The Sendai and Fukuoka consensus criteria for the management of branch duct IPMN - A meta-analysis on their accuracy

Benign Etiology for High-Risk Intraductal Papillary Mucinous Neoplasm: A Case Report and Literature Review

Intraductal papillary mucinous neoplasms are relatively common and entail a variable risk of malignant potential. The Fukuoka guidelines present criteria for the risk of malignant transformation and are used for risk stratification and treatment decision-making. However, these guidelines entail some fallibility with limited sensitivity and specificity. In this case, we present an individual who had many of the hallmarks of malignant transformation but was found to have no evidence of malignancy or high-grade dysplasia. We discuss the suspected etiology of this individual's condition and how it might arise in others, as well as a brief review of the literature on risk factors in intraductal papillary mucinous neoplasms.

Hepatic Steatosis After Partial Pancreatectomy in a Cohort of Patients with Intraductal Papillary Mucinous Neoplasm

Background/Aims

Nonalcoholic fatty liver disease (NAFLD) has been observed in patients after partial pancreatectomy. Previous studies have been performed on oncologic patients who underwent partial pancreatectomy and received adjuvant chemotherapy. By studying a cohort of patients with intraductal papillary mucinous neoplasms (IPMNs) who did not receive chemotherapy, the authors investigate the isolated effect of partial pancreatectomy on the development of fatty liver.

Methods

A retrospective search for patients with pancreatic IPMNs who underwent partial pancreatectomy at an academic center from 2006 to 2014 identified 63 patients, including 42 who had pancreaticoduodenectomy (PD) and 21 who had distal pancreatectomy (DP). Fourteen patients with preoperative hepatic steatosis, diabetes, obesity, on steroid therapy, history of malignancy, or incomplete data were excluded. No patient received chemotherapy. Liver fat signal fraction (LFSF) was computed by the Dixon method using pre- and postoperative in- and out-of-phase MRI.

Results

Of the 49 patients included in the study, 29 (59%) underwent PD and 20 (41%) underwent DP. A total of 17 patients (34%) developed fatty liver after surgery. The entire cohort developed significant weight loss, 72.1 versus 69.4 kg (P < 0.01). Postoperatively, there was significant increase in LFSF, 1.3% versus 9.6% following PD (P < 0.01), and 2.1% versus 9.4% following DP (P = 0.01).

Conclusion

Partial pancreatectomy increases the risk of NAFLD independent of chemotherapy-induced hepatotoxicity. The underlying mechanism remains unclear and possibly related to pancreatic exocrine insufficiency and malnutrition.

Predictive ability of pancreatic cyst fluid biomarkers: A systematic review and meta-analysis

BACKGROUND

Mucinous pancreatic cysts harbor the potential to progress to highly lethal pancreatic ductal adenocarcinoma (PDAC). Since these precursor cysts require cancer surveillance or surgical resection, they need to be reliably distinguished from harmless pancreatic cysts. Current clinical and radiographic assessment is imperfect and the value of cyst fluid analysis for differential diagnosis is unclear. Therefore, we set out to investigate the value of cyst fluid biomarkers in distinguishing pancreatic cysts.

METHODS

We performed a systematic review of the current literature to identify articles that evaluated the diagnostic performance of clinically relevant and promising candidate cyst fluid biomarkers, with a particular emphasis on DNA-based biomarkers. Meta-analysis was performed for biomarkers targeted at identifying cyst type and presence of high-grade dysplasia or PDAC.

RESULTS

Data from a total of 42 studies was analyzed. Mutations in KRAS and/or GNAS allowed identification of mucinous cysts with a sensitivity of 79% and specificity of 98%. This exceeded the performance of the traditional biomarker carcinoembryonic antigen (CEA; sensitivity 58%, specificity 87%). Mutations in VHL were specific for serous cystadenomas (SCAs; sensitivity 56%, specificity 99%) and help to exclude mucinous cysts. Mutations in CDKN2A, PIK3CA, SMAD4, and TP53 each had high specificities of 97%, 97%, 98%, and 95%, respectively, to identify high-grade dysplasia or PDAC in mucinous cysts.

CONCLUSIONS

Cyst fluid analysis can be a valuable tool in the characterization of pancreatic cysts, with relevant clinical implications. Our results support the use of DNA-based cyst fluid biomarkers in the multidisciplinary diagnostic work-up of pancreatic cysts.

Improving Pancreatic Cyst Management: Artificial Intelligence-Powered Prediction of Advanced Neoplasms through Endoscopic Ultrasound-Guided Confocal Endomicroscopy

Despite the increasing rate of detection of incidental pancreatic cystic lesions (PCLs), current standard-of-care methods for their diagnosis and risk stratification remain inadequate. Intraductal papillary mucinous neoplasms (IPMNs) are the most prevalent PCLs. The existing modalities, including endoscopic ultrasound and cyst fluid analysis, only achieve accuracy rates of 65-75% in identifying carcinoma or high-grade dysplasia in IPMNs. Furthermore, surgical resection of PCLs reveals that up to half exhibit only low-grade dysplastic changes or benign neoplasms. To reduce unnecessary and high-risk pancreatic surgeries, more precise diagnostic techniques are necessary. A promising approach involves integrating existing data, such as clinical features, cyst morphology, and data from cyst fluid analysis, with confocal endomicroscopy and radiomics to enhance the prediction of advanced neoplasms in PCLs. Artificial intelligence and machine learning modalities can play a crucial role in achieving this goal. In this review, we explore current and future techniques to leverage these advanced technologies to improve diagnostic accuracy in the context of PCLs.

Circulating Epithelial Cells in Patients with Intraductal Papillary Mucinous Neoplasm of the Pancreas

Intraductal papillary mucinous neoplasm (IPMN) is the most common pancreatic cyst and a precursor of pancreatic cancer (PDAC). Since PDAC has a devastatingly high mortality rate, the early diagnosis and treatment of any precursor lesion are rational. The safety of the existing guidelines on the clinical management of IPMN has been criticized due to unsatisfactory sensitivity and specificity, showing the need for further markers. Blood obtained from patients with IPMN was therefore subjected to size-based isolation of circulating epithelial cells (CECs). We isolated CECs and evaluated their cytological characteristics. Additionally, we compared Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations in CECs and the primary IPMN tissue, since KRAS mutations are very typical for PDAC. Samples from 27 IPMN patients were analyzed. In 10 (37%) patients, CECs were isolated and showed a hybrid pattern of surface markers involving both epithelial and mesenchymal markers, suggesting a possible EMT process of the cells. Especially, patients with high-grade dysplasia in the main specimen were all CEC-positive. KRAS mutations were also present in CECs but less common than in IPMN tissue. The existence of CEC in IPMN patients offers additional blood-based research possibilities for IMPN biology.

Artificial Intelligence in the Diagnosis and Treatment of Pancreatic Cystic Lesions and Adenocarcinoma

Pancreatic cancer is projected to become the second leading cause of cancer-related mortality in the United States by 2030. This is in part due to the paucity of reliable screening and diagnostic options for early detection. Amongst known pre-malignant pancreatic lesions, pancreatic intraepithelial neoplasia (PanIN) and intraductal papillary mucinous neoplasms (IPMNs) are the most prevalent. The current standard of care for the diagnosis and classification of pancreatic cystic lesions (PCLs) involves cross-sectional imaging studies and endoscopic ultrasound (EUS) and, when indicated, EUS-guided fine needle aspiration and cyst fluid analysis. However, this is suboptimal for the identification and risk stratification of PCLs, with accuracy of only 65-75% for detecting mucinous PCLs. Artificial intelligence (AI) is a promising tool that has been applied to improve accuracy in screening for solid tumors, including breast, lung, cervical, and colon cancer. More recently, it has shown promise in diagnosing pancreatic cancer by identifying high-risk populations, risk-stratifying premalignant lesions, and predicting the progression of IPMNs to adenocarcinoma. This review summarizes the available literature on artificial intelligence in the screening and prognostication of precancerous lesions in the pancreas, and streamlining the diagnosis of pancreatic cancer.

Central pancreatectomy prevents postoperative diabetes

BACKGROUND

Central pancreatectomy (CP) can be performed as an alternative surgical approach to distal pancreatectomy (DP) in the treatment of benign or low-grade malignant lesions located in the neck and body of the pancreas, aiming to reduce loss of parenchyma and therefore organ failure. The objective of this study was to evaluate the short- and long-term outcome of CP in comparison to DP.

METHODS

Patients who received CP in a large tertiary care pancreatic surgery center between 2001 and 2020 were identified from a prospectively maintained database and compared via propensity score matching with patients receiving DP during the same time period. Perioperative rate of complications and long-term outcome of pancreatic endocrine and exocrine function were evaluated.

RESULTS

One hundred and seven patients undergoing open CP were compared to 107 patients with open DP. No significant difference in rates or severity of most surgical complications could be found including postoperative pancreatic fistula, intraabdominal fluid collection, delayed gastric emptying and wound infection. However, patients receiving CP had a significantly higher risk of grade C postpancreatectomy hemorrhage (PPH) (CP: 10 patients, 9.3% versus DP: 1 patient, 0.9%; p = .0019). Perioperative mortality was comparable. Long-term follow-up of 60 matched pairs revealed significantly less patients with new-onset diabetes after CP (eight patients, 13.3%) compared to DP (22 patients, 36.7%, p = .0056).

CONCLUSION

CP offers an improved endocrine long-term outcome at the expense of a higher risk of PPH without increased perioperative mortality. As evidence on this parenchyma sparing surgical technique is sparse, more prospective data are needed.

Artificial intelligence for the detection of pancreatic lesions

PURPOSE

Pancreatic cancer is one of the most lethal neoplasms among common cancers worldwide, and PCLs are well-known precursors of this type of cancer. Artificial intelligence (AI) could help to improve and speed up the detection and classification of pancreatic lesions. The aim of this review is to summarize the articles addressing the diagnostic yield of artificial intelligence applied to medical imaging (computed tomography [CT] and/or magnetic resonance [MR]) for the detection of pancreatic cancer and pancreatic cystic lesions.

METHODS

We performed a comprehensive literature search using PubMed, EMBASE, and Scopus (from January 2010 to April 2021) to identify full articles evaluating the diagnostic accuracy of AI-based methods processing CT or MR images to detect pancreatic ductal adenocarcinoma (PDAC) or pancreatic cystic lesions (PCLs).

RESULTS

We found 20 studies meeting our inclusion criteria. Most of the AI-based systems used were convolutional neural networks. Ten studies addressed the use of AI to detect PDAC, eight studies aimed to detect and classify PCLs, and 4 aimed to predict the presence of high-grade dysplasia or cancer.

CONCLUSION

AI techniques have shown to be a promising tool which is expected to be helpful for most radiologists' tasks. However, methodologic concerns must be addressed, and prospective clinical studies should be carried out before implementation in clinical practice.

Application of Artificial Intelligence in the Management of Pancreatic Cystic Lesions

The rate of incidentally detected pancreatic cystic lesions (PCLs) has increased over the past decade and was recently reported at 8%. These lesions pose a unique challenge, as each subtype of PCL carries a different risk of malignant transformation, ranging from 0% (pancreatic pseudocyst) to 34–68% (main duct intraductal papillary mucinous neoplasm). It is imperative to correctly risk-stratify the malignant potential of these lesions in order to provide the correct care course for the patient, ranging from monitoring to surgical intervention. Even with the multiplicity of guidelines (i.e., the American Gastroenterology Association guidelines and Fukuoka/International Consensus guidelines) and multitude of diagnostic information, risk stratification of PCLs falls short. Studies have reported that 25–64% of patients undergoing PCL resection have pancreatic cysts with no malignant potential, and up to 78% of mucin-producing cysts resected harbor no malignant potential on pathological evaluation. Clinicians are now incorporating artificial intelligence technology to aid in the management of these difficult lesions. This review article focuses on advancements in artificial intelligence within digital pathomics, radiomics, and genomics as they apply to the diagnosis and risk stratification of PCLs.

The Impact of Biomarkers in Pancreatic Ductal Adenocarcinoma on Diagnosis, Surveillance and Therapy

Simple Summary

Pancreatic ductal adenocarcinoma is a leading cause of cancer death worldwide. Due to the frequently late diagnosis, early metastasis and high therapy resistance curation is rare and prognosis remains poor overall. To provide early diagnostic and therapeutic predictors, various molecules from blood, tissue and other origin e.g., saliva, urine and stool, have been identified as biomarkers. This review summarizes current trends in biomarkers for diagnosis and therapy of pancreatic ductal adenocarcinoma.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is still difficult to treat due to insufficient methods for early diagnosis and prediction of therapy response. Furthermore, surveillance after curatively intended surgery lacks adequate methods for timely detection of recurrence. Therefore, several molecules have been analyzed as predictors of recurrence or early detection of PDAC. Enhanced understanding of molecular tumorigenesis and treatment response triggered the identification of novel biomarkers as predictors for response to conventional chemotherapy or targeted therapy. In conclusion, progress has been made especially in the prediction of therapy response with biomarkers. The use of molecules for early detection and recurrence of PDAC is still at an early stage, but there are promising approaches in noninvasive biomarkers, composite panels and scores that can already ameliorate the current clinical practice. The present review summarizes the current state of research on biomarkers for diagnosis and therapy of pancreatic cancer.

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.

Enucleation for benign or borderline tumors of the pancreas: comparing open and minimally invasive surgery

BACKGROUND

The feasibility and safety of minimally invasive enucleation (ME) for benign or borderline pancreatic tumors is still unclear. The aim of this study was to compare outcomes between ME and open enucleation (OE).

METHODS

All patients undergoing pancreatic enucleation between October 2001 and January 2020 were analyzed from a prospective database. Consecutive patients undergoing ME were compared with patients undergoing OE in a matched-pair analysis (1:2).

RESULTS

Of 358 patients, undergoing enucleation, 120 matched patients (ME n = 40, OE n = 80) were included. Patients undergoing ME had less blood loss (median 50 vs. 100 ml, P = 0.025) and had a higher proportion of patients discharged by 7 days, than patients undergoing OE (38% vs. 18%, P = 0.016). The rates of clinically relevant postoperative pancreatic fistula (POPF) and major complications (Clavien grade ≥ 3) were similar between both groups. Risk factor analysis for POPF B/C showed no significant parameters associated with POPF, including tumor size and proximity to the main pancreatic duct.

CONCLUSION

Compared with conventional OE, ME reduces the amount of bleeding and allows earlier postoperative discharge, without increasing the incidence of major complications. Thus, minimally invasive enucleation should be considered for benign tumors of the pancreas when technically and oncologically feasible.

Guidelines on management of pancreatic cysts detected in high-risk individuals: An evaluation of the 2017 Fukuoka guidelines and the 2020 International Cancer of the Pancreas Screening (CAPS) consortium statements

BACKGROUND

Objectives: Pancreatic cysts are frequently detected in high-risk individuals (HRI) undergoing surveillance for pancreatic cancer. The International Cancer of the Pancreas Screening (CAPS) Consortium developed consensus recommendations for surgical resection of pancreatic cysts in HRI that are similar to the Fukuoka guidelines used for the management of sporadic cysts. We compared the performance characteristics of CAPS criteria for pancreatic cyst management in HRI with the Fukuoka guidelines originally designed for the management of cysts in non-HRI.

METHODS

Using prospectively collected data from CAPS studies, we determined for each patient with resected screen-detected cyst(s) whether Fukuoka guidelines or CAPS consensus statements would have recommended surgery. We compared sensitivity, specificity, PPV, NPV, and Receiver Operator Characteristics (ROC) curves of these guidelines at predicting the presence of high-grade dysplasia or invasive cancer in pancreatic cysts.

RESULTS

356/732 HRI had ≥ one pancreatic cyst detected; 24 had surgery for concerning cystic lesions. The sensitivity, specificity, PPV, and NPV for the Fukuoka criteria were 40%, 85%, 40%, and 85%, while those of the CAPS criteria were 60%, 85%, 50%, 89%, respectively. ROC curve analyses showed no significant difference between the Fukuoka and CAPS criteria.

CONCLUSIONS

In HRI, the CAPS and Fukuoka criteria are moderately specific, but not sufficiently sensitive for detecting advanced neoplasia in cystic lesions. New approaches are needed to guide the surgical management of cystic lesions in HRI.

Minimal main pancreatic duct dilatation in small branch duct intraductal papillary mucinous neoplasms associated with high-grade dysplasia or invasive carcinoma

BACKGROUND

The aim of this study was to determine the incidence of high-grade dysplasia (HGD) or invasive carcinoma in patients with small branch duct intraductal papillary mucinous neoplasms (BD-IPMNs).

METHODS

923 patients who underwent surgical resection for an IPMN were identified. Sendai-negative patients were identified as those without history of pancreatitis or jaundice, main pancreatic duct size (MPD) <5 mm, cyst size <3 cm, no mural nodules, negative cyst fluid cytology for adenocarcinoma, or serum carbohydrate antigen 19-9 (CA 19-9) <37 U/L.

RESULTS

BD-IPMN was identified in 388 (46.4%) patients and 89 (22.9%) were categorized as Sendai-negative. Overall, 68 (17.5%) of BD-IPMN had HGD and 62 (16.0%) had an associated invasive-carcinoma. Among the 89 Sendai-negative patients, 12 (13.5%) had IPMNs with HGD and only one patient (1.1%) had invasive-carcinoma. Of note, older age (OR 1.13, 95% CI 1.03-1.23; P = 0.008) and minimal dilation of MPD (OR 11.3, 95% CI 2.40-53.65; P = 0.002) were associated with high-risk disease in Sendai-negative patients after multivariable risk adjustment.

CONCLUSION

The risk of harboring a high-risk disease remains low in small BD-IPMNs. However, Sendai-negative patients who are older than 65 years old and those with minimal dilation of MPD (3-5 mm) are at greater risk of high-risk lesions and should be given consideration to be included as a "worrisome feature" in a future guidelines update.

Role of phosphorylated Smad3 signal components in intraductal papillary mucinous neoplasm of pancreas

BACKGROUND

Malignant intraductal papillary mucinous neoplasm (IPMN) has poor prognosis. The carcinogenesis of IPMN is not clear. The aim of this study was to clarify transitions in phosphorylated Smad3 signaling during IPMN carcinogenesis.

METHODS

By using immunohistochemistry, we examined the expression of pSmad3C and pSmad3L from 51 IPMN surgical specimens resected at our institution between 2010 and 2013. We also examined the expression of Ki-67, c-Myc and p-JNK.

RESULTS

The median immunostaining index of pSmad3C was 79.2% in low-grade dysplasia, 74.9% in high-grade dysplasia, and 42.0% in invasive carcinoma (P < 0.01), whereas that of pSmad3L was 3.4%, 4.3%, and 42.4%, respectively (P < 0.01). There was a negative relationship between the expression of pSmad3C and c-Myc (P < 0.001, r = -0.615) and a positive relationship between the expression of pSmad3L and c-Myc (P < 0.001, r = 0.696). Negative relationship between the expression of pSmad3C and Ki-67 (P < 0.01, r = -0.610) and positive relationship between the expression of pSmad3L and Ki-67 (P < 0.01, r = 0.731) were confirmed. p-JNK-positive cells were frequently observed among pSmad3L-positive cancer cells. The median of pSmad3L/pSmad3C ratio in the non-recurrence group and the recurrence group were 0.58 (range, 0.05-0.93), 3.83 (range, 0.85-5.96), respectively (P = 0.02). The median immunostaining index of c-Myc in the non-recurrence group and the recurrence group were 2.91 (range, 0-36.9) and 82.1 (range, 46.2-97.1), respectively (P = 0.02). The median immunostaining index of Ki-67 in the non-recurrence group and the recurrence group were 12.9 (range 5.7-30.8) and 90.9 (range 52.9-98.5), respectively (P = 0.02).

CONCLUSIONS

pSmad3L was upregulated in malignant IPMN. pSmad3L/pSmad3C ratio may be a useful prognostic factor in IPMN.

A retrospective study of histological outcome for IPMN after surgery in Lausanne, Switzerland: A case series

Introduction

Intraductal papillary mucinous neoplasm (IPMN) is a 21st century concept and its management is still controversial. Strong guidelines suggest that surgery is the safest way to prevent malignant evolution. Though the risk of neoplasia is still debated, high-morbidity and mortality surgery must be proposed for high-risk patients to prevent malignant and most likely fatal pancreatic neoplasia.

Methods

The aim of this study was to analyze histological results of patients who underwent operation for IPMN under the Sendai and Fukuoka guidelines. From January 2005 to August 2016, 491 consecutive patients who underwent pancreatic resection in Lausanne University Hospital were analyzed, including 18 IPMN with surgical indication according to the Sendai and Fukuoka criteria.

Results

Thirteen (68.4%) patients had benign histopathology after surgery (the non-malignant group). Of the patients with malignant pathology, four (21%) had high-grade dysplasia and two (20.1%) had invasive carcinoma (the malignant group). The median patient age (p = 0.011) and preoperative Carbohydrate Antigen 19–9 (CA19-9) (p = 0.030) were significantly higher in the malignant group than in the non-malignant group.

Discussion

The use of the current criteria is adequate, but it may be resulting in surgery on excessive numbers of patients with IPMN. A modern decision-making strategy should be based on clinical features, precise imaging data, and biological markers.

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IPMNs are pre-cancerous tumors with a potential evolution to malignant neoplasm.

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Revised guidelines can lead to surgical decision but with high morbidity and mortality linked to pancreatic surgery.

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Moderns biological markers can help to adjust surgical criteria, added to clinical and imaging features.

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More specific criteria are needed prior to resection, and could lead to more and more conservative management.

Usefulness of Deep Learning Analysis for the Diagnosis of Malignancy in Intraductal Papillary Mucinous Neoplasms of the Pancreas

Intraductal papillary mucinous neoplasms (IPMNs) are precursor lesions of pancreatic adenocarcinoma. Artificial intelligence (AI) is a mathematical concept whose implementation automates learning and recognizing data patterns. The aim of this study was to investigate whether AI via deep learning algorithms using endoscopic ultrasonography (EUS) images of IPMNs could predict malignancy.

Multiphase computed tomography radiomics of pancreatic intraductal papillary mucinous neoplasms to predict malignancy

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMNs) are non-invasive pancreatic precursor lesions that can potentially develop into invasive pancreatic ductal adenocarcinoma. Currently, the International Consensus Guidelines (ICG) for IPMNs provides the basis for evaluating suspected IPMNs on computed tomography (CT) imaging. Despite using the ICG, it remains challenging to accurately predict whether IPMNs harbor high grade or invasive disease which would warrant surgical resection. A supplementary quantitative radiological tool, radiomics, may improve diagnostic accuracy of radiological evaluation of IPMNs. We hypothesized that using CT whole lesion radiomics features in conjunction with the ICG could improve the diagnostic accuracy of predicting IPMN histology.

AIM

To evaluate whole lesion CT radiomic analysis of IPMNs for predicting malignant histology compared to International Consensus Guidelines.

METHODS

Fifty-one subjects who had pancreatic surgical resection at our institution with histology demonstrating IPMN and available preoperative CT imaging were included in this retrospective cohort. Whole lesion semi-automated segmentation was performed on each preoperative CT using Healthmyne software (Healthmyne, Madison, WI). Thirty-nine relevant radiomic features were extracted from each lesion on each available contrast phase. Univariate analysis of the 39 radiomics features was performed for each contrast phase and values were compared between malignant and benign IPMN groups using logistic regression. Conventional quantitative and qualitative CT measurements were also compared between groups, via χ² (categorical) and Mann Whitney U (continuous) variables.

RESULTS

Twenty-nine subjects (15 males, age 71 ± 9 years) with high grade or invasive tumor histology comprised the "malignant" cohort, while 22 subjects (11 males, age 70 ± 7 years) with low grade tumor histology were included in the "benign" cohort. Radiomic analysis showed 18/39 precontrast, 19/39 arterial phase, and 21/39 venous phase features differentiated malignant from benign IPMNs (P < 0.05). Multivariate analysis including only ICG criteria yielded two significant variables: thickened and enhancing cyst wall and enhancing mural nodule < 5 mm with an AUC (95%CI) of 0.817 (0.709-0.926). Multivariable post contrast radiomics achieved an AUC (95%CI) of 0.87 (0.767-0.974) for a model including arterial phase radiomics features and 0.834 (0.716-0.953) for a model including venous phase radiomics features. Combined multivariable model including conventional variables and arterial phase radiomics features achieved an AUC (95%CI) of 0.93 (0.85-1.0) with a 5-fold cross validation AUC of 0.90.

CONCLUSION

Multi-phase CT radiomics evaluation could play a role in improving predictive capability in diagnosing malignancy in IPMNs. Future larger studies may help determine the clinical significance of our findings.

Development of a new risk score for invasive cancer in branch-duct intraductal papillary mucinous neoplasms according to morphological characterization by EUS

Background and Objective

The management of branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) is determined by a number of guidelines. The current weight of risk factors by EUS predicting invasive cancer is unknown. The aim of this study is to develop a risk score for early prediction of invasive cancer according to morphological characterization by EUS in a surgical cohort.

Materials and Methods

This is an observational, multicenter retrospective study. All consecutive patients with a histologically proven BD-IPMN who underwent previous EUS between 2005 and 2017 were included. Morphological features by EUS were evaluated. A score using a logistic regression model was performed to assess the risk of invasive cancer.

Results

Of 335 patients who underwent pancreatic surgery, 131 (median age: 66 years, 50.4% - male) were included. By multivariable analysis, lymph nodes (odds ratio [OR]: 17.7 [confidence interval (CI) 95%: 2.8-112.6], P = 0.002, 4 points), main pancreatic duct ≥10 mm (OR: 8.6 [CI 95%: 1.9-39.5], P = 0.006, 2 points), abrupt change of pancreatic duct (OR: 5.5 [CI 95%: 1.4-22.2], P = 0.016, 1.5 points), and solid component (OR: 4.2 [CI 95%: 1.3-13.6], P = 0.017, 1 point) were independent factors associated with invasive cancer and included in the model. The following categories of the score (0-8.5 points) - A (0-1), B (1.5-3), C (3.5-5), and D (5.5-8.5 points) - presented a positive predictive value of 8.5%, 38.9%, 62.5%, and 100%, respectively. The area under the curve was 0.857 (P < 0.001), with an overall sensitivity and specificity of 84% and 70% in the internal validation of the score.

Conclusion

This EUS predictive score for invasive cancer in BD-IPMN has a high accuracy and could be an additional tool to consider in patient management.

Endosonographic diagnosis of advanced neoplasia in intraductal papillary mucinous neoplasms

Pancreatic cancer has a high mortality rate with minimal proven interventions. Intraductal Papillary Mucinous Neoplasms (IPMNs) are known precursor lesions for pancreatic cancer. Identification of pancreatic cysts has improved from advances in abdominal imaging. Despite multiple revisions of the international consensus recommendations and various guidelines by other major societies, successful risk stratification of the malignant potential of mucinous pancreatic cysts remains challenging. Specifically, detection and accurate classification of advanced neoplasia (high-grade dysplasia and/or adenocarcinoma) in IPMNs is suboptimal with current diagnostic strategies. Development of interventional techniques utilizing endoscopic ultrasound include - through-the-needle microforceps biopsy, next-generation or whole genome molecular analysis of cyst fluid, and needle-based confocal laser endomicroscopy. These techniques suffer from a series of limitations in technical success, diagnostic yield, and clinical feasibility, but a combination approach may offer a solution that optimizes their cyst evaluation and risk stratification. Assessment and comparison of these techniques is restricted by lack of adequate surgical specimens for testing of diagnostic accuracy, resulting in a possible sample bias. Additional large-scale multicenter studies are needed to accumulate evidence for the utility and feasibility of their translation into clinical practice. Great strides have been made in pancreatic cyst evaluation, but further research is required to improve diagnostic accuracy and clinical management of IPMNs.

Management of Incidental Pancreatic Cystic Lesions: Integrating Novel Diagnostic and Prognostic Factors With Current Clinical Guidelines

Owing to increased detection rates, the diagnosis and management of incidental pancreatic cysts has become a common predicament. Up to 13% of patients undergoing cross-sectional imaging studies for other indications are found to have pancreatic cystic lesions. Although most cystic lesions are benign, the malignant potential of several types of pancreatic cysts makes accurate classification vital to directing therapy. To this end, advances in the last decade led to better characterization of pancreatic cyst morphology and hence enhanced the ability to predict underlying histopathology, and biological behavior. Although accurate classification remains a challenge, the utilization of complementary diagnostic tools is the optimal approach to dictate management. The following review includes a description of pancreatic cysts, a critical review of current and emerging diagnostic techniques and a review of recent guidelines in the management of incidental pancreatic cysts.

Multimodal radiomics and cyst fluid inflammatory markers model to predict preoperative risk in intraductal papillary mucinous neoplasms

Purpose: Our paper contributes to the burgeoning field of surgical data science. Specifically, multimodal integration of relevant patient data is used to determine who should undergo a complex pancreatic resection. Intraductal papillary mucinous neoplasms (IPMNs) represent cystic precursor lesions of pancreatic cancer with varying risk for malignancy. We combine previously defined individual models of radiomic analysis of diagnostic computed tomography (CT) with protein markers extracted from the cyst fluid to create a unified prediction model to identify high-risk IPMNs. Patients with high-risk IPMN would be sent for resection, whereas patients with low-risk cystic lesions would be spared an invasive procedure. Approach: Retrospective analysis of prospectively acquired cyst fluid and CT scans was undertaken for this study. A predictive model combining clinical features with a cyst fluid inflammatory marker (CFIM) was applied to patient data. Quantitative imaging (QI) features describing radiomic patterns predictive of risk were extracted from scans. The CFIM model and QI model were combined into a single predictive model. An additional model was created with tumor-associated neutrophils (TANs) assessed by a pathologist at the time of resection. Results: Thirty-three patients were analyzed (7 high risk and 26 low risk). The CFIM model yielded an area under the curve (AUC) of 0.74. Adding the QI model improved performance with an AUC of 0.88. Combining the CFIM, QI, and TAN models further increased performance to an AUC of 0.98. Conclusions: Quantitative analysis of routinely acquired CT scans combined with CFIMs provides accurate prediction of risk of pancreatic cancer progression. Although a larger cohort is needed for validation, this model represents a promising tool for preoperative assessment of IPMN.

EUS-guided confocal laser endomicroscopy: prediction of dysplasia in intraductal papillary mucinous neoplasms (with video)

BACKGROUND AND AIMS

Previous studies have validated EUS-guided needle-based confocal laser endomicroscopy (nCLE) diagnosis of intraductal papillary mucinous neoplasms (IPMNs). We sought to derive EUS-guided nCLE criteria for differentiating IPMNs with high-grade dysplasia/adenocarcinoma (HGD-Ca) from those with low/intermediate-grade dysplasia (LGD).

METHODS

We performed a post hoc analysis of consecutive IPMNs with a definitive diagnosis from a prospective study evaluating EUS-guided nCLE in the diagnosis of pancreatic cysts. Three internal endosonographers reviewed all nCLE videos for the patients and identified potential discriminatory EUS-guided nCLE variables to differentiate HGD-Ca from LGD IPMNs (phase 1). Next, an interobserver agreement (IOA) analysis of variables from phase 1 was performed among 6 blinded external nCLE experts (phase 2). Last, 7 blinded nCLE-naïve observers underwent training and quantified variables with the highest IOA from phase 2 using dedicated software (phase 3).

RESULTS

Among 26 IPMNs (HGD-Ca in 16), the reference standard was surgical histopathology in 24 and cytology confirmation of metastatic liver lesions in 2 patients. EUS-guided nCLE characteristics of increased papillary epithelial "width" and "darkness" were the most sensitive variables (90%; 95% confidence interval [CI], 84%-94% and 91%; 95% CI, 85%-95%, respectively) and accurate (85%; 95% CI, 78%-90% and 84%; 95% CI, 77%-89%, respectively) with substantial (κ = 0.61; 95% CI, 0.51-0.71) and moderate (κ = 0.55; 95% CI, 0.45-0.65) IOAs for detecting HGD-Ca, respectively (phase 2). Logistic regression models were fit for the outcome of HGD-Ca as predictor variables (phase 3). For papillary width (cut-off ≥50 μm), the sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) for detection of HGD-Ca were 87.5% (95% CI, 62%-99%), 100% (95% CI, 69%-100%), and 0.95, respectively. For papillary darkness (cut-off ≤90 pixel intensity), the sensitivity, specificity, and AUC for detection of HGD-Ca were 87.5% (95% CI, 62%-99%), 100% (95% CI, 69%-100%), and 0.90, respectively.

CONCLUSIONS

In this derivation study, quantification of papillary epithelial width and darkness identified HGD-Ca in IPMNs with high accuracy. These quantifiable variables can be used in multicenter studies for risk stratification of IPMNs. (Clinical trial registration number: NCT02516488.).

Radiological and Pathological Assessment of the 2017 Revised International Association of Pancreatology Consensus Guidelines for Intraductal Papillary Mucinous Neoplasm, With an Emphasis on the Gastric Pyloric Gland Type

OBJECTIVES

This study aimed to assess the pitfalls of the current International Association of Pancreatology guidelines (IAPCG2017) for pancreatic intraductal papillary mucinous neoplasm (IPMN) and identify the criteria for future guidelines.

METHODS

Eighty surgically resected, consecutive IPMN cases were analyzed. Data including tumor site, IPMN duct type, and surgery type were collected. Based on radiological data, cases were retrospectively classified as high-risk stigmata (HRS) and non-HRS. Pathological grades and histological subtypes of IPMN cases were determined. Severe stromal sclerosis of the IPMN septa/marked parenchymal atrophy in the upstream pancreas was investigated pathologically. Positive/negative predictive values of the IAPCG2017 were calculated. Clinicopathological features of HRS-benign cases (pathologically benign IPMN cases meeting the HRS criteria) were extracted.

RESULTS

The positive/negative predictive values were 72.7%/64.0%, 70.0%/34.6%, and 54.0%/63.3% for IAPCG2017, HRS-main pancreatic duct, and HRS-nodule criteria, respectively. The 15 HRS-benign cases (18.8%) included 13 pancreatoduodenectomies and 10 cases of gastric pyloric (GP) gland subtype. Severe upstream atrophy was significantly related to IPMN malignancy, unlike the severe sclerosis of IPMN septa.

CONCLUSIONS

Benign IPMNs of GP subtype are sometimes categorized as HRS with the IAPCG2017. Collecting data on the natural course of GP-IPMN is necessary. To evaluate upstream atrophy may be of value to predict IPMN malignancy.

Elevating pancreatic cystic lesion stratification: Current and future pancreatic cancer biomarker(s)

Pancreatic ductal adenocarcinoma (PDAC) is an incredibly deadly disease with a 5-year survival rate of 9%. The presence of pancreatic cystic lesions (PCLs) confers an increased likelihood of future pancreatic cancer in patients placing them in a high-risk category. Discerning concurrent malignancy and risk of future PCL progression to cancer must be carefully and accurately determined to improve survival outcomes and avoid unnecessary morbidity of pancreatic resection. Unfortunately, current image-based guidelines are inadequate to distinguish benign from malignant lesions. There continues to be a need for accurate molecular and imaging biomarker(s) capable of identifying malignant PCLs and predicting the malignant potential of PCLs to enable risk stratification and effective intervention management. This review provides an update on the current status of biomarkers from pancreatic cystic fluid, pancreatic juice, and seromic molecular analyses and discusses the potential of radiomics for differentiating PCLs harboring cancer from those that do not.

Radiomics in stratification of pancreatic cystic lesions: Machine learning in action

Pancreatic cystic lesions (PCLs) are well-known precursors of pancreatic cancer. Their diagnosis can be challenging as their behavior varies from benign to malignant disease. Precise and timely management of malignant pancreatic cysts might prevent transformation to pancreatic cancer. However, the current consensus guidelines, which rely on standard imaging features to predict cyst malignancy potential, are conflicting and unclear. This has led to an increased interest in radiomics, a high-throughput extraction of comprehensible data from standard of care images. Radiomics can be used as a diagnostic and prognostic tool in personalized medicine. It utilizes quantitative image analysis to extract features in conjunction with machine learning and artificial intelligence (AI) methods like support vector machines, random forest, and convolutional neural network for feature selection and classification. Selected features can then serve as imaging biomarkers to predict high-risk PCLs. Radiomics studies conducted heretofore on PCLs have shown promising results. This cost-effective approach would help us to differentiate benign PCLs from malignant ones and potentially guide clinical decision-making leading to better utilization of healthcare resources. In this review, we discuss the process of radiomics, its myriad applications such as diagnosis, prognosis, and prediction of therapy response. We also discuss the outcomes of studies involving radiomic analysis of PCLs and pancreatic cancer, and challenges associated with this novel field along with possible solutions. Although these studies highlight the potential benefit of radiomics in the prevention and optimal treatment of pancreatic cancer, further studies are warranted before incorporating radiomics into the clinical decision support system.

Accuracy of Fukuoka and American Gastroenterological Association Guidelines for Predicting Advanced Neoplasia in Pancreatic Cyst Neoplasm: A Meta-Analysis

BACKGROUND

A differential diagnosis of advanced pancreatic cystic neoplasms (PCNs) is critical to determine optimal treatment. The Fukuoka and American Gastroenterological Association (AGA) guidelines are the most widely accepted criteria for the management of PCNs.

OBJECTIVE

This study aimed to evaluate the diagnostic value of these guidelines in predicting advanced neoplasia (AN).

METHODS

A comprehensive electronic search of the PubMed, EMBASE, Web of Science, Cochrane Library, and Scopus databases was conducted to identify all relevant studies evaluating the Fukuoka and AGA guidelines in surgically resected and histologically confirmed PCNs. Pooled sensitivity, specificity, and diagnostic odds ratios (DORs) were calculated as compound measures of diagnostic accuracy using the random-effects model. Summary of receiver operating characteristic (SROC) curves and the area under the curve (AUC) were also performed.

RESULTS

A total of 21 studies with 3723 patients were included in this meta-analysis. Of these studies, 15, 4, and 2 evaluated the Fukuoka guidelines, the AGA guidelines, and both guidelines, respectively. For AN prediction, the Fukuoka guidelines had a pooled sensitivity of 0.67 (95% confidence interval [CI] 0.64-0.70), pooled specificity of 0.64 (95% CI 0.62-0.66), and pooled DOR of 6.28 (95% CI 4.38-9.01), with an AUC of the SROC of 0.78. AGA guidelines showed a pooled sensitivity of 0.59 (95% CI 0.52-0.65), pooled specificity of 0.77 (95% CI 0.74-0.80), and pooled DOR of 5.84 (95% CI 2.60-13.15), with an AUC of 0.79 (95% CI 0.70-0.88).

CONCLUSION

When used alone, the Fukuoka and AGA guidelines showed similar but unsatisfactory diagnostic accuracy in the risk stratification of malignant potential of PCN. Thus, we recommend that they be applied only as a broad framework in clinical practice.

Cytologic Analysis of Pancreatic Juice Increases Specificity of Detection of Malignant IPMN-A Systematic Review

BACKGROUND & AIMS

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas can progress to cancer. Biomarkers have been identified that were reported to increase the accuracy of identification of malignant lesions; we performed a systematic review of the accuracy of these markers.

METHODS

We performed a systematic review of published studies on biomarkers of malignant IPMNs by searching MEDLINE and Web of Science databases from January 2005 through December 2017. Our methods were developed based on the Meta-analysis Of Observational Studies in Epidemiology guidelines. Pooled sensitivity, specificity, receiver operating characteristic curves, and their respective areas under the curve (AUC) were calculated from groups of markers (cell-, protein-, or DNA-based) measured in samples collected before and after surgery. A hypothetical test model was developed to determine how to meaningfully amend the revised Fukuoka guidelines, focusing on increasing test specificity for patients with IPMNs that have worrisome features.

RESULTS

We collected data from 193 published studies, comprising 12,297 patients, that analyzed 7 preoperative and 21 postoperative markers of IPMNs. The 3 biomarkers that identified malignant IPMNs with the largest AUC values were pancreatic juice cytology (AUC, 0.84; sensitivity, 0.54; specificity, 0.91), serum protein carbohydrate antigen 19-9 (AUC, 0.81; sensitivity, 0.45; specificity, 0.90), and cyst fluid cytology (AUC, 0.82; sensitivity, 0.57; specificity, 0.84). A combination of cytologic and immunohistochemical analysis of MUC1 and MUC2 in pancreatic juice samples identified malignant IPMNs with the largest AUC and sensitivity values (AUC, 0.85; sensitivity, 0.85; specificity, 0.65). In a test model, inclusion of cytologic analysis of pancreatic juice in the guideline algorithm significantly increased the specificity of detection of malignant IPMNs.

CONCLUSIONS

In a systematic review, we found cytologic analysis of pancreatic juice to have the greatest effect in increasing the specificity of detection of malignant IPMNs. We propose addition of this test to the Fukuoka guidelines for assessment of patients with IPMNs with worrisome features.

Genomic profile concordance between pancreatic cyst fluid and neoplastic tissue

BACKGROUND

DNA mutational analysis of pancreatic cystic fluid (CF) is a useful adjunct to the evaluation of pancreatic cysts. KRAS/GNAS or RAF/PTPRD/CTNNB1/RNF43 mutations are highly specific to precancerous or advanced neoplasia. Several studies recently demonstrated the ability of next-generation sequencing (NGS) analysis to detect DNA mutations in pancreatic CF, but few studies have performed a systematic comparative analysis between pancreatic CF and neoplastic surgical tissue (NT). The value of CF-NGS analysis indicators for determining surgical resection necessitates evaluation.

AIM

To confirm whether CF genomic profiles are a reliable malignancy predictor by comparing NGS mutational analyses of CF and NT.

METHODS

Patients requiring surgery for high-risk pancreatic cysts were included in a multicenter prospective pilot study. DNA from CF (collected by endoscopic ultrasound-guided fine needle aspiration (known as EUS-FNA)) and NT (collected by surgery) were analyzed by NGS. The primary objective was to compare the mutation profiles of paired DNA samples. The secondary objective was to correlate the presence of specific mutations (KRAS/GNAS, RAF/ PTPRD/CTNNB1/RNF43/POLD1/TP53) with a final cancer diagnosis. Sensitivity and specificity were also evaluated.

RESULTS

Between December 2016 and October 2017, 20 patients were included in this pilot study. Surgery was delayed for 3 patients. Concordant CF-NT genotypes were found in 15/17 paired DNA, with a higher proportion of mutated alleles in CF than in NT. NGS was possible for all pancreatic CF collected by EUS-FNA. In 2 cases, the presence of a KRAS/GNAS mutation was discordant between CF and NT. No mutations were found in 3 patients with NT or pancreatic cysts with high-grade dysplasia. The sensitivity and specificity of KRAS/GNAS mutations in CF to predict an appropriate indication for surgical resection were 0.78 and 0.62, respectively. The sensitivity and specificity of RAF/PTPRD/CTNNB1 /RNF43/POLD1/TP53 mutations in CF were 0.55 and 1.0, respectively.

CONCLUSION

Mutational analyses of CF and NT were highly concordant, confirming the value of NGS analysis of CF in the preoperative malignancy assessment. However, these results need to be confirmed on a larger scale.

A semicentennial of pancreatic pathology: the genetic revolution is here, but don't throw the baby out with the bath water!

The last 50 years have witnessed an explosion in our understanding of the pathology of pancreatic diseases. Entities known to exist 50 years ago have been defined more precisely and are now better classified. New entities, previously not recognized, have been discovered and can now be treated. Importantly, new tools have been developed that have unraveled the fundamental biological drivers of a number of pancreatic diseases. Many of these same tools have also been applied clinically, supplementing the tried and true hematoxylin and eosin stained slide with a plethora of new, highly sensitive and specific tests that improve diagnostic accuracy and delineate best treatments. As exciting as these many advances are, our knowledge of pancreatic pathology remains incomplete, and there is much to be learned.

Multi-institutional Validation Study of Pancreatic Cyst Fluid Protein Analysis for Prediction of High-risk Intraductal Papillary Mucinous Neoplasms of the Pancreas

OBJECTIVE

Preliminary work by our group suggested that proteins within the pancreatic cyst fluid (CF) may discriminate degree of IPMN dysplasia. We sought to externally validate these markers and determine whether their inclusion in a preoperative clinical nomogram could increase diagnostic accuracy.

SUMMARY BACKGROUND DATA

IPMN is the most common radiographically identifiable precursor to pancreatic cancer; however, the timing and frequency of its malignant progression are unknown, and there are currently no reliable preoperative tests that can determine the grade of dysplasia in IPMN.

METHODS

Clinical and radiographic data, as well as CF samples, were obtained from 149 patients who underwent resection for IPMN at 1 of 3 institutions. High-risk disease was defined as the presence of high-grade dysplasia or invasive carcinoma. Multianalyte bead array analysis (Luminex) of CF was performed for 4 protein markers that were previously associated with high-risk disease. Logistic regression models were fit on training data, with and without adjustment for a previously developed clinical nomogram and validated with an external testing set. The models incorporating clinical risk score were presented graphically as nomograms.

RESULTS

Within the group of 149 resected patients, 89 (60%) had low-risk disease, and 60 (40%) had high-risk disease. All 4 CF markers (MMP9, CA72-4, sFASL, and IL-4) were overexpressed in patients with high-risk IPMN (P < 0.05). Two predictive models based on preselected combinations of CF markers had concordance indices of 0.76 (Model-1) and 0.80 (Model-2). Integration of each CF marker model into a previously described clinical nomogram leads to increased discrimination compared with either the CF models or nomogram alone (c-indices of 0.84 and 0.83, respectively).

CONCLUSIONS

This multi-institutional study validated 2 CF protein marker models for preoperative identification of high-risk IPMN. When combined with a clinical nomogram, the ability to predict high-grade dysplasia was even stronger.

Risk of advanced lesions in patients with branch-duct IPMN and relative indications for surgery according to European evidence-based guidelines

BACKGROUND

European evidence-based guidelines proposed surgery for branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) based on the presence of 1-2 relative indications, depending on the comorbidity burden.

AIMS

To assess the accuracy of the guidelines in patients with relative indications in a surgical cohort of demonstrated BD-IPMNs.

METHODS

This report describes a multi-centre, observational, retrospective study. All consecutive patients with relative indications and histologically confirmed BD-IPMN were included. The main outcome was risk of invasive carcinoma in patients with relative indications.

RESULTS

Ninety-one patients with BD-IPMN underwent surgery because of absolute (n = 21), relative (n = 60), or no formal indications (n = 10). In total, there were 60 patients (mean age: 66 ± 9, 50% male) with one (n = 35, 58.3%) or ≥2 relative indications (n = 25, 41.7%). The global advanced lesion and invasive carcinoma rates were 40% and 13.3%, respectively. No risk factor was associated with high-grade dysplasia or invasive carcinoma. Patients with one indication had a lower risk of invasive carcinoma than did those with ≥2 relative indications (5.7% vs. 24%, respectively, p = 0.048); however, the advanced lesion rates were comparable (37.1% vs. 44%, p = 0.593).

CONCLUSIONS

Invasive carcinoma is considerably more frequent in patients with two or more relative indications. The surgical strategy in these selected cases should be decided on an individual basis.

Single-Cell Transcriptomics of Pancreatic Cancer Precursors Demonstrates Epithelial and Microenvironmental Heterogeneity as an Early Event in Neoplastic Progression

PURPOSE

Early detection of pancreatic ductal adenocarcinoma (PDAC) remains elusive. Precursor lesions of PDAC, specifically intraductal papillary mucinous neoplasms (IPMNs), represent a bona fide pathway to invasive neoplasia, although the molecular correlates of progression remain to be fully elucidated. Single-cell transcriptomics provides a unique avenue for dissecting both the epithelial and microenvironmental heterogeneities that accompany multistep progression from noninvasive IPMNs to PDAC.

EXPERIMENTAL DESIGN

Single-cell RNA sequencing was performed through droplet-based sequencing on 5,403 cells from 2 low-grade IPMNs (LGD-IPMNs), 2 high-grade IPMNs (HGD-IPMN), and 2 PDACs (all surgically resected).

RESULTS

Analysis of single-cell transcriptomes revealed heterogeneous alterations within the epithelium and the tumor microenvironment during the progression of noninvasive dysplasia to invasive cancer. Although HGD-IPMNs expressed many core signaling pathways described in PDAC, LGD-IPMNs harbored subsets of single cells with a transcriptomic profile that overlapped with invasive cancer. Notably, a proinflammatory immune component was readily seen in low-grade IPMNs, composed of cytotoxic T cells, activated T-helper cells, and dendritic cells, which was progressively depleted during neoplastic progression, accompanied by infiltration of myeloid-derived suppressor cells. Finally, stromal myofibroblast populations were heterogeneous and acquired a previously described tumor-promoting and immune-evading phenotype during invasive carcinogenesis.

CONCLUSIONS

This study demonstrates the ability to perform high-resolution profiling of the transcriptomic changes that occur during multistep progression of cystic PDAC precursors to cancer. Notably, single-cell analysis provides an unparalleled insight into both the epithelial and microenvironmental heterogeneities that accompany early cancer pathogenesis and might be a useful substrate to identify targets for cancer interception.See related commentary by Hernandez-Barco et al., p. 2027.

Imaging and Cytopathological Criteria Indicating Malignancy in Mucin-Producing Pancreatic Neoplasms: A Series of 68 Histopathologically Confirmed Cases

OBJECTIVES

This study aims to evaluate the performance of clinical, imaging, and cytopathological criteria in the identification of high-grade dysplasia/carcinoma (HGD/Ca) in pancreatic mucin-producing cystic neoplasms.

METHODS

Sixty-eight consecutive, histopathologically confirmed mucin-producing cystic neoplasms, evaluated by endoscopic ultrasound-guided fine-needle aspiration, were enrolled; specifically, 39 branch duct intraductal papillary mucinous neoplasms (BD-IPMNs), 21 main duct IPMNs, and 8 mucinous cystic neoplasms. The associations between HGD/Ca in histopathology and findings of endoscopic ultrasound and cytology, demographic, lifestyle, and clinical parameters were evaluated, separately in IPMNs and mucinous cystic neoplasms.

RESULTS

Age 65 years or more was associated with HGD/Ca in IPMNs. In BD-IPMNs, cyst diameter 3 cm or greater (sensitivity, 68.8%; specificity, 65.2%), a mural nodule (sensitivity, 56.3%; specificity, 78.3%), main pancreatic duct diameter 5 to 9 mm (sensitivity, 50.0%; specificity, 87.0%), and suspicious cytology (sensitivity, 81.3%; specificity, 100%) signaled the presence of HGD/Ca. Similarly, in main duct IPMNs, suspicious cytology predicted HGD/Ca with high sensitivity (88.9%) and excellent specificity (100%). Regarding cytopathological criteria, in BD-IPMNs, HGD/Ca was associated with a high nuclear/cytoplasmic ratio, background necrosis, presence of papillary structures, hypochromatic nuclei, hyperchromatic nuclei, and major nuclear membrane irregularities (thickening and/or indentations).

CONCLUSIONS

Clinical, imaging, and cytopathological criteria are useful in the identification of HGD/Ca in IPMNs.

Pancreatic Cytology

The diagnostic approach to pancreaticobiliary disease requires a multidisciplinary team in which the cytopathologist plays a crucial role. Fine-needle aspiration, obtained by endoscopic ultrasound, is the diagnostic test of choice for pancreatic lesions. Preoperative clinical management depends on many factors, many of which rely on accurate cytologic assessment. Pancreaticobiliary cytology is wrought with diagnostic pitfalls. Clinical history, imaging studies, cytology samples, and ancillary tests, including immunohistochemistry, biochemical analysis, and genetic sequencing, are integral to forming a complete diagnosis and guiding optimal patient management. This article reviews clinical aspects and the diagnostic work-up of commonly encountered diagnostic entities within the field of pancreatic cytology.

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

BACKGROUND & AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Managing Incidental Pancreatic Cysts

PURPOSE OF REVIEW

The goal of this review is to critically analyze the current literature regarding the management of incidental pancreatic cysts. Given their increased rates of detection due to the frequent use of cross-sectional imaging, correctly identifying the subset of high risk lesions that are appropriate for surgical resection is critical. However, the existing consensus and societal guidelines discussed in this review lack high quality data to create evidence-based recommendations, making achieving this important aim challenging.

RECENT FINDINGS

Several recent studies have focused on the natural history of pancreatic cysts and defining the role of endoscopic ultrasound, which remains unclear. EUS-guided diagnostic tools include molecular analysis of obtained fluid; EUS-guided FNA, FNB, and intracystic forceps biopsy of the cyst wall; and confocal endomicroscopy. While their precise role in diagnosing pancreatic cystic neoplasms remains to be defined, they represent promising innovations that may play a future role in cyst assessment and management. Large, long-term, prospective studies of incidentally identified pancreatic cysts are essential to fully understand their natural history and potential for neoplastic progression. Given the absence of such data at present, an individualized patient approach is recommended.

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

Background

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

Methods

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

Results

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

Conclusion

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

Fukuoka-Negative Branch-Duct IPMNs: When to Worry? A Study from the French Surgical Association (AFC)

BACKGROUND

This study analyzed the pathologic findings for patients with Fukuoka-negative branch-duct intraductal papillary mucinous neoplasm (BD-IPMN) who theoretically were eligible for surveillance care with follow-up assessment, but instead underwent resection.

METHODS

From January 2005 to December 2012, 820 patients underwent evaluation for IPMN. At initial staging, 319 patients had BD-IPMN, and 89 of these patients presented with Fukuoka-negative criteria. These 89 patients were included in this study.

RESULTS

Of the 89 patients, 55 (62%) underwent pancreatectomy. After pathologic examination, the ultimate diagnosis was MT-IPMN for 20 (36%) of these patients (the MT group) and BD-IPMN for 35 (64%) of these patients (the BD group). The remaining 34 patients (38%) underwent enucleation. The patients in the MT group were more likely to be male (P = 0.01) and to have a higher rate of recent (< 1 year) diabetes mellitus diagnosis (P = 0.007) than the patients in the BD group. In the multivariate analysis, diabetes mellitus was independently associated with involvement of the main pancreatic duct (P = 0.05). Malignancy was diagnosed for 14 (16%) of the 89 patients. The rate of invasive IPMN was higher in the MT group than in the BD group (20% vs. 0%, P = 0.02). The 5-year overall survival rate was 100% for the BD group and 84% for the MT group (P = 0.02). For the male patients with diabetes mellitus, the rate of malignancy rose to 67%.

CONCLUSIONS

For patients with a diagnosis of Fukuoka-negative BD-IPMN, resection should be considered primarily for male patients with a recent diabetes mellitus diagnosis.

Identification of a pyruvate-to-lactate signature in pancreatic intraductal papillary mucinous neoplasms

OBJECTIVE

We used transcriptomic profiling and immunohistochemistry (IHC) to search for a functional imaging strategy to resolve common problems with morphological imaging of cystic neoplasms and benign cystic lesions of the pancreas.

METHODS

Resected pancreatic cancer (n = 21) and normal pancreas were laser-capture micro-dissected, and transcripts were quantified by RNAseq. Functional imaging targets were validated at the protein level by IHC on a pancreatic adenocarcinoma tissue microarray and a newly created tissue microarray of resected intraductal papillary mucinous neoplasms (IPMNs) and IPMN-associated adenocarcinomas.

RESULTS

Genes encoding proteins responsible for cellular import of pyruvate, export of lactate, and conversion of pyruvate to lactate were highly upregulated in pancreatic adenocarcinoma compared to normal pancreas. Strong expression of MCT4 and LDHA was observed by IHC in >90% of adenocarcinoma specimens. In IPMNs, the pyruvate-to-lactate signature was significantly elevated in high grade dysplasia (HGD) and IPMN-associated adenocarcinoma. Additionally, cores containing HGD and/or adenocarcinoma exhibited a higher number of peri-lesional stromal cells and a significant increase in peri-lesional stromal cell staining of LDHA and MCT4. Interestingly, the pyruvate-to-lactate signature was significantly upregulated in cores containing only low grade dysplasia (LGD) from patients with histologically confirmed IPMN-associated adenocarcinoma versus LGD cores from patients with non-invasive IPMNs.

CONCLUSION

Our results suggest prospective studies with hyperpolarized [1-13C]-pyruvate magnetic resonance spectroscopic imaging are warranted. If these IHC results translate to functional imaging findings, a positive pyruvate-to-lactate imaging signature might be a risk factor for invasion that would warrant resection of IPMNs in the absence of other worrisome features.

Does next-generation sequencing of cyst fluid improve management of pancreatic cystic neoplasms?

Pancreatic cystic lesions represent a heterogeneous group of diseases ranging from benign to malignant lesions. They are increasingly being detected due to the widespread use of cross-sectional imaging. Their management is a challenge because it is often not possible to reliably discriminate between malignant and nonmalignant lesions using current imaging technology. Next-generation sequencing (NGS) has the ability of both whole genome and targeted sequencing at a low cost and from a limited amount of DNA. NGS of cyst fluid aspired by endoscopic ultrasonography-guided fine-needle aspiration provides a valuable tool in biomarker research and may in the future help improve diagnosis and management of pancreatic cystic lesions.

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

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