An evidence-based approach to the diagnosis and staging of pancreatic cancer

Next-Generation Sequencing: An Advanced Diagnostic Tool for Detection of Pancreatic Disease/Disorder

The pancreas is involved in digestion and glucose regulation in the human body. Given the recognized link between chronic pancreatitis and pancreatic cancer, addressing pancreatic disorders and pancreatic cancer is particularly challenging. This review aims to highlight the limitations of traditional methods in diagnosing pancreatic disorders and cancer and explore several next-generation sequencing (NGS) approaches as a promising alternative. There are distinct clinical symptoms that are shared by a number of clinical phenotypes of pancreatic illness induced by particular genetic mutations. Traditional diagnostic methods encompass computed tomography, magnetic resonance imaging, contrast-enhanced Doppler ultrasound, endoscopic ultrasound, endoscopic retrograde cholangiopancreatography, transabdominal ultrasound, laparoscopy, and positron emission tomography have a prognostic ability of only 5% or less and a 5-year survival rate. Genetic sequencing can be employed as an alternative to conventional diagnostic techniques. Sanger sequencing and NGS are currently largely operated genome analysis, with no exception for pancreatic disease diagnosis. The NGS methods can sequence millions to billions of short DNA fragments, enabling enormous sample screening in a short amount of time with low-abundance detection, like in 0.1%-1% mutation prevalence declining approximate cost. Whole-genome sequencing, whole-exome sequencing, RNA sequencing, and single-cell NGS are a few NGS methods utilized to diagnose pancreatic disease. For both research and clinical applications, the NGS techniques can provide a precise diagnosis of pancreatic disorders in a short amount of time at a reasonable expenditure.

The Role of PET/CT in the Imaging of Pancreatic Neoplasms

Pancreas cancer is a complex disease and its prognosis is related to the origin of the tumor cell as well as the stage of disease at the time of diagnosis. Pancreatic adenocarcinomas derive from the exocrine pancreas and are the fourth leading cause of cancer-related deaths in the United States, while well-differentiated pancreatic neuroendocrine tumors (pNETs) derived from the endocrine part of the pancreas are rare and characterized by a slow growth and good life expectancy. Surgery is the only curative treatment approach, and an accurate assessment of resectability is of paramount importance in order to avoid futile procedures. The role of molecular imaging with positron emission tomography and computed tomography ranges from indispensable for pNETs to controversial for certain scenarios in pancreatic adenocarcinomas. This review article aims to overview molecular pancreatic imaging.

PET/MRI for Gastrointestinal Imaging: Current Clinical Status and Future Prospects

Positron emission tomography (PET)/computed tomography (CT) with 2-deoxy-2-[¹⁸F]fluoro-d-glucose (FDG) has become the standard of care for the initial staging and subsequent treatment response assessment for numerous gastrointestinal malignancies. However, it is often supplemented by magnetic resonance imaging (MRI) for local tumor staging. Hybrid PET/MRI scanners, which acquire PET data and MRI data simultaneously, have the potential to provide accurate whole-body staging in a single examination. Furthermore, to address certain limitations of FDG, many new PET tracers have been developed to probe distinctive aspects of tumor biology.

Heparanase expression in blood is sensitive to monitor response to anticancer treatment in pancreatic cancer, a pilot study

BACKGROUND

/Objectives: High heparanase level was shown in maliganant tumor; however, whether or not heparanase may serve as a sensitive marker to monitor response to anticancer treatment is still unknown.

METHODS

In the pilot study, heparanase mRNA expression in peripheral blood mononuclear cell fraction (PBMC) and activity in plasma and urine were detected by quantitative real time RT-PCR and heparan-degrading enzyme assay in 31 pancreatic cancer patients.

RESULTS

Heparanase mRNA and activity in samples from cancer patients were significantly higher than that in healthy donors. Both heparanase mRNA and activity in plasma and urine decreased significantly in 17 patients who underwent R₀ resection, but increased remarkably in 6 patients when recurrence or metastasis occurred (P < 0.05). However, those who underwent R₁ or R₂ resection in 6 patients kept stable. For 8 patients who received chemotherapy, heparanase mRNA and activity in plasma and urine decreased in each of the samples (P < 0.05). Patients with high heparanase mRNA (≥a cutoff value of 1.84) in PBMC and activity in plasma (≥1.30U/ml) were associated with a poor postoperative survival (P = 0.02 and P = 0.04).

CONCLUSIONS

Heparanase mRNA in PBMC and activity in plasma are closely correlated with therapeutic responsiveness and survival time, indicating that heparanase level in blood might be a sensitive but non-specific marker to monitor patients' response to anticancer treatment and to predict survival.

Dysbindin as a novel biomarker for pancreatic ductal adenocarcinoma identified by proteomic profiling

Pancreatic adenocarcinoma (PDAC) is known to have a poor prognosis partly because of lack of effective biomarkers. In the test set, we investigated dysbindin (DTNBP1) as a potential biomarker for PDAC by comparing preoperative and postoperative serum mass spectrometry (MS) proteomic profilings. Of the included 50 PDAC patients, 42 (positivity of 84.0%) detected a lower MS peak in postoperative serums than preoperative ones which was then identified as dysbindin. In the verification set, receiver operating characteristics (ROC) were used to assess diagnostic efficiency. 550 participants were included in the verification set [250 with PDAC, 80 with benign biliary obstruction (BBO), 70 with chronic pancreatitis (CP) and 150 healthy donors (HD)]. Dysbindin was increased in PDAC patient sera than in all controls. ROC curves revealed the optimum diagnostic cutoff for dysbindin was 699.16 pg/ml [area under curve (AUC) 0.849 (95% CI 0.812-0.885), sensitivity 81.9% and specificity 84.7%]. Raised concentration of dysbindin in sera could differentiate PDAC from BBO, CP and HD. Moreover, dysbindin maintained its diagnostic accuracy for PDAC patients who were CA19-9 negative [AUC 0.875 (95% CI 0.804-0.945), sensitivity 83.0%, specificity 89.0%] and for patients with benign biliary obstruction [AUC 0.849 (95% CI 0.803-0.894), sensitivity 82.3%, specificity 84.0%].Our discovery of dysbindin may complement measurement of CA19-9 in the diagnosis of PDAC and help to discriminate PDAC from other pancreatic diseases or begin biliary obstruction.

Telomerase activity as a marker for differential diagnosis of pancreatic adenocarcinoma: a systematic review and meta-analysis

BACKGROUND

Studies evaluating the role of telomerase activity in pancreatic adenocarcinoma are inconsistent and a systemic review of the available literature may shed new light on this issue.

OBJECTIVE

To systematically review the usefulness of telomerase activity in distinguishing pancreatic cancer from other pancreatic diseases.

METHODS

A comprehensive search of the PubMed and Embase databases was conducted to identify eligible studies. Only studies evaluating telomerase activity in patients with suspected or previously diagnosed pancreatic adenocarcinomas versus nonpancreatic adenocarcinomas and published in English with a sufficient number of cases were included. The hierarchical summary receiver operating characteristic (HSROC) model was used to establish the potential value of telomerase activity in the diagnosis of pancreatic adenocarcinoma.

RESULTS

A total of 19 studies qualified for this meta-analysis. In distinguishing pancreatic adenocarcinoma from benign diseases, the pooled sensitivity and specificity of telomerase activity were 0.81 (95% CI, 0.68-0.90) and 0.97 (95% CI, 0.93-0.98), respectively; the diagnostic odds ratio (DOR) was 126.62 (95% CI, 49.94-320.99); beta was -1.16 (95% CI, -3.62-1.29), Z was -0.93, p was 0.35>0.1, and lambda was 6.86 (95% CI, 1.01-12.70). In distinguishing pancreatic adenocarcinoma from chronic pancreatitis, the pooled sensitivity and specificity of telomerase activity were 0.77 (95% CI, 0.61-0.88) and 0.97 (95% CI, 0.91-0.99), respectively; DOR was 117.28 (95% CI, 32.25-426.53); beta was -0.38 (95% CI, -1.89-1.13), Z was -0.49, p was 0.62>0.1, and lambda was 5.30 (95% CI, 3.37-7.24).

CONCLUSIONS

The present meta-analysis demonstrates that telomerase activity could be a useful biomarker for the differential diagnosis of pancreatic adenocarcinoma and benign pancreatic diseases.

Utility of serum CA19-9 levels in the diagnosis of pancreatic ductal adenocarcinoma in an endoscopic ultrasound referral population

PURPOSE

Recent data suggest the use of carbohydrate antigen (CA) 19-9 as a potential marker in the early detection of pancreatic ductal adenocarcinoma (PDAC) when used in the appropriate clinical setting. Here, we assess the utility of CA19-9 in PDAC detection in a select population of pancreatic endoscopic ultrasound (EUS) referrals.

METHODS

Retrospective review of an institutional EUS Pancreas Registry containing cases referred from November 2002 to November 2011 was completed for categorical analyses with CA19-9 level. A separate case-control study for the subset of non-elevated CA19-9 PDAC population was also performed to characterize the clinical features in this unique group of patients.

RESULTS

Two hundred eighty-three patients had available CA19-9 data in the registry and were included in the study. Compared to the typical PDAC distribution, the proportion of patients with stage I disease was significantly higher in our registry population (P < 0.0001). Elevated CA19-9 levels most often reflected a diagnosis of PDAC relative to other pancreaticobiliary diagnoses. However, we observed that 15 % of patients with PDAC had normal CA19-9 levels. Clinical characteristics for this false-negative PDAC group compared to the true-positive group demonstrated a predilection for detection of cancer in the body/tail of the pancreas (P = 0.03), increased likelihood of lymph node metastases (P = 0.03), and initial presentation with vague abdominal pain or pancreatic mass as an incidental finding on imaging studies (P = 0.01).

CONCLUSIONS

Elevated CA19-9 demonstrated a greater likelihood of PDAC diagnosis relative to benign pancreatic pathology, and higher levels of CA19-9 were in line with worse PDAC stage. Patients with normal CA19-9 PDAC may represent a unique subclass of patients, presenting with atypical clinical features, and possibly more advanced stage disease at the time of diagnosis. These patients may benefit from more diligent EUS examination or perhaps closer follow-up management.

FDG-PET in diagnosis, staging and prognosis of pancreatic carcinoma: A meta-analysis

AIM: To investigate the potential role of positron emission tomography (PET) in the diagnosis, staging and prognosis predicting of pancreatic carcinoma (PC).

METHODS: A systematic review of relevant literatures in PubMed, Embase and Cochrane Library was performed. The sensitivity and specificity of diagnostic and staging studies, and HRs for prognosis predicting studies were pooled. The bivariate model was used for diagnostic studies and the random-effect model for prognostic studies. Heterogeneity between included studies was tested using χ² test, and subgroup analysis was performed to explain the heterogeneities. All of the calculations were performed using Stata version 11.0.

RESULTS: A total of 39 studies were included. The pooled sensitivity of PET in diagnosing PC (30 studies, 1582 patients), evaluating N stating (4 studies, 101 patients) and liver metastasis (7 studies, 316 patients) were 0.91 (95%CI: 0.88-0.93), 0.64 (95%CI: 0.50-0.76), and 0.67 (95%CI: 0.52-0.79), respectively; and the corresponding specificity was 0.81 (95%CI: 0.75-0.85), 0.81 (95%CI: 0.25-0.85), and 0.96 (95%CI: 0.89-0.98), respectively. In prognosis analysis (6 studies, 198 patients), significant difference of overall survival was observed between high and low standardized uptake value groups (HR = 2.39, 95%CI: 1.57-3.63). Subgroup analysis showed that PET/CT was more sensitive than PET alone in evaluating liver metastasis of PC, 0.82 (95%CI: 0.48-0.98) and 0.67 (95%CI: 0.52-0.79), respectively.

CONCLUSION: PET can be used as a valuable diagnostic and predictive tool for PC, but its effect in the staging of PC remains indeterminate.

Ferritin as an independent mortality predictor in patients with pancreas cancer. Results of a pilot study

Prognosis of patients with pancreas cancer is very poor. The aim of the study was to test the significance of laboratory parameters in the prognosis of patients with pancreas cancer. The studied group included 57 patients (31 men, 26 women, mean age 65 ± 9 years). Blood was collected at the time of diagnosis of pancreas cancer and basic laboratory parameters, including nutritional and inflammatory markers and tumour markers were measured. Patients were followed up until death (median survival 147 days). Ferritin, iron, albumin, prealbumin, cholinesterase, haemoglobin, C-reactive protein, alkaline phosphatase and carcinoembryonic antigen were significant for patients' prognosis in univariate analysis while CA 19-9, bilirubin, liver, pancreas and kidney tests and lipids were not. Multivariate Cox regression demonstrated ferritin, iron and albumin as independent mortality predictors (RR (95%CI), per standard deviation: ferritin 1.497(1.215-2.241), p = 0.002; albumin, 0.716(0.521-0.977), p = 0.035; iron, 0.678(0.504-0.915), p = 0.010). Iron correlated significantly with albumin (r = 0.397, p = 0.002) but neither iron nor albumin correlated with ferritin. Patients who survived 100 days had significantly lower ferritin (median 239 μg/l vs. non-survivors 435 μg/l, p = 0.014), significantly higher albumin but the difference in serum iron was not quite significant. ROC analysis for ferritin revealed AUC for 100 days survival of 0.710, p = 0.007 (and 0.725, p = 0.004 for 200 days survival). AUC for albumin for 100 days survival was not significant (p = 0.073). This study points out ferritin as an independent mortality predictor in patients with pancreas cancer. High serum levels of ferritin at the time of diagnosis of pancreas cancer indicate bad prognosis of the patient.

In vivo imaging of pancreatic cancer with fluorescent proteins in mouse models

In this chapter, we describe protocols for clinically-relevant, metastatic orthotopic mouse models of pancreatic cancer, made imageable with genetic reporters. These models utilize human pancreatic-cancer cell lines which have been genetically engineered to selectively express high levels of green fluorescent protein (GFP) or red fluorescent protein (RFP). Tumors with fluorescent genetic reporters are established subcutaneously in nude mice by injection of the GFP- or RFP-expressing pancreatic cancer cell lines, and fragments of the subcutaneous tumors are then surgically transplanted onto the pancreas of additional nude mice. Loco-regional tumor growth and distant metastasis of these orthotopic tumors occurs spontaneously and rapidly throughout the abdomen in a manner consistent with clinical human disease. Highly-specific, high-resolution, real-time quantitative fluorescence imaging of tumor growth, and metastasis is achieved in vivo without the need for contrast agents, invasive techniques, or expensive imaging equipment. Transplantation of RFP-expressing tumor fragments onto the pancreas of GFP- or cyan fluorescent protein (CFP)-expressing transgenic nude mice was used to facilitate visualization of tumor-host interaction between the pancreatic cancer cells and host-derived stroma and vasculature. Such in vivo models have enabled us to visualize in real time and acquire images of the progression of pancreatic cancer in the live animal. These models can demonstrate the real-time antitumor and antimetastatic effects of novel therapeutic strategies on pancreatic malignancy. These fluorescent models are therefore powerful and reliable tools with which to investigate metastatic human pancreatic cancer and novel therapeutic strategies directed against it.

CA 19-9 in pancreatic cancer: retrospective evaluation of patients with suspicion of pancreatic cancer

CA 19.9 serum levels were prospectively determined in 573 patients admitted to hospital for suspicion of pancreatic cancer. The final diagnosis was 77 patients with no malignancy, 389 patients with pancreatic cancer, 37 neuroendocrine pancreatic cancer, 28 cholangiocarcinomas, 4 gallbladder cancer, 27 ampullary carcinomas, and 11 periampullary carcinomas. CA 19.9 was determined using a commercial assay from Roche Diagnostics, and 37 U/ml was considered as the upper limit of normality. Abnormal CA 19.9 serum levels were found in 27%, 81.5%, 85.7%, 59.3%, 63.6%, and 18.9% of patients with benign diseases, pancreatic cancer, cholangiocarcinomas, and ampullary, periampullary, or neuroendocrine tumors. Significantly higher concentrations of CA 19.9 were found in patients with than in those without malignancy or with neuroendocrine tumors. CA 19.9 serum levels were higher in pancreatic cancer or cholangiocarcinoma than in other malignancies (p < 0.0001). CA 19.9 serum levels were also correlated with tumor stage, treatment (significantly lower concentrations in resectable tumors), and tumor location (the highest in those located in the body, the lowest in those in the tail or uncinate) and site of metastases (highest in liver metastases). A trend to higher CA 19.9 serum concentrations was found in patients with jaundice, but only with statistical significance in the early stages. Using 50 or 100 U/ml in patients with jaundice, CA 19.9 was useful as an aid in the diagnosis of pancreatic cancer (sensitivity 77.9%, specificity 95.9%) as well as tumor resectability in pancreatic cancer with different cutoffs according to tumor location and bilirubin serum levels with specificities ranging from 90% to 100%. CA 19.9 is the tumor marker of choice in pancreatic adenocarcinomas, with a clear relationship with tumor location, stage, and resectability.

Secretome-based identification of ULBP2 as a novel serum marker for pancreatic cancer detection

Background

To discover novel markers for improving the efficacy of pancreatic cancer (PC) diagnosis, the secretome of two PC cell lines (BxPC-3 and MIA PaCa-2) was profiled. UL16 binding protein 2 (ULBP2), one of the proteins identified in the PC cell secretome, was selected for evaluation as a biomarker for PC detection because its mRNA level was also found to be significantly elevated in PC tissues.

Methods

ULBP2 expression in PC tissues from 67 patients was studied by immunohistochemistry. ULBP2 serum levels in 154 PC patients and 142 healthy controls were measured by bead-based immunoassay, and the efficacy of serum ULBP2 for PC detection was compared with the widely used serological PC marker carbohydrate antigen 19-9 (CA 19-9).

Results

Immunohistochemical analyses revealed an elevated expression of ULPB2 in PC tissues compared with adjacent non-cancerous tissues. Meanwhile, the serum levels of ULBP2 among all PC patients (n = 154) and in early-stage cancer patients were significantly higher than those in healthy controls (p<0.0001). The combination of ULBP2 and CA 19-9 outperformed each marker alone in distinguishing PC patients from healthy individuals. Importantly, an analysis of the area under receiver operating characteristic curves showed that ULBP2 was superior to CA 19-9 in discriminating patients with early-stage PC from healthy controls.

Conclusions

Collectively, our results indicate that ULBP2 may represent a novel and useful serum biomarker for pancreatic cancer primary screening.

Noninvasive intraductal papillary mucinous neoplasm with para-aortic lymph node metastasis: report of a case

Intraductal papillary mucinous neoplasms (IPMNs) with an invasive carcinoma component are categorized as minimally invasive or invasive. The prognosis after resection of minimally invasive IPMNs has been reported to be similar to that after resection of noninvasive IPMNs. We report a case of noninvasive branchduct IPMN with multiple lymph node metastases, including para-aortic node involvement, treated successfully by distal pancreatectomy with lymph node dissection. The patient, a 72-year-old man, had two multilocular cysts in the pancreatic body, 22 mm and 14 mm in diameter, respectively, communicating with the main pancreatic duct. The primary tumor and nodal metastases had similar patterns of mucin expression. The primary tumor contained a region of carcinoma in situ (CIS) without histological evidence of stromal invasion; thus, it was diagnosed as minimally invasive carcinoma. We report this case to emphasize two important points: first, even small branch-duct IPMNs without any indications for resection can have a component of CIS or more advanced disease; and second, even branch-duct IPMNs without any apparent invasive component can be aggressive and spread to the lymph nodes. Therefore, nodal status should be assessed carefully in every patient, even if the primary IPMN is not advanced.

Relapsed acute pancreatitis as the initial presentation of pancreatic cancer in a young man: a case report

In this report, we describe a 31-year-old man in whom acute pancreatitis was the initial feature of a subsequently diagnosed pancreatic adenocarcinoma with multiple metastases. He initially presented at our hospital with acute pancreatitis. Abdominal ultrasonography revealed a mildly dilated pancreatic duct and an enlarged pancreatic head. Although a follow-up abdominal ultrasonography revealed a progressively dilated pancreatic duct and a progressively enlarged pancreatic head, he refused further investigation and was lost to follow-up. Four months later, he returned to our hospital with relapsed acute pancreatitis. Obstructive jaundice was noted and drainage was performed. Because choledochoplasty with multiple balloon catheters was not fully effective, biliary tract bypass surgery was carried out. Intraoperative biopsy confirmed pancreatic adenocarcinoma with multiple metastases. The patient died of massive gastrointestinal bleeding a few weeks later. To our knowledge, this is the youngest case of pancreatic cancer with the uncommon initial presentation of acute pancreatitis reported in the literature. For a patient with acute pancreatitis, particularly recurrent episodes, but with no known risk factors for pancreatitis, a pancreatic neoplasm should be considered as a potential underlying cause, even in a young man.

Role of pancreatic endoscopic ultrasonography in 2010

Endoscopic ultrasonography (EUS) was introduced 25 years ago aiming at better visualization of the pancreas compared to transabdominal ultrasonography. This update discusses the current evidence in 2010 concerning the role of EUS in the clinical management of patients with pancreatic disease. Major indications of EUS are: (1) Detection of common bile duct stones (e.g. in acute pancreatitis); (2) Detection of small exo- and endocrine pancreatic tumours; and (3) Performance of fine needle aspiration in pancreatic masses depending on therapeutic consequences. EUS seems to be less useful in cases of chronic pancreatitis and cystic pancreatic lesions. Moreover the constant improvement of computed tomography has limited the role of EUS in pancreatic cancer staging. On the other hand, new therapeutic options are available due to EUS, such as pancreatic cyst drainage and celiac plexus neurolysis, offering a new field in which new techniques may arise. So the main goal of this review is to determine the exact role of EUS in a number of pancreatic and biliary diseases.

A prospective diagnostic accuracy study of 18F-fluorodeoxyglucose positron emission tomography/computed tomography, multidetector row computed tomography, and magnetic resonance imaging in primary diagnosis and staging of pancreatic cancer

OBJECTIVE

To prospectively compare the accuracy of combined positron emission tomography/computed tomography using F-fluorodeoxyglucose (FDG-PET/CT), multidetector row computed tomography (MDCT), and magnetic resonance imaging (MRI) in the evaluation of patients with suspected pancreatic malignancy.

SUMMARY BACKGROUND DATA

FDG-PET/CT imaging is increasingly used for staging of pancreatic cancer. Preliminary data suggest a significant influence of FDG-PET/CT on treatment planning, although its role is still evolving.

METHODS

Thirty-eight consecutive patients with suspicion of pancreatic malignancy were enrolled. Patients underwent a protocol including FDG-PET/CT, MDCT, and MRI combined with magnetic resonance cholangiopancreatography, all of which were blindly evaluated. The findings were confirmed macroscopically at operation and/or by histopathologic analysis (n = 29) or follow-up (n = 9). Results of TNM classification of different imaging methods were compared with clinical TNM classification.

RESULTS

Pancreatic adenocarcinoma was diagnosed in 17 patients, neuroendocrine tumor in 3, mass-forming pancreatitis in 4, cystic lesion in 6, and fibrosis in 2. Six patients had a finding of a normal pancreas. The diagnostic accuracy of FDG-PET/CT for pancreatic malignancy was 89%, compared with 76% and 79% for MDCT and MRI, respectively. In the differential diagnosis of suspected malignant biliary stricture at endoscopic retrograde cholangiopancreaticography (n = 21), FDG-PET/CT had a positive predictive value of 92%. In 17 patients with advanced pancreatic adenocarcinoma, FDG-PET/CT had a sensitivity of 30% for N- and 88% for M-staging. Both MDCT and MRI had sensitivities of 30% for N- and 38% for M-staging. Furthermore, the clinical management of 10 patients (26%) was altered after FDG-PET/CT.

CONCLUSION

FDG-PET/CT was more sensitive than conventional imaging in the diagnosis of both primary pancreatic adenocarcinoma and associated distant metastases. In contrast, the sensitivity of FDG-PET/CT was poor in detecting local lymph node metastasis, which would have been important for an assessment of resectability. We recommend the use of FDG-PET/CT in the evaluation of diagnostically challenging cases, especially in patients with biliary strictures without evidence of malignancy in conventional imaging.

Endoscopic ultrasound in the evaluation of pancreaticobiliary disorders

The close proximity of the endoscopic ultrasound probe to the pancreas coupled with the ability to perform fine needle aspiration has made endoscopic ultrasound an extremely important technique for the evaluation of both benign and malignant pancreaticobiliary disorders. In parallel to the widespread importance of diagnostic endoscopic ultrasound, the therapeutic and interventional applications of this procedure are expanding and may become a major breakthrough in the management of pancreaticobiliary diseases. This article focuses on the utility and recent advances of endoscopic ultrasound in the diagnostic evaluation pancreaticobiliary disorders and analyses the data of well established interventional procedures such as celiac plexus neurolysis and pseudocyst drainage. Moreover, the more innovative procedures, such endoscopic ultrasound-guided biliary and pancreatic ducts access and drainage and the experimental use of direct endoscopic ultrasound-guided therapy of both solid and cystic pancreatic lesions will also be reviewed.

Pancreatic adenocarcinoma tumor grade determination using contrast-enhanced magnetic resonance imaging

OBJECTIVES

To determine whether the degree of enhancement of pancreatic adenocarcinoma visualized on arterial phase gadolinium-enhanced magnetic resonance imaging (MRI) correlates with the histopathological tumor grade.

METHODS

Thirty-nine patients with pancreatic adenocarcinoma had MRI within 14 days before tumor resection. Gadolinium-chelate-enhanced (Gd) 3-dimensional gradient echo images were acquired including the arterial phase. Tumor imaging patterns on the arterial phase images were classified for low, moderate, or high degree of enhancement and compared against conventional histological grading.

RESULTS

Based on histological grading, there were 12 poorly differentiated, 2 poorly to moderately differentiated, 22 moderately differentiated, and 3 well-differentiated adenocarcinomas. There was agreement between the MRI arterial enhancement pattern and histological grading in 30 of 39 cases. The mean size of tumors grouped by enhancement pattern or grade was not significantly different between groups. Although minor discordance was found in 9 of the 39 cases, statistical analysis showed agreement between the degree of arterial enhancement on MRI and histological tumor differentiation; the Cohen's kappa value was 0.64 with a 95% confidence interval of 0.46-0.83.

CONCLUSIONS

Pancreatic adenocarcinoma arterial phase enhancement correlates with the histological grade of differentiation.

Evolving preoperative evaluation of patients with pancreatic cancer: does laparoscopy have a role in the current era?

BACKGROUND

Recent years have brought important developments in preoperative imaging and use of laparoscopic staging of patients with pancreatic adenocarcinoma (PAC). There are few data about the optimal combination of preoperative studies to accurately identify resectable patients.

STUDY DESIGN

We conducted a statewide review of all patients with surgically managed PAC from 1996 to 2003 using data from the Oregon State Cancer Registry, augmented with clinical information from primary medical record review. We documented the use of all staging modalities, including CT, endoscopic ultrasonography, and laparoscopy. Primary outcomes included resection with curative intent. The association between staging modalities, clinical features, and resection was measured using a multivariate logistic regression model.

RESULTS

There were 298 patients from 24 hospitals who met the eligibility criteria. Patients were staged using a combination of CT (98%), laparoscopy (29%), and endoscopic ultrasonography (32%). The overall proportion of patients who went to surgical exploration and were resected was 87%. Of patients undergoing diagnostic laparoscopy, metastatic disease that precluded resection was discovered in 24 (27.6%). For patients who underwent diagnostic laparoscopy and were not resected, vascular invasion was the most common determinant of unresectability (56.6%). In multivariate analysis, preoperative weight loss and surgeon decision to use laparoscopy predicted unresectability at laparotomy.

CONCLUSIONS

This population-based study demonstrates that surgeons appear to use laparoscopy in a subset of patients at high risk for metastatic disease. The combination of current staging techniques is associated with a high proportion of resectability for patients taken to surgical exploration. With current imaging modalities, selective application of laparoscopy with a dual-phase CT scan as the cornerstone of staging is a sound clinical approach to evaluate pancreatic cancer patients for potential resectability.

Comprehensive proteome analysis of an Apc mouse model uncovers proteins associated with intestinal tumorigenesis

Tumor-derived proteins may occur in the circulation as a result of secretion, shedding from the cell surface, or cell turnover. We have applied an in-depth comprehensive proteomic strategy to plasma from intestinal tumor-bearing Apc mutant mice to identify proteins associated with tumor development. We used quantitative tandem mass spectrometry of fractionated mouse plasma to identify differentially expressed proteins in plasma from intestinal tumor-bearing Apc mutant mice relative to matched controls. Up-regulated proteins were assessed for the expression of corresponding genes in tumor tissue. A subset of proteins implicated in colorectal cancer were selected for further analysis at the tissue level using antibody microarrays, Western blotting, tumor immunohistochemistry, and novel fluorescent imaging. We identified 51 proteins that were elevated in plasma with concordant up-regulation at the RNA level in tumor tissue. The list included multiple proteins involved in colon cancer pathogenesis: cathepsin B and cathepsin D, cullin 1, Parkinson disease 7, muscle pyruvate kinase, and Ran. Of these, Parkinson disease 7, muscle pyruvate kinase, and Ran were also found to be up-regulated in human colon adenoma samples. We have identified proteins with direct relevance to colorectal carcinogenesis that are present both in plasma and in tumor tissue in intestinal tumor-bearing mice. Our results show that integrated analysis of the plasma proteome and tumor transcriptome of genetically engineered mouse models is a powerful approach for the identification of tumor-related plasma proteins.

Role of endoscopic ultrasound in the diagnosis and staging of pancreatic cancer

Early diagnosis of pancreatic cancer remains a difficult task, and multiple imaging tests have been proposed over the years. The aim of this review is to describe the current role of endoscopic ultrasound (EUS) for the diagnosis and staging of patients with pancreatic cancer. A detailed search of MEDLINE between 1980 and 2007 was performed using the following keywords: pancreatic cancer, endoscopic ultrasound, diagnosis, and staging. References of the selected articles were also browsed and consulted. Despite progress made with other imaging methods, EUS is still considered to be superior for the detection of clinically suspected lesions, especially if the results of other cross-sectional imaging modalities are equivocal. The major advantage of EUS is the high negative predictive value that approaches 100%, indicating that the absence of a focal mass reliably excludes pancreatic cancer. The introduction of EUS-guided fine needle aspiration allows a preoperative diagnosis in patients with resectable cancer, as well as a confirmation of diagnosis before chemoradiotherapy for those that are not. This comprehensive review highlighted the diagnostic capabilities of EUS including the newest refinements such as contrast-enhanced EUS, EUS elastography, and 3-dimensional EUS. The place of EUS-guided biopsy is also emphasized, including the addition of molecular marker techniques.

Imaging of primary and metastatic pancreatic cancer using a fluorophore-conjugated anti-CA19-9 antibody for surgical navigation

BACKGROUND

Despite recent surgical advances, pancreatic cancer remains the fourth leading cause of cancer-related death in the United States. This is due to inaccurate staging and difficulty in achieving negative margins at the time of pancreaticoduodenectomy. CA19-9 is a carbohydrate tumor-associated antigen found in up to 94% of pancreatic adenocarcinomas. In this study we investigate the use of a fluorophore-labeled anti-CA19-9 monoclonal antibody to improve intraoperative visualization of both primary and metastatic tumors in a mouse model of pancreatic cancer.

METHODS

A monoclonal antibody specific for CA19-9 was conjugated to a green fluorophore and delivered to tumor-bearing mice as a single intravenous (IV) dose. Intravital fluorescence imaging was used to localize tumor implants 24 h after antibody administration.

RESULTS

Using fluorescence imaging, the primary tumor was clearly visible at laparotomy, as were small metastatic implants within the liver and spleen and on the peritoneum. These tumor implants, which were nearly impossible to see using standard bright-field imaging, demonstrated clear fluorescence under LED light excitation. The fluorescence signal within the tumor tissue was maintained for over 3 weeks after a single administration of the labeled antibody. Histologic evaluation of tissue from animals treated with the conjugated anti-CA19-9 antibody likewise revealed strong staining of the tumor cells with minimal background staining of the peritumoral stroma.

CONCLUSIONS

Fluorophore-labeled anti-CA19-9 offers a novel intraoperative imaging technique for enhanced visualization of primary and metastatic tumors in pancreatic cancer when CA19-9 expression is present and may improve intraoperative staging and efficacy of resection.

Carbohydrate antigen 19.9 accurately selects patients for laparoscopic assessment to determine resectability of pancreatic malignancy

BACKGROUND

Laparoscopy with laparoscopic ultrasonography (L-LUS) may be useful in the selection of patients for surgery to resect peripancreatic malignancy in addition to contrast-enhanced computed tomography (CE-CT). The present prospective study assessed the strategy of using carbohydrate antigen 19.9 (CA19.9) levels to select patients for L-LUS.

METHODS

Patients with suspected peripancreatic malignancy that appeared resectable on CE-CT were selected for immediate surgery if CA19.9 was low (up to 150 kU/l, or up to 300 kU/l if serum bilirubin was above 35 micromol/l), or to L-LUS if CA19.9 was high (over 150 kU/l, or over 300 kU/l if serum bilirubin was above 35 micromol/l). Data were assessed to determine the clinical utility of this strategy.

RESULTS

A total of 94 patients went straight to surgery, of whom 65 proved resectable: 63 of 80 with a low CA19.9 level but only two of 14 with a high CA19.9 level and gastric outlet obstruction. From 55 patients with high CA19.9 levels, L-LUS correctly identified 26 of 31 resectable tumours and eight of 24 unresectable tumours.

CONCLUSION

Using CA19.9 levels to help select patients with pancreatic malignancy for immediate surgery or L-LUS for further assessment of resectability effectively increased resection rates and reduced unnecessary laparotomies.

Serum adenosine deaminase levels in pancreatic diseases

BACKGROUND

Adenosine deaminase (ADA) is found in most tissues including the pancreas. Its role in inflammation and malignancy has been studied experimentally. To date, serum ADA levels in pancreatic diseases have not been studied before.

AIM

To assess the levels of ADA in patients with pancreatitis and cancer of the pancreas.

METHODOLOGY

Serum levels of ADA were investigated in 14 cases with acute pancreatitis (mean age 46 years; male/female 5/9), 38 with chronic pancreatitis (mean age 46 years; male/female 25/13), 21 with cancer of the pancreas (mean age 67 years; male/female 11/10), and 21 healthy controls (mean age 40 years; male/female 11/10). The ADA levels were also compared among patients with pancreatic cancer with regard to tumor size and localization and the presence of metastases. Correlation analysis between ADA and CA 19.9 was also performed.

RESULTS

Serum ADA levels were 12.66 (9.54-20.72), 12.51 (8.88-26.64), 15.36 (10.20-21.05) and 9.39 (6.58-11.84) U/l in patients with acute pancreatitis, chronic pancreatitis, pancreatic cancer, and healthy controls, respectively. Serum ADA levels were significantly higher in acute and chronic pancreatitis, and pancreatic cancer patients compared to the control group (p < 0.05). Pancreatic cancer patients had significantly higher serum ADA levels when compared with acute and chronic pancreatitis cases (p < 0.05). The serum ADA levels were comparable according to tumor size and location and the presence of metastases. There was a linear correlation between serum ADA and CA 19-9 levels (p = 0.027, r = 0.552).

CONCLUSIONS

Our data suggest that the ADA enzyme may play a role in inflammatory diseases of the pancreas. Serum ADA levels increase in pancreatic disorders especially in pancreatic cancer. It may be a serum marker for the diagnosis of pancreatic cancer.