Intraductal papillary mucinous neoplasms of the pancreas

Intra-ampullary Papillary Tubular Neoplasm (IAPN): Clinicopathologic Analysis of 72 Cases Highlights the Distinctive Characteristics of a Poorly Recognized Entity

The guidelines recently recognized the intra-ampullary papillary tubular neoplasm (IAPN) as a distinct tumor entity. However, the data on IAPN and its distinction from other ampullary tumors remain limited. A detailed clinicopathologic analysis of 72 previously unpublished IAPNs was performed. The patients were: male/female=1.8; mean age=67 years (range: 42 to 86 y); mean size=2.3 cm. Gross-microscopic correlation was crucial. From the duodenal perspective, the ampulla was typically raised symmetrically, with a patulous orifice, and was otherwise covered by stretched normal duodenal mucosa. However, in 6 cases, the protrusion of the intra-ampullary tumor to the duodenal surface gave the impression of an "ampullary-duodenal tumor," with the accurate diagnosis of IAPN established only by microscopic correlation illustrating the abrupt ending of the lesion at the edge of the ampulla. Microscopically, the preinvasive component often revealed mixed phenotypes (44.4% predominantly nonintestinal). The invasion was common (94%), typically small (mean=1.2 cm), primarily pancreatobiliary-type (75%), and showed aggressive features (lymphovascular invasion in 66%, perineural invasion in 41%, high budding in 30%). In 6 cases, the preinvasive component was pure intestinal, but the invasive component was pancreatobiliary. LN metastasis was identified in 42% (32% in those with ≤1 cm invasion). The prognosis was significantly better than ampullary-ductal carcinomas (median: 69 vs. 41 months; 3-year: 68% vs. 55%; and 5-year: 51% vs. 35%, P =0.047). In conclusion, unlike ampullary-duodenal carcinomas, IAPNs are often (44.4%) predominantly nonintestinal and commonly (94%) invasive, displaying aggressive features and LN metastasis even when minimally invasive, all of which render them less amenable to ampullectomy. However, their prognosis is still better than that of the "ampullary-ductal" carcinomas, with which IAPNs are currently grouped in CAP protocols (while IAPNs are kindreds of intraductal tumors of the pancreatobiliary tract, the latter represents the ampullary counterpart of pancreatic adenocarcinoma/cholangiocarcinoma).

Clinical development of a blood biomarker using apolipoprotein-A2 isoforms for early detection of pancreatic cancer

BACKGROUND

We have previously reported apolipoprotein A2-isoforms (apoA2-is) as candidate plasma biomarkers for early-stage pancreatic cancer. The aim of this study was the clinical development of apoA2-is.

METHODS

We established a new enzyme-linked immunosorbent sandwich assay for apoA2-is under the Japanese medical device Quality Management System requirements and performed in vitro diagnostic tests with prespecified end points using 2732 plasma samples. The clinical equivalence and significance of apoA2-is were compared with CA19-9.

RESULTS

The point estimate of the area under the curve to distinguish between pancreatic cancer (n = 106) and healthy controls (n = 106) was higher for apoA2-ATQ/AT [0.879, 95% confidence interval (CI): 0.832-0.925] than for CA19-9 (0.849, 95% CI 0.793-0.905) and achieved the primary end point. The cutoff apoA2-ATQ/AT of 59.5 μg/mL was defined based on a specificity of 95% in 2000 healthy samples, and the reliability of specificities was confirmed in two independent healthy cohorts as 95.3% (n = 106, 95% CI 89.4-98.0%) and 95.8% (n = 400, 95% CI 93.3-97.3%). The sensitivities of apoA2-ATQ/AT for detecting both stage I (47.4%) and I/II (50%) pancreatic cancers were higher than those of CA19-9 (36.8% and 46.7%, respectively). The combination of apoA2-ATQ/AT (cutoff, 59.5 μg/mL) and CA19-9 (37 U/mL) increased the sensitivity for pancreatic cancer to 87.7% compared with 69.8% for CA19-9 alone. The clinical performance of apoA2-is was blindly confirmed by the National Cancer Institute Early Detection Research Network.

CONCLUSIONS

The clinical performance of ApoA2-ATQ/AT as a blood biomarker is equivalent to or better than that of CA19-9.

Distinct Genomic Profiles of Two Small Malignant Lesions Associated With an Intraductal Papillary Mucinous Neoplasm Co-occurring in a Patient

Intraductal papillary mucinous neoplasm of the pancreas (IPMN) is characterized by cystic dilatation of the pancreatic duct system, intraductal papillary growth, and excessive mucin secretion. Although IPMN is basically a benign disease and surgical resection is not necessary, it has the potential to develop into pancreatic cancer. We recently encountered a rare case of synchronous development of two different types of malignant lesions in the pancreas associated with IPMN derived from different clones. A 74-year-old Japanese woman developed a cystic lesion in her pancreatic tail. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) was performed on two low echoic lesions in the pancreatic tail (10 mm) and body (10 mm), which were then diagnosed as malignancies. After the surgically resected pancreas was carefully examined, in addition to the tail (10 mm) and body (10 mm) tumors, an intraductal papillary mucinous adenoma (IPMA) was observed, which was continuous to the tail tumor and extending toward the body of the pancreas but not contiguous to the body tumor. Genomic analysis using targeted sequencing revealed that the malignant lesion in the pancreatic tail and two sections of adjacent IPMA lesions in the pancreatic duct were almost identical. KRAS G12D, RNF43 G29fs, PBRM1 P1471R, and PIK3CA I1058L were shared, whereas only KRAS G12D was shared between the malignant lesion in the pancreatic body and others. Multiple pancreatic cancers may occur simultaneously and/or metachronously in the context of genomic alterations in IPMN.

Surveillance of Pancreatic Cystic Neoplasms

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

Performance of the 7 th and 8 th Editions of the American Joint Committee on Cancer Staging System in Patients with Intraductal Papillary Mucinous Neoplasm-Associated PDAC : A Multi-institutional Analysis

OBJECTIVE

To validate the 7 th and 8 th editions of the AJCC staging system for patients with invasive carcinomas arising in association with IPMN (IPMN-associated PDAC).

BACKGROUND DATA

Although several studies have validated AJCC systems in patients with conventional PDAC, their applicability to IPMN-associated PDAC has not been assessed.

METHODS

Two hundred seventy-five patients who underwent resection for IPMN-associated PDAC between 1996 and 2015 at 3 tertiary centers and had data on the size of the invasive component and lymph node status were identified. Concordance probability estimates (CPE) were calculated and recursive partitioning analysis was employed to identify optimal prognostic cutoffs for T and N.

RESULTS

The CPE for the 7 th and 8 th editions of the AJCC schema were relatively good (0.64 for both) and similar for colloid and tubular subtypes (0.64 for both). The 8 th edition introduced T1a sub-staging and a new distinction between N1 and N2. The utility of the former was confirmed, although the latter did not improve prognostic discrimination. The successful validation of the 8th edition of the AJCC criteria in patients with tubular and colloid subtypes allowed us to compare these patients in early vs late T and N stages which showed that with advanced disease, the prognostic superiority of colloid tumors over their tubular counterparts diminishes.

CONCLUSIONS

Our findings support the use of the AJCC 8 th edition in the IPMN-associated PDAC population, but suggest that certain cutoffs may need to be revisited. In advanced AJCC stages, patients with colloid vs tubular subtypes have comparable prognosis.

Pancreatic Cystic Tumors: A Single-Center Observational Study

Background and Objectives: The aim of the study was to analyze the prevalence and characteristics of pancreatic cystic tumors (PCTs). Material and Methods: A retrospective analysis of the medical records of 124 patients, 102 (69%) women and 46 (31%) men, who had undergone surgery for pancreatic cystic tumors in 2014-2018. Among 148 pancreatic cysts, 24 (16%) were non-neoplasmatic and 124 (84%) were neoplasmatic. The neoplasmatic cysts (n = 124) were included in our analysis. There were five main types of PCTs: IPMN (intraductal papillary mucinous neoplasm) (n = 45), MCN (mucinous cystic neoplasm) (n = 30), SCN (serous cystic neoplasm) (n = 28), SPN (solid pseudopapillary neoplasm) (n = 8), and CPEN (cystic pancreatic endocrine neoplasm) (n = 8), as well as mixed-type tumors (n = 5). Results: A statistically significant dependency between PCT type and age was proven (p= 0.0001): IPMNs were observed in the older group of patients with an average age of 66.12 (40-79) years while SPNs were noted in the youngest group of patients with an average age of 36.22 (22-55) years. A statistically significant association between PCT type and gender (p = 0.0001) was found: IPMNs occurred among 24 (53.33%) men and 21 (46.6%) women. In the MCN and SPN groups, all patients were female (100%). Among the SCN group, the majority were women (27 (96.43%)), and there was only 1 (3.57%) man. A statistically significant dependency between PCT type and size was proven (p = 0.0007). The mean size of IPMNs was the smallest 2.95 (0.6-10 cm) and the mean size of MCNs was the largest 6.78 (1.5-19 cm). A statistically significant dependency between PCT type and tumor location was proven (p = 0.000238). The most frequent location of IPMN was the pancreatic head: 27 (60%). MCN was most frequently located in the pancreatic tail (18 (60%)). Most (10/28) SCNs were found in the pancreatic tail (10 (35.71%)). CPENs were most frequently located in the pancreatic tail (three (37.5%)) and pancreatic body and tail (three (37.5%)). SPNs were located commonly in the pancreatic head (five (62.5%)). The type of surgery depended on the tumor location. The most frequent surgery for IPMNs was pancreatoduodenectomy (44.4%), while for MCNs and SCNs, it was distal pancreatectomy (81%). The postoperative morbidity and mortality were 34.68% and 1.61%, respectively. Postoperative pancreatic fistula (POPF) was the most frequent (29%) complication. Conclusions: IPMN was the most frequent resected PCT in our material. A statistically significant association between the type of cyst and location within the pancreas, size, local lymph node involvement, and patient's age and sex was proved. POPF was the most frequent postoperative complication. In patients with PCTs, due to substantial postoperative morbidity, adequate patient selection, considering both the surgical risk as well as the long-term risk of malignant transformation, is very important during qualification for surgery.

New-Onset Diabetes Is a Potential Marker for the Malignant Transformation of Pancreatic Cysts: A Real-World Population Cohort Study

OBJECTIVES

New-onset diabetes mellitus has been shown to be associated with pancreatic cancer (PC) in the general population. Our objective was to leverage real-world data to assess the association of new-onset diabetes (NODM) with malignant transformation in a large longitudinal cohort of pancreatic cyst patients.

METHODS

A retrospective longitudinal cohort study was conducted using IBM's MarketScan claims databases from 2009 to 2017. From 200 million database subjects, we selected patients with newly diagnosed cysts without prior pancreatic pathology.

RESULTS

Of the 137,970 patients with a pancreatic cyst, 14,279 had a new diagnosis. Median follow-up was 41.6 months. Patients with NODM progressed to PC at nearly 3 times the rate of patients without a diabetes history (hazard ratio, 2.80; 95% confidence interval, 2.05-3.83) and at a significantly higher rate than patients with preexisting diabetes (hazard ratio, 1.59; 95% confidence interval, 1.14-2.21). The mean interval between NODM and cancer diagnosis was 7.5 months.

CONCLUSIONS

Cyst patients who developed NODM progressed to PC at 3 times the rate of nondiabetics and at a greater rate than preexisting diabetics. The diagnosis of NODM preceded cancer detection by several months. These results support the inclusion of diabetes mellitus screening in cyst surveillance algorithms.

DWI Metrics Differentiating Benign Intraductal Papillary Mucinous Neoplasms from Invasive Pancreatic Cancer: A Study in GEM Models

KPC (KrasG12D:Trp53R172H:Pdx1-Cre) and CKS (KrasG12D:Smad4L/L:Ptf1a-Cre) mice are genetically engineered mouse (GEM) models that capture features of human pancreatic ductal adenocarcinoma (PDAC) and intraductal papillary mucinous neoplasms (IPMN), respectively. We compared these autochthonous tumors using quantitative imaging metrics from diffusion-weighted MRI (DW-MRI) and dynamic contrast enhanced (DCE)-MRI in reference to quantitative histological metrics including cell density, fibrosis, and microvasculature density. Our results revealed distinct DW-MRI metrics between the KPC vs. CKS model (mimicking human PDAC vs. IPMN lesion): the apparent diffusion coefficient (ADC) of CKS tumors is significantly higher than that of KPC, with little overlap (mean ± SD 2.24±0.2 vs. 1.66±0.2, p<10−10) despite intratumor and intertumor variability. Kurtosis index (KI) is also distinctively separated in the two models. DW imaging metrics are consistent with growth pattern, cell density, and the cystic nature of the CKS tumors. Coregistration of ex vivo ADC maps with H&E-stained sections allowed for regional comparison and showed a correlation between local cell density and ADC value. In conclusion, studies in GEM models demonstrate the potential utility of diffusion-weighted MRI metrics for distinguishing pancreatic cancer from benign pancreatic cysts such as IPMN.

Should non-invasive diffuse main-duct intraductal papillary mucinous neoplasms be treated with total pancreatectomy?

BACKGROUND

Main-duct (MD) intraductal papillary mucinous neoplasm (IPMN) is associated with malignancy risk. There is a lack of consensus on treatment (partial or total pancreatectomy) when the MD is diffusely involved. We sought to characterize the pancreatic remnant fate after partial pancreatectomy for non-invasive diffuse MD-IPMN.

METHODS

Consecutive patients with partial pancreatectomy for non-invasive MD-IPMN from 2004 to 2016 were analyzed. Diffuse MD-IPMN was defined by preoperative imaging as dilation of the MD in the head of the pancreas more than 5 mm and involving the whole gland.

RESULTS

Of 127 patients with resected non-invasive MD-IPMN, 47 (37%) had diffuse MD involvement. Eleven of 47(23%) patients developed imaging evidence of progression or new cystic disease in the pancreatic remnant. Patients with diffuse MD-IPMN were older (73yrs vs 67yrs, p = 0.009), more likely to receive a pancreaticoduodenectomy (96% vs 56%, p < 0.001) and have high-grade dysplasia (51% vs 31%, p = 0.025) than those with focal MD involvement. Diffuse MD involvement was not associated with shorter PFS following partial pancreatectomy (p = 0.613).

CONCLUSION

Partial pancreatectomy is an appropriate surgical approach for diffuse MD-IPMN, and is not associated with earlier progression after surgery as compared to partial pancreatectomy for focal dilation.

Epidemiological Factors Associated With Intraductal Papillary Mucinous Neoplasm of the Pancreas: A Dual Center Case-Control Study

OBJECTIVE

The present study aimed to identify epidemiological factors associated with the development of intraductal papillary mucinous neoplasms (IPMN) of the pancreas comparing patients after IPMN resection with population-based controls.

METHODS

Preoperative data of 811 patients undergoing pancreatic resection for IPMN were matched in a 1:1 ratio with a random sample of volunteers from the Study of Health in Pomerania, which showed no pancreatic cyst greater than 2 mm in magnetic resonance cholangiopancreaticography.

RESULTS

A total of 811 controls with a mean age of 61.9 years (standard deviation, 8.4 years) were matched to cases with a mean age of 66.1 years (standard deviation, 9.3 years). A previous history of pancreatitis, endocrine pancreatic insufficiency was significantly more frequent in IPMN patients compared with controls (P = 0.001). Moreover, adjusted data revealed that urogenital cancer (P = 0.034), colorectal cancer (P = 0.021), as well as first-degree family history of colorectal cancer (P = 0.001) were significantly more frequent in IPMN patients.

CONCLUSIONS

A history of urogenital and colorectal cancer often coincides with IPMN, which have an indication for surgery and are associated with preoperative episodes of pancreatitis and with endocrine insufficiency. Prospective studies are needed to investigate the role of these factors in IPMN development.

Through-the-needle biopsy of pancreatic cystic lesions: current evidence and implications for clinical practice

INTRODUCTION

There is increasing evidence to support the efficacy of endoscopic ultrasound (EUS)-guided through-the-needle biopsy (TTNB) technique as a means of sampling pancreatic cystic lesions (PCLs). Results provide evidence demonstrating the benefits of this procedure over standard EUS fine-needle aspiration (FNA), thus supporting a push for its widespread implementation in clinical practice. Though this technique has demonstrated advantages, achieving these advantages in clinical practice is contingent upon careful considerations to ensure safety and efficacy.

AREAS COVERED

The purpose of this review is to assess the level of evidence supporting the use of through-the-needle biopsy, revise its main technical and procedural characteristics, and to develop suggested guidelines outlining the safe assimilation of this device in clinical practice.

EXPERT OPINION

EUS-TTNB enables more definitive and accurate diagnosis of PCLs by providing higher-quality histological samples. However, EUS-TTNB is not appropriate for all PCLs. Selection of suitable patients as well as morphology and risk factors of the cystic lesion is a crucial component of achieving the described benefits of this procedure while minimizing risks of adverse effects. Subjects with weak or absent indications for this procedure are susceptible to a range of complications and may even result in fatality.

Noninvasive risk stratification of intraductal papillary mucinous neoplasia with malignant potential by serum apolipoprotein-A2-isoforms

Intraductal papillary mucinous neoplasms (IPMNs) are premalignant lesions of pancreatic cancer. An accurate serum biomarker, which allows earlier identification of asymptomatic individuals with high-risk for developing cancer, is of urgent need. Apolipoprotein A2-isoforms (apoA2-i) have previously been identified as biomarkers in pancreatic cancer. This study investigates a potential clinical application of the serum apoA2-i for risk stratification of IPMN and associated cancer. The concentrations of apoA2-i were retrospectively determined in 523 patient sera specimen, composed of 305 IPMNs with preinvasive lesions with different grades of dysplasia and invasive cancer, 140 pancreatic ductal adenocarcinoma, 78 with other cystic lesions and healthy controls cohorts, using an apoA2-i enzyme-linked immunosorbent assay kit. The diagnostic performance of serum apoA2-i was assessed and compared to routine clinical marker CA 19-9. ApoA2-i levels were significantly reduced in all IPMN samples regardless of stage compared to healthy controls. Receiver operating characteristic curve analysis of IPMNs with high-grade dysplasia and IPMN with associated carcinoma revealed the area under curve (AUC) of 0.91 and >0.94, respectively. The respective sensitivities were 70% and 83% with a specificity of 95%, and significantly higher than the gold standard biomarker CA 19-9. AUC values of apoA2-i for detecting IPMN-associated carcinoma of colloid and ductal subtypes were 0.990 and 0.885, respectively. ApoA2-i has the potential to early detect the risk of malignancy of patients with IPMN. The serological apoA2-i test in combination with imaging modalities could help improve the diagnosis of IPMN malignancy. Further validation in larger and independent international cohort studies is needed.

State-of-the-art surgical treatment of IPMNs

Background

A “pandemic” of incidentally discovered pancreatic cyst neoplasms (PCNs) is ongoing. Among PCNs, intraductal papillary mucinous cystic neoplasms (IPMNs) are the most common and with their complex biology could represent a precursor lesion of pancreatic cancer. Although multiple guidelines exist to guide their treatment, there are still many “gray areas” on indications for surgery for IPMNs.

Methods

The current indications for surgery of IPMNs were reappraised, considering potential discrepancies between available evidence and guidelines policies. The practice at a high-volume center for the diagnosis and treatment of PCN was presented and discussed.

Results

Most IPMNs do not and will never require surgery, as they won’t progress to malignancy. The current literature is solid in identifying high-grade dysplasia (HGD) as the right and timely target for IPMN resection, but how to precisely assess its presence remains controversial and guidelines lack of accuracy in this regard. Multiple tumorigenic pathways of progression of IPMNs exist, and their knowledge will likely lead to more accurate tests for malignancy prediction in the future.

Conclusions

The surgical management of IPMNs still is a matter of debate. Indication for resection should be considered only in highly selected cases with the ideal target of HGD. Clinicians should critically interpret the guidelines’ indications, refer to a multidisciplinary team discussion, and always consider the outcome of an adequate counselling with the patient.

Low high-density lipoprotein cholesterol levels are associated with malignant intraductal papillary mucinous neoplasms: A multicenter study

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMNs) can potentially undergo malignant transformation. Studies have shown that high-density lipoprotein cholesterol (HDL-c) was associated with the risk of cancer. In this study, the association between HDL-c and the incidence of malignancy in IPMNs was investigated.

MATERIALS AND METHODS

226 patients with histologically proven IPMNs who underwent surgery were included in the present study. Patients were assigned to a training group (n = 151) and validation group (n = 75). Patients' demographic information, clinical data, and histopathological evaluation findings were obtained from medical records. Malignant IPMNs were defined as lesions that showed high grade dysplasia and invasive carcinoma. Logistic regression analyses were used to show the association between HDL-c and malignant IPMNs. Receiver operating characteristic (ROC) curves were generated to analyze predictive performance.

RESULTS

The prevalence of low HDL-c levels was higher in patients with malignant IPMNs than in those with non-malignant IPMNs (P < 0.01) in both the training group and validation group. The prevalence of malignant IPMNs decreased with an increase in HDL-c levels both in patients with all types of IPMNs, as well as in those with branch-duct IPMNs (BD-IPMNs).Logistic analysis showed that low HDL-c levels were associated with malignant IPMNs (odds ratio (OR) = 20.56, 95 % confidence interval (CI): 2.58-163.64, P < 0.01) in all types of IPMNs and BD-IPMNs (OR = 17.6, 95 %CI: 1.16-268.46, P = 0.02 ).The predictive performance of mural nodules plus low HDL-c levels was higher than that of mural nodules alone or mural nodules plus cyst size for the identification of malignant BD-IPMNs.

CONCLUSIONS

HDL-c levels may serve a potential biomarker for identifying malignant IPMNs and improve the predictive ability of malignancy in BD-IPMNs.

Cytology adds value to monoclonal antibody Das-1 testing for detection of high-risk pancreatic cysts

INTRODUCTION

Determining the risk of malignancy in a pancreatic cyst (PC) is a clinical and diagnostic challenge. Monoclonal antibody (mAb) Das-1 test was shown to have high sensitivity, specificity, and accuracy in detecting high-risk (HR) cysts. Das-1 mAb test detects HR mucinous cysts with high-grade dysplasia (HGD), invasive carcinoma, and/or intestinal-type epithelium. Correlation of mAb Das-1 testing of PC fluids with cytomorphologic findings has not been evaluated.

MATERIALS AND METHODS

We correlated cytology with mAb Das-1 test results and resection histology in 26 PCs. There were 18 intraductal papillary mucinous neoplasms (IPMN), 1 intraductal oncocytic papillary neoplasm (IOPN), 4 mucinous cystic neoplasms (MCN), 2 serous cystadenomas, and 1 cystic pancreatic neuroendocrine tumor (PanNET). HR cysts included cysts with high-grade atypia on cytology or HGD on histology, invasive carcinoma, IOPNs, and cystic PanNETs. Intestinal type IPMNs were also HR cysts on histology.

RESULTS

In 17 cases (65.38%), cytology and mAb Das-1 test correlated with histology. There were 2 (7.69%) mAb Das-1 test negative HR PCs diagnosed by cytology. Five (19.23%) mAb Das-1 test positive HR PCs had mucin only or cells with low-grade dysplasia on cytology. Two mAb Das-1 test positive HR PCs had nondiagnostic cytology. HR IOPN and cystic PanNET were not detected by mAb Das-1 test.

CONCLUSION

The mAb Das-1 is a sensitive and specific biomarker for detecting HR mucinous PCs. Adding cytology to mAb Das-1 testing improves the sensitivity for the detection of nonmucinous HR PC. Together, cytology with mAb Das-1 testing is more accurate than either one alone.

New onset diabetes predicts progression of low risk pancreatic mucinous cysts

BACKGROUND

Patients with low-risk lesions require ongoing surveillance since the rate of progression to pancreatic cancer (PC), while small, is much greater than in the general population. Our objective was to study the relationship between new onset diabetes (NODM) and progression in patients with low risk mucinous cysts.

METHODS

We evaluated a prospectively maintained cohort of 442 patients with a suspected mucinous cyst without worrisome features (WF) or high-risk stigmata (HRS). Multivariable Cox models were developed for progression to WF and HRS, with diabetes status formulated as both time independent and dependent covariates. The adjusted cumulative risk of progression was calculated using the corrected group prognosis method.

RESULTS

The 5-year cumulative progression rates to WFs and HRS were 12.8 and 3.6%, respectively. After controlling for other risk factors, the development of NODM was strongly associated with progression to HRS (HR = 11.6; 95%CI, 3.5-57.7%), but not WF. Among patients with the smallest cysts (<10 mm) at baseline, those who developed NODM had a 5-year adjusted cumulative risk of progression to HRS of 8.6% (95%CI, 0.0%-20.2%), compared to only 0.8% (95%CI, 0.0%-2.3%) for patients without NODM. Among patients with the largest cysts (20-29 mm), those who developed NODM during surveillance had a 5-year adjusted cumulative risk of progression of 53.5% (95%CI, 19.6%-89.9%) compared to only 7.5% (95%CI, 1.6%-15.2%) for patients without NODM.

CONCLUSION

New onset diabetes may predict progression in patients with low risk mucinous cysts. Pending validation with large-scale studies, these findings support regular diabetes screening among patients surveilled for suspected IPMNs or MCNs.

Use of antibiotic prophylaxis is not needed for endoscopic ultrasound-guided fine-needle aspiration of pancreatic cysts: a meta-analysis

BACKGROUND

There is limited evidence on the use of antibiotic prophylaxis prior to endoscopic ultrasound-guided fine-needle aspiration of pancreatic cysts. The aim of this meta-analysis was to evaluate the efficacy of antibiotic prophylaxis in this setting.

RESEARCH DESIGN AND METHODS

Bibliographic search was performed through January 2020. The primary outcome was infection rate. Additional endpoints were severe infection rate and overall rates of adverse events.

RESULTS

Six studies, of which one was a randomized controlled trial and five were retrospective, with 1706 patients were included. Most patients were female, and body/tail was the most frequent location of cystic lesions. Overall, eight infectious events were observed in the antibiotic group (0.77%), whereas 12 events were registered in the control group (1.7%), with no difference in terms of infection rate (odds ratio 0.65, 95% confidence interval 0.24-1.78; p = 0.40). Again, no difference was observed between the two study groups in terms of either severe infection (odds ratio 0.88, 0.13-5.82; p = 0.89) and overall adverse event rate (odds ratio 1.09, 0.73-1.65; p = 0.67).

CONCLUSIONS

Prophylactic antibiotics do not seem to substantially reduce the risk of infections after endoscopic ultrasound-guided fine-needle aspiration of pancreatic cystic lesions, and routine use of prophylactic antibiotics should be questioned.

Needle-based confocal laser endomicroscopy in pancreatic cysts: a meta-analysis

There is currently limited evidence supporting the use of needle-based confocal laser endomicroscopy in pancreatic cystic lesions. Aim of this study was to provide a pooled estimate of the diagnostic performance and safety profile of this technique in patients with pancreatic cysts. Computerized bibliographic search on the main databases was performed through November 2019. Pooled effects were calculated using a random-effects model by means of DerSimonian and Laird test. Primary endpoint was diagnostic accuracy. Secondary outcomes were pooled sensitivity, specificity, and mean procedural time. Ten studies enrolling 536 patients were included. Eight articles, of which five prospective series, compared confocal laser endomicroscopy to cytology/cystic fluid analysis. Most patients were female and body/tail was the most frequent location of pancreatic cysts. Mucinous cysts were prevalent in most of the included studies. Diagnostic accuracy with confocal laser endomicroscopy was 88.6% (83.7-93.4%) and sensitivity analysis according to study quality, design, and treatment arms confirmed the above reported result. Pooled sensitivity and specificity were 82.4% (74.7-90.1%) and 96.6% (94.3-99%), respectively. Both accuracy and sensitivity resulted higher in patients with mucinous cysts (91.4 and 94.9%, respectively). Confocal laser endomicroscopy clearly outperformed fine-needle aspiration in terms of diagnostic accuracy (odds ratio 3.94, 1.58-9.82; P = 0.003). A mean of 6.094 minutes (4.91-7.26) was needed to complete the procedure and no significant adverse event was registered. Our meta-analysis speaks in favor of the use of needle-based confocal laser endomicroscopy as a safe and effective tool in the diagnostic algorithm of pancreatic cysts.

Diagnostic yield of EUS-guided through-the-needle biopsy in pancreatic cysts: a meta-analysis

BACKGROUND AND AIMS

There is currently limited evidence supporting the use of EUS-guided through-the-needle biopsy for sampling pancreatic cystic lesions. The aim of this meta-analysis was to provide a pooled estimate of the diagnostic performance of through-the-needle biopsy for sampling of pancreatic cysts.

METHODS

A bibliographic search on the main databases was performed in September 2019. Pooled effects were calculated using a random-effects model by means of the DerSimonian and Laird test. The primary outcome was sample adequacy. Additional endpoints were diagnostic accuracy, optimal histologic core procurement, mean number of needle passes, pooled specificity, and sensitivity. Adverse event rates were also analyzed.

RESULTS

Eleven studies enrolling 490 patients were included. Eight articles compared through-the-needle biopsy with cytology/cystic fluid analysis. Most patients were female, and the body/tail was the most frequent location of cystic lesions. Sample adequacy with through-the-needle biopsy was 85.3% (78.2%-92.5%), and subanalysis performed according to cyst morphology, size, and location confirmed the result. Through-the-needle biopsy clearly outperformed FNA both in terms of sample adequacy (odds ratio, 4.83; 95% confidence interval, 1.63-14.31; P =.004) and diagnostic accuracy (odds ratio, 3.44; 95% confidence interval, 1.32-8.96; P =.01). The pooled diagnostic accuracy rate, sensitivity, and specificity of through-the-needle biopsy were 78.8%, 82.2%, and 96.8%, respectively. A mean of 3.121 (2.98-3.25) passes through the cyst was needed to obtain adequate histologic samples. The incidence rates of mild bleeding and pancreatitis were 4% and 2%, respectively.

CONCLUSION

Our meta-analysis speaks in favor of the use of through-the-needle biopsy as a safe and effective tool in EUS-guided tissue acquisition of pancreatic cysts.

Promoter DNA Hypermethylation of the Cysteine Dioxygenase 1 (CDO1) Gene in Intraductal Papillary Mucinous Neoplasm (IPMN)

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) involves adenoma (IPMA), a precancerous lesion, cancer (IPMC) including high-grade dysplasia (HGD), and invasive carcinoma (IC). DNA markers of IPMN are required for detection of invasive disease, and cysteine dioxygenase 1 (CDO1) gene promoter hypermethylation is a potential candidate. However, it has never been investigated in the context of IPMN.

PATIENTS AND METHODS

A total of 107 IPMN tumor tissues, including 41 IPMC and 66 IPMA, were studied. CDO1 promoter methylation was quantified using TaqMan quantitative methylation-specific polymerase chain reaction (qMSP) in patients with IPMN and other pancreatic cystic disorders after pancreatectomy.

RESULTS

The methylation values (TaqMeth Vs) of CDO1 increased when noncancerous pancreas tissues were compared with IPMA and HGD (p < 0.0001). Among IPMC, the TaqMeth Vs in IC were not significantly higher than in HGD. The TaqMeth Vs of the solid tumors were higher than those of the cystic tumors (p = 0.0016), which were in turn higher than the corresponding noncancerous tissues (p < 0.0001). Prognostic analysis revealed that high TaqMeth Vs (≥ 14.1) resulted in a poorer prognosis than low TaqMeth Vs (< 14.1) (p < 0.0001). In other pancreatic cystic diseases, only malignant mucinous cystic neoplasm showed DNA hypermethylation of its promoter. A pilot study in pancreatic juice confirmed methylation in all IPMN samples but not in benign pancreatic diseases (p = 0.0277).

CONCLUSIONS

CDO1 promoter hypermethylation is extremely specific to IPMN and may accumulate with IPMN tumor progression during the adenoma-carcinoma sequence. It might be a promising candidate as a diagnostic marker of pancreatic cystic diseases.

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.

Cross Validation of the Monoclonal Antibody Das-1 in Identification of High-Risk Mucinous Pancreatic Cystic Lesions

BACKGROUND & AIMS

Although pancreatic cystic lesions (PCLs) are frequently and incidentally detected, it is a challenge to determine their risk of malignancy. In immunohistochemical and enzyme-linked immunosorbent assay (ELISA) analyses of tissue and cyst fluid from pancreatic intraductal papillary mucinous neoplasms, the monoclonal antibody Das-1 identifies those at risk for malignancy with high levels of specificity and sensitivity. We aimed to validate the ability of Das-1 to identify high-risk PCLs in comparison to clinical guidelines and clinical features, using samples from a multicenter cohort.

METHODS

We obtained cyst fluid samples of 169 PCLs (90 intraductal papillary mucinous neoplasms, 43 mucinous cystic neoplasms, and 36 non-mucinous cysts) from patients undergoing surgery at 4 tertiary referral centers (January 2010 through June 2017). Histology findings from surgical samples, analyzed independently and centrally re-reviewed in a blinded manner, were used as the reference standard. High-risk PCLs were those with invasive carcinomas, high-grade dysplasia, or intestinal-type intraductal papillary mucinous neoplasms with intermediate-grade dysplasia. An ELISA with Das-1 was performed in parallel using banked cyst fluid samples. We evaluated the biomarker's performance, generated area under the curve values, and conducted multivariate logistic regression using clinical and pathology features.

RESULTS

The ELISA for Das-1 identified high-risk PCLs with 88% sensitivity, 99% specificity, and 95% accuracy, at a cutoff optical density value of 0.104. In 10-fold cross-validation analysis with 100 replications, Das-1 identified high-risk PCLs with 88% sensitivity and 98% specificity. The Sendai, Fukuoka, and American Gastroenterological Association guideline criteria identified high-risk PCLs with 46%, 52%, and 74% accuracy (P for comparison to Das-1 ELISA <.001). When we controlled for Das-1 in multivariate regression, main pancreatic duct dilation >5 mm (odds ratio, 14.98; 95% confidence interval, 2.63-108; P < .0012), main pancreatic duct dilation ≥1 cm (odds ratio, 47.9; 95% confidence interval, 6.39-490; P < .0001), and jaundice (odds ratio, 6.16; 95% confidence interval, 1.08-36.7; P = .0397) were significantly associated with high-risk PCLs.

CONCLUSIONS

We validated the ability of an ELISA with the monoclonal antibody Das-1 to detect PCLs at risk for malignancy with high levels of sensitivity and specificity. This biomarker might be used in conjunction with clinical guidelines to identify patients at risk for malignancy.

Pancreatic sphincterotomy improves pain symptoms due to branch-duct intrapapillary mucinous neoplasia without worrisome features: a multicenter study

Introduction Branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) require follow-up to detect worrisome features (WF). Data are missing about endoscopic pancreatic sphincterotomy (PS) for symptomatic IPMN.

Patients and methods This was a retrospective multicenter study in four expert centers. Patients treated with endoscopic PS for symptomatic (painful) BD-IPMN without WF were included. Age, sex, follow-up time, characteristics of IPMNs and endoscopic retrograde cholangiopancreatographies (ERCPs), and indications for surgery were recorded.

Results In total, 21 patients were included (median age 68 years, range 45 – 87 years). The median number of cysts was 2 (range 1 – 10), located in the head (59 %), body/tail (17 %), or multifocal (24 %). ERCP including PS was completed in all of the cases, with biliary sphincterotomy in 33 %. Clinical efficacy after one session was 81 % (17/21). Among the failures, one had a second successful PS and three were operated. The final efficacy was 86 % (18/21). Seven patients were operated after a mean of 19 months: four for WF, three for pain. The histopathology showed four low grade dysplasia, one high grade dysplasia, and two no dysplasia. No adenocarcinoma occurred during a follow-up of 99 months (range 14 – 276 months).

Conclusions Endoscopic PS for symptomatic IPMN without WF is effective in more than 80 % of cases, without increasing the risk for adenocarcinoma.

Overview and comparison of guidelines for management of pancreatic cystic neoplasms

Pancreatic cysts are identified at an increasing frequency. Although mucinous cystic neoplasms represent a pre-malignant condition, the majority of these lesions do not progress to cancer. Over the last 10 years several societies have established guidelines for the diagnosis, initial evaluation and surveillance of these lesions. Here we provide an overview of five commonly used guidelines: 2015 American Gastroenterological Association, 2017 International Association of Pancreatology, American College of Gastroenterology 2018, European Study Group and American College of Radiology. We describe the similarities and differences between the methods used to formulate these guidelines, the population they target and their approaches towards initial evaluation and surveillance of cystic lesions.

Diagnosis and management of pancreatic cystic neoplasms

This review outlines the current classification of pancreatic cystic lesions, with a particular emphasis on pancreatic cystic neoplasms (PCNs). It will describe the diagnostic approach to PCNs, with reference to clinicopathological features, cross-sectional radiology and endoscopic ultrasound. This review will conclude with an evidence-based discussion of the management of PCNs focused on recent clinical guidelines.

[The mistakes in diagnosis of pancreatic intraductal papillary mucinous tumor]

It is presented surgical treatment of the patient with pancreatic intraductal papillary mucinous tumor who was under observation with diagnosis of chronic pancreatitis for a long time. Recurrent tumor with possible malignant transformation to carcinoma was suspected in 5 years after pancreaticoduodenectomy. It was supposed to perform pancreatic stump extirpation. Redo surgery did not reveal any tumor. The cause of recurrent pain was pancreatic duct obliteration at the level of anastomosis.

Cyst Fluid Biosignature to Predict Intraductal Papillary Mucinous Neoplasms of the Pancreas with High Malignant Potential

BACKGROUND

Current standard-of-care technologies, such as imaging and cyst fluid analysis, are unable to consistently distinguish intraductal papillary mucinous neoplasms (IPMNs) of the pancreas at high risk of pancreatic cancer from low-risk IPMNs. The objective was to create a single-platform assay to identify IPMNs that are at high risk for malignant progression.

STUDY DESIGN

Building on the Verona International Consensus Conference branch duct IPMN biomarker review, additional protein, cytokine, mucin, DNA, and microRNA cyst fluid targets were identified for creation of a quantitative polymerase chain reaction-based assay. This included messenger RNA markers: ERBB2, GNAS, interleukin 1β, KRAS, MUCs1, 2, 4, 5AC, 7, prostaglandin E2R, PTGER2, prostaglandin E synthase 2, prostaglandin E synthase 1, TP63; microRNA targets: miRs 101, 106b, 10a, 142, 155, 17, 18a, 21, 217, 24, 30a, 342, 532, 92a, and 99b; and GNAS and KRAS mutational analysis. A multi-institutional international collaborative contributed IPMN cyst fluid samples to validate this platform. Cyst fluid gene expression levels were normalized, z-transformed, and used in classification and regression analysis by a support vector machine training algorithm.

RESULTS

From cyst fluids of 59 IPMN patients, principal component analysis confirmed no institutional bias/clustering. Lasso (least absolute shrinkage and selection operator)-penalized logistic regression with binary classification and 5-fold cross-validation used area under the curve as the evaluation criterion to create the optimal signature to discriminate IPMNs as low risk (low/moderate dysplasia) or high risk (high-grade dysplasia/invasive cancer). The most predictive signature was achieved with interleukin 1β, MUC4, and prostaglandin E synthase 2 to accurately discriminate high-risk cysts from low-risk cysts with an area under the curve of up to 0.86 (p = 0.002).

CONCLUSIONS

We have identified a single-platform polymerase chain reaction-based assay of cyst fluid to accurately predict IPMNs with high malignant potential for additional studies.

Current indications and yield of endoscopic ultrasound and ancillary techniques in pancreatic cystic neoplasms

An increase in the diagnosis of pancreatic cystic neoplasm has been described lately. Surgical treatment or surveillance is advised depending on the type of lesion diagnosed. The most accurate diagnostic approach is needed to make the best therapeutic decision. Endoscopic ultrasound is a very valuable tool in the evaluation of pancreatic cystic neoplasm. It generates high-quality images and allows the possibility of sampling the cystic fluid for cytology, microbiological and molecular evaluation. Even with this evaluation, the sensitivity of this approach is not always adequate. New technological resources have been developed to try to improve the diagnostic accuracy of pancreatic cystic neoplasms. The two most promising techniques are needle-based confocal laser endomicroscopy and contrast-enhanced harmonic endoscopic ultrasound. Needle-based confocal laser endomicroscopy allows a microscopic evaluation of mucosal glands and vascular pattern, to differentiate mucinous from non-mucinous lesions. Contrast-enhanced harmonic endoscopic ultrasound is used for the vascular evaluation of the microcirculation of the cyst wall and mural nodule, mainly to make the difference between malignant nodules and mucus plugs. A combination of these different diagnostic techniques can improve the diagnostic accuracy of pancreatic cystic neoplasms to offer the adequate therapeutic decision.

Surgery of Cystic Tumors of the Pancreas - Why, When, and How?

The management of cystic pancreatic neoplasms has increasingly gained clinical attention due to their frequent incidental detection by cross-sectional imaging and their potential for progression to pancreatic cancer. Surgical resection is warranted for all mucinous cystic neoplasms, solid pseudopapillary neoplasms, and main-duct intraductal papillary mucinous neoplasms since these lesions harbor a major risk for malignant transformation. For branch-duct IPMN (BD-IPMN), the risk for malignancy is considerably lower so that some lesions may be safely followed while others require surgical resection. The clinical challenge lies in making the correct preoperative diagnosis and estimation of the risk of malignancy in BD-IPMN. Therefore, the existing evidence and current guidelines on the management of cystic lesions of the pancreas are summarized and controversially discussed from a surgical point of view.

A Functional Spatial Analysis Platform for Discovery of Immunological Interactions Predictive of Low-Grade to High-Grade Transition of Pancreatic Intraductal Papillary Mucinous Neoplasms

Intraductal papillary mucinous neoplasms (IPMNs), critical precursors of the devastating tumor pancreatic ductal adenocarcinoma (PDAC), are poorly understood in the pancreatic cancer community. Researchers have shown that IPMN patients with high-grade dysplasia have a greater risk of subsequent development of PDAC in the remnant pancreas than do patients with low-grade dysplasia. In this study, we built a computational prediction model that encapsulates the spatial cellular interactions in IPMNs that play key roles in the transformation of low-grade IPMN cysts to high-grade cysts en route to PDAC. Using multiplex immunofluorescent images of IPMN cysts, we adopted algorithms from spatial statistics and functional data analysis to create metrics that summarize the spatial interactions in IPMNs. We showed that an ensemble of models learned using these spatial metrics can robustly predict, with high accuracy, (1) the dysplasia grade (low vs high grade) and (2) the risk of a low-grade cyst progressing to a high-grade cyst. We obtained high classification accuracies on both tasks, with areas under the curve of 0.81 (95% confidence interval: 0.71-0.9) for task 1 and 0.81 (95% confidence interval: 0.7-0.94) for task 2. To the best of our knowledge, this is the first application of an ensemble machine learning approach for discovering critical cellular spatial interactions in IPMNs using imaging data. We envision that our work can be used as a risk assessment tool for patients diagnosed with IPMNs and facilitate greater understanding and investigation of the cellular interactions that cause transition of IPMNs to PDAC.

Intraductal papillary mucinous neoplasms of the pancreas: Clinical association with KRAS

Intraductal papillary mucinous neoplasms of the pancreas (IPMN) are among the most important precancerous lesions in the pancreas. V‑Ki‑ras 2 Kirsten rat sarcoma viral oncogene homolog (KRAS) is one of the most important genes involved in pancreatic neoplasms, and exhibits a high mutation rate in pancreatic ductal adenocarcinomas and pancreatic intraepithelial neoplasia. The present study aimed to further elucidate the associations among IPMN subtypes (gastric, intestinal, pancreatobiliary and oncocytic), pathological classifications [low‑grade, intermediate‑grade, and high‑grade IPMN, and associated minimally invasive carcinoma (invasive depth ≤0.5 cm) and advanced invasive carcinoma (invasive depth >0.5 cm)]. A total of 56 cases of IPMN were studied using scorpion amplified refractory mutation system analysis of KRAS mutations, pathological features and prognosis. KRAS mutations were identified in 50% (28/56 cases). The frequency was 60% (9/15 cases) in gastric‑type, 52.6% (10/19 cases) in intestinal‑type, 47.3% (9/19 cases) in pancreatobiliary‑type and zero (0/3 cases) in oncocytic‑type IPMN. Except for oncocytic type IPMN, the frequencies of KRAS mutations in IPMN with low, intermediate and high grade, and IPMN‑associated carcinoma were 58.3% (7/12 cases), 27.3% (3/11 cases), 80% (4/5 cases) and 56% (14/25 cases), respectively. With more advanced dysplasia and invasion, the prevalence of KRAS mutations in intestinal‑type IPMN increased (P=0.012). The Kaplan‑Meier survival curve demonstrated that survival rate was not associated with KRAS mutation (log‑rank test; P=0.308). The prevalence of KRAS mutations was lowest in intestinal‑type IPMN, and was in proportion to the degree of dysplasia and invasion. Therefore, KRAS mutation in IPMN does not correlate with histological subtype, dysplasia grade, depth of invasion or survival.

Pancreatic inflammation and atrophy are not associated with pancreatic cancer concomitant with intraductal papillary mucinous neoplasm

BACKGROUND

Inflammation-induced carcinogenesis in pancreatic ductal adenocarcinoma (PDAC) has been reported; however, its involvement in PDAC with intraductal papillary mucinous neoplasm (IPMN) remains unclear. We herein investigated the relationship between pancreatic atrophy and inflammation and the incidence of PDAC concomitant with IPMN.

METHODS

This study included 178 consecutive patients who underwent surgical resection for PDAC with IPMN (N = 21) and IPMN (N = 157) between April 2001 and October 2016. A multivariable logistic regression analysis was conducted to assess the relationship between pancreatic inflammation and atrophy and the incidence of PDAC concomitant with IPMN, with adjustments for clinical characteristics and imaging features. Pathological pancreatic inflammation and atrophy were evaluated in resected specimens.

RESULTS

High degrees of pancreatic inflammation and atrophy were not associated with the incidence of PDAC with IPMN (multivariable odds ratio [OR] = 0.5, 95% confidence interval [CI] = 0.07 to 3.33, P = .52, adjusted by clinical characteristics, OR = 0.9, 95% CI = 0.10 to 5.86, P = .91, adjusted by imaging studies; OR = 0.2, 95% CI = 0.009 to 1.31, P = .10, adjusted by clinical characteristics, OR = 0.2, 95% CI = 0.01 to 1.43, P = .12, adjusted by imaging studies, respectively).

CONCLUSIONS

Pancreatic inflammation and atrophy were not associated with pancreatic cancer concomitant with IPMN.

Intraductal Papillary Mucinous Neoplasms of the Pancreas: Strategic Considerations

Intraductal papillary mucinous neoplasms (IPMN) are cystic neoplasms with the potential for progression to pancreatic cancer. Recognized by the global medical community just over two decades ago, IPMN have gained great epidemiological and clinical relevance thanks to the widespread use of cross-sectional abdominal imaging, which has led to a surge in the number of incidental pancreatic cysts being diagnosed. As our understanding of this disease has improved, we now know that some IPMN have a very elevated risk of cancer and require surgical resection, while others are low-risk lesions and can be followed. The approach to IPMN must therefore strike a balance between preventing the over-utilization of surgery and the timely recognition and treatment of patients with high-risk lesions. Several clinical, radiographic, and laboratory parameters have been proposed to risk-stratify IPMN, leading to the publication of management guidelines that do not always converge in their recommendations. The goal of this clinical therapeutic review is to describe the strategic approach to IPMN at the Massachusetts General Hospital, and how our current understanding, management algorithm, and future directions have been informed by research efforts at our institution and other centers.

[Branch duct intraductal papillary mucinous neoplasm - surgical approach]

Due to increasing precision of modern imaging modalities, intraductal papillary mucinous neoplasms (IPMN) of the pancreas are found with increasing prevalence. Despite their malignant potential IPMN are often kept under surveillance and are not immediately resected. The 2012 International Consensus Guidelines of Fukuoka have been widely accepted for the management of IPMN. They recommend surgical resection for branch duct IPMN with "high risk stigmata", while branch duct IPMN with "worrisome features" should undergo observation without immediate resection. Consequently, patients with asymptomatic branch duct IPMN and a presumed low malignant potential mostly undergo primary surveillance to avoid surgery-related morbidity and mortality following pancreatic resection; however, with respect to the cumulative risk of malignant transformation over time, surgical resection might also be indicated for patients with branch duct IPMN with "worrisome features". This article discusses the indications for surgery and different options of resection of branch duct IPMN.

Pancreatic Cysts and Guidelines

Pancreatic cysts, especially incidental asymptomatic ones seen on noninvasive imaging such as CT or MR imaging, remain a clinical challenge. The etiology of such cysts may range from benign cysts without any malignant potential such as pancreatic pseudocysts and serous cystadenomas to premalignant or frankly malignant cysts such as mucinous cystic neoplasms, intraductal papillary mucinous neoplasms, cystic degeneration associated with solid tumors such as pancreatic ductal adenocarcinoma or pancreatic endocrine neoplasms, and solid pseudopapillary neoplasms. The clinical challenge in 2017 is to accurately preoperatively diagnose them and their malignant potential before deciding about surgery, surveillance or doing nothing. This review will focus on the currently available clinical guidelines for doing so.

Management of patients with pancreatic cystic lesions: A case-based survey

BACKGROUND

Pancreatic cystic lesions (PCL), including intraductal papillary mucinous neoplasia (IPMN), harbor different malignant potential and the optimal management is often challenging. The present study aims to depict the compliance of experts with current consensus guidelines and the accuracy of treatment recommendations stratified by the medical specialty and hospital volume.

METHODS

An international survey was conducted using a set of 10 selected cases of PCL that were presented to a cohort of international experts on pancreatology. All presented cases were surgically resected between 2004 and 2015 and histopathological examination was available. Accuracy of the treatment recommendations was based on the European and international consensus guideline algorithms, and the histopathological result.

RESULTS

The response rate of the survey was 26% (46 of 177 contacted experts), consisting of 70% surgeons and 30% gastroenterologists/oncologists (GI/Onc). In the case of main-duct IPMN (MD-IPMN), surgeons preferred more often the surgical approach in comparison with the GI/Onc (55 versus 44%). The mean accuracy rate based on the European and international consensus guidelines, and the histopathological result, were 71/76/38% (surgeons), and 70/73/34% (GI/Onc), respectively. High-volume centers achieved insignificantly higher accuracy scores with regard to the histopathology. Small branch-duct IPMN with cysts <2 cm and malignant potential were not identified by the guideline algorithms.

CONCLUSION

The survey underlines the complexity of treatment decisions for patients with PCL; less than 40% of the recommendations were in line with the final histopathology in this selected case panel. Experts and consensus guidelines may fail to predict malignant potential in small PCL.

Diversity of Precursor Lesions For Pancreatic Cancer: The Genetics and Biology of Intraductal Papillary Mucinous Neoplasm

Pancreatic ductal adenocarcinoma (PDA), one of the most lethal cancers worldwide, is associated with two main types of morphologically distinct precursors—pancreatic intraepithelial neoplasia (PanIN) and intraductal papillary mucinous neoplasm (IPMN). Although the progression of PanIN into invasive cancer has been well characterized, there remains an urgent need to understand the biology of IPMNs, which are larger radiographically detectable cystic tumors. IPMNs comprise a number of subtypes with heterogeneous histopathologic and clinical features. Although frequently remaining benign, a significant proportion exhibits malignant progression. Unfortunately, there are presently no accurate prognosticators for assessing cancer risk in individuals with IPMN. Moreover, the fundamental mechanisms differentiating PanIN and IPMN remain largely obscure, as do those that distinguish IPMN subtypes. Recent studies, however, have identified distinct genetic profiles between PanIN and IPMN, providing a framework to better understand the diversity of the precursors for PDA. Here, we review the clinical, biological, and genetic properties of IPMN and discuss various models for progression of these tumors to invasive PDA.

Smoking Status and the Incidence of Pancreatic Cancer Concomitant With Intraductal Papillary Mucinous Neoplasm

OBJECTIVES

The effect of smoking status on the incidence of pancreatic ductal adenocarcinoma (PDAC) concomitant with intraductal papillary mucinous neoplasm (IPMN) has not been clarified. This study investigated the association of smoking status with PDAC concomitant with IPMN.

METHODS

The subjects were 124 consecutive patients undergoing resection of IPMNs (intraductal papillary mucinous adenoma (IPMA): N = 77, invasive IPMN: N = 31, and PDAC with IPMN: N = 16) between April 2008 and October 2015. The associations between smoking status (never/former/current smoker) or cumulative pack-years (0-19/20-39/≥40) and the incidence of PDAC concomitant with IPMN or invasive IPMN were evaluated.

RESULTS

Current smoking, not former smoking, was associated with the incidence of PDAC concomitant with IPMN (PDAC with IPMN vs IPMN alone; P = 0.004, PDAC with IPMN vs IPMA; P = 0.004, PDAC with IPMN vs invasive IPMN; P = 0.04, respectively), but not that of invasive IPMN (invasive IPMN vs IPMA; P = 0.85). Cumulative pack-years were higher in patients who had PDAC concomitant with IPMN than in patients with invasive IPMN (P = 0.04). Cumulative pack-years were not associated with smoking status (current vs former).

CONCLUSIONS

Current smoking, not former smoking, was associated with the incidence of PDAC concomitant with IPMN. Cessation of smoking may be recommended for patients with IPMN.

hsa-miR-96 and hsa-miR-217 Expression Down-Regulates with Increasing Dysplasia in Pancreatic Intraepithelial Neoplasias and Intraductal Papillary Mucinous Neoplasms

AIM: To compare the clinicopathological features of pancreatic intraepithelial neoplasias (PanINs) and intraductal papillary mucinous neoplasms (IPMNs), and to investigate the role of hsa-miR-96 and hsa-miR-217 in these two lesions. Methods: Formalin-fixed paraffin-embedded pancreatic specimens were selected in this study, including 58 cases of pancreatic intraepithelial neoplasias (PanINs), 45 cases of pancreatic ductal adenocarcinomas (PDAs), and 57 cases of intraductal papillary mucinous neoplasms (IPMNs). MiRNAs hsa-miR-96 and hsa-miR-217 were detected using locked nucleic acid in situ hybridization (LNA-ISH) with the NBT/BCIP staining system. The differences in miRNA expression among sample sets were analyzed with the Chi-squared test. Results: PanIN-PDAs were inclined to present with higher rate of invasion (p=0.033), lymph node metastasis (p=0.0004) and poorer differentiation (p<0.001). Of the 45 PDAs, only 2 cases were within AJCC Ⅰstage, while there were 11 cases of IPMN associated carcinomas (p=0.0018). In PanIN-1, PanIN-2 and PanIN-3, the expression of hsa-miR-96 was 91.3% (22/23), 78.6%(12/17) and 22.2%(4/18) respectively, while the expression of hsa-miR-217 was 95.7%(22/23) , 70.6% (12/17) and 27.8% (5/18). In IPMN with low-grade, intermediate-grade, high-grade dysplasia, associated carcinoma, the expression of hsa-miR-96 was 67%(9/13), 64%(7/11), 43%(3/7) and 27%(7/26) respectively, while the expression of hsa-miR-217 was 77%(10/13), 64%(7/11), 29%(2/7) and 38%(10/26). The expression of hsa-miR-96 and hsa-miR-217 in PanIN-1 lesions was not significantly different from that in the normal pancreatic ductal epithelium. However, their expression in PanIN-2/3 lesions was significantly different from that in normal pancreatic ductal epithelium (P<0.01). No difference was observed between PanIN derived adenocarcinomas and IPMN-associated carcinomas. Conclusion: IPMN associated carcinomas were in a statistically earlier stage than PanIN- PDAs at the time of operation. Abnormal expression of hsa-miR-96 and of hsa-miR-217 was observed in premalignant lesions (PanINs and IPMNs) of pancreatic carcinoma and down-regulated with increasing grades of PanINs and IPMNs. These microRNAs may serve as potentially early biomarker and act as tumor suppressor genes.

Thermal ablation of pancreatic cyst with a prototype endoscopic ultrasound capable radiofrequency needle device: A pilot feasibility study

BACKGROUND AND OBJECTIVES

Pancreatic cysts are evaluated by endoscopic ultrasound and fine needle aspiration (EUS). The only accepted treatment is pancreatectomy, which is associated with morbidity and mortality. This study evaluated the optimal thermal dosimetry of a novel radiofrequency ablation device using a standard electrosurgical unit in ex vivo cyst models.

METHODS

A modified EUS 22-gauge monopolar needle prototype with a tip electrode connected to a standard electrosurgical unit (Erbe USA, Marietta, GA, USA) was used to induce a subboiling point temperature. A cyst model was created using 2-cm sections of porcine small intestine ligated and filled with saline. After ablation, the cyst models were prepared for pathological evaluation. The epithelial layers were measured in at least two different sites with a micrometer and compared with the corresponding control sample.

RESULTS

Thirty-two cyst models were ablated with maximum temperatures of 50°C, 60°C, 90°C, and 97°C in 8, 11, 11, and 2 cysts, respectively. Longer ablation times were required to induce higher temperatures. A trend in the reduction in thickness of the measured layers was observed after exposure to higher temperatures. A temperature over 50°C was required for the ablation of the muscularis, submucosa, and villi, and over 60°C was required to ablate the mucosal crypts.

CONCLUSIONS

In a preclinical model, a novel radiofrequency EUS-capable needle connected to a standard electrosurgical unit using standard low-voltage coagulation provided ablation in a temperature-dependent fashion with a threshold of at least 60°C and a safe cyst margin below 97°C. This potentially will allow low-cost, convenient cyst ablation.

Spectrum and Classification of Cystic Neoplasms of the Pancreas

As patients are living longer and axial imaging is more widespread, increasing numbers of cystic neoplasms of the pancreas are found. Intraductal papillary mucinous neoplasms and mucinous cystic neoplasms are the most common. The revised Sendai guidelines provide a safe algorithm for expectant management of certain cystic neoplasms; however, studies are ongoing to identify further subgroups that can be treated nonoperatively. For those patients with high-risk clinical features or symptoms, surgical resection can be performed safely at high-volume pancreatic centers. Accurate diagnosis is critical for accurate decision making.

Association between serum SPan-1 and lymph node metastasis in invasive intraductal papillary mucinous neoplasm of the pancreas

BACKGROUND AND AIM

Lymph node metastasis predicts poorer prognoses in patients with invasive intraductal papillary mucinous neoplasms of the pancreas (IPMNs). Factors associated with lymph node metastasis of invasive IPMN remain unclear. Therefore, this study aimed to define factors associated with lymph node metastasis of invasive IPMN.

METHODS

Between June 2000 to August 2015, 156 consecutive patients with IPMN underwent surgical resection at Kobe University Hospital, and were enrolled in this study. The relationship between lymph node metastasis and clinical characteristics, including imaging studies and serum tumor markers, was evaluated. A multivariate logistic regression analysis was performed to assess the relationship between serum tumor markers and the presence of lymph node metastasis of IPMN, adjusted for clinical characteristics.

RESULTS

Lymph node metastasis was observed in 7.7% (12/156) of IPMNs via a pathological examination. The multivariate logistic regression analysis revealed that serum SPan-1 was associated with the presence of lymph node metastasis of IPMN (odds ratio [OR] = 7.32; 95% confidence interval [CI] = 1.10 to 56.0; P = 0.04). In addition, survival was poorer among serum SPan-1-positive patients than SPan-1 negative patients (Log-rank test; P = 0.0002). Lymph node enlargement was detected preoperatively on computed tomography scans in only 16.7% (2/12) of cases that were positive for lymph node metastasis.

CONCLUSIONS

Elevated serum SPan-1 was associated with lymph node metastasis in this cohort of patients who underwent resection for invasive IPMN.

Enucleation: A treatment alternative for branch duct intraductal papillary mucinous neoplasms

BACKGROUND

Small, asymptomatic, branch-duct intraductal papillary mucinous neoplasms of the pancreas are often kept under surveillance despite their malignant potential. The management of branch-duct intraductal papillary mucinous neoplasm is controversial with regard to indications and extent of any operative intervention. The present study aimed to evaluate enucleation as an alternative operative approach for branch-duct intraductal papillary mucinous neoplasms to exclude and prevent malignancy.

METHODS

For branch-duct intraductal papillary mucinous neoplasms of <30 mm in diameter and an acceptable distance from the main pancreatic duct, enucleation was considered as the operative approach of choice. All patients scheduled for enucleation of branch-duct intraductal papillary mucinous neoplasm on the basis of these features between January 2004 and September 2014 were analyzed. Among these, patients with successful enucleation were compared with those who were scheduled for enucleation but converted intraoperatively to pancreatic resection (intention-to-treat analysis). End points were hospital morbidity and mortality as well as histopathology and functional outcome at a mean follow-up of 32 months.

RESULTS

In the study, 115 patients with presumed branch-duct intraductal papillary mucinous neoplasm and the intention to perform pancreatic enucleation were included; 87 enucleations were performed in 74 patients. In 41 patients, enucleation was converted to a pancreatic resection (procedure-specific success rate 64%); indications for conversion included location or size (46%), presence of multicystic lesions (39%), or involvement of the main pancreatic duct (15%). Of the 74 patients with enucleation, 64 branch-duct intraductal papillary mucinous neoplasms revealed low- (85%), 11% moderate dysplasia-, and 4% high-grade dysplasia on histology. Among converted resections, 6 intraductal papillary mucinous neoplasms revealed high-grade dysplasia or invasive carcinoma (15%). Intention-to-treat analysis with patients converted to pancreatic resection showed that enucleations resulted in less blood loss (100 vs 400 mL) and a shorter operation time (146 vs 255 minutes; P < .001 each). Postoperative morbidity including postoperative pancreatic fistula was similar in both groups. No mortality occurred after enucleation; after formal resection, 1 patient died due to multiorgan failure. Both hospital stay (10 vs 14 days) and rates of postoperative endocrine and exocrine dysfunction rates were less after enucleation (P < .02 each). Intraductal papillary mucinous neoplasm-specific recurrence rates (3% vs 6%) were similar in both groups.

CONCLUSION

Enucleation is a safe procedure that can be performed successfully in a high proportion of branch-duct intraductal papillary mucinous neoplasms and should be considered instead of standard resections as an important function-preserving alternative. Limitations may occur due to malignancy, size, localization, multilocularity, or main-duct involvement requiring conversion to a formal, anatomic resection. Beside the advantages in the short-term course, functional outcome seems to be superior after enucleation, and intraductal papillary mucinous neoplasm-specific recurrence rates are not increased compared with standard resections, at least at a mean follow-up of 32 months.

Pancreatic resection for intraductal papillary mucinous neoplasm- a thirteen-year single center experience

BACKGROUND

The purpose of this study is to review our results for pancreatic resection in patients with intraductal papillary mucinous neoplasm (IPMN) with and without associated carcinoma.

METHODS

A total of 54 patients undergoing pancreatic resection for IPMN in a single university surgical center (Medical University of Graz) were reviewed retrospectively. Their survival rates were compared to those of patients with pancreatic ductal adenocarcinoma.

RESULTS

Twenty-four patients exhibit non-invasive IPMN and thirty patients invasive IPMN with associated carcinoma. The mean age is 67 (+/-11) years, 43 % female. Surgical strategies include classical or pylorus-preserving Whipple procedure (n = 30), distal (n = 13) or total pancreatectomy (n = 11), and additional portal venous resection in three patients (n = 3). Median intensive care stay is three days (range 1 - 87), median in hospital stay is 23 days (range 7 - 87). Thirty-day mortality is 3.7 %. Median follow up is 42 months (range 0 - 127). One-, five- and ten-year overall actuarial survival is 87 %; 84 % and 51 % respectively. Median overall survival is 120 months. Patients with non-invasive IPMN have significantly better survival than patients with invasive IPMN and IPMN-associated carcinoma (p < 0.008). In the subgroup of invasive IPMN with associated carcinoma, a positive nodal state, perineural invasion as well as lymphovascular infiltration are associated with poor outcome (p < 0.0001; <0.0001 and =0.001, respectively). Elevated CA 19-9(>37 U/l) as well as elevated lipase (>60 U/l) serum levels are associated with unfavorable outcome (p = 0.009 and 0.018; respectively). Patients operated for pancreatic ductal adenocarcinoma show significantly shorter long-term survival than patients with IPMN associated carcinoma (p = 0.001).

CONCLUSIONS

Long-term outcome after pancreatic resection for non-invasive IPMN is excellent. Outcome after resection for invasive IPMN with invasive carcinoma is significantly better than for pancreatic ductal adenocarcinoma. In low- and intermediate risk IPMN with no clear indication for immediate surgical resection, a watchful waiting strategy should be evaluated carefully against surgical treatment individually for each patient.