Evidence-based diagnosis and staging of pancreatic cancer

Endoscopic ultrasonography can diagnose distal biliary strictures without a mass on computed tomography

AIM: To assess the diagnostic ability of endoscopic ultrasonography (EUS) for evaluating causes of distal biliary strictures shown on endoscopic retrograde cholangiopancreatography (ERCP) or magnetic resonance cholangiopancreatography (MRCP), even without identifiable mass on computed tomography (CT).

METHODS: The diagnostic ability of EUS was retrospectively analyzed and compared with that of routine cytology (RC) and tumor markers in 34 patients with distal biliary strictures detected by ERCP or MRCP at Dokkyo Medical School Hospital from December 2005 to December 2008, without any adjacent mass or eccentric thickening of the bile duct on CT that could cause biliary strictures. Findings considered as benign strictures on EUS included preservation of the normal sonographic layers of the bile duct wall, irrespective of the presence of a mass lesion. Other strictures were considered malignant. Final diagnosis of underlying diseases was made by pathological examination in 18 cases after surgical removal of the samples, and by clinical follow-up for > 10 mo in 16 cases.

RESULTS: Seventeen patients (50%) were finally diagnosed with benign conditions, including 6 “normal” subjects, while 17 patients (50%) were diagnosed with malignant disease. In terms of diagnostic ability, EUS showed 94.1% sensitivity, 82.3% specificity, 84.2% positive predictive value, 93.3% negative predictive value (NPV) and 88.2% accuracy for identifying malignant and benign strictures. EUS was more sensitive than RC (94.1% vs 62.5%, P = 0.039). NPV was also better for EUS than for RC (93.3% vs 57.5%, P = 0.035). In addition, EUS provided significantly higher sensitivity than tumor markers using 100 U/mL as the cutoff level of carbohydrate antigen 19-9 (94.1% vs 53%, P = 0.017). On EUS, biliary stricture that was finally diagnosed as malignant showed as a hypoechoic, irregular mass, with obstruction of the biliary duct and invasion to surrounding tissues.

CONCLUSION: EUS can diagnose biliary strictures caused by malignant tumors that are undetectable on CT. Earlier detection by EUS would provide more therapeutic options for patients with early-stage pancreaticobiliary cancer.

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.

CT-guided biopsies of pancreatic lesions: impact of contrast application prior to versus following needle placement

RATIONALE AND OBJECTIVES

Pancreatic lesions are frequently detected in pancreatic phase only, which may lead to false negative findings in CT-guided biopsies. We evaluated the accuracy and complication rate of CT guided biopsies of pancreatic lesions with i.v.-contrast application following needle placement in comparison to biopsy after contrast enhanced CT.

MATERIALS AND METHODS

In 30 patients planning and needle placement was performed on the basis of a native planning CT and prior diagnostic CT or MRT. After needle placement contrast enhanced CT was performed to confirm needle course and adjusted if necessary (group 1). In 30 additional patients biopsy was planned based on contrast enhanced CT and needle was placed in the lesion. Control scans confirmed correct needle position (group 2). An 18G coaxial system was used for both groups. Statistical analysis was performed with Student's t and Fisher's exact test for comparison of lesion size, location as well as accuracy and complication rates.

RESULTS

Mean lesion size was significantly smaller in group 1 (31 mm vs. 39 mm; p = 0.02). Diagnostic accuracy and sensitivity for malignancy in group 1 was 93% and 92% versus 80% and 77% in group 2. Complications related to the procedure, i.e. haematoma (n = 5, group 1/n = 2, group 2) and pain (n = 0, group 1/n = 2, group 2) did not statistically differ.

CONCLUSION

CT-guided biopsy of pancreatic lesions with i.v.-contrast application following needle placement is a reliable method and provides superior accuracy compared to biopsies performed after contrast enhanced planning CT.

Serum peptidome profiling revealed platelet factor 4 as a potential discriminating Peptide associated with pancreatic cancer

PURPOSE

Mass spectrometry-based serum peptidome profiling is a promising tool to identify novel disease-associated biomarkers, but is limited by preanalytic factors and the intricacies of complex data processing. Therefore, we investigated whether standardized sample protocols and new bioinformatic tools combined with external data validation improve the validity of peptidome profiling for the discovery of pancreatic cancer-associated serum markers.

EXPERIMENTAL DESIGN

For the discovery study, two sets of sera from patients with pancreatic cancer (n = 40) and healthy controls (n = 40) were obtained from two different clinical centers. For external data validation, we collected an independent set of samples from patients (n = 20) and healthy controls (n = 20). Magnetic beads with different surface functionalities were used for peptidome fractionation followed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). Data evaluation was carried out by comparing two different bioinformatic strategies. Following proteome database search, the matching candidate peptide was verified by MALDI-TOF MS after specific antibody-based immunoaffinity chromatography and independently confirmed by an ELISA assay.

RESULTS

Two significant peaks (m/z 3884; 5959) achieved a sensitivity of 86.3% and a specificity of 97.6% for the discrimination of patients and healthy controls in the external validation set. Adding peak m/z 3884 to conventional clinical tumor markers (CA 19-9 and CEA) improved sensitivity and specificity, as shown by receiver operator characteristics curve analysis (AUROC(combined) = 1.00). Mass spectrometry-based m/z 3884 peak identification and following immunologic quantitation revealed platelet factor 4 as the corresponding peptide.

CONCLUSIONS

MALDI-TOF MS-based serum peptidome profiling allowed the discovery and validation of platelet factor 4 as a new discriminating marker in pancreatic cancer.

Accuracy and Cost Comparison of Ultrasound Versus Alternative Imaging Modalities, Including CT, MR, PET, and Angiography

Ultrasound (US) has become widely used in clinical medicine for the diagnosis of a variety of disease processes. The unique ability of US to provide accurate information through an efficacious, painless, portable, and nonionizing method has expanded its role and application in diverse medical settings. Given the current economic environment and the related interest in creating the greatest value for health care expenditures, US has been evaluated to compare its clinical accuracy/efficacy and cost-effectiveness versus other imaging modalities. The following literature review reports the results of research studies aimed at comparing the accuracy/efficacy and cost of US versus alternative imaging modalities, including magnetic resonance imaging, computed tomography, contrast angiography, and single-photon emission computed tomography.

Preoperative tissue diagnosis for tumours of the pancreas

BACKGROUND

Preoperative biopsy of pancreatic lesions suspected of malignancy is controversial.

METHODS

A systematic Medline literature search was carried out. Diagnostic studies reporting quantitative preoperative pancreatic biopsy data were evaluated.

RESULTS

The analysis included 53 studies, mostly of a retrospective nature. Despite acceptable rates for sensitivity and specificity, the negative predictive value of percutaneous and endoscopic ultrasonography-guided biopsies was 60-70 per cent. Biopsy results were considered to be essential for directing non-surgical therapy in advanced disease. However, they were of limited value in planning the treatment of resectable solid or cystic tumours, or focal lesions in the setting of chronic pancreatitis.

CONCLUSIONS

Biopsy of suspected pancreatic malignancies with systemic spread or local irresectability is indicated for planning palliative or neoadjuvant therapy. Preoperative biopsy of potentially resectable pancreatic tumours is not generally advisable, as malignancy cannot be ruled out with adequate reliability.

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.

Staging of pancreatic adenocarcinoma by imaging studies

Imaging studies play a crucial role in the diagnosis and management of patients with pancreatic adenocarcinoma. Computed tomography (CT) is the most widely available and best-validated modality for imaging patients with pancreatic adenocarcinoma. To maximize the diagnostic efficacy of CT, use of a pancreas protocol is mandatory. The sensitivity of CT for diagnosis of pancreatic adenocarcinoma (89%-97%) and its positive predictive value for predicting unresectability (89%-100%) are high. The positive predictive value of CT for predicting resectability (45%-79%) is low because the diagnostic criteria for diagnosing vascular invasion by tumor favors specificity over sensitivity to avoid denying surgery to patients with potentially resectable tumor. Furthermore, the sensitivity of CT for small hepatic and peritoneal metastases is limited. Magnetic resonance imaging has not been shown to perform better than CT for the diagnosis and staging of pancreatic adenocarcinoma, but can be helpful as an adjunct to CT, particularly for evaluation of small hepatic lesions that cannot be fully characterized by CT. Ultrasound is often the first study obtained in patients with obstructive jaundice or unexplained abdominal pain, but its utility for diagnosis and staging of patients with pancreatic adenocarcinoma is limited. Positron emission tomography/CT combines the functional information provided by positron emission tomography with the anatomic information provided by CT and is a promising modality for imaging of patients with pancreatic adenocarcinoma, but its utility has not been established. Endoscopic ultrasound is generally considered superior to CT for the diagnosis and local staging of pancreatic cancer, but is limited by availability and inability to assess for distant metastases.

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A. Sauvanet Several factors argue for extended lymphadenectomy in surgery for pancreatic adenocarcinoma: 1) lymph node extension is an adverse prognostic factor; 2) some tumor recurrences are only loco-regional suggesting that initial resection was insufficient; 3) some retrospective studies suggest that extension of lymphadenectomy improves post-resection survival. Extended lymphadenectomy, including circumferential dissection of both the celiac axis and the superior mesenteric artery and resection of para-aortic nodes, was evaluated by 4 randomized trials; globally there was no survival benefit. Extended lymphadenectomy increases, at least transiently, the risk of post-operative diarrhea. Its influence on the rate of loco-regional recurrences has not been evaluated. However, this technique should not be definitively and globally precluded since a more radical resection was associated with a trend toward better long-term survival in the trial with the largest number of patients.

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A. Sauvanet Several factors argue for extended lymphadenectomy in surgery for pancreatic adenocarcinoma: 1) lymph node extension is an adverse prognostic factor; 2) some tumor recurrences are only loco-regional suggesting that initial resection was insufficient; 3) some retrospective studies suggest that extension of lymphadenectomy improves post-resection survival. Extended lymphadenectomy, including circumferential dissection of both the celiac axis and the superior mesenteric artery and resection of para-aortic nodes, was evaluated by 4 randomized trials; globally there was no survival benefit. Extended lymphadenectomy increases, at least transiently, the risk of post-operative diarrhea. Its influence on the rate of loco-regional recurrences has not been evaluated. However, this technique should not be definitively and globally precluded since a more radical resection was associated with a trend toward better long-term survival in the trial with the largest number of patients.

Borderline resectable pancreatic cancer: on the edge of survival

BACKGROUND

Patients with borderline resectable pancreatic cancer are at high risk of having positive surgical margins due to involvement of the tumor with adjacent vasculature. This article reviews the management of this subset of pancreatic cancer patients.

METHODS

The authors review the current definitions of borderline resectable pancreatic cancer and how it is diagnosed and staged. The history, current approaches, and future directions in neoadjuvant therapy for borderline resectable pancreatic cancer are also reviewed with emphasis on various chemotherapy regimens that have been used. The application of intensity-modulated radiation therapy and image-guided radiation therapy that accounts for respiratory motion to targeting the gross tumor volume in the pancreas are discussed, and the promise of integrating targeted therapies in neoadjuvant treatment programs is highlighted.

RESULTS

The use of neoadjuvant treatment programs that employ gemcitabine-based chemotherapy regimens followed by chemoradiation increases the likelihood of subsequent margin-negative resection in borderline resectable pancreatic cancer.

CONCLUSIONS

There has been progress in the imaging, staging, surgical technique, and the use of chemotherapy and chemoradiotherapy in the management of borderline resectable pancreatic cancer. Patients can benefit from multidisciplinary management at high-volume pancreatic cancer treatment centers.

Endoscopic ultrasonography findings in patients with non-specific changes of the pancreas on computed tomography: a single-center experience

Inconclusive findings on abdominal computerized tomography (CT) scans such as "enlarged or prominent pancreas" are commonly reported; however, their clinical significance is not clearly understood. The objective was to evaluate the efficacy of endoscopic ultrasound (EUS) in a cohort of patients with indeterminate findings on CT. We undertook a retrospective, single-center study at a tertiary care university hospital. About 107 consecutive patients (56 men) underwent EUS evaluation for inconclusive CT findings. The main intervention was EUS with fine needle aspiration (FNA) The main outcome measurement was to describe lesions identified by EUS in this cohort of patients. About 22 patients (21%) had pancreatic adenocarcinoma, 14 (13%) had chronic pancreatitis, 28 (26%) had benign lesions, and 35 patients (33%) had a normal EUS exam. Pancreatic cancer was more likely to be found on EUS in patients with significant weight loss (OR 10.1; 95% CI: 3.3-30.60), hyperbilirubinemia (OR 9; 95% CI: 3-26.0), or common bile duct (CBD) dilatation (OR 3.2; 95% CI: 1.25-8.5). The limitations of the study were that we were unable to control the uniformity of CT interpretation because the scans were reviewed by multiple radiologists. There were also limited follow-up data on patients who had benign lesions or normal EUS. In conclusion, EUS is an effective modality for evaluating pancreatic lesions in patients with inconclusive findings on abdominal CT. This assists in the prompt diagnosis and institution of appropriate treatment strategies for a variety of pancreatic diseases including cancer. In the setting of inconclusive CT findings, patients with hyperbilirubinemia, significant weight loss, or CBD dilatation should undergo EUS evaluation as they are at a higher risk of having underlying pancreatic cancer.

Combined EUS with FNA and ERCP for the evaluation of patients with obstructive jaundice from presumed pancreatic malignancy

BACKGROUND

An EUS-guided FNA (EUS-FNA) and a therapeutic ERCP are frequently required for the evaluation of patients who were seen for an obstructing periampullary lesion.

OBJECTIVE

To determine the feasibility and outcomes of combining an EUS-FNA and a therapeutic ERCP into a single session.

DESIGN

Retrospective single-center study.

SETTING

Tertiary-referral cancer center.

PATIENTS

A total of 114 patients with a suspected malignant obstructing lesion in the pancreatic head.

INTERVENTIONS

An EUS with or without FNA plus an ERCP.

MAIN OUTCOME MEASUREMENTS

Duration, diagnostic yield, and complication rate of the combined procedures.

RESULTS

The mean (SD) total procedure time (EUS, with or without FNA plus ERCP) was 73.6 +/- 30 minutes, with a median of 66 minutes (range 25-148 minutes). In many cases, cytologic diagnosis from FNA became available during an ERCP, which obviated the need for further sampling. EUS-FNA had a sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of 84.6%, 100%, 100%, 62.9%, and 87.8%, respectively. During an ERCP, endoscopic sphincterotomies were performed in 51 patients, and biliary stents were placed in 96 patients. Twelve patients (10.5%) had a complication, with 6 having postprocedural pancreatitis.

LIMITATIONS

Retrospective single-center experience.

CONCLUSIONS

Combined EUS-FNA and therapeutic ERCP is technically feasible, with a complication rate no higher than the component procedures, while efficiently providing tissue diagnosis and biliary drainage.

Preoperative evaluation of pancreatic adenocarcinoma

The preoperative evaluation of resectability for pancreatic cancer fails to identify up to 25% of patients who are unfortunately found to be unresectable at surgical exploration. Inoperative findings in this circumstance is usually due to either small volume metastatic disease or regional tumor invasion. While advances in computed tomography (CT) technology has increased accuracy of local tumor extent, occult metastatic disease remains a common problem. Although 2-[(18)F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) has been demonstrated to be useful in the staging of many malignancies (e.g. esophageal cancer, recurrent colorectal cancer, lung cancer), it has not been found to significantly increase the accuracy of determining resectability preoperatively in pancreatic cancer, especially with regard to detection of small volume metastatic disease. There are a variety of pancreatic cancer-specific antigens which are being developed as a method for targeted molecular imaging; we provide preliminary data targeting the integrin alpha(v)beta(6) to demonstrate the potential feasibility of this approach. Further developments may allow the accurate determination of patients with resectable pancreatic cancer, and more importantly, those with unresectable disease that may forego unnecessary surgery, the associated morbidity, and the subsequent delay of appropriate therapy.

Early detection and staging of adenocarcinoma of the pancreas

Early diagnosis is likely to improve the outcome and survival in patients who have pancreatic cancer. The sensitivity and specificity of current screening methods, however, limit their applicability to individuals at high risk for developing pancreatic cancer. Further development of serum markers may lead to improved diagnostic accuracy and allow screening to be implemented more broadly. Proteomic profiling and evaluation of panels of markers hold particular promise for the future. This article provides a review of current methods and results for the early detection and staging of pancreatic cancer, and discusses some potential areas for future development.

Systematic review, including meta-analyses, on the management of locally advanced pancreatic cancer using radiation/combined modality therapy

There is no consensus on the management of locally advanced pancreatic cancer, with either chemotherapy or combined modality approaches being employed (Maheshwari and Moser, 2005). No published meta-analysis (Fung et al, 2003; Banu et al, 2005; Liang, 2005; Bria et al, 2006; Milella et al, 2006) has included randomised controlled trials employing radiation therapy. The aim of this systematic review was to compare the following: (i) chemoradiation followed by chemotherapy (combined modality therapy) vs best supportive care (ii) radiotherapy vs chemoradiation (iii) radiotherapy vs combined modality therapy (iv) chemotherapy vs combined modality therapy (v) 5FU-based combined modality treatment vs another-agent-based combined modality therapy. Relevant randomised controlled trials were identified by searching databases, trial registers and conference proceedings. The primary end point was overall survival and secondary end points were progression-free survival/time-to-progression, response rate and adverse events. Survival data were summarised using hazard ratio (HR) and response-rate/adverse-event data with relative risk. Eleven trials involving 794 patients met the inclusion criteria. Length of survival with chemoradiation was increased compared with radiotherapy alone (two trials, 168 patients, HR 0.69; 95% confidence interval (CI) 0.51-0.94), but chemoradiation followed by chemotherapy did not lead to a survival advantage over chemotherapy alone (two trials, 134 patients, HR 0.79; CI 0.32-1.95). Meta-analyses could not be performed for the other comparisons. A survival benefit was demonstrated for chemoradiation over radiotherapy alone. Chemoradiation followed by chemotherapy did not demonstrate any survival advantage over chemotherapy alone, but important clinical differences cannot be ruled out due to the wide CI.