Soichiro Kawata

Role of the preoperative usefulness of the pathological diagnosis of pancreatic diseases.

Pancreatic cancer is the fifth leading cause of cancer death and has the lowest survival rate of any solid cancer. Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) is currently capable of providing a cytopathological diagnosis of pancreatic malignancies with a higher diagnostic power, with a sensitivity and specificity of 85%-89% and 98%-99%, compared to pancreatic juice cytology (PJC), whose sensitivity and specificity are only 33.3%-93% and 83.3%-100%. However, EUS-FNA is not effective in the cases of carcinoma in situ and minimally invasive carcinoma because both are undetectable by endoscopic ultrasonography, although PJC is able to detect them. As for the frequency of complications such as post endoscopic retrograde cholangiopancreatography pancreatitis, EUS-FNA is safer than PJC. To diagnose pancreatic cancer appropriately, it is necessary for us to master both procedures so that we can select the best methods of sampling tissues while considering the patient’s safety and condition.

Development of a device for detecting target specimens from EUS-guided FNA samples

Background and study aims: Specimens collected by fine needle are microscopic and contain blood; therefore, the presence of a target specimen within a sample is often difficult to confirm. Although rapid on-site evaluation (ROSE) during endoscopic ultrasound-guided fine needle aspiration biopsy (EUS-FNA) is beneficial, many health care facilities are unable to apply this technique due to a lack of cytopathologists. The aim of this study was to develop and validate a device that detects the target specimen within pancreatic tumor EUS-FNA samples. Patients and methods: Fifty-eight consecutive patients with solid pancreatic masses were studied for a preliminary case series at a tertiary-care university hospital (Tottori University Hospital, Yonago, Japan). The material collected was checked with a target sample check illuminator (TSCI) and was evaluated by one cytopathologist. Results: The agreement rate between the TSCI and histopathology was 93.7 %. Further testing procedures were not needed in 91.4 % of patients, and the mean number of needle punctures was 1.2 after a single pass using TSCI. No adverse events were encountered with the procedure. Conclusions: With the introduction of the TSCI in EUS-FNA, it became possible to both collect the minimum necessary target samples by EUS-FNA and to end further procedures, even without performing ROSE.

Clinical Impact of the KL-6 Concentration of Pancreatic Juice for Diagnosing Pancreatic Masses.

Background and Aim. Pancreatic juice cytology (PJC) is considered optimal for differentially diagnosing pancreatic masses, but the accuracy of PJC ranges from 46.7% to 93.0%. The aim of this study was to evaluate the clinical impact of measuring the KL-6 concentration of pancreatic juice for diagnosing pancreatic masses. Methods. PJC and the KL-6 concentration measurements of pancreatic juice were performed for 70 consecutive patients with pancreatic masses (39 malignancies and 31 benign). Results. The average KL-6 concentration of pancreatic juice was significantly higher for pancreatic ductal adenocarcinomas (PDACs) (167.7 ± 396.1 U/mL) and intraductal papillary mucinous carcinomas (IPMCs) (86.9 ± 21.1 U/mL) than for pancreatic inflammatory lesions (17.5 ± 15.7 U/mL, P = 0.034) and intraductal papillary mucinous neoplasms (14.4 ± 2.0 U/mL, P = 0.026), respectively. When the cut-off level of the KL-6 concentration of pancreatic juice was 16 U/mL, the sensitivity, specificity, and accuracy of the KL-6 concentration of pancreatic juice alone were 79.5%, 64.5%, and 72.9%, respectively. Adding the KL-6 concentration of pancreatic juice to PJC when making a diagnosis caused the values of sensitivity and accuracy of PJC to increase by 15.3% (P = 0.025) and 8.5% (P = 0.048), respectively. Conclusions. The KL-6 concentration of pancreatic juice may be as useful as PJC for diagnosing PDACs.

Diagnostic usefulness of KL-6 concentration of bile in biliary tract cancer

The sensitivity of bile cytology for biliary tract cancer varies from 6-64%, and hence remains unsatisfactory. Sialylated carbohydrate antigen KL-6 mucin is positive in biliary tract cancer tissues and serum KL-6 levels are significantly increased in intrahepatic ductal adenocarcinoma patients compared with healthy individuals. The aim of the present study was to evaluate the usefulness of the KL-6 concentration of bile for the diagnosis of biliary tract cancer. Bile cytology and measurements of bile KL-6 concentration were conducted for 43 patients (25 biliary tract cancers and 18 benign biliary disease). The concentration of KL-6 in the bile of the biliary tract cancer group was compared with the benign biliary disease group. The diagnostic ability was assessed by using receiver operating characteristic curves (ROC). The mean KL-6 concentration of bile for biliary tract cancer (34.6±51.6 U/ml) was increased compared with benign biliary disease (5.2±3.9 U/ml, P<0.001). The area under the ROC for diagnosis of biliary tract cancer was 0.84 for benign biliary disease. When the cut-off level of the KL-6 concentration of bile was 8.6 U/ml, the sensitivity, specificity, and accuracy of the KL-6 concentration of bile alone for the diagnosis of biliary tract cancer were 72, 89, and 79%, respectively. Adding the bile KL-6 concentration to bile cytology measurements, the sensitivity for the diagnosis of biliary tract cancer was increased significantly (100%, P=0.0184). The KL-6 concentration of bile may strengthen the sensitivity of bile cytology for biliary tract cancer.

Efficacy and safety of pancreatic juice cytology by using synthetic secretin in the diagnosis of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is difficult to detect in its early stages with the poorest prognosis of all cancers. To improve the prognosis, a precise diagnosis is needed when we suspect PDAC. Although endoscopic ultrasound‐guided fine‐needle aspiration biopsy (EUS‐FNA) is a widely accepted modality for the diagnosis of PDAC, its sensitivity is 85–89%, and approximately 10% of PDAC cases cannot be diagnosed. The main causes that interrupt the diagnosis of PDAC by using EUS‐FNA are tumor size, presence of a vessel or the main pancreatic duct along the puncture route, and difficulty in withdrawing anticoagulant. Pancreatic juice cytology (PJC), the sensitivity of which is 33.3–65.8%, is a method for the diagnosis of PDAC cases in which carrying out of EUS‐FNA is difficult. To diagnose PDAC appropriately, we need to improve the diagnostic ability of PJC.

Protein expression of Fragile Histidine Triad and cyclooxgenase‑2 in serrated neoplasia of the colorectum

The adenoma-carcinoma sequence (ACS) and the serrated pathway are two distinct developmental routes leading to the formation of colorectal carcinoma (CRC). However, the mechanism triggered by the serrated pathway remains unclear. Therefore, to clarify the molecular and clinicopathological characteristics of the serrated tumorigenic pathway, immunohistochemistry was used to examine the expression of Fragile Histidine Triad (FHIT), cyclooxygenase-2 (COX-2), MutL homolog 1 (MLH1), MutS protein homolog 2 (MSH2) and P53 in endoscopically resected samples of 62 serrated polyps. These samples included 20 hyperplastic polyps (HPs), 16 traditional serrated adenomas (TSAs), 26 sessile serrated adenoma/polyps (SSA/Ps), 20 non-serrated adenomas, 20 carcinoma in adenomas (CIAs) and 18 early pure CRCs without any adenoma component (EPCs). FHIT expression was markedly reduced or absent in 50% of TSA samples, 92.3% of SSA/Ps and 44% of EPCs, but only rarely in HPs, non-serrated adenomas and CIAs. COX-2 expression was more common in non-serrated adenomas compared with in serrated polyps, and was present in 25 and 3.2% of the cases respectively (P<0.01). Furthermore, COX-2 expression was more frequent in CIAs (60%) compared with in EPCs (22.2%; P<0.05). The incidence of negative COX-2 expression was higher in FHIT-negative SSA/Ps compared with in FHIT-positive SSA/Ps (P=0.08). A total of 16.7% of EPC samples and 11.5% of SSA/Ps demonstrated a loss of MLH1/MSH2 expression, but none of the other tumor types did. P53 overexpression was significantly increased in EPC (77.8%) and CIA (60%) samples compared with in HP (0%), TSA (6.6%), SSA/P (0%) and non-serrated adenoma (10%) samples (P<0.01). These findings demonstrated that there are different expression patterns between the serrated pathway and ACS, indicating that aberrant FHIT and inhibited COX-2 expression may be associated with serrated tumorigenesis. In addition, this data indicated that EPC may contain tumors derived from the serrated pathway as well as ACS.

Expression of methylation-modulated tumor-related genes in endoscopically resected early esophageal squamous neoplasia

Smoking and alcohol consumption are major risk factors for the development of esophageal squamous cell carcinoma (ESCC). Recent studies have demonstrated that smoking and alcohol consumption may be associated with altered DNA methylation in human cancer development. The aim of the present study was to evaluate methylation-modulated protein expression of tumor-related genes (TRGs) in the early stages of esophageal squamous neoplasia (ESN). ESN tissue samples (n=141) comprising 19 cases of low-grade intraepithelial neoplasia (LGIN), 70 of high-grade intraepithelial neoplasia/carcinoma in situ (HGIN/CIS) and 52 of invasive cancer, were endoscopically resected. The methylation-modulated protein expression of 5 TRGs [fragile histidine triad (FHIT), E-cadherin, MutL homolog 1 (MLH1) /MutS homolog 2 (MSH2) and cyclooxygenase-2 (COX-2)] as well as p53 was examined with immunohistochemistry, and their expression was compared with patient clinicopathological characteristics. Reduced or loss of FHIT, E-cadherin, MLH1/MSH2 and COX-2 expression was detected in 26.3 (5/19), 5.3 (1/19), 0 (0/19) and 63.2% (12/19) of LGIN cases, 61.4 (43/70), 18.6 (13/70), 7.1 (5/70) and 65.7% (46/70) of HGIN/CIS cases, and 78.8 (41/52), 50.0 (26/52), 11.5 (6/52) and 59.6% (31/52) of invasive cancer cases, respectively. Reduced or absent expression of FHIT and E-cadherin was significantly associated with neoplastic progression (FHIT, P=0.0007; E-cadherin, P=0.00014). The mean number of TRGs (FHIT, E-cadherin, MLH1/MSH2, and COX-2) that exhibited reduced or absent expression in LGIN, HGIN/CIS and invasive cancer specimens was 1.12±0.61, 1.66±0.93 and 2.09±0.96, respectively, demonstrating a significant stepwise increment from LGIN to HGIN/CIS and then to invasive cancer (P<0.05). p53 overexpression was frequently detected in ESN with head and neck carcinomas. However p53 overexpression was not significantly associated with ESN progression. An increase in the number of the 5 TRG proteins with reduced or loss of expression in the early stages of esophageal tumorigenesis was demonstrated, and their decreased expression was observed to be associated with tumor progression. Therefore, smoking and alcohol drinking may be associated with not only carcinogenesis but also the progression of ESN.

Frequent aberrant p53 and Fhit expression in endoscopically resected superficial hypopharyngeal cancer and esophageal cancer

In the last decade, the incidence rate of detection rate of superficial head, neck and esophageal squamous cell carcinomas has increased with the development of endoscopic imaging techniques. These cancers are thought to arise independently subsequent to tissue exposure to a common carcinogen e.g. alcohol or tobacco. This phenomenon has been termed field cancerization. To determine the molecular background of the development of hypopharyngeal squamous cell carcinomas (HPSCCs) and double esophageal squamous cell carcinomas (DESCCs), the present study immunohistochemically assessed tumor-related protein expression [p53, Fhit (fragile histidine triad), E-cadherin and activation-induced cytidine deaminase (AID)], and subsequently determined the correlation between protein expression and clinicopathological data. Tumor specimens of 9 HPSCCs and 9 DESCCs were endoscopically obtained from 8 patients with HPSCC. The 9 DESCCs, including 5 synchronous and 4 metachronous lesions, were all obtained from four patients with HPSCC. The overexpression of p53 and loss of Fhit expression was immunohistochemically detected in 8 (88.9%) and 8 (88.9%) of the 9 HPSCCs and in 8 (88.9%) and 8 (88.9%) of the 9 DESCCs, respectively, which demonstrated the high frequency of such expression. Additionally, 7 out of 9 HPSCCs, and 7 out of 9 DESCCs demonstrated aberrant expression of p53 and Fhit. The rate of aberrant AID and E-cadherin expression was 67 and 44% in HPSCCs and 44 and 44% in DESCC, respectively. These results suggested that aberrant p53 and Fhit expression was involved in the development of HPSCC and their DESCC, and that their expression may be used for the prediction of DESCC development in patients with HPSCC, thereby acting as a biomarker of field cancerization.

Utility of virtual touch quantification in the diagnosis of pancreatic ductal adenocarcinoma

This study aimed to compare the tissue stiffness of pancreatic ductal adenocarcinoma (PDAC) with that of pancreatic parenchyma using virtual touch quantification (VTQ). SWV was measured in 34 PDAC lesions and in pancreatic parenchyma of both controls and patients. SWVs in PDAC lesions were significantly higher than in pancreatic parenchyma in both healthy controls and in patients with PDAC. The area under the ROC for diagnosis of PDAC was 0.94 for pancreatic parenchyma in healthy controls, and 0.85 for pancreatic parenchyma in patients with PDAC. VTQ can provide a useful and additional information for diagnosis of PDAC.