Differentiation of chronic pancreatitis from pancreatic cancer: recent advances in molecular diagnosis

Pancreatic Cancer in Chronic Pancreatitis: Pathogenesis and Diagnostic Approach

Chronic pancreatitis is one of the main risk factors for pancreatic cancer, but it is a rare event. Inflammation and oncogenes work hand in hand as key promoters of this disease. Tobacco is another co-factor. During alcoholic chronic pancreatitis, the cumulative risk of cancer is estimated at 4% after 15 to 20 years. This cumulative risk is higher in hereditary pancreatitis: 19 and 12% in the case of PRSS1 and SPINK1 mutations, respectively, at an age of 60 years. The diagnosis is difficult due to: (i) clinical symptoms of cancer shared with those of chronic pancreatitis; (ii) the parenchymal and ductal remodeling of chronic pancreatitis rendering imaging analysis difficult; and (iii) differential diagnoses, such as pseudo-tumorous chronic pancreatitis and paraduodenal pancreatitis. Nevertheless, the occurrence of cancer during chronic pancreatitis must be suspected in the case of back pain, weight loss, unbalanced diabetes, and jaundice, despite alcohol withdrawal. Imaging must be systematically reviewed. Endoscopic ultrasound-guided fine-needle biopsy can contribute by targeting suspicious tissue areas with the help of molecular biology (search for KRAS, TP53, CDKN2A, DPC4 mutations). Short-term follow-up of patients is necessary at the clinical and paraclinical levels to try to diagnose cancer at a surgically curable stage. Pancreatic surgery is sometimes necessary if there is any doubt.

CGAT: Cell Graph ATtention Network for Grading of Pancreatic Disease Histology Images

Early detection of Pancreatic Ductal Adenocarcinoma (PDAC), one of the most aggressive malignancies of the pancreas, is crucial to avoid metastatic spread to other body regions. Detection of pancreatic cancer is typically carried out by assessing the distribution and arrangement of tumor and immune cells in histology images. This is further complicated due to morphological similarities with chronic pancreatitis (CP), and the co-occurrence of precursor lesions in the same tissue. Most of the current automated methods for grading pancreatic cancers rely on extensive feature engineering involving accurate identification of cell features or utilising single number spatially informed indices for grading purposes. Moreover, sophisticated methods involving black-box approaches, such as neural networks, do not offer insights into the model's ability to accurately identify the correct disease grade. In this paper, we develop a novel cell-graph based Cell-Graph Attention (CGAT) network for the precise classification of pancreatic cancer and its precursors from multiplexed immunofluorescence histology images into the six different types of pancreatic diseases. The issue of class imbalance is addressed through bootstrapping multiple CGAT-nets, while the self-attention mechanism facilitates visualization of cell-cell features that are likely responsible for the predictive capabilities of the model. It is also shown that the model significantly outperforms the decision tree classifiers built using spatially informed metric, such as the Morisita-Horn (MH) indices.

A chronocoulometric LNA sensor for amplified detection of K-ras mutation based on site-specific DNA cleavage of restriction endonuclease

An amplified chronocoulometric Locked nucleic acid (LNA) sensor (CLS) for selective electrochemical detection of K-ras mutation was developed based on site-specific DNA cleavage of restriction endonuclease EcoRI. Thiolated-hairpin LNA probe with palindrome structure of stem was immobilized on the gold nanoparticles modified gold electrode (NG/AuE). It can be cleaved by EcoRI in the absence of K-ras mutation-type DNA (complementary with the loop part of hairpin probe), but cannot be cleaved in the presence of mutation-type DNA. The difference before and after enzymatic cleavage was then monitored by chronocoulometric biosensor. Electrochemical signals are generated by chronocoulometric interrogation of Hexaammineruthenium (III) chloride (RuHex) that quantitatively binds to surface-confined hairpin LNA probe via electrostatic interactions. The results suggested this CLS had a good specificity to distinguish the K-ras mutation-type, wild-type and non-complementary sequence. There was a good linear relationship between the charge and the logarithmic function of K-ras mutation-type DNA concentration. The detection limit had been estimated as 0.5 fM. It is possible to qualitatively and quantitatively detect K-ras point mutation in pancreatic cancer.

Analysis of microRNAs in pancreatic fine-needle aspirates can classify benign and malignant tissues

BACKGROUND

MicroRNAs (miRNAs) are RNA molecules that are involved in the regulation of many cellular processes, including those related to human cancers. The aim of this study was to determine, as a proof of principle, whether specific candidate miRNAs could be detected in fine-needle aspirate (FNA) biopsies of pancreatic ductal adenocarcinoma (PDAC) and could accurately differentiate malignant from benign pancreatic tissues.

METHODS

We used TaqMan(R) assays to quantify miRNA levels in FNA samples collected in RNARetain (n = 16) and compared the results with a training set consisting of frozen macrodissected pancreatic samples (n = 20).

RESULTS

Quantitative reverse-transcription PCR analysis confirmed that miRNA levels are affected in PDAC FNAs and correlate well with the changes observed in the training set of frozen pancreatic samples. Analysis of the amounts produced for a few specific miRNAs enabled identification of PDAC samples. The combination of miR-196a and miR-217 biomarkers further improved the ability to distinguish between healthy tissue, PDAC, and chronic pancreatitis in the training set (P = 8.2 x 10(-10)), as well as segregate PDAC FNA samples from other FNA samples (P = 1.1 x 10(-5)). Furthermore, we showed that miR-196a production is likely specific to PDAC cells and that its incidence paralleled the progression of PDAC.

CONCLUSIONS

To the best of our knowledge, this study is the first to evaluate the diagnostic potential of miRNAs in a clinical setting and has shown that miRNA analysis of pancreatic FNA biopsy samples can aid in the pathologic evaluation of suspicious cases and may provide a new strategy for improving the diagnosis of pancreatic diseases.

Protein expression profiling reveals distinctive changes in serum proteins associated with chronic pancreatitis

OBJECTIVE

Testing of serum for protein patterns to monitor progression of suspected to definite chronic pancreatitis (CP).

METHODS

Serum samples of CP patients and healthy volunteers were fractionated on anion exchange columns and analyzed by surface-enhanced laser desorption/ionization-time-of-flight mass spectrometry to elucidate CP-related protein alterations and to identify biomarkers for this disease. Potential biomarkers were purified and identified by mass spectrometry.

RESULTS

In total, 258 protein peaks were found that discriminated between the 2 groups. Analysis revealed 28 most prominent peaks on immobilized metal affinity capture coupled with Cu and CM10 protein chips, covering the m/z range between 3.3 and 33.3 kd. Performing multivariate pattern analysis, the best pattern model was obtained using fraction 6 on immobilized metal affinity capture coupled with Cu arrays with a sensitivity of 96% and a specificity of 84%. Using a combination of matrix-assisted laser desorption-ionization-time-of-flight mass spectrometry and immunodepletion, we identified 14-m/z peaks. The proteins were found to be significantly decreased in CP serum and were identified as retinol-binding protein, serum amyloid-alpha, apolipoprotein A-II (Apo A-II), Apo C-I, Apo C-II, Apo C-III, and transthyretin and truncated forms thereof.

CONCLUSIONS

Distinct protein profile differences exist between normal and CP serum and reflect the metabolic and inflammatory condition in CP patients. The identified protein panel may eventually serve as a diagnostic marker set for CP.

A case of intraductal papillary mucinous tumour following recurrent attacks of pancreatitis lasting 26 years

We report an interesting case of a patient with neither family nor personal history for pancreatic diseases that was admitted to our department in 1982, at the age of 25 years. At that time, medical history, absence of alcohol abuse, and radiological imaging suggested a diagnosis of idiopathic chronic pancreatitis. The patient underwent a left-pancreatectomy, with histological confirmation of chronic pancreatitis. He was asymptomatic until 1988, when episodes of pain arose, requiring a pancreatico-jejunostomy. No further problems ensued until 2004 when radiological investigation following pain-related symptoms revealed enormous dilation of the pancreatic duct. A pylorus-preserving pancreaticoduodenectomy resulting in total pancreatectomy was performed. Histological examination revealed an intraductal papillary mucinous non-invasive carcinoma. Review of the previously resected specimen revealed former misdiagnosis. This tumour usually affects an elderly population and nowadays is recognised as a possible cause of chronic obstructive pancreatitis. This report represents a slippery case of misdiagnosis and demonstrates that follow-up is always mandatory following a diagnosis of idiopathic chronic pancreatitis.

Chronic pancreatitis, pancreatic adenocarcinoma and the black box in-between

Pancreatic cancer is a challenging disease for patients, doctors and researchers who for decades have searched for a cure for this deadly malignancy. Although existing mouse models of pancreatic cancer have shed light on the mechanistic basis of the neoplastic conversion of the pancreas, their impact in terms of offering new diagnostics and therapeutic modalities remains limited. Chronic pancreatitis is an inflammatory disease of the pancreas that is associated with a gradual damage of the organ and an increased risk of developing neoplastic lesions. In this review, we propose that detailed studies of chronic inflammatory processes in the pancreas will provide insights into the evolution of pancreatic cancer. This information may prove useful in the design of effective therapeutic strategies to battle the disease.

Differentiating pancreatic cancer from pseudotumorous chronic pancreatitis

The differentiation between pancreatic carcinoma and pseudotumorous pancreatitis continues to be a challenge. Several diagnostic imaging and endoscopic modalities can assist in making the differentiation, but the accuracy of each method varies. Radiologic imaging techniques include transabdominal ultrasound, computed tomography, magnetic resonance imaging, magnetic resonance cholangiopancreatography, and positron emission tomography. Endoscopic techniques include endoscopic ultrasonography, intraductal ultrasonography, and endoscopic retrograde cholangiopancreatography with brush cytology of pancreatobiliary strictures, endoscopic forceps biopsy, and analysis of pancreatic juices for malignant cells. Tumor markers appear to be promising, but further studies are needed to define the role of these markers.