grade dysplasia was used as the cutoff for malignancy. When parenchymal masses and local-regional extensions were also considered as overt signs of malignancy, the ability to identify invasive IPMNs significantly increased (AUC = 0.87 for CT and AUC = 0.88 for MR imaging), with high sensitivity (94.3%), while maintaining specificity (69.1%).

CONCLUSION

The diagnostic performance of multidetector CT and MR imaging with MRCP for identifying the malignant potential of pancreatic IPMNs was similar and showed good intermodality agreement, suggesting that follow-up with either modality may be used.

Prevalence of extra-pancreatic cysts in patients with cystic pancreatic lesions detected by endoscopic ultrasound

Background and Objectives:

Extra-pancreatic cysts (EPCs) are incidentally found in patients with pancreatic cystic lesions (PCLs). The aim of this study is to find the prevalence of concurrent EPC in patients with PCLs, investigate associations with neoplastic lesions, and compare the prevalence of EPC to a control population.

Materials and Methods:

A retrospective study of patients who underwent endoscopic ultrasound (EUS) over a 3-year period. The study group consisted of patients with PCLs. The control group included equal number of matched (age and sex) patients who had undergone EUS for reasons other than evaluation of PCLs. All patients had undergone computed tomography (CT) that was reviewed for EPCs.

Results:

A total of 191 patients were found to have PCLs. One patient with Von Hippel-Lindau (VHL) disease was excluded. Majority of the patients were female (60%); most PCLs were solitary (68.9%), unilocular (56.8%), predominantly located in the head of the pancreas (37.4%); and mean PCL diameter was 28.12 ± 18.4mm. EUS-guided fine-needle aspiration (FNA) was performed in 171 (90%) patients with 73 (42.7%) PCLs demonstrating cysts with benign epithelial cells, 37 (21.6%) mucinous cysts, 18 (10.5%) mucinous adenocarcinomas, 11 (6.4%) neuroendocrine tumors, nine intraductal papillary mucinous cystic neoplasms (IPMNs), six pseudocysts, five serous cyst adenomas (SCAs), and five with inadequate sampling. An EPC was observed in 97 of 190 (51.18%) patients with PCLs and in 67 of 190 (35.3%) controls (P < 0.001). The distribution of EPCs in PCL patients and controls (n = 190) were 32.1% vs. 15.8% (P < 0.001) for liver cysts, 30.0% vs. 20.5% (P = 0.04) for renal cysts, and 3.7% vs. 1.6% (P = 0.34) for cysts in other organs. Mean liver cyst diameter (15.6 mm vs. 10.1 mm, P = 0.23) and renal cyst diameter (20.4 mm vs. 20.1 mm, P = 0.95) were not statistically different in PCL patients compared to controls. Multivariate analysis demonstrated that among patients with PCLs, EPCs increased with age (mean age 69.6 vs. 62.4 years, P ≤ 0.001, odds ratio (OR) 1.06, 95% confidence interval (CI) 1.03, 1.09), and male gender was associated with higher chance of finding renal cysts (OR 2.17, P = 0.021, 95% CI 1.13, 4.19). There was no association between FNA result and prevalence or type of EPC.

Conclusion:

The prevalence of EPCs in patients with PCLs was significantly higher than in a matched control group. Among patients with PCLs, a liver cyst is the most common EPC. Increasing age is associated with higher prevalence of EPCs.

Branch duct intraductal papillary mucinous neoplasm of the pancreas: single-center experience with 324 patients who underwent surgical resection

Backgrounds/Aims

International treatment guidelines for branch duct intraductal papillary mucinous neoplasm (BD-IPMN) of the pancreas have been proposed, for features associated with malignancy and invasiveness. We investigated the clinicopathological characteristics that are predictive of malignancy or invasiveness and disease recurrence.

Methods

A review of 324 patients with resected and pathologically confirmed BD-IPMN, between March 1997 and December 2013, was conducted.

Results

There were 144 (44.4%) low grade dysplasia (LGD), 138 (42.6%) intermediate grade dysplasia (IMGD), 17 (5.3%) high grade dysplasia (HGD), and 25 (7.7%) invasive carcinoma (invIPMC) cases. The 5-year survival rates were 98.1% for LGD, 95.3% for IMGD, 100% for HGD, and 71.8% for invIPMC. Through a univariate analysis, the male sex was associated with malignancy, and CA19-9 was related to both malignant and invasive IPMN. The high risk or worrisome features of the international guidelines were associated with both malignant and invasive IPMN: the total bilirubin of the head/uncinate lesion, tumor size, mural nodule, and the size of the main pancreatic duct (MPD). Through a multivariate analysis, the male sex, elevated CA19-9, mural nodule, and dilated MPD diameter were independently correlated with the malignant IPMN. The elevated CA19-9 and dilated MPD diameter were also correlated with invasive carcinoma. The patient age and the initial pathological diagnosis were strongly associated with disease recurrence following surgical resection.

Conclusions

The high risk or worrisome features in the current treatment guidelines for BD-IPMN are confined to the morphological characteristics of the disease. Patient factors and biological features should also be considered in order to develop optimal therapeutic or surveillance strategies.

Natural History and Management of Intraductal Papillary Mucinous Neoplasms: Current Evidence

Background

With the use of modern cross-sectional abdominal imaging modalities, an increasing number of cystic pancreatic lesions are identified incidentally. Although there is no pathological diagnosis available in most cases, it is believed that the majority of these lesions display small branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) of the pancreas. Even though a number of large clinical series have been published, many uncertainties remain with regard to this entity of mucinous cystic neoplasms.

Methods

Systematic literature review.

Results

Main-duct (MD) and mixed-type IPMNs harbor a high risk of malignant transformation. It is conceivable that most IPMNs with involvement of the main duct tend to progress to invasive carcinoma over time. Thus, formal oncologic resection is the treatment of choice in surgically fit patients. In contrast, the data regarding BD-IPMN remain equivocal, resulting in conflicting concepts. To date, it is not clear whether and which BD-IPMNs progress to carcinoma and how long this progression takes.

Conclusion

While patients with MD-IPMNs should undergo surgical resection if comorbidities and life expectancy permit this, the management of small BD-IPMNs remains controversial. Population-based studies with long-term follow-up are needed to define which cohort of patients can be observed safely without immediate resection.

IPMN involving the main pancreatic duct: biology, epidemiology, and long-term outcomes following resection

OBJECTIVES

To describe the characteristics of intraductal papillary mucinous neoplasms (IPMNs) with predominant involvement of the main pancreatic duct (MPD), analyzing predictors for survival and recurrence.

BACKGROUND

IPMNs involving the MPD harbor a high likelihood of malignancy and different biological features. The appropriateness of including cases with minimal noncircumferential MPD involvement has been challenged because these show clinicopathological features that are similar to branch duct IPMN. Accordingly, their exclusion has led to a redefinition of MPD IPMN (MD-IPMN).

METHODS

Retrospective review of resected MD-IPMN from 1990 to 2013. All slides were reviewed by a single pancreatic pathologist and classified on the basis of epithelial type and invasive component.

RESULTS

A total of 223 patients underwent resection for IPMN involving the MPD. Of these, 50 were excluded because of minimal MPD involvement. Among the 173 patients analyzed, median age was 68 years and 55% were males. Predominant epithelial phenotype was intestinal (50%). Forty-eight patients (28%) had low- or intermediate-grade dysplasia, whereas 125 (72%) had either high-grade dysplasia (33%) or invasive carcinoma (39%). Of the 67 invasive IPMNs, 39 were tubular carcinomas (58%) and invasion was minimal (<5 mm) in 28 (42%). The 5-year overall survival rate was 69% and the disease-specific survival rate was 83%. The estimated recurrence rate at 10 years was 25%. Size and type of the invasive component, lymph node positivity, and a positive resection margin were predictors for both survival and recurrence (P < 0.05).

CONCLUSIONS

MD-IPMN is mainly intestinal-type and malignant. After resection, it has a very favorable prognosis, especially in the absence of macroscopic invasive carcinoma.

Pancreatic cystic neoplasms: Review of current knowledge, diagnostic challenges, and management options

Pancreatic cystic lesions are being detected with increasing frequency, largely due to advances in cross-sectional imaging. The most common neoplasms include serous cystadenomas, mucinous cystic neoplasms, intraductal papillary mucinous neoplasms, solid pseudopapillary neoplasms, and cystic pancreatic endocrine neoplasms. Computed tomography (CT), magnetic resonance imaging (MRI), and endoscopic ultrasound (EUS) are currently used as imaging modalities. EUS-guided fine needle aspiration has proved to be a useful diagnostic tool, and enables an assessment of tumor markers, cytology, chemistries, and DNA analysis. Here, we review the current literature on pancreatic cystic neoplasms, including classification, diagnosis, treatment, and recommendations for surveillance. Data for this manuscript was acquired via searching the literature from inception to December 2014 on PubMed and Ovid MEDLINE.

Surgical treatment and prognosis of 96 cases of intraductal papillary mucinous neoplasms of the pancreas: a retrospective cohort study

INTRODUCTION

The indications, the extent and type of surgery for intraductal papillary mucinous neoplasm (IPMN) are still controversial. This study aimed to investigate clinical manifestation, individualized surgical treatment, and prognosis of IPMN of pancreas.

METHODS

The clinical data of 96 IPMN cases treated in our hospital between January 2006 and December 2013 were retrospectively analyzed. Among the 96 patients (58 male and 38 female), 46 were main-duct type, 29 were branch-duct type, 21 were mixed type. Pancreatectomy was performed on 78 cases, including pancreaticoduodenectomy on 43 patients, distal pancreatectomy on 25, segmental pancreatectomy on 6, and total pancreatectomy on 4. A regular follow-up without surgical treatment was performed on 18 cases with asymptomatic side branch IPMN less than 3 cm in diameter.

RESULTS

The overall postoperative morbidity rate was 33.3%, and there was no perioperative mortality. 46 cases were non-invasive IPMN, 32 cases were invasive IPMN including 14 cases with lymph node metastasis. The five-year survival rate for patients with non-invasive and invasive carcinomas was 96.2% and 35.2%, respectively. The prognosis of invasive cases with lymph node metastasis was significantly worse than those without lymph node metastasis. No progression was found during the follow-up in 18 asymptomatic small branch duct type IPMN patients.

CONCLUSION

IPMN has a relative good prognosis. Main duct type and mixed type IPMN have a higher malignant potential, and should receive surgical treatment. Patients of branch duct type IPMN with lesion <3 cm in diameter and without clinical manifestations can be managed with close follow-up.

An increased total resected lymph node count benefits survival following pancreas invasive intraductal papillary mucinous neoplasms resection: an analysis using the surveillance, epidemiology, and end result registry database

Background

The therapeutic effect of lymph node dissection for pancreas invasive intraductal papillary mucinous neoplasms (IPMN) remains unclear. The study investigated whether cancer-specific survival (CSS) and overall survival (OS) rates among invasive IPMN patients improve when more lymph nodes are harvested during surgery.

Study Design

The study cohort was retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. The lymph node count was categorized into quartiles. The relationship between lymph node count and survival was analyzed using Kaplan–Meier curves and a Cox proportional-hazards model. The stage migration was assessed by Chi-square tests. Propensity score matching (PSM) was used to minimize confounding variables between groups.

Results

In total, 1,080 patients with resected invasive IPMNs from 1992 to 2011 were included. Univariate and multivariate Cox models indicated that an increased lymph node count independently improves survival. The Kaplan-Meier and log-rank tests identified 16 nodes as an optimal cut-off value that yielded a significant survival benefit for all invasive IPMN patients. The stage migration effect existed in this cohort. After PSM, the 5-year CSS increased from 36% to 47%, and the median survival rate increased from 30 months to 40 months by increasing the lymph node count to over 16, alone. The 5-year OS rate also provided additional support for this result.

Conclusion

Increased lymph node counts were associated with improved survival in invasive IPMN patients. One cut-off value of lymph node count was 16 for this improvement.

EZH2 is associated with malignant behavior in pancreatic IPMN via p27Kip1 downregulation

BACKGROUND

The epigenetic mechanism of tumorigenesis in pancreatic intraductal papillary mucinous neoplasm (IPMN) remains largely unknown. The aim of this study is to examine the role of enhancer of zeste homologue 2 (EZH2) alteration in pancreatic IPMN progression.

METHODS

Fifty-four surgically resected pancreatic IPMN specimens, including a total of 181 lesions (normal duct in 48, adenoma in 50, borderline atypia in 53, carcinoma in situ (CIS) in 19, and invasive carcinoma in 11) were analyzed by immunohistochemical staining (EZH2, Ki-67, p27Kip1). Using paraffin embedded sections, total RNA was successfully extracted from 20 IPMN lesions (borderline IPMN in 9, CIS in 6, invasive carcinoma in 5) and 7 pancreatic normal ducts, and then levels of EZH2 and p27Kip1 mRNA were analyzed by real time PCR.

RESULTS

In immunohistochemical analysis, cell proliferative activity revealed by Ki-67 positive nuclei was increased during IPMN progression (normal duct<adenoma<borderline atypia<CIS ≈ invasive carcinoma). EZH2 expression displayed a similar pattern (normal duct<adenoma<borderline atypia<CIS ≈ invasive carcinoma) with cell proliferative activity. EZH2 expression in malignant (CIS and invasive carcinoma) IPMNs was significantly higher than that in adenoma and borderline-atypia IPMNs. EZH2 expression level in IPMN lesions was positively correlated with the Ki-67 positive nuclear ratio (p<0.0001). EZH2-positive cells in malignant IPMN did not express p27Kip1. EZH2 mRNA expressions in malignant lesions were significantly higher than those in benign lesions (p<0.0001). In contrast, p27Kip1 mRNA in malignant lesions was significantly decreased compared to those in benign lesion (p<0.05), and there was an inverse correlation between EZH2 and p27Kip1 mRNA levels (p = 0.0109).

CONCLUSION

EZH2 is associated with the accelerated cell proliferation and malignant step in pancreatic IPMN via the downregulation of p27Kip1.

Systematic review and meta-analysis comparing the surgical outcomes of invasive intraductal papillary mucinous neoplasms and conventional pancreatic ductal adenocarcinoma

OBJECTIVE

The aim of this study was to summarize the current literature comparing the surgical outcomes of invasive intraductal papillary mucinous neoplasms (IPMN(INV)) and conventional pancreatic ductal adenocarcinomas (PDAC) in order to determine the differences in disease characteristics and prognosis.

METHODS

Systematic review of the literature yielded 12 comparative studies reporting the clinicopathological characteristics and overall survival (OS) of 1,450 patients with IPMN(INV) with 19,304 patients with conventional PDAC.

RESULTS

IPMN(INV) had a significantly lower likelihood of tumors extending beyond the pancreas [27.6 vs. 94.3 %; T4 vs. T1: odds ratio (OR) 0.111, 95 % confidence intervals (CI) 0.057-0.214], nodal metastasis (45.4 vs. 62.9 %: OR 0.507, 95 % CI 0.347-0.741), positive margin (14.2 vs. 28.3 %; OR 0.438, 95 % CI 0.322-0.596), perineural invasion (49.2 vs. 76.5 %; OR 0.304, 95 % CI 0.106-0.877) and vascular invasion (25.2 vs. 45.7 % OR 0.417, 95 % CI 0.177-0.980) when compared with PDAC. The 5-year OS of IPMN(INV) was significantly better than PDAC [31.4 vs. 12.4 %: hazard ratio (HR) 0.659, 95 % CI 0.574-0.756]. The tubular subtype had a poorer 5-year OS and demonstrated significantly more aggressive features such as nodal metastases, vascular invasion, and perineural invasion compared with the colloid subtype.

CONCLUSION

IPMN(INV) were significantly more likely to present at an earlier stage and were less likely to demonstrate nodal involvement, perineural invasion and vascular invasion. When controlled for stage, IPMN(INV) had an improved OS when compared with PDAC in the early stages.

Does preoperative cross-sectional imaging accurately predict main duct involvement in intraductal papillary mucinous neoplasm?

Main pancreatic duct (MPD) involvement is a well-demonstrated risk factor for malignancy in intraductal papillary mucinous neoplasm (IPMN). Preoperative radiographic determination of IPMN type is heavily relied upon in oncologic risk stratification. We hypothesized that radiographic assessment of MPD involvement in IPMN is an accurate predictor of pathological MPD involvement. Data regarding all patients undergoing resection for IPMN at a single academic institution between 1992 and 2012 were gathered prospectively. Retrospective analysis of imaging and pathologic data was undertaken. Preoperative classification of IPMN type was based on cross-sectional imaging (MRI/magnetic resonance cholangiopancreatography (MRCP) and/or CT). Three hundred sixty-two patients underwent resection for IPMN. Of these, 334 had complete data for analysis. Of 164 suspected branch duct (BD) IPMN, 34 (20.7%) demonstrated MPD involvement on final pathology. Of 170 patients with suspicion of MPD involvement, 50 (29.4%) demonstrated no MPD involvement. Of 34 patients with suspected BD-IPMN who were found to have MPD involvement on pathology, 10 (29.4%) had invasive carcinoma. Alternatively, 2/50 (4%) of the patients with suspected MPD involvement who ultimately had isolated BD-IPMN demonstrated invasive carcinoma. Preoperative radiographic IPMN type did not correlate with final pathology in 25% of the patients. In addition, risk of invasive carcinoma correlates with pathologic presence of MPD involvement.

Intranuclear cytoplasmic inclusions are a specific feature of intraductal papillary mucinous neoplasms that distinguish contaminating gastric epithelium

INTRODUCTION

Low-grade intraductal papillary mucinous neoplasms (IPMN) are challenging to diagnose because of an absence of reliable morphologic or immunohistochemical features to distinguish them from contaminating gastric foveolar epithelium. After noting intranuclear cytoplasmic inclusions (ICIs) in some cases of IPMN, we investigated whether ICIs could be used as a specific feature to distinguish IPMN from gastric foveolar epithelium.

MATERIALS AND METHODS

A consecutive cohort of 61 transduodenal endoscopic fine-needle aspirations of histologically or clinically verified pancreatic IPMNs without high-grade dysplasia from 2005 to 2012 were identified. A control cohort of 24 endoscopic fine-needle aspirations containing gastric epithelium was selected from transgastric specimens of nonpancreatic targets from the same period. Every fragment of mucinous epithelium in the 2 cohorts was examined in alcohol-fixed and cell block sections at high magnification to identify ICIs.

RESULTS

ICIs were observed in 31% (19 of 61) of cases in mucinous epithelial fragments obtained by fine-needle aspirations from low-grade IPMNs. When present, they were seen in about 1% of all cells. No ICIs were identified in the control cohort of 24 patients with normal gastric epithelium (P = 0.001 Fisher exact test). BRAF mutation (V600E) testing was performed on 5 IPMN cases, and was negative in all cases including 2 with and 3 without ICIs. KRAS mutation testing was performed on 9 cases of IPMN cases. Two cases with ICIs tested positive for KRAS mutations. Four cases without ICIs also tested positive, and 3 cases without ICIs tested negative.

CONCLUSIONS

ICIs are a specific morphologic feature found in about one third of low-grade IPMNs, but absent in gastric foveolar epithelium. There is no obvious molecular correlate with the presence of ICIs.

Metabolic system alterations in pancreatic cancer patient serum: potential for early detection

Background

The prognosis of pancreatic cancer (PC) is one of the poorest among all cancers, due largely to the lack of methods for screening and early detection. New biomarkers for identifying high-risk or early-stage subjects could significantly impact PC mortality. The goal of this study was to find metabolic biomarkers associated with PC by using a comprehensive metabolomics technology to compare serum profiles of PC patients to healthy control subjects.

Methods

A non-targeted metabolomics approach based on high-resolution, flow-injection Fourier transform ion cyclotron resonance mass spectrometry (FI-FTICR-MS) was used to generate comprehensive metabolomic profiles containing 2478 accurate mass measurements from the serum of Japanese PC patients (n=40) and disease-free subjects (n=50). Targeted flow-injection tandem mass spectrometry (FI-MS/MS) assays for specific metabolic systems were developed and used to validate the FI-FTICR-MS results. A FI-MS/MS assay for the most discriminating metabolite discovered by FI-FTICR-MS (PC-594) was further validated in two USA Caucasian populations; one comprised 14 PCs, six intraductal papillary mucinous neoplasims (IPMN) and 40 controls, and a second comprised 1000 reference subjects aged 30 to 80, which was used to create a distribution of PC-594 levels among the general population.

Results

FI-FTICR-MS metabolomic analysis showed significant reductions in the serum levels of metabolites belonging to five systems in PC patients compared to controls (all p<0.000025). The metabolic systems included 36-carbon ultra long-chain fatty acids, multiple choline-related systems including phosphatidylcholines, lysophosphatidylcholines and sphingomyelins, as well as vinyl ether-containing plasmalogen ethanolamines. ROC-AUCs based on FI-MS/MS of selected markers from each system ranged between 0.93 ±0.03 and 0.97 ±0.02. No significant correlations between any of the systems and disease-stage, gender, or treatment were observed. Biomarker PC-594 (an ultra long-chain fatty acid), was further validated using an independently-collected US Caucasian population (blinded analysis, n=60, p=9.9E-14, AUC=0.97 ±0.02). PC-594 levels across 1000 reference subjects showed an inverse correlation with age, resulting in a drop in the AUC from 0.99 ±0.01 to 0.90 ±0.02 for subjects aged 30 to 80, respectively. A PC-594 test positivity rate of 5.0% in low-risk reference subjects resulted in a PC sensitivity of 87% and a significant improvement in net clinical benefit based on decision curve analysis.

Conclusions

The serum metabolome of PC patients is significantly altered. The utility of serum metabolite biomarkers, particularly PC-594, for identifying subjects with elevated risk of PC should be further investigated.

Gemcitabine in patients with intraductal papillary mucinous neoplasm with an associated invasive carcinoma of the pancreas

OBJECTIVES

The standard chemotherapy for invasive ductal carcinoma of the pancreas (IDC) is gemcitabine; however, the efficacy of gemcitabine in invasive intraductal papillary mucinous neoplasm with an associated invasive carcinoma of the pancreas (IPMN-IC) is still unknown.

METHODS

Because it is difficult to distinguish between IPMN-IC and IDC based only on radiological findings in advanced unresectable cases, recurrent cases after surgical resection were analyzed to identify the efficacy of gemcitabine monotherapy for IPMN-IC.

RESULTS

Between 1992 and 2010, 128 patients with IPMN-IC and 548 patients with IDC underwent pancreatic resection at the National Cancer Center Hospital. Twelve patients with IPMN-IC and 73 patients with IDC had recurred after surgery and subsequently underwent gemcitabine at the standard dosage. The disease-control rates were comparable between the IPMN-IC and IDC patients (58.3% vs 59.4%). The median progression-free survival was 2.8 and 4.1 months in the IPMN-IC and IDC patients, respectively (P = 0.46). Also, no statistically significant difference in the median survival times was observed between the 2 groups (9.3 vs 8.8 months, respectively; P = 0.09).

CONCLUSIONS

Among patients who had IPMN-IC and IDC with recurrent disease after resection, there was no significant difference in treatment outcomes after gemcitabine.

aPKCλ/ι is a beneficial prognostic marker for pancreatic neoplasms

Pancreatic cancer is a lethal disease. Overall survival is typically 6 months from diagnosis. Determination of prognostic factors in pancreatic cancer that would allow identification of patients who could potentially benefit from aggressive treatment is important. However, until date, there are no established reliable prognostic factors for pancreatic cancer patients. Herein, we propose a beneficial biomarker which is significantly correlated with the prognosis in pancreatic cancer patients. Atypical protein kinase C λ/ι (aPKCλ/ι) is overexpressed and has been implicated in the progression of several cancers. We tested the expression levels of aPKCλ/ι in two types of pancreatic neoplasm, pancreatic ductal adenocarcinoma (PDAC) and intraductal papillary mucinous neoplasms (IPMNs), by immunohistochemistry. Examination of the aPKCλ/ι expression levels in surgically resected specimens of PDCA (n = 115) demonstrated that the expression levels of aPKCλ/ιin PDAC had prognostic implications, independent of the Tumor-Node-Metastasis classification and World Health Organization tumor grade. In the case of IPMNs (n = 46) also, the expression levels of aPKCλ/ιin IPMN were found to be of prognostic importance, independent of the World Health Organization histological grade or morphological type. Interestingly, high expression levels of aPKCλ/ι were significantly correlated with a worse histological grade (p = 0.010) and advanced stage of the tumor (p = 0.0050) in IPMN patients. These findings suggest that high expression levels of aPKCλ/ι could be involved in the malignant transformation of IPMNs. Based on these observations, we propose the expression level of aPKCλ/ι as a prognostic marker common to different types of pancreatic neoplasms.

Imaging of indeterminate pancreatic cystic lesions: a systematic review

BACKGROUND

Pancreatic cystic lesions are an increasing problem and investigation of these cysts can be fraught with difficulty. There is currently no gold standard for diagnosis or surveillance. This review was undertaken to determine the present reliability of the characterisation, assessment of malignant potential and diagnosis of pancreatic cystic lesions using available imaging modalities.

METHODS

A Medline search using the terms 'pancreatic', 'pancreas', 'cyst', 'cystic', 'lesions', 'imaging', 'PET'. 'CT', 'MRI' and 'EUS' was performed. Publications were screened to include studies examining the performance of CT, MRI, MRCP, EUS and 18-FDG PET in the determination of benign or malignant cysts, cyst morphology and specific diagnoses.

RESULTS

Nineteen studies were identified that met the inclusion criteria. 18-FDG PET had a sensitivity and specificity of 57.0-94.0% and 65.0-97.0% and an accuracy of 94% in determining benign versus malignant cysts. CT had a sensitivity and specificity of 36.3-71.4% and 63.9-100% in determining benign disease but had an accuracy of making a specific diagnosis of 39.0-44.7%. MRI had a sensitivity and specificity of 91.4-100.0% and 89.7% in assessing main pancreatic duct communication.

CONCLUSION

CT is a good quality initial investigation to be used in conjunction with clinical data. MRCP can add useful information regarding MPD communication but should be used judiciously. PET may have a role in equivocal cases to determine malignancy. Further examination of CT-PET in this patient group is warranted.