Expression ofK homology domainContaining proteinOverexpressed in cancer in pancreatic FNA for diagnosing adenocarcinoma of pancreas

Research advances of N6-methyladenosine in diagnosis and therapy of pancreatic cancer

BACKGROUND

N6-methyladenosine (m6A) is the addition of a methyl group on the N6 position of adenosine and is the most prevalent and abundant epigenetic modification in eukaryote mRNA. m6A marks are added to mRNA by the m6A methyltransferase complex ("writers"), removed by m6A demethylases ("erasers"), and recognized by m6A-binding proteins ("readers"). Recent evidence has shown that the m6A modification plays a crucial role in the pathogenic mechanism and malignant progression of pancreatic cancer, with roles in cell survival, proliferation, migration, invasion, tumor metastasis, and drug resistance.

METHODS

Literature was searched in Pubmed and Web of Science for the following keywords: "N6-methyladenosine", "pancreatic cancer", "epigenetic modification", "immunotherapy".

RESULTS

Among classical m6A regulators, while METTL3, METTL14, WTAP, FTO, YTHDF2, IGF2BP1-3, hnRNPC, and NKAP are upregulated in pancreatic cancer, METTL16 and ALKBH5 are downregulated in pancreatic cancer. m6A modification has been investigated in pancreatic cancer therapy.

CONCLUSION

Dysregulated m6A and its related factors in pancreatic cancer cells and patients indicate their potential values as novel biomarkers in pancreatic cancer diagnosis and targeted therapy.

A Promising Diagnostic Role of Immunohistochemical Expression of Insulin-Like Growth Factor II mRNA Binding Protein 3 (IMP3) in Pancreatic Lesions Using Endoscopic Ultrasound-Guided Fine Needle Aspiration (EUS-FNA) Cytology

BACKGROUND

Poor prognosis and short survival of patients harboring pancreatic cancer emerge how advanced disease it is. In a trial to achieve the earliest and most accurate diagnosis to manage this progressive disease, we proposed that using endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) with an adjuvant diagnostic immunohistochemical marker would give better diagnostic results. IMP3 has gained recently wide attention, as many studies found that IMP3 has not only diagnostic but also prognostic role in different types of malignancies.

AIM OF THE STUDY

This prospective work is to assess the diagnostic role of EUS-FNA combined with the immunohistochemical expression of IMP3 on different benign and malignant pancreatic lesions.

MATERIAL AND METHOD

The included pancreatic lesions (n = 140) were obtained by EUS-FNA technique and stained for IMP3 immunohistochemically. Paraffin blocks from patients who underwent excision (n = 92) or core biopsies (n = 48) were performed for confirming diagnosis.

RESULTS

The combined method for diagnosis showed that IMP3 was positive in 78.7%, 91.7%, 100% PAC, mucinous neoplasm with high grade dysplasia, and IPMN with high grade dysplasia, respectively, while almost all benign lesions showed negative IMP3. Also, this method showed sensitivity (78.26%), specificity (95.83%), and accuracy (84.3%).

CONCLUSION

EUS-FNA cytology with IMP3 could be a reliable diagnostic tool especially for assessment of malignant pancreatic lesions.

Diagnostic value of IMP3 and p53 immunohistochemical staining in EUS-guided fine-needle aspiration for solid pancreatic tumors

We previously identified insulin-like growth factor-II messenger ribonucleic acid-binding protein 3 (IMP3) as a valuable marker to distinguish malignant from benign lesions in pancreatic solid masses. The aim of this prospective study was to evaluate the usefulness of IMP3 and p53 immunohistochemical staining in endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) samples for pancreatic solid masses. The study recruited 90 consecutive patients with pancreatic masses, including 62 pancreatic ductal adenocarcinomas (PDACs), 11 benign tumors, and 17 other tumors, who underwent EUS-FNA, and conducted IMP3 and p53 immunohistochemical staining. The main outcome measurement was improved diagnostic utility using IMP3 and p53 immunohistochemical staining. IMP3 and p53 expressions were detected in 60.8% and 49.4% of malignant lesions, 69.4% and 58.1% of PDACs, and 0% of benign lesions, respectively. In PDAC and benign tumors, the use of IMP3 and/or p53 immunostaining increased the sensitivity of cytohistological analysis from 88.7 to 93.5%, although the difference was not statistically significant. The sensitivity of histological analysis combined with that of IMP3 staining was 91.9%, which was significantly greater than that of histology alone (80.6%). The use of IMP3 and p53 immunohistochemical staining did not significantly improve the sensitivity of cytohistological analysis; however, IMP3 staining may be helpful for the histological analysis of malignant pancreatic tumors.

Design of an immunohistochemistry biomarker panel for diagnosis of pancreatic adenocarcinoma

BACKGROUND

Challenges still exist in differentiating pancreatic adenocarcinoma from benign disease. The use of adjuvant testing of tissue biopsies has demonstrated potential diagnostic value. We designed a proof of concept study to first validate four individual immunohistochemistry biomarkers and then combine them into a panel to boost overall diagnostic sensitivity.

METHODS

Malignant and benign pancreas from 27 pancreaticoduodenectomy specimens underwent immunohistochemistry staining with VHL, IMP3, S100A4, S100P. Using ROC curve analysis, threshold criteria for number of cells staining were chosen for each biomarker. Biomarkers were then evaluated as a panel for their ability to discriminate malignant from benign specimens.

RESULTS

Diagnostic sensitivity of VHL, IMP3, S100A4, and S100P were 75.0%, 79.2%, 45.8%, and 0%. When VHL, IMP3, and S100A4 were grouped into a panel, they were able to distinguish cancer from normal tissue with a sensitivity of 100% and a specificity of 96%.

CONCLUSIONS

The high diagnostic value of an IHC panel consisting of VHL, IMP3, and S100A4 on surgical specimens suggests the need for future prospective studies of these biomarkers on biopsy specimens.

The Insulin-Like Growth Factor 2 mRNA Binding Protein IMP2/IGF2BP2 is Overexpressed and Correlates with Poor Survival in Pancreatic Cancer

The insulin-like growth factor 2 (IGF2) mRNA binding protein IMP2 (IGF2BP2) is an oncogenic protein known to be overexpressed in different tumor types. Pancreatic cancer is a very lethal cancer that requires early diagnosis and new treatment options. The aim of our study was to investigate the role of IMP2 in the initiation and progression of pancreatic ductal adenocarcinoma (PDAC). IMP2 was significantly overexpressed in a human precursor (PanIN) lesions suggesting IMP2 as a marker for early stages of PDAC. In a PDAC cohort of matched normal and tumor samples IMP2 showed overexpression in tumor tissues compared with normal pancreatic tissue. Strict correlation analysis (threshold R² > 0.75) revealed 22 genes highly positively and 9 genes highly negatively correlating with IMP2. Besides genes involved in the inhibition of apoptosis (Bcl-XL), especially factors involved in ubiquitination were strongly correlated with IMP2 expression: SMURF1 and FBXO45. Moreover, protein kinase C (PKC) signaling pathway was distinctly affected: DXS1179E encoding PKC iota, PKC substrate PLEK2, and inositol triphosphate receptor IP3R3 were positively correlated with IMP2 expression. Besides tumor initiation, IMP2 also seemed to have an impact on tumor progression. TGF-β treatment of Panc-1 pancreatic cancer cells to induce epithelial-mesenchymal transition (EMT) was accompanied by increased IMP2 expression. EMT is important for cancer cells to gain migratory and invasive potential, which is essential for metastasis. Concordantly, circulating tumor cells showed higher IMP2 levels as compared with normal tissue from tumor origin and with normal hematological cells. Accordingly, IMP2 protein levels correlated with poor survival. In conclusion, as IMP2 seems to promote tumor progression of PDAC, it might be an interesting diagnostic and prognostic marker as well as a novel target for the treatment of PDAC.

Immunohistochemical staining for S100P, SMAD4, and IMP3 on cell block preparations is sensitive and highly specific for pancreatic ductal adenocarcinoma

INTRODUCTION

The diagnosis of pancreatic ductal adenocarcinoma (PDA) on endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) material is often challenging. An immunohistochemical (IHC) panel may help establish the diagnosis of PDA in cases limited by sample size or ambiguous cytology. S100P, IMP3, and SMAD4 are 3 IHC markers that have shown promise as individual markers for PDA that have never been tested together as a panel. In this study, we evaluated the individual and combined efficacy of S100P, IMP3, and SMAD4 for the detection of PDA.

MATERIALS AND METHODS

S100P, IMP3, and SMAD4 IHC staining was performed on cell blocks (CBs) procured from pancreatic EUS-FNA procedures. The cohort included CBs that were diagnostic for PDA (n = 35), suspicious but nondiagnostic for PDA (n = 2), as well as CBs with benign pancreatic ductal epithelium (n = 12) and benign reactive pancreatic ductal epithelium (n = 18). A positive result for IMP3 and S100P was defined as moderate or strong staining of >10% of ductal cells. Complete lack of SMAD4 nuclear staining was considered a positive result-any nuclear SMAD4 staining was considered a negative result.

RESULTS

Two and 3 IHC marker panels were almost always more specific than individual IHC markers. Positivity for at least 2 of 3 IHC markers was a sensitive (91.89%) and highly specific (100%) marker of PDA.

CONCLUSIONS

The 3 IHC marker panel composed of S100P, IMP3, and SMAD4 is highly specific for PDA. Future studies should evaluate efficacy in a cohort with more atypical and suspicious cases.

A quarter century of EUS-FNA: Progress, milestones, and future directions

Tissue acquisition using EUS has considerably evolved since the first EUS-FNA was reported 25 years ago. Its introduction was an important breakthrough in the endoscopic field. EUS-FNA has now become a part of the diagnostic and staging algorithm for the evaluation of benign and malignant diseases of the gastrointestinal tract and of the organs in its proximity, including lung diseases. This review aims to present the history of EUS-FNA development and to provide a perspective on the recent developments in procedural techniques and needle technologies that have significantly extended the role of EUS and its clinical applications. There is a bright future ahead for EUS-FNA in the years to come as extensive research is conducted in this field and various technologies are continuously implemented into clinical practice.

Immunohistochemical analysis of IMP3 and p53 expression in endoscopic ultrasound-guided fine needle aspiration and resected specimens of pancreatic diseases

BACKGROUND

Insulin-like growth factor II messenger ribonucleic acid-binding protein 3 (IMP3) is a valuable marker that distinguishes malignant from benign lesions and predicts prognosis.

METHODS

First, we evaluated IMP3 expression in 77 resected specimens of pancreatic ductal adenocarcinoma (PDAC), intraductal papillary mucinous neoplasm (IPMN), and chronic pancreatitis (CP). Eleven PDAC patients preoperatively underwent endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). Survival analysis of IMP3 and clinicopathological factors was performed. IMP3 and p53 expression was evaluated in another 127 EUS-FNA samples of solid pancreatic masses to compare the diagnostic value of routine and immunohistochemical staining.

RESULTS

IMP3 expression was detected in 72.3%, 50%, 20%, and 0% of PDAC, malignant IPMN, benign IPMN, and CP, respectively. Evaluation of IMP3 expression in EUS-FNA specimens coincided with that in resected specimens in 10 of 11. IMP3 expression correlated with tumor differentiation in PDAC samples (p = .006) and with poor prognosis through univariate analysis (p = .045). Tumor differentiation and lymph node metastasis were significantly associated with poor prognosis through multivariate analysis. In EUS-FNA specimens, the sensitivity, specificity, and accuracy of cytohistological analysis were 80.8%, 100%, and 85.0%, respectively. IMP3 and p53 expression were detected in 80.8% and 44.9% of malignant and 0% and 5% of benign lesions. Combined with IMP3 immunostaining, the sensitivity, specificity and accuracy of cytohistological analysis significantly increased to 87.9%, 100%, and 90.8% (p = .016), respectively. Meanwhile, p53 staining had no impact on the results.

CONCLUSIONS

IMP3 immunohistochemical staining can improve the diagnostic accuracy of EUS-FNA for malignant pancreatic tumors.

Diagnostic Value of S100p, IMP3, Maspin, and pVHL in the Differantial Diagnosis of Pancreatic Ductal Adenocarcinoma and Normal/chronic Pancreatitis in Fine Needle Aspiration Biopsy

Introduction:

Differentiation between pancreatic ductal adenocarcinoma (PDAC) from benign mimickers is a well-known problem in cytological materials. Recent studies incorporated biological markers into this question and some studies showed that expression of S100P, IMP3, and maspin as well as nonexpression of von Hippel-Lindau gene product (pVHL) were significantly correlated with PDAC. In this study, we aimed to investigate diagnostic value of maspin, IMP3, S100P, and pVHL immunostaining in fine needle aspiration biopsies (FNABs) of pancreatic lesions.

Materials and Method:

In all, 33 cases of FNAB cell blocks of PDAC and 34 cases of surgical non-neoplastic pancreas specimens which were retrieved from the archives slides from 2007 to 2011 were included in this study. All the cases were stained with maspin, IMP3, S100P, and pVHL. Expression patterns of markers were scored and compared with benign mimickers. Test performance of each antibody and possible antibody combinations were also evaluated.

Results:

The study was composed of 33 PDAC and 34 control cases (8 chronic pancreatitis, 3 mucinous cystic neoplasm, and 23 nontumoral pancreatic tissue of PDAC). Diagnostic sensitivity for malignancy in S100P, IMP3, and maspin was 84.8%, 81.8%, and 87.5%, respectively. Specificity of these three markers was 100%. Sensitivity and specificity of pVHL for detecting nontumoral pancreatic tissue were 100% and 81.8%, respectively. When maspin, IMP3, and S100P expression were used together as triple test, sensitivity was 62.5% and specificity 100%. However, when any two of each three markers were evaluated (triple test/dual response), sensitivity reached 93.8% and specificity 100%.

Conclusion:

We observed that dual response in triple test (positive staining with two of these three markers) of maspin, IMP3, and S100P immunocytochemistry is very sensitive and specific in differential diagnosis of PDA and non-neoplastic pancreatic lesions. pVHL may have an additional role, when triple assessment is not satisfactory.

Practical Immunohistochemistry in Neoplastic Pathology of the Gastrointestinal Tract, Liver, Biliary Tract, and Pancreas

CONTEXT

- Immunomarkers with diagnostic, therapeutic, or prognostic values have been increasingly used to maximize the benefits of clinical management of patients with neoplastic diseases of the gastrointestinal tract, liver, biliary tract, and pancreas.

OBJECTIVES

- To review the characteristics of immunomarkers that are commonly used in surgical pathology practice for neoplasms of the gastrointestinal tract, liver, biliary tract, and pancreas, and to summarize the clinical usefulness of immunomarkers that have been discovered in recent years in these fields.

DATA SOURCES

- Data sources include literature review, authors' research data, and personal practice experience.

CONCLUSIONS

- Immunohistochemistry is an indispensable tool for the accurate diagnosis of neoplastic diseases of the gastrointestinal tract, liver, biliary tract, and pancreas. Useful immunomarkers are available to help distinguish malignant neoplasms from benign conditions, determine organ origins, and subclassify neoplasms that are morphologically and biologically heterogeneous. Specific immunomarkers are also available to help guide patient treatment and assess disease aggressiveness, which are keys to the success of personalized medicine. Pathologists will continue to play a critical role in the discovery, validation, and application of new biomarkers, which will ultimately improve patient care.

IMP3 and p16 expression in squamous cell carcinoma of the head and neck: A comparative immunohistochemical analysis

Expression of p16 has been established as a good surrogate marker for high-risk human papillomavirus (HPV) infection in oropharyngeal squamous cell carcinoma (OPSCC) patients, and it has been associated with an improved prognosis, irrespective of the actual HPV status. Conversely, the human insulin-like growth factor II mRNA binding protein 3 (IMP3) has been related to aggressiveness in several types of tumors. The aim of the present study was to investigate and compare p16 and IMP3 as markers of favorable and unfavorable behavior, respectively, in head and neck SCC (HNSCC), with particular reference to the HPV status. Both markers were analyzed by immunohistochemical analysis of 156 HNSCC samples originating from the oropharynx (n=81), oral cavity (n=44), larynx (n=15), hypopharynx (n=10) and nasopharynx (n=6). The HPV status was examined in a randomly selected representative subcohort (n=38) using polymerase chain reaction. Of the 156 HNSCC samples, 81 (51.9%) and 54 (34.6%) were positive for IMP3 and p16, respectively. IMP3 expression (P=0.022), p16 expression (P<0.001) and the combination of these markers (P<0.001) were significantly associated with tumor site. In particular, 69/81 (85%) OPSCC samples were positive for either one or both markers compared with 36/75 (48%) SCC samples from other sites. p16 expression was significantly associated with HPV infection (P=0.017) and a trend towards a negative association between IMP3 expression and HPV infection was observed (P=0.053). The results of the present study suggested that IMP3 and p16 are more frequently expressed in OPSCC compared with other HNSCCs. The prognostic impact of IMP3 on OPSCC remains to be investigated in a larger series with an extended follow-up period.

Diagnostic value of IMP3 and mesothelin in differentiating pancreatic ductal adenocarcinoma from chronic pancreatitis

BACKGROUND

The discrimination between pancreatic ductal adenocarcinoma (PDA) and chronic pancreatitis may be confusing at both clinical and radiologic levels. So, the search for biomarkers able to distinguish both clinical conditions is of great interest.

AIM

This study was undertaken to assess the value of insulin-like growth factor II mRNA binding protein 3 (IMP3) and mesothelin to differentiate PDA from non-neoplastic/reactive pancreatic duct epithelium.

METHODS

Immunohistochemical staining for IMP3 and mesothelin was performed on 40 formalin-fixed, paraffin-embedded tissue sections of PDA, 20 biopsies of chronic pancreatitis and 10 normal pancreatic tissue obtained from tumor-free surgical margins. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy were calculated.

RESULTS

IMP3 immunoreactivity was observed in 34 of 40 (85%) cases of PDA. The staining reaction was moderate to strong in 30 (75%) cases and diffuse in 26 (65%) cases. Eighteen of 20 (90%) biopsies of chronic pancreatitis were negative for IMP3, while the other two cases (10%) showed weak and focal IMP3 immunoreactivity. On the other hand, mesothelin demonstrated positive immunoreactivity in 30 of 40 (75%) cases of PDA. The staining reaction was moderate to strong in 24 (60%) cases and diffuse in 22 (55%) cases. Sixteen of 20 (80%) biopsies of chronic pancreatitis were negative for mesothelin, while weak and focal mesothelin staining was detected in the other 4 cases. All normal pancreatic tissues were negative for IMP3 and mesothelin expression. IMP3 showed higher sensitivity (85%) and specificity (90%) than mesothelin (75% and 80%, respectively).

CONCLUSIONS

Our results showed that IMP3 immunostaining has a higher sensitivity and specificity than mesothelin for the diagnosis of PDA. IMP3 and mesothelin may be useful markers in distinguishing neoplastic from reactive lesions of the pancreas in instances where this is impossible by morphology alone in surgical pathology practice.

Endoscopic ultrasound-guided fine-needle aspiration cytology in pancreaticobiliary carcinomas: diagnostic efficacy of cell-block immunocytochemistry

BACKGROUND

Endoscopic ultrasound-guided fine-needle aspiration cytology was demonstrated to be a useful tool for the diagnosis and staging of pancreaticobiliary neoplastic lesions. Nonetheless, the diagnostic value of this procedure may be limited by low cellularity of the specimen, contamination of intestinal cells and unfeasibility of ancillary immunocytochemical procedures. The present study was to evaluate its usefulness in the diagnosis of neoplastic lesions.

METHODS

A series of 46 pancreaticobiliary carcinomas with available cell block preparations was submitted to immunocytochemistry against cytokeratins, carcinoembryonic antigen, E-cadherin, CD10 and p53. The sensitivity, specificity, positive and negative predictive values of the cytological smear in the discrimination of malignant lesions were calculated and compared with those of cell block preparation with the immunocytochemical stains against p53 and CD10.

RESULTS

According to our findings, the use of cell block preparations together with immunostains against p53 and CD10 allowed to discriminate malignant versus benign specimens with higher sensitivity than the only cytological examination. In detail, CD10 immunostaining was of significant help for the discrimination between cytological contaminants, such as benign gastrointestinal cells, and the neoplastic elements of pancreaticobiliary well differentiated adenocarcinomas. Also, intense nuclear immunoreactivity for p53 was encountered in about 2/3 of the cases and identified pancreatic malignancy with high sensitivity.

CONCLUSIONS

We suggest that immunocytochemistry against both CD10 and p53 could be applied case by case, mainly to differentiate gastrointestinal and pancreatic benign cellular contaminants showing hyperplasia or reactive changes from differentiated pancreaticobiliary adenocarcinomas.

The involvement of insulin-like growth factor 2 binding protein 3 (IMP3) in pancreatic cancer cell migration, invasion, and adhesion

Background

Over-expression of insulin-like growth factor 2 mRNA binding protein 3 (IMP3) is correlated with poor prognosis in pancreatic ductal adenocarcinoma (PDAC). Previous studies examining other cancer types have implicated IMP3 in the regulation of several cellular functions that are characteristic of tumour cells. However, the role of this oncofetal protein in PDAC progression remained unclear.

Methods

Using siRNA, we examined the effect of IMP3 inhibition on the motility, invasive ability, and matrix adhesion of PDAC cells. In addition, we also evaluated the expression of cytoskeleton-associated genes following IMP depletion.

Results

Knockdown of IMP3 significantly decreased the motility, invasion, and extracellular matrix adhesion of select PDAC cells in vitro. In addition, IMP3-depleted cells exhibited lower levels of CD44 protein and KIF11 mRNA. Moreover, we also observed a reduction in downstream RhoA signaling following IMP3 knockdown, indicating that IMP3 modulates the levels of proteins involved in cytoskeletal organization.

Conclusions

These results suggest that IMP3 facilitates PDAC progression by enhancing the pro-metastatic behaviour of tumour cells.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1251-8) contains supplementary material, which is available to authorized users.

Utility of immunohistochemistry in the pancreatobiliary tract

CONTEXT

Immunohistochemistry has become a useful ancillary study in the identification and classification of pancreatic neoplasms. The diagnostic accuracy has been significantly improved because of the continuous discoveries of tumor-associated biomarkers and the development of effective immunohistochemical panels.

OBJECTIVES

To identify and classify pancreatic neoplasms by immunohistochemistry.

DATA SOURCES

Literature review and authors' research data and personal practice experience were used.

CONCLUSIONS

To better guide therapeutic decisions and predict the prognostic outcome, it is crucial to make an accurate diagnosis of a pancreatic neoplasm. Application of appropriate immunohistochemical panels enables pathologists to differentiate pancreaticobiliary adenocarcinomas from reactive conditions and to identify rare types of pancreatic neoplasms. Knowing the utilities and pitfalls of each tumor-associated biomarker is essential to avoiding a potential diagnostic error because an absolutely cancer-specific biomarker does not exist. This article reviews frequently used tumor-associated biomarkers, provides lists of effective immunohistochemical panels, and recommends a diagnostic algorithm as a standard approach to pancreatic neoplasms.

The role of the oncofetal IGF2 mRNA-binding protein 3 (IGF2BP3) in cancer

The post-transcriptional control of gene expression mediated by RNA-binding proteins (RBPs), long non-coding RNAs (lncRNAs) as well as miRNAs is essential to determine tumor cell fate and thus is a major determinant in cancerogenesis. The IGF2 mRNA binding protein family (IGF2BPs) comprises three RBPs. Two members of the family, IGF2BP1 and IGF2BP3, are bona fide oncofetal proteins, which are de novo synthesized in various human cancers. In vitro studies revealed that IGF2BPs serve as post-transcriptional fine-tuners modulating the expression of genes implicated in the control of tumor cell proliferation, survival, chemo-resistance and metastasis. Consistently, the expression of both IGF2BP family members was reported to correlate with an overall poor prognosis and metastasis in various human cancers. Due to the fact that most reports used a pan-IGF2BP antibody for studying IGF2BP expression in cancer, paralogue-specific functions can barely be evaluated at present. Nonetheless, the accordance of IGF2BPs' role in promoting an aggressive phenotype of tumor-derived cells in vitro and their upregulated expression in aggressive malignancies provides strong evidence that IGF2BPs are powerful post-transcriptional oncogenes enhancing tumor growth, drug-resistance and metastasis. This suggests IGF2BPs as powerful biomarkers and candidate targets for cancer therapy.

Expression of KOC, S100P, mesothelin and MUC1 in pancreatico-biliary adenocarcinomas: development and utility of a potential diagnostic immunohistochemistry panel

BACKGROUND

Pancreatico-biliary adenocarcinomas (PBA) have a poor prognosis. Diagnosis is usually achieved by imaging and/or endoscopy with confirmatory cytology. Cytological interpretation can be difficult especially in the setting of chronic pancreatitis/cholangitis. Immunohistochemistry (IHC) biomarkers could act as an adjunct to cytology to improve the diagnosis. Thus, we performed a meta-analysis and selected KOC, S100P, mesothelin and MUC1 for further validation in PBA resection specimens.

METHODS

Tissue microarrays containing tumour and normal cores in a ratio of 3:2, from 99 surgically resected PBA patients, were used for IHC. IHC was performed on an automated platform using antibodies against KOC, S100P, mesothelin and MUC1. Tissue cores were scored for staining intensity and proportion of tissue stained using a Histoscore method (range, 0-300). Sensitivity and specificity for individual biomarkers, as well as biomarker panels, were determined with different cut-offs for positivity and compared by summary receiver operating characteristic (ROC) curve.

RESULTS

The expression of all four biomarkers was high in PBA versus normal ducts, with a mean Histoscore of 150 vs. 0.4 for KOC, 165 vs. 0.3 for S100P, 115 vs. 0.5 for mesothelin and 200 vs. 14 for MUC1 (p < .0001 for all comparisons). Five cut-offs were carefully chosen for sensitivity/specificity analysis. Four of these cut-offs, namely 5%, 10% or 20% positive cells and Histoscore 20 were identified using ROC curve analysis and the fifth cut-off was moderate-strong staining intensity. Using 20% positive cells as a cut-off achieved higher sensitivity/specificity values: KOC 84%/100%; S100P 83%/100%; mesothelin 88%/92%; and MUC1 89%/63%. Analysis of a panel of KOC, S100P and mesothelin achieved 100% sensitivity and 99% specificity if at least 2 biomarkers were positive for 10% cut-off; and 100% sensitivity and specificity for 20% cut-off.

CONCLUSION

A biomarker panel of KOC, S100P and mesothelin with at least 2 biomarkers positive was found to be an optimum panel with both 10% and 20% cut-offs in resection specimens from patients with PBA.

Sensitivity of alternative testing for pancreaticobiliary cancer: a 10-y review of the literature

BACKGROUND

Biliary strictures present a diagnostic challenge to differentiate benign disease from hepatopancreaticobiliary (HPB) malignancies. Endoscopic retrograde cholangiopancreatography cytology is commonly performed in these patients; however, its sensitivity for diagnosis of HPB malignancy is poor (41.6%). Many adjunctive tests have been investigated to improve the sensitivity of HPB biopsies. To determine the best tests available, however, we reviewed the literature and performed a comparative analysis of all recently investigated tests and their sensitivities.

METHODS

A PubMed search identified articles published between 2003 and 2014, describing alternate methods for diagnosing HPB malignancies, reported sensitivity, final pathology, and had data available online. Meta-analysis was conducted for tests with multiple articles. Tests with the highest sensitivity and specificities were reported.

RESULTS

A total of 77 studies were identified. Meta-analysis was performed on the sensitivity of EUS-FNA (74.2%), fluorescence in situ hybridization (54.2%), immunostain of insulin-like growth factor 2 mRNA-binding Protein 3 (IMP3; 80.4%), IMP3 + cytology (86.4%), K homology domain containing protein overexpressed in cancer (KOC; 85.9%), S100P (77.8%), serum CA19-9 (69.3%), and K-ras mutations (47.0%) to detect malignancy. Ultimately, 12 tests were identified with superior sensitivity (85.3%-100%) and specificities (81.6%-100%) including stricture scrapping, brush sectioning, IMP3 stain + cytology, IMP3+S100A4, bile carcinoembryonic cell adhesion molecule 6 protein (±CA19-9), bile micro RNA (miRNA)-135b, serum miRNA-RNU2-1f, serum miRNA-21 (+CA19-9), peripheral blood mononuclear cells miRNA-27a-3p (+CA19-9), serum miRNA-16 + miRNA-196a (+CA19-9), peripheral blood mononuclear cells mRNAs h-TERT + CK20 + CEA + C-MET.

CONCLUSIONS

We recommend immunostaining with a panel of IMP3+KOC + S100A4 + cytology to achieve maximum sensitivity and specificity from HPB biopsies. One biliary protein (carcinoembryonic cell adhesion molecule 6) and several RNAs (bile and blood) offer exceptional sensitivity and specificity and should be tested prospectively in larger populations. Overall, this review identifies several tests to improve the sensitivity of diagnostic algorithms to identify HPB malignancies.

Use of IMP3, S100P, and pVHL immunopanel to aid in the interpretation of bile duct biopsies with atypical histology or suspicious for malignancy

Histologic evaluation of an endoscopic bile duct biopsy for malignancy is a known challenge. Our prior study has shown that the insulin-like growth factor-II mRNA binding protein-3 (IMP3), S100P, and the von Hippel-Lindau gene product (pVHL) are a useful immunopanel for the distinction between adenocarcinoma and benign biliary epithelium. To further evaluate the usefulness of the IMP3, S100P, and pVHL immunopanel to aid in the interpretation of bile duct biopsies, 16 histologically challenging bile duct biopsies that exhibited atypical histology or features suspicious for malignancy were immunohistochemically stained for IMP3, S100P, and pVHL. Clinical follow-up data were obtained for each case. The results showed that in the 11 cases that showed adenocarcinoma during follow-up, the following staining patterns in atypical/suspicious cells in the initial biopsies were observed: IMP3-positive/S100P-positive/pVHL-negative or reduced (n=6), IMP3-negative/S100P-positive/pVHL-negative or reduced (n=4), and IMP3-positive/S100P-negative/pVHL-negative (n=1). In the 5 follow-up-proven benign cases, 2 biopsies showed an IMP3-negative/S100P-positive/pVHL-positive pattern in atypical cells and 1 was negative for all 3 proteins. The remaining 2 biopsies exhibited an IMP3-positive/S100P-positive/pVHL-negative or reduced pattern in atypical cells that were histologically considered dysplastic on retrospective review. These observations reaffirm that bile duct adenocarcinoma frequently shows positive IMP3 and/or S100P staining with reciprocal negative or reduced pVHL expression. This staining pattern can also be seen in dysplastic epithelium in the absence of invasive carcinoma. On the contrary, benign biliary epithelium typically lacks IMP3 immunoreactivity and may retain normal pVHL expression. However, caution should be exercised when using this immunopanel in the interpretation of challenging bile duct biopsies, because S100P and pVHL stains may give rise to variable patterns that can be difficult to interpret.

Expression of insulin-like growth factor II mRNA-binding protein 3 predicts early recurrence and poor prognosis in intrahepatic cholangiocarcinoma

INTRODUCTION

Insulin-like growth factor-II mRNA-binding protein 3 (IMP3), a newly identified oncofetal RNA-binding protein, plays a pivotal role in the regulation of cell growth and migration during early stages of embryogenesis, and is found to be expressed in various human cancers. In this study, we elucidated the clinicopathological significance of IMP3 expression in intrahepatic cholangiocarcinoma (ICC).

METHODS

From March 1995 to December 2003, 61 surgically resected, unifocal primary ICCs were studied. IMP3 protein expression was detected by immunohistochemical staining.

RESULTS

IMP3 protein was expressed in 25 of 61 ICCs (41.0%). In addition to correlating with tumor grade (p = 0.0276), tumor stage (p = 0.0059), lymphovascular invasion (p = 0.0198), serum carbohydrate antigen 19-9 level (p = 0.0146), IMP3 expression predicted early tumor recurrence (ETR) (p = 0.0059) and was a strong indicator of worse disease-free survival (p = 0.0001) and overall survival (p = 0.0007). Even though we did not find that IMP3 expression exerted prognostic impact independent of tumor stage, multivariate analysis confirmed that IMP3 expression was an independent risk factor of high-stage tumor and ETR (p = 0.0170, and p = 0.0052, respectively), and thus it contributed to poor prognosis in ICC patients.

CONCLUSIONS

IMP3 expression can serve as a novel maker for ETR and prognostic prediction, and may be a target for adjuvant therapy of patients with ICC after tumor resection.

Reevaluation and identification of the best immunohistochemical panel (pVHL, Maspin, S100P, IMP-3) for ductal adenocarcinoma of the pancreas

CONTEXT

Differentiation of ductal adenocarcinoma of the pancreas from nonneoplastic pancreatic tissues can be challenging, especially in small biopsy and fine-needle aspiration specimens.

OBJECTIVE

To investigate the utility of 26 immunohistochemical markers (CAM 5.2, CK [cytokeratin] 7, CK20, CK17, CK19, MUC1, MUC2, MUC4, MUC5AC, MUC6, p53, DPC4/SMAD4, CDX2, pVHL [von Hippel-Lindau tumor suppressor gene protein], S100P, IMP-3 [insulin-like growth factor 2 messenger RNA binding protein 3], maspin, mesothelin, claudin 4, claudin 18, annexin A8, fascin, PSCA [prostate stem cell antigen], MOC31, CEA [carcinoembryonic antigen], and CA19-9 [cancer antigen 19-9]) in the diagnosis of ductal adenocarcinoma of the pancreas.

DESIGN

Immunohistochemical staining for these markers was performed in 60 cases of pancreatic ductal adenocarcinoma on routine and tissue microarray sections. In addition, immunohistochemical staining for maspin, S100P, IMP-3, and pVHL was performed on cell blocks from 67 pancreatic fine-needle aspiration cases, including 44 cases of pancreatic ductal adenocarcinoma.

RESULTS

The results demonstrated that (1) more than 90% of cases of ductal adenocarcinoma were positive for maspin, S100P, and IMP-3; (2) nearly all adenocarcinoma cases were negative for pVHL, whereas nonneoplastic ducts and acini were positive for pVHL in all cases; (3) normal/reactive pancreatic ducts were frequently positive for CK7, CK19, MUC1, MUC6, CA19-9, MOC31, PSCA, mesothelin, annexin A8, claudin 4, and claudin 18; (4) normal pancreatic ducts were usually negative for IMP-3, maspin, S100P, CK17, MUC2, MUC4, and MUC5AC; (5) 60% of adenocarcinomas were negative for DPC4/SMAD4; and (6) strong background staining was frequently seen with fascin, PSCA, and annexin A8.

CONCLUSIONS

pVHL, maspin, S100P, and IMP-3 constitute the best diagnostic panel of immunomarkers for confirming the diagnosis of pancreatic ductal adenocarcinoma in both surgical and fine-needle aspiration specimens.

Insulin-like growth factor 2 mRNA-binding proteins (IGF2BPs): post-transcriptional drivers of cancer progression?

The insulin-like growth factor-2 mRNA-binding proteins 1, 2, and 3 (IGF2BP1, IGF2BP2, IGF2BP3) belong to a conserved family of RNA-binding, oncofetal proteins. Several studies have shown that these proteins act in various important aspects of cell function, such as cell polarization, migration, morphology, metabolism, proliferation and differentiation. In this review, we discuss the IGF2BP family’s role in cancer biology and how this correlates with their proposed functions during embryogenesis. IGF2BPs are mainly expressed in the embryo, in contrast with comparatively lower or negotiable levels in adult tissues. IGF2BP1 and IGF2BP3 have been found to be re-expressed in several aggressive cancer types. Control of IGF2BPs’ expression is not well understood; however, let-7 microRNAs, β-catenin (CTNNB1) and MYC have been proposed to be involved in their regulation. In contrast to many other RNA-binding proteins, IGF2BPs are almost exclusively observed in the cytoplasm where they associate with target mRNAs in cytoplasmic ribonucleoprotein complexes (mRNPs). During development, IGF2BPs are required for proper nerve cell migration and morphological development, presumably involving the control of cytoskeletal remodeling and dynamics, respectively. Likewise, IGF2BPs modulate cell polarization, adhesion and migration in tumor-derived cells. Moreover, they are highly associated with cancer metastasis and the expression of oncogenic factors (KRAS, MYC and MDR1). However, a pro-metastatic role of IGF2BPs remains controversial due to the lack of ‘classical’ in vivo studies. Nonetheless, IGF2BPs could provide valuable targets in cancer treatment with many of their in vivo roles to be fully elucidated.

Detection of IGF2BP3, HOXB7, and NEK2 mRNA expression in brush cytology specimens as a new diagnostic tool in patients with biliary strictures

Introduction

It is a challenging task to distinguish between benign and malignant lesions in patients with biliary strictures. Here we analyze whether determination of target gene mRNA levels in intraductal brush cytology specimens may be used to improve the diagnosis of bile duct carcinoma.

Materials and Methods

Brush cytology specimens from 119 patients with biliary strictures (malignant: n = 72; benign: n = 47) were analyzed in a retrospective cohort study. mRNA of IGF-II mRNA-binding protein 3 (IGF2BP3), homeobox B7 (HOXB7), Forkhead box M1 (FOXM1), kinesin family member 2C (KIF2C) and serine/threonine kinase NEK2 was determined by semi-quantitative RT-PCR using the ΔCt method.

Results

IGF2BP3 (p<0.0001), HOXB7 (p<0.0001), and NEK2 (p<0.0001) mRNA expression levels were significantly increased in patients with cholangiocarcinoma or pancreatic cancer. Median ΔCt values differed by 3.5 cycles (IGF2BP3), 2.8 cycles (HOXB7) and 1.3 cycles (NEK2) corresponding to 11-fold, 7-fold and 2.5-fold increased mRNA levels in malignant versus benign samples. Sensitivity to detect biliary cancer was 76.4% for IGF2BP3 (80.9% specificity); 72.2% for HOXB7 (78.7% specificity) and 65.3% for NEK2 (72.3% specificity), whereas routine cytology reached only 43.1% sensitivity (85.4% specificity). Diagnostic precision was further improved, when all three molecular markers were assessed in combination (77.8% sensitivity, 87.2% specificity) and achieved 87.5% sensitivity and 87.2% specificity when molecular markers were combined with routine cytology.

Conclusions

Our data suggest that measuring IGF2BP3, HOXB7 and NEK2 mRNA levels by RT-PCR in addition to cytology has the potential to improve detection of malignant biliary disorders from brush cytology specimens.

Human pancreatic cancer fusion 2 (HPC2) 1-B3: a novel monoclonal antibody to screen for pancreatic ductal dysplasia

BACKGROUND.: Pancreatic ductal adenocarcinoma is rarely detected early enough for patients to be cured. The objective of the authors was to develop a monoclonal antibody to distinguish adenocarcinoma and precancerous intraductal papillary mucinous neoplasia (IPMN) from benign epithelium. METHODS.: Mice were immunized with human pancreatic adenocarcinoma cells and monoclonal antibodies were screened against a panel of archived pancreatic tissue sections, including pancreatitis (23 cases), grade 1 IPMN (16 cases), grade 2 IPMN (9 cases), grade 3 IPMN (13 cases), and various grades of adenocarcinoma (17 cases). One monoclonal antibody, human pancreatic cancer fusion 2 (HPC2) 1-B3, which specifically immunostained adenocarcinoma and all grades of IPMN, was isolated. Subsequently, HPC2 1-B3 was evaluated in a retrospective series of 31 fine-needle aspiration (FNA) biopsies from clinically suspicious pancreatic lesions that had long-term clinical follow-up. RESULTS.: HPC2 1-B3 was negative in all 31 cases of chronic pancreatitis that were tested. In contrast, HPC2 1-B3 immunostained the cytoplasm and luminal surface of all 16 well- to moderately differentiated pancreatic ductal adenocarcinomas. It demonstrated only weak focal staining of poorly differentiated carcinomas. All high-grade IPMNs were found to be positive for HPC2 1-B3. The majority of low-grade to intermediate-grade IPMNs were positive (66% of cases). Immunostaining a separate series of pancreatic FNA cell blocks for HPC2 1-B3 demonstrated that the relative risk for detecting at least low-grade dysplasia (2.0 [95% confidence interval, 1.23-3.26]) was statistically significant (P = .002 by the Fisher exact test). CONCLUSIONS.: To reduce the mortality of pancreatic cancer, more effective early screening methods are necessary. The data from the current study indicate that a novel monoclonal antibody, HPC2 1-B3, may facilitate the diagnosis of early pancreatic dysplasia.

Insulin-like growth factor II mRNA-binding protein 3 (IMP3) expression in hepatocellular carcinoma. A clinicopathological analysis with emphasis on diagnostic value

AIMS

Patients with hepatocellular carcinoma (HCC) usually present with advanced disease and rarely qualify for curative therapy. Immunohistochemical markers that help to discriminate benign from malignant processes early, and that have prognostic significance, would be useful. Expression of the oncofetal protein insulin-like growth factor II mRNA-binding protein 3 (IMP3) in malignant cells of different tumour types correlates with reduced overall survival.

METHODS AND RESULTS

Tissue microarrays (TMAs) containing 55 normal liver samples, 365 HCCs (122 with corresponding non-tumorous liver), 10 hepatocellular adenomas, 13 focal nodular hyperplasias and nine dysplastic nodules from western European patients were stained for IMP3. IMP3 was analysed in 61 core needle biopsies and findings were compared to glypican-3 and CD34. HCCs in TMAs were strongly positive for IMP3 in 18.4% of cases compared to absent expression in normal and non-tumorous liver tissue and benign liver tumours. Patients with IMP3 expression in HCCs showed significantly poorer overall survival in multivariate analysis (P = 0.044). Of the 61 core needle biopsies analysed, 32 (52.5%) of the HCCs were IMP3-positive.

CONCLUSIONS

In core needle biopsies, IMP3 expression seems to be of limited use as a single marker for the diagnosis of HCC, given a sensitivity of 52%, but it may be helpful in combination with other markers.

The novel monoclonal antibody HPC2 and N-cadherin distinguish pancreatic ductal adenocarcinoma from cholangiocarcinoma

Metastatic pancreatic ductal adenocarcinoma and primary cholangiocarcinoma are morphologically very similar and, therefore, challenging to distinguish in liver biopsies. The distinction is important because surgical management and prognosis differ significantly. Several immunohistochemical markers have been evaluated to aid this diagnosis, but aside from N-cadherin, which labels cholangiocarcinoma, few provide the combination of good sensitivity and specificity. Our laboratory recently developed the novel monoclonal antibody human pancreatic cancer fusion #2 (HPC2) that recognizes pancreatic cancer. We hypothesized that the combination of our new marker and N-cadherin can assist in distinguishing metastatic pancreatic cancer from cholangiocarcinoma. We immunostained resections of 60 pancreatic ductal adenocarcinomas and 31 cholangiocarcinomas for the HPC2 and N-cadherin antigens. We also stained 24 gallbladder adenocarcinomas, 11 ampullary adenocarcinomas, and 10 metastatic colonic adenocarcinomas to the liver. Sections were independently scored by 2 pathologists with good agreement using both markers (κ statistics, 0.62-0.64; P < .0001). HPC2 was observed in 80% of pancreatic cancers (48/60), 82% of ampullary (9/11), and 32% (10/31) of cholangiocarcinomas. N-cadherin stained 27% (16/60) of the pancreas cases and 58% (18/31) of the cholangiocarcinomas. Gallbladder and colon cancers were usually double negative (18/24 and 8/10, respectively). Each marker provided significant likelihood ratios to separate pancreatic cancer (HPC2, 2.48 [1.46-4.19]; P < .0001) from cholangiocarcinoma (N-cadherin, 2.17 [1.3-3.64]; P < .01). The combination of both markers provided even better specificity and positive likelihood ratios. We conclude that HPC2 and N-cadherin significantly improve accurate classification of pancreatic cancer and cholangiocarcinoma.

S100P, von Hippel-Lindau gene product, and IMP3 serve as a useful immunohistochemical panel in the diagnosis of adenocarcinoma on endoscopic bile duct biopsy

Histopathologic distinction between benign and malignant bile duct epithelial lesions on endoscopic biopsies can be extremely challenging because of limited material, crush artifact, and compounding inflammatory and/or reactive changes particularly after stent placement. In this study, a total of 72 endoscopic bile duct biopsies, including 40 adenocarcinomas and 32 benign cases, were immunohistochemically examined for the expression of S100P, von Hippel-Lindau gene product (pVHL), and IMP3 to evaluate their diagnostic value. The results showed that 36 adenocarcinomas (90%) exhibited strong nuclear and cytoplasmic staining for S100P, of which 30 (83.3%) showed diffuse immunoreactivity. Intermediate to strong cytoplasmic staining for IMP3 was demonstrated in 31 tumors (77.5%) (15 diffuse, 16 focal). Completely negative staining for pVHL was observed in 37 adenocarcinomas. In the remaining 3 tumors, focal (1) or diffuse (2) membranous and cytoplasmic pVHL immunoreactivity was detected. Twenty-eight tumors (70%) showed a S100P+/IMP3+/pVHL- staining pattern, 6 (15%) with a S100P+/IMP3-/pVHL- pattern, and 2 (5%) with a S100P-/IMP3+/pVHL- pattern. All 32 benign biopsies were completely negative for IMP3 with the exception of 2 cases with focal dysplasia where focal immunoreactivity was observed. Thirty benign biopsies (93.8%) were positive for pVHL with a diffuse staining pattern observed in 28 cases (93.3%). Eight benign biopsies (25%) showed focal S100P positivity. Twenty-two benign biopsies (68.8%) displayed a S100P-/IMP3-/pVHL+ staining pattern. In conclusion, an immunohistochemical panel consisting of S100P, pVHL, and IMP3 can be helpful in distinguishing adenocarcinoma from reactive epithelial changes on challenging bile duct biopsies. The findings of focal S100P and/or IMP3 expression with reciprocal loss of pVHL immunoreactivity in a few benign biopsies suggest a use of these markers in the detection of early epithelial dysplasia that may be beyond histologic recognition.

Insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3) overexpression in pancreatic ductal adenocarcinoma correlates with poor survival

Background

Pancreatic ductal adenocarcinoma is a lethal disease with a 5-year survival rate of 4% and typically presents in an advanced stage. In this setting, prognostic markers identifying the more agrressive tumors could aid in managment decisions. Insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3, also known as IMP3 or KOC) is an oncofetal RNA-binding protein that regulates targets such as insulin-like growth factor-2 (IGF-2) and ACTB (beta-actin).

Methods

We evaluated the expression of IGF2BP3 by immunohistochemistry using a tissue microarray of 127 pancreatic ductal adenocarcinomas with tumor grade 1, 2 and 3 according to WHO criteria, and the prognostic value of IGF2BP3 expression.

Results

IGF2BP3 was found to be selectively overexpressed in pancreatic ductal adenocarcinoma tissues but not in benign pancreatic tissues. Nine (38%) patient samples of tumor grade 1 (n = 24) and 27 (44%) of tumor grade 2 (n = 61) showed expression of IGF2BP3. The highest rate of expression was seen in poorly differentiated specimen (grade 3, n = 42) with 26 (62%) positive samples. Overall survival was found to be significantly shorter in patients with IGF2BP3 expressing tumors (P = 0.024; RR 2.3, 95% CI 1.2-4.8).

Conclusions

Our data suggest that IGF2BP3 overexpression identifies a subset of pancreatic ductal adenocarcinomas with an extremely poor outcome and supports the rationale for developing therapies to target the IGF pathway in this cancer.

Advances in pancreatic cancer detection

Pancreatic cancer represents a major challenge for research studies and clinical management. No specific tumor marker for the diagnosis of pancreatic cancer exists. Therefore, extensive genomic, transcriptomic, and proteomic studies are being developed to identify candidate markers for use in high-throughput systems capable of large cohort screening. Understandably, the complex pathophysiology of pancreatic cancer requires sensitive and specific biomarkers that can improve both early diagnosis and therapeutic monitoring. The lack of a single diagnostic marker makes it likely that only a panel of biomarkers is capable of providing the appropriate combination of high sensitivity and specificity. Biomarker discovery using novel technology can improve prognostic upgrading and pinpoint new molecular targets for innovative therapy.

Biomarkers in the diagnosis and early detection of pancreatic cancer

BACKGROUND

Pancreatic cancer, owing to its raising incidence and aggressiveness, is a major challenge, both for research and for clinical management. As pancreatic cancer has a complex pathophysiology, in addition to improving the methods of early diagnosis, sensitive and specific biomarkers are a prerequisite.

OBJECTIVE

As there is no specific tumor marker for pancreatic cancer diagnosis, extensive genomics/transcriptomics and proteomics studies have been developed with the aim of finding candidate markers and contributing to high-throughput systems for large cohort screening.

METHODS

A literature review was done to study these biomarkers in relation to diagnosis, prognosis and therapy targets in pancreatic cancer.

RESULTS/CONCLUSION

For early diagnosis improvement, only a panel of soluble biomarkers could provide the appropriate combination between high sensitivity and specificity. Prognostic upgrading would benefit from biomarker discovery and validation performed on tumor tissue. New technology could delineate molecular targets for innovative therapy in pancreatic cancer.

Differential diagnosis of pancreatic tumors by molecular analysis of clinical specimens

OBJECTIVE

To describe the capabilities and limitations of the current state of the art in pancreatic cancer diagnostics and to discuss recent progress in the development of novel, highly accurate molecular diagnostic approaches.

RESULTS

Molecular analyses currently under evaluation as novel diagnostic tests include detection of point mutations, genomic imbalances, aberrant methylation patterns and gene expression changes on the mRNA and protein levels in pancreatic juice, fine needle aspiration biopsies and brush cytologies.

CONCLUSIONS

In exploratory studies, several candidate molecular markers show great potential to serve as general indicators of malignancy, but need to be validated in large, controlled, prospective studies. Multiplexing of diagnostic tests, e.g. in the form of specialized DNA microarrays, may provide more differentiated diagnoses such as the distinction of various tumor types or prognostic information for individual patients. The MolDiag-Paca consortium is strongly engaged in advancing these developments on a European level.