Kosuke Tsutsumi

An increase in the number of predictive factors augments the likelihood of malignancy in branch duct intraductal papillary mucinous neoplasm of the pancreas

BACKGROUND International consensus guidelines for the management of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas provide several factors that can be used to predict which IPMNs will become malignant.The sensitivity of each factors predictive accuracy, however, is relatively low, making it difficult to determine the appropriate treatment in individual cases. The aim of this study was to investigate whether increasing the number of predictive factors might augment the sensitivity of the established guidelines to detect malignant IPMNs. METHODS The medical records of 138 patients with IPMNs resected at our institution were reviewed. Possible malignant predictors were analyzed by univariate and multivariate analysis, and the effects of the number of factors and the predictive score of the pathologic results were examined. The cutoff points for the number of predictors to discriminate between malignant and nonmalignant IPMNs were established by constructing receiver operating characteristic curves. RESULTS A predictive analysis could not be carried out for the main duct IPMNs because of the high prevalence of malignancy and the small number of significant predictors associated with them. For malignant branch duct IPMNs, however, we identified 4 predictive factors that helped determine the correct diagnosis as follows: (1) the presence of a cyst ≥30 mm in diameter; (2) the presence of mural nodules; (3) a history of acute pancreatitis; and (4) atypical results of pancreatic juice cytology. An increase in the number of these factors significantly affected the sensitivity to predict malignancy. The area under the curve for the number of predictors for malignant branch duct IPMNs was 0.856, and the sensitivity and specificity were 96% and 71%, respectively, when the cutoff point was set at 2. The predictive scoring system also showed the same values of sensitivity and specificity for the number of factors. CONCLUSION Patients with branch duct IPMNs who have 2 or more of the 4 predictive factors described above should undergo standard pancreatectomy with lymph node dissection, whereas patients who present with 0 or 1 predictive factor can be treated by minimal pancreatectomy without nodal dissection or by careful observation without resection. All patients with main duct IPMNs, therefore, should be treated with resection as suspected malignancies.

Comparative Study of Laparoscopic and Open Distal Pancreatectomy

BACKGROUND Laparoscopic distal pancreatectomy (LDP) has been shown to be an effective surgical option for benign lesions in the body and tail of the pancreas. However, its advantages and disadvantages have not been well characterized. In this study, we compared the outcomes of LDP and open pancreatectomy performed in our clinic. MATERIALS AND METHODS Peri- and postoperative outcomes were retrospectively compared between patients with benign pancreatic disorders who underwent open distal pancreatectomy (ODP) (n = 35) and those who underwent LDP (n = 40). The peri- and postoperative factors analyzed included operative time, blood loss, hospital stay, postoperative recovery, biochemical findings, and complications. RESULTS LDP was associated with significantly less operative blood loss (363 versus 606 mL; P = 0.001) and shorter hospital stay (22 versus 27 day; P = 0.009), but longer operative time (342 versus 250 min; P = 0.000), compared with ODP. There were no significant differences between the two groups in complication rates or postoperative recovery, except for the significantly shorter duration of postoperative pain-killer intake and earlier improvement of the biochemical analysis in LDP than in ODP. CONCLUSIONS LDP appears to be a safe, desirable procedure for the management of benign pancreatic diseases, with outcomes similar to ODP.

Analysis of risk factors for recurrence after curative resection of well-differentiated pancreatic neuroendocrine tumors based on the new grading classification

It is difficult to predict the malignant potential of pancreatic neuroendocrine tumors (PNETs) precisely. This study investigated the validity of a new grading system adopted by the World Health Organization 2010 classification to determine risk factors for recurrence of PNETs.

MicroRNA Expression Analyses in Preoperative Pancreatic Juice Samples of Pancreatic Ductal Adenocarcinoma

CONTEXT Cytological assessment of pancreatic juice is commonly used to diagnose pancreatic ductal adenocarcinoma; however, the sensitivity of cytological assessment has been reported to be low. MicroRNAs are small RNAs regulating various cellular processes and have recently been identified as possible markers of malignant diseases including pancreatic ductal adenocarcinoma. OBJECTIVE The purposes of this study were to prove the existence of microRNAs in pancreatic juice and to determine whether specific microRNAs in pancreatic juice could be used for detecting pancreatic ductal adenocarcinoma. METHODS Relative expression levels of microRNA-21 and microRNA-155 in formalin-fixed paraffin-embedded tissues of resected specimens (no. 13) and pancreatic juice samples collected using preoperative endoscopic retrograde cholangiopancreatography (no. 21) were quantified and their expression levels were then compared to pancreatic ductal adenocarcinoma and chronic pancreatitis. RESULTS Relative expression levels of microRNA-21 in tissue and pancreatic juice samples were significantly higher in pancreatic ductal adenocarcinoma than those in chronic pancreatitis (P=0.009 and P=0.021, respectively). The same results were obtained in the expression levels of microRNA-155 in tissue and pancreatic juice between pancreatic ductal adenocarcinoma and chronic pancreatitis (P=0.014 and P=0.021, respectively). Expression levels of microRNA-21 and microRNA-155 did not correlate with the preoperative cytological results of pancreatic juice. CONCLUSION MicroRNA-21 and microRNA-155 in pancreatic juice have the potential of becoming biomarkers for diagnosing pancreatic ductal adenocarcinoma.

Multifocal Pancreatic Ductal Adenocarcinomas Concomitant with Intraductal Papillary Mucinous Neoplasms of the Pancreas Detected by Intraoperative Pancreatic Juice Cytology. A Case Report

CONTEXT Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas have been detected with increasing frequency as a result of the progression of diagnostic modalities. Recently, invasive ductal carcinoma of the pancreas concomitant with IPMNs has been the focus of attention. CASE REPORT We report the case of a 57-year-old man with multifocal ductal carcinomas of the pancreas concomitant with IPMNs detected by intraoperative cytology. During a follow-up for branch duct IPMNs, a stenotic lesion of the main duct in the pancreatic body was found by ERCP, and brush cytology of the stenosis revealed an adenocarcinoma. A distal pancreatectomy was proposed; however, intraoperative pancreatic juice cytology from the pancreatic head also revealed adenocarcinoma, and a total pancreatectomy was finally carried out. Pathological examination of the resected specimen showed multifocal ductal carcinomas and IPMNs in the distal pancreas, and invasive ductal carcinoma in the pancreatic head which had not been detected by preoperative imaging studies. CONCLUSIONS Surgeons should be aware of the possibility of multifocal carcinomas in patients with concomitant IPMNs. Intraoperative pancreatic juice cytology should always be performed in order to confirm the absence of carcinoma in the pancreas to be left in place after planned resection.

A History of Acute Pancreatitis in Intraductal Papillary Mucinous Neoplasms of the Pancreas Is a Potential Predictive Factor for Malignant Papillary Subtype

Background/Aims: There are several reports regarding intraductal papillary mucinous neoplasms (IPMNs) detected after the occurrence of acute pancreatitis. Although the presence of symptoms is regarded as a factor for predicting malignant IPMNs, there have been few reports demonstrating whether a history of acute pancreatitis is a predictor of malignancy. The aim of this study was to evaluate the relationship between a history of acute pancreatitis and clinicopathological features of IPMNs including the papillary subtype. Methods: The data of 150 IPMNs resected between 1990 and 2009 were retrospectively reviewed. They were classified into IPMNs with or without history of acute pancreatitis, and then the clinicopathological features were compared between the 2 groups. Results: Nineteen (13%) of the 150 patients had a history of acute pancreatitis. Nine of them had repeated episodes of pancreatitis; however, severe pancreatitis was uncommon. The diameter of the main pancreatic duct of the pancreatitis group was significantly larger than that of the nonpancreatitis group (p = 0.04). The pancreatitis group had a significantly higher frequency of carcinoma derived from IPMNs than the nonpancreatitis group (p = 0.03). The incidence of intestinal-type IPMNs in the pancreatitis group was significantly higher than that in the nonpancreatitis group (p < 0.001). Conclusion: Acute pancreatitis associated with IPMNs could predict malignant intestinal-type tumor.

Expression of claudin-4 (CLDN4) mRNA in intraductal papillary mucinous neoplasms of the pancreas

Claudin-4, encoding a protein for tight junction formation and function, is highly overexpressed in pancreatic ductal adenocarcinoma and is also associated with invasive adenocarcinomas arising in intraductal papillary mucinous neoplasms of the pancreas. However, the expression pattern of claudin-4 during neoplastic progression of intraductal papillary mucinous neoplasms remains unknown. Using quantitative real-time reverse transcription-PCR, we analyzed claudin-4 mRNA in a panel of 14 pancreatic cancer cell lines and in formalin-fixed paraffin-embedded tissues from 80 patients with intraductal papillary mucinous neoplasms of different histological grades and papillary subtypes. Increased expression of claudin-4 was confirmed in all the pancreatic cancer cell lines tested as compared with normal ductal epithelial cells and fibroblast cultures. The claudin-4 expression was significantly higher in high-grade intraductal papillary mucinous neoplasms (borderline neoplasm and carcinoma) than in low-grade intraductal papillary mucinous neoplasms (adenoma) (P<0.0001). In addition, claudin-4 mRNA levels were significantly higher in intestinal-type intraductal papillary mucinous neoplasms than in non-intestinal-type intraductal papillary mucinous neoplasms based on papillary subclassification (P<0.0001). Our findings suggest that claudin-4 expression is associated with neoplastic progression of intraductal papillary mucinous neoplasms and, especially, with a distinct pathway to intestinal differentiation.

Targeting the hedgehog signaling pathway with interacting peptides to Patched-1.

BackgroundThe hedgehog (Hh) signaling pathway is aberrantly activated in many cancers. Overproduction of sonic hedgehog (Shh), a ligand in the Hh pathway, increases Hh signaling activity by inhibiting Patched-1 (Ptch1), a suppressive receptor in the Hh pathway. The purpose of this study was to establish a novel strategy for treating pancreatic cancer and other Hh-dependent cancers through control of the tumor-suppressive function of Ptch1.MethodsWe synthesized seven interacting peptides to the amino-acid sequence of the Ptch1 docking site for Shh. Human pancreatic cancer cell lines (AsPC-1, SUIT2) were cultured in the presence or absence of the peptides. Cell proliferation was assessed by cell counting and by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The activity of the Hh pathway was estimated by real-time polymerase chain reaction of the target gene product Gli1. To confirm their anti-tumor activity in vivo, the effect of the peptides in a mouse model of pancreatic cancer was determined. Finally, the Hh signaling activity of the xenograft was examined.ResultsThree of the interacting peptides to Ptch1 suppressed the proliferation of the two pancreatic cancer cell lines and decreased the expression of Gli1, both in vitro and in vivo.ConclusionsThis study suggests that interacting peptides to Ptch1 may be a new tool for controlling the Hh-dependent growth of pancreatic cancer.

Different incretin responses after pancreatoduodenectomy and distal pancreatectomy.

Objectives Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are known as incretins to stimulate insulin secretion. The aims of this study were to investigate the postoperative &bgr;-cell function and hormonal responses of GLP-1 and GIP after pancreatoduodenectomy (PD) and distal pancreatectomy (DP). Methods Oral glucose tolerance tests were performed in 34 patients (20 PD and 14 DP) before and 1 month after operation. The changes in the serum glucose and insulin concentrations, homeostasis model assessment of insulin resistance, and pancreatic &bgr;-cell function (BCF) were analyzed. GLP-1 and GIP were also measured. Results There was no patient with postoperative deterioration of glucose tolerance after PD, whereas impairment of glucose metabolism was observed after DP. Homeostasis model assessment of insulin resistance decreased after PD, whereas those after DP showed no change. The postoperative BCF were lower than preoperative values in both groups. GLP-1 increased after DP but not after PD, whereas GIP decreased after PD but not after DP. Conclusions The changes in glucose metabolism and incretin responses were different between PD and DP. The increased level of GLP-1 after DP might reflect the relatively insufficient BCF; and thus, perioperative administration of GLP-1 might improve the diabetic condition after DP.

Expression of glucose transporter-1 is correlated with hypoxia-inducible factor 1α and malignant potential in pancreatic neuroendocrine tumors

The present study aimed to investigate the prognostic usefulness of the expression of glucose transporter type 1 (GLUT-1) and GLUT-2, hypoxia-inducible factor 1α (HIF-1α) and insulin-like growth factor II messenger RNA-binding protein 3 (IMP3) in pancreatic neuroendocrine tumors (pNETs). Immunohistochemical staining for GLUT-1, GLUT-2, HIF-1α and IMP3 was performed in 70 pNET specimens. The expression of GLUT-1 and HIF-1α was significantly higher in the World Health Organization grade 2 (G2), neuroendocrine carcinoma cases and mixed-type pNETs compared with the G1 cases. Vessel invasion, a high Ki-67 labeling index and a high mitotic count were significantly more frequent in the GLUT-1- and HIF-1α-positive cases compared with the negative cases. Lymph node metastasis was significantly higher in the GLUT-1-positive cases than in the negative cases. Insulin expression was significantly higher in the IMP3-positive cases than the negative cases. The GLUT-1 expression group experienced a significantly poor disease-free survival rate compared with the negative GLUT-1 expression group. HIF-1α expression was significantly correlated with poor disease-free survival and overall survival rates. A multivariate analysis revealed that lymph node metastasis was an independent risk factor for disease-free survival in all cases. In the G1/G2 group, tumor size and lymph node metastasis were independent risk factors for disease-free survival. Overall, the results suggested that GLUT-1 is a useful prognostic biomarker for pNETs.