Intraductal papillary mucinous neoplasm of the pancreas: an update

Subtype-associated complexity and prognostic significance of the NLRP3 inflammasome landscape in pancreatic neoplasms

Intraductal papillary mucinous neoplasm (IPMN) can progress into malignant pancreatic cancer, posing challenges in accurately assessing the risk of malignancy. While the nucleotide-binding oligomerization domain (NOD)-like receptor pyrin domain containing 3 (NLRP3) inflammasome pathway's role in pancreatic ductal adenocarcinoma (PDAC) has been extensively studied, its implications in IPMN remain unexplored. This study aimed to investigate the prognostic significance of NLRP3 inflammasome-related proteins across IPMN subtypes and their associations with tumor characteristics, with a secondary focus on comparing expression patterns in IPMN and PDAC. A cohort of 187 patients (100 IPMN and 87 PDAC) underwent high-dimensional histopathological imaging using the multiplexed immunohistochemical consecutive staining on single slide method and a semi-automated image analysis workflow. Expression levels of NLRP3, apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC), caspase-1, interleukin-1 beta, interleukin-18 (IL-18), interleukin-1 receptor antagonist, and interleukin-18 binding protein (IL-18BP) were evaluated and compared between IPMN and PDAC samples. The relationships between protein expression and tumor characteristics were examined. Principal component analysis distinguished between intestinal and nonintestinal clusters based on NLRP3-associated proteins. Lower IL-18 expression was linked to the intestinal subtype, while higher caspase-1 was linked to the pancreatobiliary subtype. Elevated caspase-1 and ASC expression were associated with invasiveness in IPMN. No significant correlation was found between the examined proteins and later-stage tumor characteristics in invasive cases. The IL-18/IL-18BP ratio was an independent prognostic factor in invasive IPMN. Our findings highlight the prognostic significance of IL-18 and the IL-18/IL-18BP ratio in invasive IPMNs. These results point to a complex regulation of NLRP3 inflammasome proteins, especially effector cytokines, in pancreatic neoplasms, which are strongly linked to subtype and prognosis.

Pancreatic cancer incidence trends in the United States from 2000-2017: Analysis of Surveillance, Epidemiology and End Results (SEER) database

Background: Recent incidence trends of pancreatic cancers were reviewed by demographics and histologic type to observe any new findings.

Methods: Data was used from the Surveillance, Epidemiology, and End Results (SEER) registry 18 (2000-2017) and it underwent temporal trend analysis. Pancreatic cancer incidence rates were reported based on histological subtype and demographics.

Results: The incidence rate of white males increased significantly during 2000-2017 (annual percent change (APC) = 3.5%) compared to previously reported APCs. The incidence of white females grew from an APC of 1.29% to 2.9%. Rates among black ethnicity increased with an APC of 4.2%. Rates among Hispanics and other ethnicities also showed increment. The rates for ductal adenocarcinoma showed a positive trend in all races, with the APC ≥ 6 % for females and APC ≥ 6.5 % for males. The rates of non-secretory endocrine tumors showed a decline in both genders of all five races in recent years after showing an initial positive trend till 2010. Rates for pancreatic adenocarcinoma continued to rise in all ethnicities from 2000-2017. Interestingly, there was a rise in carcinoid type pancreatic neuroendocrine tumors (PNETs) in all ethnicities. Cumulatively, males had a higher incidence than females; male to female Incidence Risk Ratio (IRRs) was 1.32. The IRR was > 1 for age groups ≥ 35 years. The male to female IRRs was less than 1 for cystic adenocarcinoma, secretory endocrine, and solid pseudopapillary carcinomas (IRR = 0.5, 0.9, and 0.2 respectively, confidence intervals 0.4–0.6 and 0.9-1.3, 0.2–0.3, respectively).

Conclusion: Pancreatic cancer incidence continued to rise in the years 2000-2017. However, incidence differed by demographics and histologic type. Interestingly, recent years discerned a rise in PNETs (carcinoid type) which has not been reported previously.

Pancreatobiliary Flow Dynamics: Association Between Bile and Pancreatic Juice Evaluated With Cine-Dynamic Magnetic Resonance Cholangiopancreatography Using Spatially Selective Inversion Recovery Pulse

BACKGROUND

The physiological flow patterns and the reciprocal relationship between pancreatic juice and bile excretion dynamics have not been clearly elucidated by imaging.

PURPOSE

To assess the physiological flow patterns of bile and pancreatic juice simultaneously in order to clarify the pancreatobiliary flow dynamics using cine-dynamic magnetic resonance cholangiopancreatography (MRCP) with a spatial selective inversion recovery (IR) pulse.

STUDY TYPE

Retrospective.

POPULATION

A total of 85 patients with physiologically normal pancreatobiliary flow without ductal dilatation (normal group) and 19 patients with dilated pancreatic duct.

FIELD STRENGTH/SEQUENCE

A 3 T, fast spin echo sequence with IR pulse to nullify the signal of static pancreatic juice and bile.

ASSESSMENT

The frequency and secretion grade of the antegrade and reverse flow of the pancreatic juice and bile on cine-dynamic MRCP were visually evaluated. Additionally, the reciprocal relationship between pancreatic juice and bile flow was evaluated based on its flow patterns.

STATISTICAL TESTS

Spearman's rank correlation coefficient analysis and the Kruskal-Wallis and Mann-Whitney U tests were used. P values of <0.05 were considered to indicate statistical significance.

RESULTS

In the normal group, the antegrade pancreatic juice flow and no bile flow pattern was most frequently observed (29%), followed by the no pancreatic juice flow and no bile flow pattern (23%), the antegrade pancreatic juice flow and antegrade bile flow pattern (22%), and the no pancreatic juice flow and reverse bile flow pattern (9%). The flow of the pancreatic juice and bile were synchronized with each other in 47%, while they were not in 53%. In the dilated pancreatic duct group, the mean secretion grade of the antegrade bile and pancreatic juice flow was significantly lower than in the normal group.

DATA CONCLUSION

Cine-dynamic MRCP with a spatially selective IR pulse can visualize the variations of the physiological flow patterns of bile and pancreatic juice including 53% of unsynchronized patterns.

LEVEL OF EVIDENCE

4 TECHNICAL EFFICACY: Stage 5.

The Dilemma of the Dilated Main Pancreatic Duct in the Distal Pancreatic Remnant After Proximal Pancreatectomy for IPMN

OBJECTIVE(S)

A dilated main pancreatic duct in the distal remnant after proximal pancreatectomy for intraductal papillary mucinous neoplasms (IPMN) poses a diagnostic dilemma. We sought to determine parameters predictive of remnant main-duct IPMN and malignancy during surveillance.

METHODS

Three hundred seventeen patients underwent proximal pancreatectomy for IPMN (Indiana University, 1991-2016). Main-duct dilation included those ≥ 5 mm or "dilated" on radiographic reports. Statistics compared groups using Student's T/Mann-Whitney U tests for continuous variables or chi-square/Fisher's exact test for categorical variables with P < 0.05 considered significant.

RESULTS

High-grade/invasive IPMN or adenocarcinoma at proximal pancreatectomy predicted malignant outcomes (100.0% malignant outcomes; P < 0.001) in remnant surveillance. Low/moderate-grade lesions revealed benign outcomes at last surveillance regardless of duct diameter. Twenty of 21 patients undergoing distal remnant reoperation had a dilated main duct. Seven had main-duct IPMN on remnant pathology; these patients had greater mean maximum main-duct diameter prior to reoperation (9.5 vs 6.2 mm, P = 0.072), but this did not reach statistical significance. Several features showed high sensitivity/specificity for remnant main-duct IPMN.

CONCLUSIONS

Remnant main-duct dilation after proximal pancreatectomy for IPMN remains a diagnostic dilemma. Several parameters show a promise in accurately diagnosing main-duct IPMN in the remnant.

Characteristics and Clinical Outcomes of Individuals at High Risk for Pancreatic Cancer: A Descriptive Analysis from a Comprehensive Cancer Center

Pancreatic cancer (PC), a leading cause of cancer-related deaths in the United States, is typically diagnosed at an advanced stage. To improve survival, there is an unmet need to detect pre-malignant lesions and early invasive disease. Prime populations to study for early detection efforts include cohorts of high risk individuals (HRI): those with increased risk to develop pre-malignant pancreatic cysts and PC because of a familial or hereditary predisposition to the disease and those in the general population of sporadic cases who are incidentally found to harbor a pre-malignant pancreatic cyst. The objective of this study was to describe the characteristics and clinical outcomes of cohorts of HRI identified at Moffitt Cancer Center. We set out to determine the uptake of screening, the prevalence and characteristics of solid and cystic pancreatic lesions detected via screening or as incidental findings, and the age at which lesions were detected. Of a total of 329 HRI, roughly one-third were found to have pancreatic lesions, most of which constituted pre-malignant cysts known as intraductal papillary mucinous neoplasms. Individuals with the highest genetic risk for PC were found to have smaller cysts at a much earlier age than sporadic cases with incidental findings; however, many individuals at high genetic risk did not have abdominal imaging reports on file. We also identified a subset of HRI at moderate genetic risk for PC that were found to have cystic and solid pancreatic lesions as part of a diagnostic work-up rather than a screening protocol. These findings suggest the pancreatic research community should consider expanding criteria for who should be offered screening. We also emphasize the importance of continuity of care between cancer genetics and gastrointestinal oncology clinics so that HRI are made aware of the opportunities related to genetic counseling, genetic testing, and screening.

Interpreting body MRI cases: classic findings in abdominal MRI

Few things in radiology are "pathognomonic" in their appearance or presentation. However, having an awareness of those findings which are specific to a certain entity is important when interpreting imaging studies. These classic findings can be identified with many imaging modalities, but no modality provides as many recognizable observations as an MRI. This results from the large variety of pulse sequences that provide high contrast resolution, prior to and following contrast administration. In this article, the most classically recognized abdominal findings are presented including the following: Liver: Cyst, hemangioma, focal nodular hyperplasia, hepatic adenoma, hemosiderosis, hepatocellular carcinoma. Spleen: Cyst, hemangioma, lymphangioma, hemosiderosis, Gandy-Gamna bodies. Biliary system: Biliary stones and choledocholithiasis, pneumobilia, choledochal cyst. Gallbladder: Adenomyomatosis, sludge, surgical clips in the gallbladder fossa. Pancreas: Pancreatic divisum, intraductal papillary mucinous neoplasm, pseudocyst, autoimmune pancreatitis, chronic pancreatitis, adenocarcinoma. Kidneys: Simple cyst, hemorrhagic cyst, renal sinus cyst, angiomyolipoma, solid mass.

Annexin A10 is a candidate marker associated with the progression of pancreatic precursor lesions to adenocarcinoma

Annexins are a multigene family of calcium and phospholipid-binding proteins that play important roles in calcium signaling, cell motility, differentiation and proliferation. Our previous mass spectrometry-based proteomics study revealed that annexin A10 (ANXA10) was uniquely overexpressed in pancreatic CD24+ adenocarcinoma cells that were dissected from clinical PDAC tissues but was absent in CD24- adjacent normal cells. The correlation between ANXA10 expression and the progression of pancreatic cancer remains unknown. In this study, we performed an immunostaining assay to evaluate ANXA10 expression in 155 primary human tissue specimens, including normal pancreas, chronic pancreatitis (CP), pancreatic adenocarcinoma (PDAC), pancreatic intraepithelial neoplasia (PanIN, the most important precursor of PDAC), and intraductal papillary mucinous neoplasm (IPMN). The immunostaining result showed that ANXA10 was significantly overexpressed in PanINs, IPMNs, and PDACs but negative in normal pancreas and the majority of chronic pancreatitis tissues. Statistical analysis revealed that ANXA10 expression was significantly associated with PDAC and its precursor lesions (p<0.0001). Abundant ANXA10 expression was predominantly present in pancreatic ductal epithelial cells of PanINs, IPMNs, and tumor cells of PDACs. Since PDAC develops through a series of PanINs which in turn arise from pancreatic ducts, the consistent overexpression of ANXA10 in ductal epithelial cells in PanINs and PDACs but negative in normal pancreatic ducts suggests that ANXA10 could serve as a potential marker indicating the presence of PDAC at its earliest precancerous stages. Double immunostaining of ANXA10 and CD24 showed that there was a large overlap between these two markers in PDAC and high-grade neoplasia lesions. The statistical analysis showed that the coexpression of ANXA10 and CD24 was significantly correlated with the progression of pancreatic precursor lesions towards PDACs.

Pancreatic cancer from bench to bedside: molecular pathways and treatment options

In the last forty years the pancreatic cancer treatment has made advances, however; still novel drugs are needed. It is known that the five year survival rate remains around 5%. The best treatment option still remains surgery, if patients are diagnosed early. In the last decade the biology of pancreatic cancer has been vastly explored and novel agents such as; tyrosine kinase agents, or vaccines have been added as a treatment perspective. The big challenge is now to translate this knowledge in better outcomes for patients. In this current review we will present information from pancreatic cancer diagnosis to molecular pathways and treatment options; current and future.

Developmental Pathways Direct Pancreatic Cancer Initiation from Its Cellular Origin

Pancreatic ductal adenocarcinoma (PDA) is characterized by an extremely poor prognosis, since it is usually diagnosed at advanced stages. In order to employ tools for early detection, a better understanding of the early stages of PDA development from its main precursors, pancreatic intraepithelial neoplasia (PanIN), and intraductal papillary mucinous neoplasm (IPMN) is needed. Recent studies on murine PDA models have identified a different exocrine origin for PanINs and IPMNs. In both processes, developmental pathways direct the initiation of PDA precursors from their cellular ancestors. In this review, the current understanding of early PDA development is summarized.

Cyst Features and Risk of Malignancy in Intraductal Papillary Mucinous Neoplasms of the Pancreas: Imaging and Pathology

Background

Intraductal papillary mucinous neoplasms (IPMNs) display diverse macroscopic, histological, and immunohistochemical characteristics with typical morphological appearance in magnetic resonance imaging. Depending on those, IPMNs may show progression into invasive carcinomas with variable frequency. Overall, IPMN-associated invasive carcinomas are found in about 30% of all IPMNs, revealing phenotpyes comparable with conventional ductal adenocarcinomas or mucinous (colloid) carcinomas of the pancreas. In Sendai-negative side-branch IPMNs, however, the annual risk of the development of invasive cancer is 2%; thus, risk stratification with regard to imaging and preoperative biomarkers and cytology is mandatory.

Methods and Results

The present study addresses the radiological and interventional preoperative measures including histological features to determine the risk of malignancy and the prognosis of IPMNs.

Conclusion

While preoperative imaging largely relies on the detection of macroscopic features of IPMNs, which are associated with a divergent risk of malignant behavior, in resected specimens the determination of the grade of dysplasia and the detection of an invasive component are the most important features to estimate the prognosis of IPMNs.

Pancreatic cystic neoplasms: a review of preoperative diagnosis and management

Pancreatic cystic neoplasms (PCNs) are a diverse group of neoplasms in the pancreas, and are more increasingly encountered with widespread abdominal screening and improved imaging techniques. The most common types of PCNs are serous cystic neoplasms (SCNs), mucinous cystic neoplasms (MCNs), and intraductal papillary mucinous neoplasms (IPMNs). Clinicians frequently feel bewildered in the differential diagnosis and subsequent management among the various types of lesions in the pancreas, which may lead to overtreatment or delayed treatment. The current review provides recent developments in the understanding of the three most common types of PCNs, the latest modalities used in preoperative diagnosis and differential diagnosis, as well as the most up to date management. Suggestions for diagnosis and differential diagnosis of SCNs, MCNs, and IPMNs are also provided for young surgeons. Better understanding of these neoplasms is essential for clinicians to make accurate diagnosis and to provide the best management for patients.