Pathology of intraductal papillary mucinous neoplasms

Precursor lesions in familial and hereditary pancreatic cancer

Infiltrating ductal adenocarcinoma of the pancreas, referred to here as "pancreatic cancer," is one of the deadliest of all of the solid malignancies. The five-year survival rate in the United States for individuals diagnosed today with pancreatic cancer is a dismal 12%. Many invasive cancers, including pancreatic cancer, however, arise from histologically and genetically well-characterized precursor lesions, and these precancers are curable. Precursor lesions therefore are an attractive target for early detection and treatment. This is particularly true for individuals with an increased risk of developing invasive cancer, such as individuals with a strong family history of pancreatic cancer, and individuals with a germline variant known to increase the risk of developing pancreatic cancer. There is therefore a need to understand the precursor lesions that can give rise to invasive pancreatic cancer in these individuals.

Multi-omic profiling of intraductal papillary neoplasms of the pancreas reveals distinct expression patterns and potential markers of progression

In order to advance our understanding of precancers in the pancreas, 69 pancreatic intraductal papillary neoplasms (IPNs), including 64 intraductal papillary mucinous neoplasms (IPMNs) and 5 intraductal oncocytic papillary neoplasms (IOPNs), 32 pancreatic cyst fluid samples, 104 invasive pancreatic ductal adenocarcinomas (PDACs), 43 normal adjacent tissues (NATs), and 76 macro-dissected normal pancreatic ducts (NDs) were analyzed by mass spectrometry. A total of 10,246 proteins and 22,284 glycopeptides were identified in all tissue samples, and 756 proteins with more than 1.5-fold increase in abundance in IPMNs relative to NDs were identified, 45% of which were also identified in cyst fluids. The over-expression of selected proteins was validated by immunolabeling. Proteins and glycoproteins overexpressed in IPMNs included those involved in glycan biosynthesis and the immune system. In addition, multiomics clustering identified two subtypes of IPMNs. This study provides a foundation for understanding tumor progression and targets for earlier detection and therapies.

Significance

This multilevel characterization of intraductal papillary neoplasms of the pancreas provides a foundation for understanding the changes in protein and glycoprotein expression during the progression from normal duct to intraductal papillary neoplasm, and to invasive pancreatic carcinoma, providing a foundation for informed approaches to earlier detection and treatment.

Systematic review of challenging issues in pathology of intraductal papillary mucinous neoplasms

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMNs) are a cystic precursor to pancreatic cancer. IPMNs deemed clinically to be at high-risk for malignant progression are frequently treated with surgical resection, and pathological examination of the pancreatectomy specimen is a key component of the clinical care of IPMN patients.

METHODS

Systematic literature reviews were conducted around eight topics of clinical relevance in the examination of pathological specimens in patients undergoing resection of IPMN.

RESULTS

This review provides updated perspectives on morphological subtyping of IPMNs, classification of intraductal oncocytic papillary neoplasms, nomenclature for high-grade dysplasia, assessment of T stage, distinction of carcinoma associated or concomitant with IPMN, role of molecular assessment of IPMN tissue, role of intraoperative assessment by frozen section, and preoperative evaluation of cyst fluid cytology.

CONCLUSIONS

This analysis provides the foundation for data-driven approaches to several challenging issues in the pathology of IPMNs.

Pancreatic Intraductal Papillary Mucinous Neoplasms: A Narrative Review

Introduction

Intraductal papillary mucinous neoplasms (IPMNs) are the most frequent cystic pancreatic neoplasm. They derive from the main pancreatic duct or branch ducts.

Aim

This narrative review aims to present and compare the current guidelines on the management of IPMNs.

Materials and methods

We reviewed the most important scientific literature on the management of IPMNs.

Discussion

The clinical presentation of IPMNs is usually nonspecific; common symptoms are abdominal pain, weight loss, and jaundice. There are no sex differences, and the incidence increases with age. It is considered a premalignant lesion associated with synchronous or metachronous carcinomas. Multifocal sites within the pancreas and the presence of solid components, like mural nodules, are predictive factors for developing malignancy. Magnetic resonance imaging (MRI) is the imaging technique of choice. However, computed tomography (CT) and endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) can also contribute to the diagnosis. Resection is the optimal treatment for IPMNs that arise from the main duct, while several indications are suggested for the surgery on IPMNs of branch ducts.

Conclusion

The decision on surgery is not always a simple task and should be based on high-risk features of the neoplasm. In any case, re-examination and follow-up are highly recommended.

Screening for pancreatic cancer has the potential to save lives, but is it practical?

INTRODUCTION

Most patients with pancreatic cancer present with advanced stage, incurable disease. However, patients with high-grade precancerous lesions and many patients with low-stage disease can be cured with surgery, suggesting that early detection has the potential to improve survival. While serum CA19.9 has been a long-standing biomarker used for pancreatic cancer disease monitoring, its low sensitivity and poor specificity have driven investigators to hunt for better diagnostic markers.

AREAS COVERED

This review will cover recent advances in genetics, proteomics, imaging, and artificial intelligence, which offer opportunities for the early detection of curable pancreatic neoplasms.

EXPERT OPINION

From exosomes, to circulating tumor DNA, to subtle changes on imaging, we know much more now about the biology and clinical manifestations of early pancreatic neoplasia than we did just five years ago. The overriding challenge, however, remains the development of a practical approach to screen for a relatively rare, but deadly, disease that is often treated with complex surgery. It is our hope that future advances will bring us closer to an effective and financially sound approach for the early detection of pancreatic cancer and its precursors.

Use of Autoreactive Antibodies in Blood of Patients with Pancreatic Intraductal Papillary Mucinous Neoplasms (IPMN) for Grade Distinction and Detection of Malignancy

(1) Background: A reliable non-invasive distinction between low- and high-risk pancreatic intraductal papillary mucinous neoplasms (IPMN) is needed to effectively detect IPMN with malignant potential. This would improve preventative care and reduce the risk of developing pancreatic cancer and overtreatment. The present study aimed at exploring the presence of autoreactive antibodies in the blood of patients with IPMN of various grades of dysplasia. (2) Methods: A single-center cohort was studied composed of 378 serum samples from patients with low-grade IPMN (n = 91), high-grade IPMN (n = 66), IPMN with associated invasive cancer (n = 30), pancreatic ductal adenocarcinoma (PDAC) stages T1 (n = 24) and T2 (n = 113), and healthy controls (n = 54). A 249 full-length recombinant human protein microarray was used for profiling the serum samples. (3) Results: 14 proteins were identified as potential biomarkers for grade distinction in IPMN, yielding high specificity but mediocre sensitivity. (4) Conclusions: The identified autoantibodies are potential biomarkers that may assist in the detection of malignancy in IPMN patients.

Incidence of pancreatic cancer during long-term follow-up in patients with incidental pancreatic cysts smaller than 2 cm

PURPOSE

To assess the long-term malignancy risk of incidental small pancreatic cysts.

MATERIALS AND METHODS

In this HIPAA-compliant, IRB-approved, retrospective, multi-institutional study, the long-term incidence of pancreatic cancer was compared between patients with and without small pancreatic cysts. Patients with incidental pancreatic cysts ≥ 0.5 and < 2.0 cm in maximal diameter, detected on MRI performed between 1999 and 2011, represented the "small pancreatic cyst" group. Patients that underwent MRI between 2005 and 2011 and had no reported pancreatic cysts represented the comparison "no cyst" group.

RESULTS

The "small pancreatic cyst" group included 267 patients, ages 63.4 ± 11.8 years, 166/267 (62%) women with a mean follow-up of 8.6 ± 4.3 years, median 9.2 years; the "no cyst" group included 1,459 patients, ages 64.6 ± 12 years, 794/1,459 (54%) women with a mean follow-up of 7.0 ± 4.2 years, median 7.8 (p values 0.12, 0.02, < 0.001, respectively). Two/267 (0.7%) patients developed pancreatic cancer at a separate location from the known cyst in the "small pancreatic cyst" group, with a cancer rate of 0.9 (95% CI 0.1-3.1) cases per 1,000 patient-years. In the "no cyst" cohort, 18/1,459 (1.2%) patients developed pancreatic cancer, with a cancer rate of 1.8 (95% CI 1.2-3.1) cases per 1,000 patient-years (p = 0.6). The all-cause mortality was similar in both groups: 57/267 (21%) vs. 384/1,459 (26%) (p = 0.09).

CONCLUSION

The long-term risk of pancreatic malignancy in asymptomatic patients with incidental pancreatic cysts less than 2 cm is 0.9 cases per 1,000 patient-years of follow-up, similar to those without pancreatic cysts. These very few pancreatic cancers developed at a separate location from the known cyst.

KEY POINTS

• After a median of 9.2 years of follow-up, the risk of pancreatic malignancy in patients with an asymptomatic small pancreatic cyst was 0.9 cases per 1,000 patient-years of follow-up, similar to those without pancreatic cysts. • Very few pancreatic cancer cases developed in the location separate from the known pancreatic cyst.