EUS-FNA Samples Research Articles

PANCREATIC CANCER ASSOCIATED GENE EXPRESSION FROM FNA SAMPLES DIFFERENTIATES NEOPLASTIC FROM BENIGN PANCREATIC DISEASES.

Background: Detection of pancreatic cancer is difficult. In the current study we hypothesized that the expression level of specific pancreatic cancer genes (SPC-1,-2,-3) can be detected by Q-PCR from EUS-FNA samples and can accurately distinguish chronic pancreatitis from pancreatic cancer. Methods: All samples were analyzed using Taqman probes in Q-RT-PCR. Microdissected frozen samples from pancreatic adenocarcinoma (5), normal pancreas (5) and chronic pancreatitis (5) served as a training set. For analysis of the test set, a diagnostic cut-off value was chosen as the mean plus one SE of the chronic pancreatitis training set values. Samples taken with EUS aspiration needles from resected pancreatic lesions were used as the test set. Results: All three biomarker genes showed diagnostic levels of expression in all pancreatic adenocarcinoma specimens (6). Furthermore, these biomarkers were elevated in other pancreatic neoplasms including mucinous cystadenoma (2), mucinous cystadenocarcinoma (1), and ampullary adenocarcinoma (1). In contrast, the levels of these biomarkers were not elevated in any non-neoplastic condition, including chronic pancreatitis (1) and normal pancreas (2). In samples from diseases requiring surgery, SPC-1, SPC-2 and SPC-3 levels ranged from 2 to30-fold (mean=8), 5 to 1897-fold (mean=455), and 1 to 40-fold (mean=16) the cut-off level, respectively. Whereas, in samples from conditions not requiring surgery SPC-1, SPC-2, and SPC-3 levels ranged from 0.0006 to 0.022-fold (mean=0.086), 0.002 to 0.09-fold (mean=0.059), and 0 to 0.087-fold (mean=0.031), the cut-off level, respectively. There was no overlap in values between these two groups. Conclusions: The selected biomarkers accurately distinguished all cases of pancreatic cancer. Furthermore, the biomarkers also predicted those conditions which would require surgical intervention. Measurement of these bio-markers in samples from in vivo EUS-FNA may be useful in the management of patients with indeterminate pancreatic lesions.

Detection of lymph node micrometastases by gene promoter hypermethylation in samples obtained by endosonography- guided fine-needle aspiration biopsy.

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has become a fundamental procedure for gastrointestinal and lung cancer staging. However, there is growing evidence that micrometastases are present in lymph nodes, which cannot be detected with standard pathological methods. The aim of this study was to evaluate whether hypermethylation gene promoter analysis was feasible on samples obtained by EUS-FNA from lymph nodes, as well as to establish the usefulness of this strategy for the detection of micrometastases in patients with gastrointestinal and non-small cell lung cancer. Suspicious lymph nodes based on EUS findings from consecutive patients with esophageal, gastric, rectal, and non-small cell lung cancer were sampled by EUS-FNA. Hypermethylation analysis of the MGMT, p16(INK4a), and p14(ARF) gene promoter CpG islands were performed by methylation-specific PCR. Effectiveness of conventional cytology, methylation analysis, and their combination were established with respect to the definitive diagnosis. Twenty-seven patients were included, thus representing a total of 42 lymph nodes (esophageal cancer, n = 11; rectal cancer, n = 7; gastric cancer, n = 3; and lung cancer, n = 21). According to definitive diagnosis, 21 (50%) corresponded to metastatic lymph nodes. Sensitivity, specificity, and overall accuracy of conventional cytology were 76%, 100%, and 88%, respectively, whereas the corresponding values for the methylation analysis were 81%, 67%, and 74%, respectively. Combination of both techniques increased sensitivity (90%) but decreased specificity (67%) with respect to conventional cytology. In conclusion, it is feasible to detect occult neoplastic cells in EUS-FNA samples by hypermethylation gene promoter analysis. Moreover, addition of methylation analysis to conventional cytology may increase its sensitivity at the expenses of a decrease in its specificity.

Diagnostic Yield of Standard Brush Cytology (BC) Versus EUS-FNA for Pancreatic Cancer with Associated Malignant Biliary Stricture. Is It Time to Bury the Standard Biliary Brush?

Background: Despite the use of modified biliary brushing techniques and triple sampling devices, EUS-FNA remains a superior modality of tissue sampling for pancreatic cancer. Given EUS-FNA is highly sensitive for obtaining a tissue diagnose in pancreas cancers, the value of adding BC of associated biliary strictures is unclear. In our institution all patients considered for palliative or neoadjuvant chemoradiotherapy undergo pretreatment EUS-FNA for tissue diagnosis. Those with obstructive jaundice also undergo ERCP. Aim: We compared the cancer detection rates of standard BC and EUS-FNA in patients with pancreas cancer with associated malignant biliary stricture to determine if BC increased the diagnostic yield beyond that of EUS-FNA alone. Methods: ERCP and EUS-FNA records from 3/01 to 11/03 were retrospectively reviewed. 23 patients with an ultimate tissue diagnosis of pancreas cancer underwent both standard BC of biliary stricture and EUS-FNA of pancreatic mass. BC and FNA cytology results were reported as negative, atypical, suspicious or positive for malignancy. For the purpose of this study, atypical or suspicious samples were considered as negative. Results: All BC and EUS-FNA samples had sufficient cellularity for cytologic evaluation. BC was positive 0/23 (0%). EUS-FNA was positive 20/23 (87%). All five cases of suspicious BC were positive by EUS-FNA. Three patients with pancreas cancer missed by EUS were diagnosed at surgery. Results: Sensitivity of BC and EUS-FNA are 0 and 87% respectively. Sensitivity increases to 22 and 91%, respectively when suspicious specimens are considered as positive. Conclusions: EUS is superior to standard BC for tissue diagnosis in patients with pancreatic cancer and associated biliary stricture. Adding standard BC to EUS-FNA does not increase the cancer detection rate. If EUS-FNA is to be performed on patients with a pancreatic mass our work suggests the effort and cost involved in obtaining BC of associated biliary strictures is not worthwhile. Further studies should be performed to determine if enhanced brushing techniques or multimodality sampling of malignant biliary strictures increases cancer detection rate beyond that of EUS-FNA in this population.

Transcript Heterogeneity in Pancreatic Cancer Revealed by Microarray Expression Profiling Derived from EUS-FNA Tissue

Transcript Heterogeneity in Pancreatic Cancer Revealed by Microarray Expression Profiling Derived from EUS-FNA Tissue Shiro Urayama, Albert Truong Purpose: Previously we have reported the feasibility of expression profiling using the endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) specimen. In this study, we have investigated whether transcript expression heterogeneity were evident in the tissue specimen obtained. Methods: After obtaining IRB approval for human tissue specimen usage, aspirated pancreatic sample obtained during EUS-FNA on pancreatic cancer patients was immediately placed in RNA stabilizer and subsequently stored in 808C freezer. Total RNAwas extracted per standard fashion and cDNA was constructed using T7 promoter-flanked oligo (dT) primer, reverse transcriptase, and DNA polymerase, followed by in vitro transcription. Second round amplificationwas performed on the product to obtain adequate amplified RNA for cDNA microarray analysis. Amplified RNA from commercially available human pancreatic adenocarcinoma cell lines were also synthesized in a similar fashion and expression analysis performed on the arrays. Results: Total of 10 patients with diagnosis of pancreatic adenocarcinoma were included. Three human pancreatic cancer cell lines were used. The yield of the amplified RNA ranged from 2 to 20 ug from the tissue specimen. The purity of the yield was adequate (A260/A280>1.8) per spectrophotometric measurement. Cancer pathway specific gene array (containing 96 genes representative of 15 signal transduction pathways involved in oncogenesis) was used and revealed heterogeneity of the expression profiles among pancreatic cancer patients and human pancreatic cancer cell lines. Conclusions: Expression profiling using EUSFNA samples reveal transcript heterogeneity among the pancreatic adenocarcinoma tissues and cell lines. This information warrants further study and opens a potential for further tumor characterization which may lead to targetted therapies for pancreatic cancer.