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

Diagnosis and Management of Pancreatic Cysts

As pancreatic cyst incidence rises, likely due to the ubiquitous increase in cross-sectional imaging, their management presents multiple challenges for both the practitioner and patient. It is critical that all pancreatic cysts are appropriately characterized, as treatment decisions depend on an accurate diagnosis. Diagnostic modalities such as cytology, biopsy, and cyst fluid biomarkers allow for definitive diagnosis of virtually all lesions. Some cysts, such as intraductal papillary mucinous neoplasms, mucinous cystic neoplasms, and cystic pancreatic endocrine neoplasms, have malignant potential and must be surveyed. Other cysts, such as serous cystadenomas and pancreatic fluid collections, do not have malignant potential. Surveillance strategies vary widely depending on cyst type and size and while multiple medical societies advocate surveillance, their published surveillance guidelines are heterogenous. Cysts with high-risk stigmata or worrisome features are usually resected, depending on the patient's surgical fitness. In patients unfit for resection, newer endoscopic ablative techniques are advocated. Controversial aspects regarding cyst management include whether surveillance can be stopped, how surveillance should be performed, and the extensive financial burden cyst management places on the health care system. Further study into the natural history of cystic lesions, including definitive determination of the rate of malignant transformation for each cyst type, is essential.

Association of high-risk stigmata and worrisome features with advanced neoplasia in intraductal papillary mucinous neoplasms (IPMN): A systematic review

BACKGROUND

This systematic review aimed to assess the diagnostic accuracy of the International Consensus Fukuoka Guidelines (ICG2017) in identifying high-risk lesions of Intraductal Papillary Mucinous Neoplasms (IPMNs).

METHODS

The ICG2017 revision committee conducted a comprehensive literature review to establish evidence-based statements on IPMNs. The review focused on articles examining the diagnostic value of imaging features (e.g., cyst or main pancreatic duct diameter), clinical symptoms associated with IPMN, and serum biomarkers. Five clinical questions regarding high-risk stigmata (HRS) and worrisome features (WF) in the ICG2017 guidelines were addressed.

RESULTS

A total of 210 articles were reviewed. The findings revealed a significant association between the presence of mural nodules ≥5 mm in diameter or solid components with contrast enhancement and the diagnosis of high-grade dysplasia or invasive carcinoma. Contrast-enhanced diagnostic tools, such as CT, MRI, or EUS, demonstrated the highest prediction rate and were recommended. Positive cytology was identified as an HRS, while symptoms like acute pancreatitis and cyst diameter growth ≥2.5 mm per year were considered WFs. The use of nomograms and multiple diagnostic factors was recommended for optimal IPMN management.

CONCLUSIONS

This systematic review provides evidence supporting the improved diagnostic accuracy of ICG2017 in identifying high-risk lesions of IPMN. The multidisciplinary incorporation of HRS and WF based on imaging findings and clinical symptoms is crucial. These findings should inform the revision of ICG2017, enhancing the evaluation and management of IPMN patients. By implementing these recommendations, clinicians can make more informed decisions, leading to better diagnosis and treatment outcomes for high-risk IPMN cases.

Digital spatial profiling of intraductal papillary mucinous neoplasms: Toward a molecular framework for risk stratification

The histopathologic heterogeneity of intraductal papillary mucinous neoplasms (IPMN) complicates the prediction of pancreatic ductal adenocarcinoma (PDAC) risk. Intratumoral regions of pancreaticobiliary (PB), intestinal (INT), and gastric foveolar (GF) epithelium may occur with either low-grade dysplasia (LGD) or high-grade dysplasia (HGD). We used digital spatial RNA profiling of dysplastic epithelium (83 regions) from surgically resected IPMN tissues (12 patients) to differentiate subtypes and predict genes associated with malignancy. The expression patterns of PB and GF lesions diverged from INT, suggesting that PB and GF arise from a common lineage. Transcriptional dysregulation within PB lesions mirrored that of PDAC, whereas INT and GF foci did not. Tumor necrosis factor/nuclear factor κB (TNF-NFκB) and cell cycle (cycling S and cycling G₂-M) programs occurred with relative prominence in PB and INT subtypes, respectively. Together, this study delineates markers of high-risk IPMN and insights into malignant progression.

Simultaneous and sequential combination of genetic and epigenetic biomarkers for the presence of high-grade dysplasia in patients with pancreatic cyst: Discovery in cyst fluid and test in pancreatic juice

BACKGROUND/OBJECTIVES

Screening patients with intraductal papillary mucinous neoplasms (IPMN) has the primary goal of identifying potentially curable noninvasive precursors. We aimed to evaluate the diagnostic impact of genetic and epigenetic biomarkers in the presence of noninvasive precursors.

METHODS

Mutated KRAS/GNAS and methylated SOX17/TBX15/BMP3/TFPI2 DNA were assessed by droplet digital PCR in a discovery cohort of 70 surgically aspirated cyst fluids, and diagnostic performances for differentiating high-grade dysplasia (HGD) from low-grade dysplasia (LGD) was evaluated. We then tested these markers using an independent test cohort consisting of 156 serially collected pancreatic juice samples from 30 patients with IPMN.

RESULTS

Mutated KRAS and GNAS are specific for IPMNs but are not helpful for the prediction of histological grades. Cyst fluids from IPMN with HGD showed higher methylation levels of SOX17 (median, 0.141 vs. 0.021; P = 0.086) and TBX15 (median, 0.030 vs. 0.003; P = 0.028) than those with LGD. The combination of all tested markers yielded a diagnostic performance with sensitivity of 69.6%, and specificity of 90.0%. Among the 30 pancreatic juice samples exhibiting the highest abundance of KRAS/GNAS mutations in each patient in the test cohort, patients with histologically proven HGD due to pancreatic resection had a significantly higher prevalence (100% vs. 31%, P = 0.018) and abundance (P = 0.037) of methylated TBX15 than those without cytohistological diagnosis undergoing surveillance.

CONCLUSIONS

A simultaneous and sequential combination of mutated and methylated DNA markers in pancreatic cyst fluid and juice sample markers can help detect noninvasive pancreatic precursor neoplasms.

The Landmark Series: Intraductal Papillary Mucinous Neoplasms of the Pancreas-From Prevalence to Early Cancer Detection

Modern series report a prevalence of pancreatic cysts in the general population of up to 50% in prospective studies. Of these, about half will be pancreatic cystic neoplasms (PCNs) that have varying degrees of malignant potential. Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are the most common PCNs and are known predecessors of pancreatic adenocarcinoma. Critically, they are one of the only radiographically identifiable precursors of pancreatic cancer and thus provide an opportunity for early cancer detection and surgical resection with curative intent. The combination of high prevalence and potential for malignant degeneration underscore the relevance of discussing the best management of IPMNs and improving the existing standard of care. Landmark data on IPMN prevalence, guidelines, surveillance, biomarkers, and immune landscape are highlighted.

Circulating cytokines allow for identification of malignant intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMNs) are the precursor lesions of pancreatic cancers, requiring active surgical intervention during cancer development. However, the current criteria for predicting malignant IPMNs remain challenging and limited. Hence, this study aimed to assess the discriminatory performance of circulating cytokines, including TNF-α, IL-2R, IL-6, and IL-8, then build a novel predictive model to improve the diagnostic accuracy.

METHOD

A total of 131 retrospective (from March 2016 to December 2019) and 53 prospective (from March 2020 to January 2021) patients who were histologically confirmed as IPMNs were consecutively collected and analyzed.

RESULT

The circulating levels of TNF-α, IL-2R, IL-6, and IL-8 were significantly elevated in malignant IPMNs, and were verified as independent factors for malignant IPMNs (p < 0.05). Then, a novel score, the circulating cytokine score (CCS), was calculated and demonstrated as an independent predictive indicator with a higher area under the curve (AUC) than each cytokine alone (p < 0.001). Besides the CCS, two high-risk stigmata features, the presence of solid component (PSC), and main pancreatic duct (MPD) dilation ≥10 mm were also demonstrated as independent indicators for predicting malignant IPMNs. Finally, a novel nomogram incorporating the CCS and these two high-risk stigmata features presented a remarkable diagnostic performance, both in the training and validation cohorts with AUCs of 0.928 and 0.873, respectively.

CONCLUSION

The CCS can be considered a novel independent predictive indicator for malignant IPMNs. Additionally, the formulated nomogram model integrating the CCS, PSC, and MPD ≥10 mm can be a valuable and promising tool for predicting the malignant transformation of IPMNs during long-term follow-ups to assist in timely and accurate surgical decisions.

Surgical treatment for pancreatic cystic lesions-implications from the multi-center and prospective German StuDoQ|Pancreas registry

PURPOSE

The detection of pancreatic cystic lesions (PCL) causes uncertainty for physicians and patients, and international guidelines are based on low evidence. The extent and perioperative risk of resections of PCL in Germany needs comparison with these guidelines to highlight controversies and derive recommendations.

METHODS

Clinical data of 1137 patients who underwent surgery for PCL between 2014 and 2019 were retrieved from the German StuDoQ|Pancreas registry. Relevant features for preoperative evaluation and predictive factors for adverse outcomes were statistically identified.

RESULTS

Patients with intraductal papillary mucinous neoplasms (IPMN) represented the largest PCL subgroup (N = 689; 60.6%) while other entities (mucinous cystic neoplasms (MCN), serous cystic neoplasms (SCN), neuroendocrine tumors, pseudocysts) were less frequently resected. Symptoms of pancreatitis were associated with IPMN (OR, 1.8; P = 0.012) and pseudocysts (OR, 4.78; P < 0.001), but likewise lowered the likelihood of MCN (OR, 0.49; P = 0.046) and SCN (OR, 0.15, P = 0.002). A total of 639 (57.2%) patients received endoscopic ultrasound before resection, as recommended by guidelines. Malignancy was histologically confirmed in 137 patients (12.0%), while jaundice (OR, 5.1; P < 0.001) and weight loss (OR, 2.0; P = 0.002) were independent predictors. Most resections were performed by open surgery (N = 847, 74.5%), while distal lesions were in majority treated using minimally invasive approaches (P < 0.001). Severe morbidity was 28.4% (N = 323) and 30d mortality was 2.6% (N = 29). Increased age (P = 0.004), higher BMI (P = 0.002), liver cirrhosis (P < 0.001), and esophageal varices (P = 0.002) were independent risk factors for 30d mortality.

CONCLUSION

With respect to unclear findings frequently present in PCL, diagnostic means recommended in guidelines should always be considered in the preoperative phase. The therapy of PCL should be decided upon in the light of patient-specific factors, and the surgical strategy needs to be adapted accordingly.

Invasive and Noninvasive Progression After Resection of Noninvasive Intraductal Papillary Mucinous Neoplasms

OBJECTIVE

To define frequencies, pattern of progression (invasive vs noninvasive), and risk factors of progression of resected noninvasive intraductal papillary mucinous neoplasms (IPMNs).

BACKGROUND

There is a risk of progression in the remnant pancreas after resection of IPMNs.

METHODS

Four hundred forty-nine consecutive patients with resected IPMNs from 1995 to 2018 were included to the study. Patients with invasive carcinoma or with follow-up <6 months were excluded. Noninvasive progression was defined as a new IPMN, increased main pancreatic duct size, and increased size of an existing lesion (5 mm compared with preoperative imaging). Invasive progression was defined as development of invasive cancer in the remnant pancreas or metastatic disease.

RESULTS

With a median follow-up of 48.9 months, progression was identified in 124 patients (27.6%); 108(24.1%) with noninvasive and 16(3.6%) with invasive progression. Median progression follow-up was longer for invasive progression (85.4 vs 55.9 months; P = 0.001). Five-and 10-year estimates for a cumulative incidence of invasive progression were 6.4% and 12.9% versus 26.9% and 41.5% for noninvasive progression. After risk adjustment, multifocality (HR 4.53, 95% CI 1.34-15.26; P = 0.02) and high-grade dysplasia (HGD) in the original resection (HR 3.60, 95% CI 1.13-11.48; P = 0.03) were associated with invasive progression.

CONCLUSIONS

Progression to invasive carcinoma can occur years after the surgical resection of a noninvasive IPMN. HGD in the original resection is a risk factor for invasive progression but some cases of low-grade dysplasia also progressed to cancer. Patients with high-risk features such as HGD and multifocal cysts should be considered for more intensive surveillance and represent an important cohort for future trials such as anti-inflammatory or prophylactic immunotherapy.

Perioperative risk of pancreatic head resection-nomogram-based prediction of severe postoperative complications as a decisional aid for clinical practice

PURPOSE

To develop nomograms for pre- and early-postoperative risk assessment of patients undergoing pancreatic head resection.

METHODS

Clinical data from 956 patients were collected in a prospectively maintained database. A test (n = 772) and a validation cohort (n = 184) were randomly generated. Uni- and multi-variate analysis and nomogram construction were performed to predict severe postoperative complications (Clavien-Dindo Grades III-V) in the test cohort. External validation was performed with the validation cohort.

RESULTS

We identified ASA score, indication for surgery, body mass index (BMI), preoperative white blood cell (WBC) count, and preoperative alkaline phosphatase as preoperative factors associated with an increased perioperative risk for complications. Additionally to ASA score, BMI, indication for surgery, and the preoperative alkaline phosphatase, the following postoperative parameters were identified as risk factors in the early postoperative setting: the need for intraoperative blood transfusion, operation time, maximum WBC on postoperative day (POD) 1-3, and maximum serum amylase on POD 1-3. Two nomograms were developed on the basis of these risk factors and showed accurate risk estimation for severe postoperative complications (ROC-AUC-values for Grades III-V-preoperative nomogram: 0.673 (95%, CI: 0.626-0.721); postoperative nomogram: 0.734 (95%, CI: 0.691-0.778); each p ≤ 0.001). Validation yielded ROC-AUC-values for Grades III-V-preoperative nomogram of 0.676 (95%, CI: 0.586-0.766) and postoperative nomogram of 0.677 (95%, CI: 0.591-0.762); each p = 0.001.

CONCLUSION

Easy-to-use nomograms for risk estimation in the pre- and early-postoperative setting were developed. Accurate risk estimation can support the decisional process, especially for IPMN-patients with an increased perioperative risk.

Intraductal Papillary Mucinous Neoplasms: Have IAP Consensus Guidelines Changed our Approach?: Results from a Multi-institutional Study

OBJECTIVE

To evaluate the influence of consensus guidelines on the management of intraductal papillary mucinous neoplasms (IPMN) and the subsequent changes in pathologic outcomes.

BACKGROUND

Over time, multiple guidelines have been developed to identify high-risk IPMN. We hypothesized that the development and implementation of guidelines should have increased the percentage of resected IPMN with high-risk disease.

METHODS

Memorial Sloan-Kettering (MSK), Johns Hopkins (JH), and Massachusetts General Hospital (MGH) databases were queried for resected IPMN (2000-2015). Patients were categorized into main-duct (MD-IPMN) versus branch-duct (BD-IPMN). Guideline-specific radiographic/endoscopic features were recorded. High-risk disease was defined as high-grade dysplasia/carcinoma. Fisher's exact test was used to detect differences between institutions. Logistic regression evaluated differences between time-points [preguidelines (pre-GL, before 2006), Sendai (SCG, 2006-2012), Fukuoka (FCG, after 2012)].

RESULTS

The study included 1210 patients. The percentage of BD-IPMN with ≥1 high-risk radiographic feature differed between centers (MSK 69%, JH 60%, MGH 45%; P < 0.001). In MD-IPMN cohort, the presence of radiographic features such as solid component and main pancreatic duct diameter ≥10 mm also differed (solid component: MSK 38%, JH 30%, MGH 18%; P < 0.001; duct ≥10 mm: MSK 49%, JH 32%, MGH 44%; P < 0.001). The percentage of high-risk disease on pathology, however, was similar between institutions (BD-IPMN: P = 0.36, MD-IPMN: P = 0.48). During the study period, the percentage of BD-IPMN resected with ≥1 high-risk feature increased (52% pre-GL vs 67% FCG; P = 0.005), whereas the percentage of high-risk disease decreased (pre-GL vs FCG: 30% vs 20%). For MD-IPMN, there was not a clear trend towards guideline adherence, and the rate of high-risk disease was similar over the time (pre-GL vs FCG: 69% vs 67%; P = 0.63).

CONCLUSION

Surgical management of IPMN based on radiographic criteria is variable between institutions, with similar percentages of high-risk disease. Over the 15-year study period, the rate of BD-IPMN resected with high-risk radiographic features increased; however, the rate of high-risk disease decreased. Better predictors are needed.

Multi-institutional Validation Study of Cyst Fluid Protein Biomarkers in Patients With Cystic Lesions of the Pancreas

OBJECTIVE

Prospective evaluation of 2 clinical-molecular models in patients with unknown pathology who underwent endoscopic ultrasound with fine-needle aspiration (EUS-FNA) for a cystic lesion of the pancreas.

SUMMARY OF BACKGROUND DATA

Preoperative prediction of histologic subtype (mucinous vs nonmucinous) and grade of dysplasia in patients with pancreatic cystic neoplasms is challenging. Our group has previously published 2 clinical-molecular nomograms for intraductal papillary mucinous neoplasms (IPMN) that incorporated both clinical/radiographic features and cyst fluid protein markers (sFASL, CA72-4, MMP9, IL-4).

METHODS

This multiinstitutional study enrolled patients who underwent EUS-FNA for a cystic lesion of the pancreas. Treatment recommendations regarding resection were based on standard clinical, radiographic, and endoscopic features. Predicted probabilities of high-risk IPMN (high-grade dysplasia/invasive cancer) were calculated using the previously developed clinical-molecular nomograms.

RESULTS

Cyst fluid was obtained from 100 patients who underwent diagnostic EUS-FNA. Within this group there were 35 patients who underwent resection, and 65 were monitored radiographically. Within the group that underwent resection, 26 had low-risk IPMN or benign non-IPMN lesions, and 9 had high-risk IPMN. Within the surveillance group, no patient progressed to resection or developed cancer after a median follow-up of 12 months (range: 0.5-38). Using the clinical/radiographic nomogram alone, 2 out of 9 patients with high-risk IPMN had a predicted probability >0.5. In the clinical-molecular models, 6 of 9 patients in model 1, and 6 of 9 in model 2, had scores >0.5.

CONCLUSIONS

This prospective study of patients with unknown cyst pathology further demonstrates the importance of cyst fluid protein analysis in the preoperative identification of patients with high-risk IPMN. Longer follow-up is necessary to determine if this model will be useful in clinical practice.

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.

Cyst fluid metabolites distinguish malignant from benign pancreatic cysts

OBJECTIVES

Current standard of care imaging, cytology, or cystic fluid analysis cannot reliably differentiate malignant from benign pancreatic cystic neoplasms. This study sought to determine if the metabolic profile of cystic fluid could distinguish benign and malignant lesions, as well as mucinous and non-mucinous lesions.

Methods

Metabolic profiling by untargeted mass spectrometry and quantitative nuclear magnetic resonance was performed in 24 pancreatic cyst fluid from surgically resected samples with pathological diagnoses and clinicopathological correlation.

Results

(Iso)-butyrylcarnitine distinguished malignant from benign pancreatic cysts, with a diagnostic accuracy of 89%. (Iso)-butyrylcarnitine was 28-fold more abundant in malignant cyst fluid compared with benign cyst fluid (P=.048). Furthermore, 5-oxoproline (P=.01) differentiated mucinous from non-mucinous cysts with a diagnostic accuracy of 90%, better than glucose (82% accuracy), a previously described metabolite that distinguishes mucinous from non-mucinous cysts. Combined analysis of glucose and 5-oxoproline did not improve the diagnostic accuracy. In comparison, standard of care cyst fluid carcinoembryonic antigen (CEA) and cytology had a diagnostic accuracy of 40% and 60% respectively for mucinous cysts. (Iso)-butyrylcarnitine and 5-oxoproline correlated with cyst fluid CEA levels (P<.0001 and P<.05 respectively). For diagnosing malignant pancreatic cysts, the diagnostic accuracies of cyst size > 3 cm, ≥ 1 high-risk features, cyst fluid CEA, and cytology are 38%, 75%, 80%, and 75%, respectively.

Conclusions

(Iso)-butyrylcarnitine has potential clinical application for accurately distinguishing malignant from benign pancreatic cysts, and 5-oxoproline for distinguishing mucinous from non-mucinous cysts.

Risk of the Watch-and-Wait Concept in Surgical Treatment of Intraductal Papillary Mucinous Neoplasm

Importance

The natural history of intraductal papillary mucinous neoplasms (IPMNs) remains uncertain. The inconsistencies among published guidelines preclude accurate decision-making. The outcomes and potential risks of a conservative watch-and-wait approach vs a surgical approach must be compared.

Objective

To provide an overview of the surgical management of IPMNs, focusing on the time of resection.

Design, Setting, and Participants

This cohort study was conducted in a single referral center; all patients with pathologically proven IPMN who received a pancreatic resection at the institution between October 2001 and December 2019 were analyzed. Preoperatively obtained images and the medical history were scrutinized for signs of progression and/or malignant features. The timeliness of resection was stratified into too early (adenoma and low-grade dysplasia), timely (intermediate-grade dysplasia and in situ carcinoma), and too late (invasive cancer). The perioperative characteristics and outcomes were compared between these groups.

Exposures

Timeliness of resection according to the final pathological findings.

Main Outcomes and Measures

The risk of malignant transformation at the final pathology.

Results

Of 1439 patients, 438 (30.4%) were assigned to the too early group, 504 (35.1%) to the timely group, and 497 (34.5%) to the too late group. Radiological criteria for malignant conditions were detected in 53 of 382 patients (13.9%), 149 of 432 patients (34.5%), and 341 of 385 patients (88.6%) in the too early, timely, and too late groups, respectively (P < .001). Patients in the too early group underwent more parenchyma-sparing resections (too early group, 123 of 438 [28.1%]; timely group, 40 of 504 [7.9%]; too late group, 5 of 497 [1.0%]; P < .001), while morbidity (too early group, 112 of 438 [25.6%]; timely group, 117 of 504 [23.2%]; too late group, 158 of 497 [31.8%]; P = .002) and mortality (too early group, 4 patients [0.9%]; timely, 4 [0.8%]; too late, 13 [2.6%]; P = .03) were highest in the too late group. Of the 497 patients in the too late group, 124 (24.9%) had a previous history of watch-and-wait care.

Conclusions and Relevance

Until the biology and progression patterns of IPMN are clarified and accurate guidelines established, a watch-and-wait policy should be applied with caution, especially in IPMN bearing a main-duct component. One-third of IPMNs reach the cancer stage before resection. At specialized referral centers, the risks of surgical morbidity and mortality are justifiable.

Biomarkers in the diagnosis of pancreatic cancer: Are we closer to finding the golden ticket?

Pancreatic cancer (PC) is a leading cause of cancer related mortality on a global scale. The disease itself is associated with a dismal prognosis, partly due to its silent nature resulting in patients presenting with advanced disease at the time of diagnosis. To combat this, there has been an explosion in the last decade of potential candidate biomarkers in the research setting in the hope that a diagnostic biomarker may provide a glimmer of hope in what is otherwise quite a substantial clinical dilemma. Currently, serum carbohydrate antigen 19-9 is utilized in the diagnostic work-up of patients diagnosed with PC however this biomarker lacks the sensitivity and specificity associated with a gold-standard marker. In the search for a biomarker that is both sensitive and specific for the diagnosis of PC, there has been a paradigm shift towards a focus on liquid biopsy and the use of diagnostic panels which has subsequently proved to have efficacy in the diagnosis of PC. Currently, promising developments in the field of early detection on PC using diagnostic biomarkers include the detection of microRNA (miRNA) in serum and circulating tumour cells. Both these modalities, although in their infancy and yet to be widely accepted into routine clinical practice, possess merit in the early detection of PC. We reviewed over 300 biomarkers with the aim to provide an in-depth summary of the current state-of-play regarding diagnostic biomarkers in PC (serum, urinary, salivary, faecal, pancreatic juice and biliary fluid).

Narrative review of intraductal papillary mucinous neoplasms: pathogenesis, diagnosis, and treatment of a true precancerous lesion

OBJECTIVE

Although considerable progress has been made in our understanding of intraductal papillary mucinous neoplasm (IPMN) of the pancreas, there are still some problems to be solved.

BACKGROUND

IPMN is one of the most important precancerous lesions of pancreatic cancer, but the relationship between IPMN and pancreatic cancer, and the specific mechanism of the development from IPMN to invasive carcinoma, remain to be explored in depth. With the development of imaging, the detection rate of IPMN has been greatly improved. However, the degree of malignancy of IPMN is difficult to assess, and its classification criteria and surgical treatment strategies are still controversial. Therefore, there is an urgent need for the best treatment plan for IPMN and research that can better predict IPMN recurrence and tumor malignancy.

METHODS

From the online database Web of Science (https://webofknowledge.com/) and PubMed (https://pubmed.ncbi.nlm.nih.gov/), we use specific retrieval strategies to retrieve relevant articles based on the topics we discussed, and we review and discuss them.

CONCLUSIONS

This paper discusses the related research and progress of IPMN in recent years to improve the understanding of the incidence, diagnosis, treatment, and prognosis of this disease. The follow-up and monitoring of IPMN is particularly important, but the specific strategy also remains controversial.

Radiomics for the Diagnosis and Differentiation of Pancreatic Cystic Lesions

Radiomics, also known as quantitative imaging or texture analysis, involves extracting a large number of features traditionally unmeasured in conventional radiological cross-sectional images and converting them into mathematical models. This review describes this approach and its use in the evaluation of pancreatic cystic lesions (PCLs). This discipline has the potential of more accurately assessing, classifying, risk stratifying, and guiding the management of PCLs. Existing studies have provided important insight into the role of radiomics in managing PCLs. Although these studies are limited by the use of retrospective design, single center data, and small sample sizes, radiomic features in combination with clinical data appear to be superior to the current standard of care in differentiating cyst type and in identifying mucinous PCLs with high-grade dysplasia. Combining radiomic features with other novel endoscopic diagnostics, including cyst fluid molecular analysis and confocal endomicroscopy, can potentially optimize the predictive accuracy of these models. There is a need for multicenter prospective studies to elucidate the role of radiomics in the management of PCLs.

Molecular Diagnosis of Cystic Neoplasms of the Pancreas: a Review

BACKGROUND

The prevalence of incidental pancreatic cystic neoplasms (PCNs) has increased dramatically with advancements in cross-sectional imaging. Diagnostic imaging is limited in differentiating between benign and malignant PCNs. The aim of this review is to provide an overview of biomarkers that can be used to distinguish PCNs.

METHODS

A review of the literature on molecular diagnosis of cystic neoplasms of the pancreas was performed.

RESULTS

Pancreatic cysts can be categorized into inflammatory and non-inflammatory lesions. Inflammatory cysts include pancreatic pseudocysts. Noninflammatory lesions include both mucinous and non-mucinous lesions. Mucinous lesions include intraductal papillary mucinous neoplasm (IPMN) and mucinous cystic neoplasm. Non-mucinous lesions include serous cystadenoma and solid-pseudopapillary tumor of the pancreas. Imaging, cyst aspiration, and histologic findings, as well as carcinoembryonic antigen and amylase are commonly used to distinguish between cyst types. However, molecular techniques to detect differences in genetic mutations, protein expression, glycoproteomics, and metabolomic profiling are important developments in distinguishing between cyst types.

DISCUSSION

Nomograms incorporating common clinical, laboratory, and imaging findings have been developed in a better effort to predict malignant IPMN. The incorporation of top molecular biomarker candidates to nomograms may improve the predictive ability of current models to more accurately diagnose malignant PCNs.

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.

Molecular Diagnostics and Testing for Pancreatic Cysts

PURPOSE OF REVIEW

In current clinical practice, the diagnosis and management of pancreatic cystic lesions (PCLs) are based on guidelines that combine clinical and imaging findings. These guidelines usefully identify a large category of low-risk PCLs that do not require treatment. However, they have limited accuracy for diagnosis of advanced neoplasia in worrisome and high-risk PCLs. Novel molecular markers that can accurately detect advanced neoplasia in PCLs can transform the care of patients with PCLs. We reviewed the recent medical literature on molecular diagnostics of PCLs and summarized molecular biomarkers assayed in cyst fluid, pancreatic juice, and blood.

RECENT FINDINGS

Several studies have been recently published describing promising early results in genetic, epigenetic, and protein biomarkers from cyst fluid to help in both histologic diagnosis and detection of advanced neoplasia. The majority of studies have been completed using opportunistically collected archival cyst fluid and few report validation in independent sample sets. Results of ongoing multicenter prospective validation studies are awaited and will help define the best combination of cyst fluid molecular markers. In multifocal PCLs communicating with the pancreatic ductal system, a pancreatic juice biomarker is likely to be less invasive and more informative. Novel biomarkers in pancreatic juice and blood are in early phases of study.

SUMMARY

The field of molecular diagnostic biomarkers for PCLs is rapidly evolving with several promising candidate markers being prospectively evaluated. In the near future, these novel molecular markers, combined with advances in imaging technology, will transform clinical decision-making in the management of PCLs and improve patient outcomes.

Stratifying Intraductal Papillary Mucinous Neoplasms by Cyst Fluid Analysis: Present and Future

A significant proportion of patients with intraductal papillary mucinous neoplasms (IPMNs) undergo surgical resection in order to prevent or treat pancreatic cancer at the risk of significant perioperative morbidity. Efforts have been made to stratify the potential risk of malignancy based on the clinical and radiographic features of IPMN to delineate which cysts warrant resection versus observation. An analysis of the cyst fluid obtained by preoperative endoscopic examination appears to be correlative of cyst type and risk, whereas serum markers and radiographic findings have not yet reached a level of sensitivity or specificity that proves they are clinically meaningful. In this review, we investigate the current cyst fluid analysis studies and present those that have shown promise in effectively stratifying high-risk versus low-risk lesions. While new cyst fluid markers continue to be identified, additional efforts in testing panels and marker composites in conjunction with clinical algorithms have also shown promise in distinguishing dysplasia and the risk of malignancy. These should be tested prospectively in order to determine their role in guiding the surveillance of low-risk lesions and to evaluate the new markers detected by proteomics and genetic sequencing.

Development of a stratification tool to identify pancreatic intraductal papillary mucinous neoplasms at lowest risk of progression

BACKGROUND

Because most pancreatic intraductal papillary mucinous neoplasms (IPMNs) will never become malignant, currently advocated long-term surveillance is low-yield for most individuals.

AIM

To develop a score chart identifying IPMNs at lowest risk of developing worrisome features or high-risk stigmata.

METHODS

We combined prospectively maintained pancreatic cyst surveillance databases of three academic institutions. Patients were included if they had a presumed side-branch IPMN, without worrisome features or high-risk stigmata at baseline (as defined by the 2012 international Fukuoka guidelines), and were followed ≥ 12 months. The endpoint was development of one or more worrisome features or high-risk stigmata during follow-up. We created a multivariable prediction model using Cox-proportional logistic regression analysis and performed an internal-external validation.

RESULTS

875 patients were included. After a mean follow-up of 50 months (range 12-157), 116 (13%) patients developed worrisome features or high-risk stigmata. The final model included cyst size (HR 1.12, 95% CI 1.09-1.15), cyst multifocality (HR 1.49, 95% CI 1.01-2.18), ever having smoked (HR 1.40, 95% CI 0.95-2.04), history of acute pancreatitis (HR 2.07, 95% CI 1.21-3.55), and history of extrapancreatic malignancy (HR 1.34, 95% CI 0.91-1.97). After validation, the model had good discriminative ability (C-statistic 0.72 in the Mayo cohort, 0.71 in the Columbia cohort, 0.64 in the Erasmus cohort).

CONCLUSION

In presumed side branch IPMNs without worrisome features or high-risk stigmata at baseline, the Dutch-American Risk stratification Tool (DART-1) successfully identifies pancreatic lesions at low risk of developing worrisome features or high-risk stigmata.

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 Fluid Interleukin-1β Complements Prostaglandin E2 and Serum Carbohydrate Antigen 19-9 in Prediction of Intraductal Papillary Mucinous Neoplasm Dysplasia

OBJECTIVES

We sought to determine if interleukin (IL)-1β and prostaglandin E2 (PGE2) (inflammatory mediators in pancreatic fluid) together with serum carbohydrate antigen (CA) 19-9 could better predict intraductal papillary mucinous neoplasm (IPMN) dysplasia than individual biomarkers alone.

METHODS

Pancreatic cyst fluid (n = 92) collected via endoscopy or surgery (2003-2016) was analyzed for PGE2 and IL-1β (enzyme-linked immunosorbent assay). Patients had surgical pathology-proven IPMN. Threshold values (PGE2 [>1100 pg/mL], IL-1β [>20 pg/mL], and serum CA 19-9 [>36 U/mL]) were determined.

RESULTS

Levels of IL-1β were higher in high-grade dysplasia (HGD)/invasive-IPMN (n = 42) compared with low/moderate IPMN (n = 37) (median [range], 54.6 [0-2671] vs 5.9 [0-797] pg/mL; P < 0.001; area under curve [AUC], 0.766). Similarly, PGE2 was higher in HGD/invasive IPMN (n = 45) compared with low/moderate IPMN (n = 47) (median [range], 1790 [20-15,180] vs. 140 [10-14,630] pg/mL; P < 0.001; AUC, 0.748). Presence of elevated PGE2 and IL-1β (AUC, 0.789) provided 89% specificity and 82% positive predictive value (PPV) for HGD/invasive IPMN. Elevated levels of all 3 provided 100% specificity and PPV for HGD/invasive IPMN.

CONCLUSIONS

Cyst fluid PGE2, IL-1β, and serum CA 19-9 in combination optimize specificity and PPV for HGD/invasive IPMN and may help build a panel of markers to predict IPMN dysplasia.

Novel Methylated DNA Markers Discriminate Advanced Neoplasia in Pancreatic Cysts: Marker Discovery, Tissue Validation, and Cyst Fluid Testing

OBJECTIVES

Pancreatic cystic lesions (PCLs) may be precancerous. Those likely to harbor high-grade dysplasia (HGD) or pancreatic cancer (PC) are targets for surgical resection. Current algorithms to predict advanced neoplasia (HGD/PC) in PCLs lack diagnostic accuracy. In pancreatic tissue and cyst fluid (CF) from PCLs, we sought to identify and validate novel methylated DNA markers (MDMs) that discriminate HGD/PC from low-grade dysplasia (LGD) or no dysplasia (ND).

METHODS

From an unbiased whole-methylome discovery approach using predefined selection criteria followed by multistep validation on case (HGD or PC) and control (ND or LGD) tissues, we identified discriminant MDMs. Top candidate MDMs were then assayed by quantitative methylation-specific polymerase chain reaction on archival CF from surgically resected PCLs.

RESULTS

Of 25 discriminant MDMs identified in tissue, 13 were selected for validation in 134 CF samples (21 cases [8 HGD, 13 PC], 113 controls [45 ND, 68 LGD]). A tree-based algorithm using 2 CF-MDMs (TBX15, BMP3) achieved sensitivity and specificity above 90%. Discrimination was significantly better by this CF-MDM panel than by mutant KRAS or carcinoembryonic antigen, with areas under the receiver operating characteristic curve of 0.93 (95% confidence interval: 0.86-0.99), 0.71 (0.57-0.85), and 0.72 (0.60-0.84), respectively. Cutoffs for the MDM panel applied to an independent CF validation set (31 cases, 56 controls) yielded similarly high discrimination, areas under the receiver operating characteristic curve = 0.86 (95% confidence interval: 0.77-0.94, P = 0.2).

DISCUSSION

Novel MDMs discovered and validated in tissue accurately identify PCLs harboring HGD/PC. A panel of 2 MDMs assayed in CF yielded results with potential to enhance current risk prediction algorithms. Prospective studies are indicated to optimize and further evaluate CF-MDMs for clinical use.

The diagnosis and management of intraductal papillary mucinous neoplasms of the pancreas: has progress been made?

Intraductal papillary mucinous neoplasms (IPMN) of the pancreas are premalignant mucin-producing epithelial tumors that arise from the pancreatic ductal system. These cystic tumors represent 15-30% of cystic lesions of the pancreas [Basturk et al. in Am J Surg Pathol 39(12):1730-1741, 1; Ferrone et al. in Arch Surg (Chicago, Ill: 1960) 144(5):448-454, 2, Kosmahl et al. in Virchows Arch Int J Pathol 445(2):168-178, 3; Spinelli et al. in Ann Surg. 239(5):651-657, 4]. It is believed that IPMN can progress from low-grade dysplasia to high-grade dysplasia to invasive cancer, and this pathway of progression accounts for 20-30% of pancreatic cancer [Adsay et al. in Am J Surg Pathol 28(7):839-848, 5; Tanaka et al. in J Gastroenterol 40(7):669-675, 6; Wu et al. in Sci Transl Med 3(92):92ra66, 7]. Furthermore, it is also widely believed that IPMN represent a field defect of the pancreas in which the entire ductal system is at risk of developing invasive carcinoma, not only in the area of radiographically detectable IPMN, and thus the remaining gland should undergo surveillance after partial pancreatectomy [Salvia et al. in Ann Surg 239(5):678-685, 8; Izawa et al. in Cancer 92(7):1807-1817, 9; Yamaguchi and Tanaka in Jpn J Clin Oncol 41(7):836-840, 10]. Increasingly, surgeons are faced with the dilemma between recommending highly complex resections-that have significant morbidity and mortality-in patients who may have low-risk IPMN (low-grade dysplasia), or alternatively, recommending observation for those who could possibly be harboring a radiographically occult malignancy. Given the complexity of the management decisions for patients with IPMN, the purpose of this paper is to review the current literature and to provide a summary of how accurate we are currently with the identification of high-grade dysplasia or progression to carcinoma in patients who present with IPMN.

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.

Preoperative risk prediction for intraductal papillary mucinous neoplasms by quantitative CT image analysis

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMNs) are radiographically identifiable potential precursor lesions of pancreatic adenocarcinoma. While resection is recommended when main duct dilation is present, management of branch duct IPMN (BD-IPMN) remains controversial. This study sought to evaluate whether preoperative quantitative imaging features of BD-IPMNs could distinguish low-risk disease (low- and intermediate-grade dysplasia) from high-risk disease (high-grade dysplasia and invasive carcinoma).

METHODS

Patients who underwent resection between 2005 and 2015 with pathologically proven BD-IPMN and a preoperative CT scan were included in the study. Quantitative image features were extracted using texture analysis and a novel quantitative mural nodularity feature developed for the study. Significant features on univariate analysis were combined with clinical variables to build a multivariate prediction model.

RESULTS

Within the study group of 103 patients, 76 (74%) had low-risk disease and 27 (26%) had high-risk disease. Quantitative imaging features were prognostic of low-vs. high-risk disease. The model based only on clinical variables achieved an AUC of 0.67 and 0.79 with the addition of quantitative imaging features.

CONCLUSION

Quantitative image analysis of BD-IPMNs is a novel method that may enable risk stratification. External validation may provide a reliable non-invasive prognostic tool for clinicians.

Pancreatic Juice Mutation Concentrations Can Help Predict the Grade of Dysplasia in Patients Undergoing Pancreatic Surveillance

Purpose: The measurement of mutations in pancreatic juice samples collected from the duodenum during endoscopic ultrasound (EUS) may improve the diagnostic evaluation of patients undergoing pancreatic surveillance. Our aim was to evaluate the accuracy of using pancreatic juice mutation concentrations to predict the presence and histologic grade of neoplasia in the pancreas.Experimental Design: Digital next-generation sequencing (NGS) of pancreatic juice DNA using a targeted 12-gene panel was performed on 67 patients undergoing pancreatic evaluation during EUS, including patients with pancreatic ductal adenocarcinoma, patients who subsequently underwent pancreatic resection for precursor lesions, patients undergoing surveillance for their familial/inherited susceptibility to pancreatic cancer, and normal pancreas disease controls.Results: Patients with pancreatic cancer or high-grade dysplasia as their highest grade lesion had significantly higher pancreatic juice mutation concentrations than all other subjects (mean/SD digital NGS score; 46.6 ± 69.7 vs. 6.2 ± 11.6, P = 0.02). Pancreatic juice mutation concentrations distinguished patients with pancreatic cancer or high-grade dysplasia in their resection specimen from all other subjects with 72.2% sensitivity and 89.4% specificity [area under the curve (AUC) = 0.872]. Mutant TP53/SMAD4 concentrations could distinguish patients with pancreatic cancer or high-grade dysplasia in their resection specimen from all other subjects with 61.1% sensitivity and 95.7% specificity (AUC = 0.819). Among 31 high-risk individuals under surveillance, 2 of the 3 individuals with most abnormal pancreatic juice mutation profiles also had the most abnormalities on pancreatic imaging.Conclusions: Pancreatic juice mutation analysis using digital NGS has potential diagnostic utility in the evaluation of patients undergoing pancreatic surveillance. Clin Cancer Res; 24(12); 2963-74. ©2018 AACRSee related commentary by Lipner and Yeh, p. 2713.