Hiroyuki Konomi

Long-term consequence of endoscopic sphincterotomy for bile duct stones

BACKGROUND There are many reports of early- and intermediate-term results of endoscopic sphincterotomy. However, few data are available on long-term clinical outcome of endoscopic sphincterotomy for removal of common bile duct stones. METHODS Of 419 patients who underwent endoscopic sphincterotomy, follow-up data were obtained in 410 patients (98%). The period ranged from 1 month to 20 years (average 122 months). RESULTS Late complications included recurrence of stones (12.3%), acute cholangitis, acute cholecystitis (22% of 32 patients with gallstones, 0% of 88 patients without gallstones), new gallstone formation (6 patients), liver abscess (5 patients), and biliary carcinoma (8 patients). All of the recurrent stones were bilirubinate irrespective of the type of stone at sphincterotomy. Cholangitis and liver abscess occurred in 31% and 11%, respectively, of patients with residual intrahepatic stones but not in patients with complete intrahepatic stone clearance. CONCLUSIONS Late complications occur in a considerable proportion of patients after endoscopic sphincterotomy for the treatment of common bile duct stones, including stone recurrence, acute cholecystitis (which occurs only in patients with gallstones), liver abscess in patients with residual intrahepatic stones, and biliary carcinoma. The fact that the recurrent stones are invariably of the bilirubinate type, irrespective of the type of stones at initial treatment, suggests that bacterial infestation due to ablation of the sphincter mechanism may have a causative role.

The Role of S100A6 in Pancreatic Cancer Development and Its Clinical Implication as a Diagnostic Marker and Therapeutic Target

Recent microarray analyses showed that the S100 family contains members that are candidate diagnostic markers or therapeutic targets. In the present study, to evaluate the involvement of S100A6 in pancreatic cancer and its clinical usefulness for diagnosis, we examined S100A6 mRNA expression in pancreatic tissues and pancreatic juice from patients with different pancreatic diseases. To investigate the role of S100A6 in carcinogenesis of pancreatic cancer and the potential of S100A6 as a diagnostic marker for early detection of pancreatic cancer, we did immunohistochemistry and microdissection-based mRNA analysis of pancreatic normal ducts, pancreatic intraepithelial neoplasias, and invasive ductal carcinomas. We also used in vitro experiments and microarray analysis with RNA interference to evaluate the functional role of S100A6 and its potential as a therapeutic target for pancreatic cancer. S100A6 mRNA levels were significantly higher in carcinoma specimens than in nonneoplastic tissues. In pancreatic juice, there was a significant difference in S100A6 expression between patients with carcinoma and those with nonneoplastic disease. Receiver operating characteristic curves revealed that S100A6 might be a useful marker for diagnosis of pancreatic cancer. Immunohistochemistry and microdissection-based analysis showed differential expression of S100A6 among normal ducts, pancreatic intraepithelial neoplasias, and invasive ductal carcinomas. In vitro data showed that inhibition of S100A6 decreased proliferation and invasiveness of cancer cells, and these findings were supported by microarray data. Our present results suggest that quantitation of S100A6 mRNA is a promising tool for diagnosis of pancreatic cancer, and that S100A6 may be a promising therapeutic target for pancreatic cancer.

Laparoscopic pancreatic surgery: Current indications and surgical results

Background: Although minimally invasive surgery has achieved worldwide acceptance in various fields, laparoscopic surgery for pancreatic diseases has been reported only rarely. The purpose of this study was to evaluate the outcomes and feasibility of laparoscopic pancreatic surgery. Methods: Fifteen patients, comprising eight men and seven women with an average age of 54 years, underwent laparoscopic pancreatic surgery. Distal pancreatectomy was indicated for solid tumors (n = 4), cystic lesions (n = 3), and chronic pancreatitis (n = 2). Cystogastrostomy was performed for pseudocysts (n = 4) and enucleation for insulinomas (n = 2). The lesions varied in size from 1 to 9 cm (2.9 ± 2.4 cm) and were located in the pancreatic head (n = 2), body (n = 3), or tail (n = 10). For distal pancreatectomy, the splenic artery was divided and the parenchyma was transected with a linear stapler. Laparoscopic ultrasonography was used to determine the distance between the tumor and the main pancreatic duct for enucleation as well as to localize the lesion for distal pancreatectomy. Cystogastrostomy, 4.5 cm in length, was also performed with the linear stapler through the window of the lesser omentum. Results: Mean operation time was 249 ± 70 min (293 ± 58 min in distal pancreatectomy, 185 ± 14 min in enucleation, 204 ± 50 min in cystogastrostomy), and mean blood loss was 138 ± 184 g (213 ± 227 g, 75 ± 35 g, 38 ± 48 g, respectively). Two distal pancreatectomies (13%) were converted to open surgery due to severe peripancreatic inflammation. There was no related mortality, but there were two cases (15%) of pancreatic fistula, one in a distal pancreatectomy case and the other in an enucleation case, and both were treated conservatively. Conclusions: Laparoscopic pancreatic surgery is safe and feasible for patients with benign tumors and cystic lesions.

S100P Is an Early Developmental Marker of Pancreatic Carcinogenesis

Purpose: Our goal was to clarify the involvement and clinical significance of S100P in pancreatic carcinogenesis. Experimental Design: We examined S100P expression in 45 bulk pancreatic tissues; in microdissected cells, including invasive ductal carcinoma (IDC) cells (20 sections), pancreatic intraepithelial neoplasia (PanIN) cells (12 sections), intraductal papillary mucinous neoplasm (IPMN) cells (19 sections), and normal epithelial cells (11 sections); and in pancreatic juice samples from 99 patients with pancreatic diseases (32 cancer, 35 IPMN, and 32 chronic pancreatitis samples). We used quantitative real-time reverse transcription-PCR with gene-specific priming to measure S100P in these various types of samples. Results: In bulk tissue analyses, pancreatic cancer and IPMN expressed significantly higher levels of S100P than did nonneoplastic pancreas (P < 0.017 and P = 0.0013, respectively). Microdissection analyses revealed that IPMN expressed significantly higher levels of S100P than did IDC (P < 0.0001) and PanIN (P = 0.0031), although S100P expression did not differ between IDC and PanIN (P = 0.077). In pancreatic juice analyses, cancer and IPMN juice expressed significantly higher levels of S100P than did pancreatitis juice (both P < 0.0001). Receiver operating characteristic curve analyses revealed that measurement of S100P in pancreatic juice was useful for discriminating neoplastic disease from chronic pancreatitis (area under the curve = 0.837; 95% confidence interval, 0.749-0.903). Conclusion:S100P may be an early developmental marker of pancreatic carcinogenesis, and measurement of S100P in pancreatic juice may be useful for early detection of pancreatic cancer or screening of early pancreatic carcinogenesis.

Twist, a novel oncogene, is upregulated in pancreatic cancer: Clinical implication of Twist expression in pancreatic juice

Despite evidence that Twist, a highly conserved basic helix‐loop‐helix transcription factor, is a novel oncogene, there are no reports describing Twist expression in pancreatic cancer. Intraductal papillary mucinous neoplasm (IPMN) and pancreatic intraepithelial neoplasia (PanIN) are precursor lesions of pancreatic cancer. To clarify involvement of Twist expression in pancreatic cancer, we used quantitative reverse transcription‐polymerase chain reaction and examined Twist expression in pancreatic cancer, IPMN, and non‐neoplastic pancreas using bulk tissues (11 cancers, 18 IPMNs, and 15 non‐neoplastic pancreata), microdissected cells (cancer from 22 sections, IPMN from 19 sections, PanIN from 6 sections, and pancreatitis‐affected epithelial cells from 14 sections), and pancreatic juice (16 from cancer, 28 from IPMN, and 17 from pancreatitis). Twist expression differed significantly between cancer and IPMN bulk tissues (p < 0.0001) but not between cancer and non‐neoplastic tissues. Twist expressions differed significantly between microdissected cancer cells, IPMN cells, and pancreatitis‐affected cells (all comparisons, p < 0.017). PanIN cells expressed significantly lower levels of Twist than did IDC cells (p = 0.016). Twist expression differed significantly between cancer and IPMN juice samples (p = 0.0002) but not between cancer and pancreatitis juice samples. Receiver operation characteristic curve analyses revealed that measurement of Twist was more useful for discriminating cancer from IPMN than from chronic pancreatitis (p = 0.009). Our results suggest that Twist is involved in tumor progression of pancreatic cancer and that measurement of Twist in pancreatic juice may be useful to differentiate pancreatic cancer from nonmalignant neoplasms such as IPMN.

S100A11, A Putative Tumor Suppressor Gene, Is Overexpressed in Pancreatic Carcinogenesis

Purpose: Recent microarray analyses revealed that expression of S100A11 is up-regulated in pancreatic cancer. The aim of the present study was to evaluate the association of S100A11 with pancreatic carcinogenesis. Experimental Design: We measured S100A11 mRNA expression in various clinical samples related to pancreatic cancer and its precursor lesions, intraductal papillary mucinous neoplasm (IPMN) and pancreatic intraepithelial neoplasia, by quantitative reverse transcription-PCR. Results: Levels of S100A11 were significantly higher in pancreatic cancer (n = 22) and IPMN (n = 18) bulk tissues than in nonneoplastic bulk tissues (n = 22; P < 0.0001 for both). Levels of S100A11 did not differ between pancreatic cancer and IPMN bulk tissues. In microdissection analyses, however, IPMN cells (n = 21) expressed significantly higher levels of S100A11 than did cancer cells (n = 23; P = 0.003). The median level of S100A11 expression was higher in pancreatic intraepithelial neoplasia cells (n = 6) than in cancer cells. In pancreatic juice analyses, cancer-related (n = 24; P = 0.004) and IPMN-related (n = 18; P = 0.001) juice expressed significantly higher levels of S100A11 than did chronic pancreatitis–related juice (n = 23). Conclusions: The present data suggest that expression of S100A11, a putative tumor suppressor gene, is increased in the early stage of pancreatic carcinogenesis and decreased during subsequent progression to cancer. Analysis of the S100A11 level in pancreatic juice may be an effective tool for screening of patients with high-risk lesions that could progress to pancreatic cancer or detecting early-stage pancreatic cancer.

Pancreatic juice cytology in IPMN of the pancreas

Background: Intraductal papillary-mucinous neoplasm (IPMN) of the pancreas is a disease ranging from adenoma to borderline (with moderate dysplasia) and further to carcinoma (noninvasive and invasive) and surgical strategy is different by the grades of dysplasia. Methods: Preoperativepancreatic juice cytology in IPMN was reviewed in 71 patients with IPMN who underwent surgical resection. Results: The IPMN was adenoma in 48 patients, borderline in 13 and carcinoma (invasive) in 10. The sensitivity of pancreatic juice cytology in malignant IPMN was 40% (4/10). In 4 patients with the 48 IPM adenomas, diagnosis of pancreatic juice cytology was class IV or V. One of the 4 cases was considered to be an overdiagnosis of cytology, but the other 3 cases were considered to be a consequence of accompanying carcinoma in situ (or PanIN-3) (2 patients) or invasive ductal adenocarcinoma (1 patient) apart from IPMN. Sensitivity of pancreatic juice cytology was higher in IPMN of the main duct type with mucin hypersecretion and with mural nodules. Conclusions: These findings suggest that pancreatic juice cytology in IPMN is useful especially in the main duct type with mucin hypersecretion and mural nodules. When the diagnosis of pancreatic juice cytology is malignant in otherwise benign-looking IPMNs, coexistence of pancreatic carcinoma should be suspected.

S100A6 is increased in a stepwise manner during pancreatic carcinogenesis: clinical value of expression analysis in 98 pancreatic juice samples.

There are few reports describing the diagnostic significance of S100A6 expression in clinical samples obtained from patients with pancreatic disease. In the present study, we measured S100A6 expression in pancreatic tissues and juice to evaluate its involvement in pancreatic carcinogenesis. We did quantitative real-time reverse transcription-PCR to measure mRNA expression in microdissected cells and pancreatic juice samples. Microdissected invasive ductal carcinoma and intraductal papillary mucinous neoplasm (IPMN) cells expressed significantly higher levels of S100A6 than did microdissected pancreatitis-affected epithelial and normal cells (all comparison; P < 0.008). Median levels of S100A6 in invasive ductal carcinoma were higher than those in IPMN, and those in pancreatitis-affected epithelial cells tended to be higher than those in normal cells, although these differences were not statistically significant. In analyses of pancreatic juice, IPMN and pancreatic cancer samples expressed significantly higher levels of S100A6 than did chronic pancreatitis samples (both; P < 0.017), but levels in pancreatic cancer and IPMN samples did not differ form each other. Receiver operating characteristic (ROC) curve analysis revealed that measurement of S100A6 was useful for discriminating cancer (area under the ROC curve, 0.864) or IPMN (area under the ROC curve, 0.749) from chronic pancreatitis. The present data suggest that expression of S100A6 is increased in a stepwise manner during pancreatic carcinogenesis and may be a biomarker for evaluating malignant potential. Measurement of S100A6 in pancreatic juice may be useful to detect early pancreatic cancer or identify individuals with high-risk lesions that may progress to pancreatic cancer. (Cancer Epidemiol Biomarkers Prev 2007;16(4):649–54)

Sonic hedgehog is an early developmental marker of intraductal papillary mucinous neoplasms: clinical implications of mRNA levels in pancreatic juice.

Intraductal papillary mucinous neoplasms (IPMNs) are common cystic tumours of the pancreas. Sonic hedgehog (SHH) is involved in gastric epithelial differentiation and pancreatic carcinogenesis. However, a comprehensive analysis of SHH expression in IPMN has not yet been performed. In the present study, one‐step quantitative real‐time reverse transcription‐polymerase chain reaction with gene‐specific priming was used to examine mRNA levels in various types of clinical samples. SHH expression in IPMN was measured and the possible association of gastric epithelial differentiation with development of IPMN was evaluated. In bulk tissue analyses (IPMNs, 11 pancreatic cancer, and 20 normal pancreatic tissues), IPMN expressed significantly higher levels of SHH than did normal pancreas (IPMN versus normal pancreas, p = 0.0025; pancreatic cancer versus normal pancreas, p = 0.0132), but SHH expression did not differ between IPMN and pancreatic cancer (p = 0.3409). In microdissection analyses (infiltrating ductal carcinoma cells from 20 sections, IPMN cells from 20 sections, pancreatitis‐affected epithelial cells from 11 sections, and normal epithelial cells from 12 sections), IPMN cells expressed significantly higher levels of SHH than did cancer cells, normal cells, or pancreatitis‐affected ductal cells (all comparisons, p < 0.008). Pancreatic juice analyses (20 samples from pancreatic cancers, 31 samples from IPMNs, and 27 samples from chronic pancreatitis) revealed that SHH expression differed significantly between IPMN juice and pancreatitis juice (p < 0.0001), and between cancer juice and pancreatitis juice (p = 0.0125). Receiver operating characteristic curve analyses revealed that SHH measurement in pancreatic juice was useful for discriminating IPMN from chronic pancreatitis (area under the curve = 0.915; 95% confidence interval: 0.796–0.976). The data suggest that overexpression of SHH is an early event in the development of IPMN and that SHH measurement in pancreatic juice may provide some advantages for the treatment or follow‐up of a subset of patients with IPMN or chronic pancreatitis. Copyright

Quantitative analysis of MUC1 and MUC5AC mRNA in pancreatic juice for preoperative diagnosis of pancreatic cancer

Pancreatic juice is a promising type of diagnostic sample for pancreatic cancer, and members of the mucin (MUC) family are diagnostic candidates. To evaluate the utility of MUC family members as diagnostic markers, we measured MUC mRNA expression in pancreatic tissues and pancreatic juice obtained from patients with different pancreatic diseases as well as in pancreatic cancer cell lines by real‐time PCR. Furthermore, to support the possibility of early diagnosis by quantification of MUC1 and MUC5AC, immunohistochemistry and microdissection‐based quantitative analysis of mRNA were carried out. There was no significant correlation between MUC1 and MUC5AC expression in cell lines. When β‐actin was used as a reference gene, median MUC1 and MUC5AC mRNA expression levels were remarkably greater in tumoral tissues than in non‐tumoral tissues, but median MUC4 and MUC6 mRNA expression levels were not. Receiver operating characteristic curve analysis showed that quantitative analysis of MUC1 and MUC5AC mRNA in pancreatic juice is better diagnostic modality than that of MUC4 and MUC6 mRNA. Immunohistochemistry showed that MUC1 and MUC5AC were highly expressed in invasive ductal carcinomas (IDC) and moderately expressed in high‐grade pancreatic intraepithelial neoplasia (PanIN); no staining was observed in normal ducts. Analysis of cells isolated by microdissection showed stepwise upregulation of MUC1 and MUC5AC in the development of high‐grade PanIN to IDC. Our results suggest that MUC1 and MUC5AC are upregulated stepwise in pancreatic carcinogenesis and that quantitative assessment of MUC1 and MUC5AC mRNA in pancreatic juice has high potential for preoperative diagnosis of pancreatic cancer.