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Our objective was to explore alteration of the epidermal growth factor receptor (EGFR) signaling pathway in ampullary carcinoma. Immunohistochemical studies were employed to evaluate expression of amphiregulin as well as expression and activation of EGFR. A lab-developed assay was used to identify mutations in the EGFR pathway genes, including KRAS, BRAF, PIK3CA, PTEN, and AKT1. A total of 52 ampullary carcinomas were identified, including 25 intestinal-type and 24 pancreatobiliary-type tumors, with the intestinal type being associated with a younger age at diagnosis (P=0.03) and a better prognosis (P<0.01). Expression of amphiregulin correlated with better differentiation (P<0.01), but no difference was observed between two major histologic types. Expression and activation of EGFR was more commonly seen in the pancreatobiliary type (P<0.01). Mutations were detected in 50% of the pancreatobiliary type and 60% of the intestinal type. KRAS was the most common gene mutated in the pancreatobiliary type (42%) as well as the intestinal type (52%). Other mutations detected included PIK3CA, SMAD4 and BRAF. KRAS mutations at codons 12 and 13 did not adversely affect overall survival. In conclusion, EGFR expression and activation were different between intestinal- and pancreatobiliary-type ampullary carcinoma. KRAS mutation was common in both histologic types; however, the incidence appeared to be lower in the pancreatobiliary type compared with its pancreatic counterpart, pancreatic ductal adenocarcinoma. Mutational analysis of the EGFR pathway genes may provide important insights into personalized treatment for patients with ampullary carcinoma.
OBJECTIVE AND BACKGROUND - Morbidity, mortality, and length of hospital stay after pancreaticoduodenectomy (PD) have significantly decreased over recent decades. Despite this progress, early readmission rates after PD have been reported as high as 50%. Few reports have delineated factors associated with readmission after PD.
METHODS - The medical records of 6 high-volume institutions were reviewed for patients who underwent PD between 2005 and 2010. Data collection included patient characteristics, medical comorbidities, and perioperative factors. Analysis included readmissions up to 90 days after PD.
RESULTS - A total of 1302 patients underwent PD across all institutions. The 30-day and 90-day readmission rates were 15% and 19%, respectively. The most common reasons for 30-day readmission included infectious complications (n = 65) and delayed gastric emptying (n = 29). The most common reasons for readmission after 90 days included wound infections and intra-abdominal abscess (n = 75) and failure to thrive (n = 38). On multivariate analysis, factors associated with higher readmission rates included a preoperative diagnosis of chronic pancreatitis, higher transfusion requirements, and postoperative complications including intra-abdominal abscess and pancreatic fistula (all P < 0.02). Factors not associated with higher readmission rates included advanced age, body mass index, cardiovascular/pulmonary comorbidities, diabetes, steroid use, Whipple type (standard vs pylorus preserving PD), preoperative endobiliary stenting, and vascular reconstruction.
CONCLUSIONS - These multi-institutional data represent a large experience of PD without the biases typically of single center studies. Factors related to infection, nutritional status, and delayed gastric emptying were the most common reasons for readmission after PD. Postoperative complications including pancreatic fistula predicted higher rates of readmission.
Hepaticojejunostomy is a standard biliary reconstruction method for infantile living donor liver transplantation (LDLT), but choledochocholedochostomy for infants is not generally accepted yet. Ten pediatric recipients weighing no more than 10 kg underwent duct-to-duct choledochocholedochostomy (DD) for biliary reconstruction for LDLT. Patients were followed up for a median period of 26.8 months (range: 4.0-79.0 months). The incidence of posttransplant biliary complications for DD was compared with that for Roux-en-Y hepaticojejunostomy (RY). No DD patients and 1 RY patient (5%) developed biliary leakage (P > 0.05), and biliary stricture occurred in 1 DD patient (10%) and none of the RY patients (P > 0.05); none of the DD patients and 5 RY patients (25%) suffered from uncomplicated cholangitis after LDLT (P > 0.05), and 1 DD patient (10%) and 2 RY patients (10%) died of causes unrelated to biliary complications. In conclusion, both hepaticojejunostomy and choledochocholedochostomy resulted in satisfactory outcome in terms of biliary complications, including leakage and stricture, for recipients weighing no more than 10 kg.
Biliary complications following orthotopic liver transplantation have been reported in 10% to 30% of patients. Most surgeons perform an end-to-end choledochocholedochostomy with interrupted sutures for biliary reconstruction. The goal of this study was to compare biliary complications between interrupted suture (IS) and continuous suture (CS) techniques during liver transplantation in which an end-to-end choledochocholedochostomy over an internal biliary stent was performed. A retrospective cohort study of 100 consecutive liver transplants occurring between December 2003 and July 2005 was conducted. An end-to-end choledochocholedochostomy over an internal biliary stent was performed during liver transplantation. Data were analyzed using Kaplan-Meier methods, t tests, and chi-square tests of proportions. IS and CS techniques were used in 59 and 41 patients, respectively, for biliary reconstruction during liver transplantation. Mean follow-up time for the CS group was 17 +/- 8 months and 15 +/- 7 months for the IS group (P = .21). The overall biliary complication rate was 15%. There was no difference in the proportion of leaks (CS = 7.3%, IS = 8.5%; P = .83) or strictures (CS = 9.8%, IS = 5.1%; P = .37) between groups. Kaplan-Meier event rates show no difference in leaks (P = .79), strictures (P = .41), graft survival (P = .52), and patient survival (P = .32) by anastomosis type. In conclusion, there was no difference in biliary complications, graft survival, or patient survival between the 2 groups. CS and IS techniques for biliary reconstruction during liver transplantation yield comparable outcomes.
(c) 2007 AASLD.
BACKGROUND & AIMS - Pdx1 plays a pivotal role in pancreas organogenesis and specification of some types of cells in the duodenum and antral stomach. However, its expression is not restricted to pancreas, duodenum, and antral stomach but is also found in the common bile duct during embryogenesis. This study aimed to elucidate the role of Pdx1 in the development of the common bile duct, major duodenal papilla, and duodenum.
METHODS - Expression pattern of pdx1 during embryogenesis and the morphology of the common bile duct, major duodenal papilla, and duodenum in pdx1 null mice were analyzed.
RESULTS - The major duodenal papilla, peribiliary glands, and mucin-producing cells in the common bile duct were not formed in pdx1 null mice. Pdx1 null mice had shorter periampullary duodenal villi than wild-type mice at postnatal stages associated with reduced cell proliferation and increased apoptosis of the duodenal epithelial cells. Loss of the major duodenal papilla allowed duodeno-biliary reflux and bile infection, resulting in the formation of brown pigment biliary stones in pdx1 null mice, and antibiotics treatment significantly reduced the incidence of biliary stone formation.
CONCLUSIONS - Pdx1 is required for proper development of the major duodenal papilla, peribiliary glands, and mucin-producing cells in the common bile duct and for maintenance of the periampullary duodenal epithelial cells during perinatal period. Bile infection because of loss of the major duodenal papilla plays a significant role in the formation of brown pigment biliary stones in pdx1 null mice.
Bile leaks occur in up to 27 per cent of liver transplant patients after biliary reconstruction. Synthetic sealants have not been investigated for these biliary procedures. We performed a randomized controlled study to evaluate a novel absorbable polyethylene glycol/collagen biopolymer sealant (CT3 Surgical Sealant) after incomplete end-to-end choledochocholedochostomy (CDCD) in pigs. Pigs (n = 18) underwent transection of the common bile duct and incomplete CDCD over a T-tube, leaving a one-sixth circumferential defect anteriorly. Animals were randomly assigned to treatment (CDCD with sealant, n = 9) or control (no sealant, n = 9). Drains were used to monitor leak volume and bilirubin (bili) concentration. Cholangiography was performed on postoperative day 3. Leaks were defined as drain bili/serum bill > 3, total drain output > 10 mL/kg, and/or extravasation on cholangiography. Animals sacrificed at 3 and 8 weeks (n = 4 and n = 5 from each group, respectively) underwent pathologic examination of the CDCD site. Statistical methods included Student's t test, chi2, linear regression, and analysis of variance procedures. The control group had a higher drain output rate over the first 4 postoperative days than the treatment group (P < 0.05, analysis of variance). Five of nine (56%) control and one of nine (11%) treatment animals had a bile leak (P < 0.05, chi2). There was no major inflammatory response to the sealant versus controls. We conclude that CT3 is effective in decreasing biliary leaks in an incomplete CDCD porcine model with no major adverse pathologic changes. This sealant should be considered for trials for biliary reconstruction in humans.
Alterations in genes involved in cell cycle regulation are common in many tumor types. In pancreatic adenocarcinomas, inactivating mutations in the CDKN2 gene, encoding the cyclin-dependent kinase inhibitor p16, are frequently observed. CDKN2 mutations have also been identified in the germline of 50% of patients with hereditary melanoma. Interestingly, such patients also have an increased risk for pancreatic cancers. In melanoma-prone kindreds with CDKN2 wild-type status, a mutation in one of the targets of p16, cyclin-dependent kinase 4 (CDK4) was reported, which abolishes p16 inhibition. To test the possible involvement of CDK4 mutations in pancreatic carcinoma, we analyzed sequence alterations in the p16-binding domain of CDK4 in DNA isolated from 32 tumors in the head region of the pancreas. Alterations in the CDK4 region between codon 1 and codon 56 were not observed in any of the tumors. Our results do not support disruption of the p16 pathway through CDK4 mutation as an oncogenic mechanism in pancreatic head tumorigenesis.
BACKGROUND - Many patients with carcinoma of the pancreas die because their disease is not detected until late in its course. Methods that detect these cancers earlier will improve patient outcome. Over 80% of pancreatic carcinomas contain mutations in codon 12 of the K-ras gene. Screening duodenal fluid for these mutations may lead to early detection of these cancers and assist in establishing a diagnosis of pancreatic carcinoma.
METHODS - Polymerase chain reaction (PCR), with and without restriction enzyme-mediated mutant enrichment, was performed on DNA isolated from duodenal fluid specimens from 61 patients who underwent pancreaticoduodenectomy (Whipple's operation) for either periampullary cancer or a benign condition of the pancreas. Representative sections of pancreas pathology (primary carcinoma, benign tumor, or chronic pancreatitis) from the patients with duodenal fluid specimens containing amplifiable DNA were also analyzed for K-ras mutations. Wild-type and mutant K-ras were detected by hybridization of the PCR products with K-ras codon 12 mutant and wild-type specific probes.
RESULTS - Seven of the 61 duodenal fluid specimens contained DNA that did not amplify. Thirteen (24% of the 54 duodenal fluid specimens with amplifiable DNA and 21% of the total of 61 specimens) contained activating point mutations at codon 12 of the K-ras gene. Mutations were detected in 13 of the 51 duodenal fluid specimens from patients with cancer (sensitivity, 25%), whereas mutations were not detected in any of the 9 amplifiable duodenal fluid specimens from patients with benign conditions of the pancreas (specificity, 100%). One duodenal fluid specimen from a patient with adenocarcinoma of the pancreas had two different K-ras mutations. DNA from three of the primary carcinomas did not amplify or was not available. Twenty-nine (69%) of the 42 primary tumors with amplifiable DNA contained K-ras mutations, whereas 3 (30%) of the 10 pancreata with benign conditions harbored mutations. Twenty-two (65%) of 34 ductal adenocarcinomas of the pancreas with amplifiable DNA had K-ras mutations. It is noteworthy that the same mutation was present in both the duodenal fluid and the primary carcinomas of 11 (92%) of the 12 patients who had primary tumors with amplifiable DNA as well as K-ras mutations in their duodenal fluid specimens.
CONCLUSIONS - The identification of genetic alterations in cancer-causing genes in duodenal fluid may form the basis for the development of new approaches to the detection of carcinoma of the pancreas. Some pancreata without cancer, however, may also harbor K-ras mutations, potentially limiting the specificity of K-ras-based tests.
AIMS - To investigate the prevalence of K-ras codon 12 point mutations in ampullary neoplasms, to explore their clinical usefulness, and to test whether the detection of these mutations could be used to identify ampullary malignancies at an early stage.
METHODS - Forty one tumour specimens from 28 patients with ampullary neoplasms were analysed for activating point mutations in K-ras codon 12 using a sensitive polymerase chain reaction (PCR) based assay.
RESULTS - Eleven (39%) of the 28 primary tumours harboured point mutations in K-ras. Mutations were identified in seven (41%) of the 17 carcinomas and four (36%) of the 11 adenomas. Four of the possible six permutations in codon 12 were found in these 11 samples. This spectrum of mutations is different from pancreatic carcinoma but resembles that of colorectal neoplasms. Cytological brush specimens were available in 11 cases, and in all of these specimens, the K-ras status in the primary tumour and brush specimens was identical.
CONCLUSIONS - K-ras codon 12 point mutations occur in about 40% of ampullary neoplasms at a relatively early stage in tumorigenesis. The pattern of mutations in these tumours resembles that of the adenoma-carcinoma sequence in the colorectum. These results indicate that ampullary neoplasms can be detected at an early stage by searching for genetic alterations in the K-ras oncogene in cytological brush specimens.