The molecular genetics of pancreatic ductal carcinoma.

Pancreatic ductal carcinoma remains the 4th leading cause of cancer death in both men and women in the United States, with an overall 5-year survival of less than 3%. Over the last decade, significant advances have been made in our understanding of the molecular biology of pancreatic ductal carcinoma, with pancreatic cancer now considered one of the better characterized neoplasms at the genetic level. The advances in the understanding of the molecular genetics of pancreatic cancer initially focused on events that occur in the development and early genetic progression of the disease. This progression has been associated with the accumulation of multiple genetic alterations in various cancer-causing genes, leading to the development of a histological and genetic progression model. In the model, pancreatic cancer develops from non-invasive intraepithelial precursor lesions termed pancreatic intraepithelial neoplasias, with each progressive stage associated with accumulated mutations in oncogenes, tumor-suppressor genes, and mismatch repair genes. Other aspects of the development of pancreatic ductal carcinoma, such as tumor invasion, tumor-stromal interaction, metastasis, and chemotherapeutic resistance are more poorly understood. Recent studies utilizing global gene expression methodologies have provided insight into some of these processes and have allowed for the development of potential tumor markers which could be used for early detection and diagnosis of this difficult disease. In order to improve the survival of patients with pancreatic carcinoma, we need to better understand the fundamental changes that occur in pancreatic ductal carcinoma. The following article reviews the genetic mutations and syndromes known to be associated with pancreatic ductal carcinoma as well as recent advances in the study of global gene expression.

Intraductal papillary mucinous neoplasms of the pancreas: an increasingly recognized clinicopathologic entity.

OBJECTIVE: To assess the authors' experience with intraductal papillary mucinous neoplasms of the pancreas (IPMNs). SUMMARY BACKGROUND DATA: Intraductal papillary mucinous neoplasms of the pancreas are being recognized with increasing frequency. METHODS: All patients who underwent pancreatic resection for an IPMN at the Johns Hopkins Hospital between January 1987 and December 2000 were studied. The data were compared with those of 702 concurrent patients with infiltrating ductal adenocarcinoma of the pancreas not associated with an IPMN resected by pancreaticoduodenectomy. RESULTS: In the 13-year time period, 60 patients underwent pancreatic resection for IPMNs, with 40 patients undergoing resection in the past 3 years. Mean age at presentation was 67.4 +/- 1.4 years. The most common presenting symptom in patients with IPMNs was abdominal pain (59%). Most IPMNs were in the head of the pancreas or diffusely involved the gland, with 70% being resected via pancreaticoduodenectomy, 22% via total pancreatectomy, and 8% via distal pancreatectomy. Twenty-two patients (37%) had IPMNs with an associated infiltrating adenocarcinoma. In a subset of IPMNs immunohistochemically stained for the Dpc4 protein (n = 50), all of the intraductal or noninvasive components strongly expressed Dpc4, whereas 84% of associated infiltrating cancers expressed Dpc4. The 5-year survival rate for all patients with IPMNs (n = 60) was 57%. CONCLUSION: Intraductal papillary mucinous neoplasms represent a distinct clinicopathologic entity being recognized with increasing frequency. IPMNs are clinically, histologically, and genetically disparate from pancreatic ductal adenocarcinomas. The distinct clinical features, the presumably long in situ or noninvasive phase, and the good long-term survival of patients with IPMNs offer a unique opportunity for early diagnosis, curative resection, and further studies of the molecular genetics and natural history of these unusual neoplasms.

Differing rates of loss of DPC4 expression and of p53 overexpression among carcinomas of the proximal and distal bile ducts.

BACKGROUND: Biliary tract carcinomas are clinically heterogeneous. It is not known if molecular heterogeneity underlies the clinical differences. METHODS: The authors evaluated 128 bile duct carcinomas, 88 of the distal common bile duct and 40 of more proximal origin (28 perihilar carcinomas, 12 intrahepatic carcinomas), immunohistochemically for abnormalities in the expression of the products of the DPC4 and p53 tumor-suppressor genes. Prognostic factors were evaluated in the series of distal bile duct carcinomas for which follow-up information was available. RESULTS: The authors found that a significantly higher percentage of distal bile duct carcinomas (55%) demonstrated loss of DPC4 expression than did the proximal bile duct carcinomas (15%; P < 0.001). They also found that a significantly higher percentage of the distal tumors abnormally expressed the p53 gene product (51% vs. 26%; P < 0.001). Among the distal common bile duct carcinomas, the presence of poorly differentiated histology correlated with decreased survival in multivariate analysis, while labeling for p53 or Dpc4, margin status, lymph node status, and tumor dimension did not correlate significantly with survival. CONCLUSIONS: These results demonstrate that abnormalities in DPC4 and p53 gene expression are frequent in distal common bile duct carcinomas, just as they are in pancreatic ductal adenocarcinoma, suggesting that these two tumor types might share a similar molecular pathogenesis. They also show that proximal and distal bile duct carcinomas have different patterns of inactivation of tumor-suppressor genes, indicating that they often arise through different molecular mechanisms likely reflecting their differing etiologies.

High-throughput drug screening of the DPC4 tumor-suppressor pathway in human pancreatic cancer cells.

OBJECTIVE: To screen a library of small chemicals for compounds that activate the DPC4 signal transduction pathway in a human pancreatic cancer cell line. SUMMARY BACKGROUND DATA: Various tumor-suppressor genes are mutated in all human cancers. Specifically, DPC4 (deleted in pancreatic carcinoma, locus 4 or MADH4/SMAD4) is a tumor-suppressor gene mutated in approximately 50% of human pancreatic adenocarcinomas. DPC4 plays an important role in the well-studied transforming growth factor-beta (TGFbeta) signaling pathway. It would be useful to identify therapies that augment or restore the downstream functions of this critical signal transduction pathway, in hopes that such therapy would have a rational role in anticancer therapy. METHODS: Using a commercially available plasmid vector with a luciferase reporter gene already incorporated, a DPC4-specific reporter construct was genetically engineered. This was done by inserting six copies of the palindromic Smad binding element (6SBE), which is a DNA binding element specific for DPC4, in front of the minimal promoter in the plasmid. This construct was then stably integrated into the genome of a human pancreatic cancer cell line (PANC-1) that has wild-type DPC4. Several stably transfected clones were tested for basal luciferase expression and inducibility with TGFbeta, which is known to activate the DPC4 signal transduction pathway. A single transfected clone was chosen for the drug screen based on basal luciferase (reporter) expression and TGFbeta inducibility. A systematic screen of the chemical library was then performed, using luciferase activity to detect DPC4 activity and induction of the signaling pathway. RESULTS: A high-throughput system based on this stably integrated reporter system was used to screen a library of 16,320 random compounds to identify agents that conferred robust augmentation of the DPC4 signal transduction pathway. Of the 16,320 compounds screened, 11 were associated with a 2- to 5-fold induction of luciferase activity, and one with a 12-fold activation. The latter compound was shown to be a novel histone deacetylase inhibitor and was further characterized. CONCLUSIONS: These results confirm the feasibility of a specific high-throughput reporter system to screen a large compound library in human cells efficiently. The screening identified several compounds capable of augmenting DPC4-specific luciferase reporter activity, and a specific mechanism for one compound was identified. The discovery of such agents will aid our understanding of complex tumor-suppressive signaling pathways and may identify other potential therapeutic targets within this critical signaling pathway. In addition, random drug screening provides an unbiased method for identifying drugs or lead compounds for potential therapeutic use.

Randomized prospective evaluation of frozen-section analysis for follicular neoplasms of the thyroid.

OBJECTIVE: To evaluate the clinical utility of frozen section in patients with follicular neoplasms of the thyroid in a randomized prospective trial. SUMMARY BACKGROUND DATA: The finding of a follicular neoplasm on fine-needle aspiration prompts many surgeons to perform intraoperative frozen section during thyroid lobectomy. However, the focal distribution of key diagnostic features of malignancy contributes to a high rate of noninformative frozen sections. METHODS: The series comprised 68 consecutive patients with a solitary thyroid nodule in whom fine-needle aspiration showed a follicular neoplasm. Patients were excluded for bilateral or nodal disease, extrathyroidal extension, or a definitive fine-needle aspiration diagnosis. Final pathologic findings were compared with frozen sections, and cost analyses were performed. RESULTS: Sixty-one patients met the inclusion criteria. Twenty-nine were randomized to the frozen-section group and 32 to the non-frozen-section group. In the non-frozen-section group, one patient was excluded when gross examination of the specimen was suggestive of malignancy and a directed frozen section was diagnostic of follicular carcinoma. Frozen-section analysis rendered a definitive diagnosis of malignancy in 1 of 29 (3.4%) patients, who then underwent a one-stage total thyroidectomy. In the remaining 28 patients, frozen section showed a "follicular or Hürthle cell neoplasm." Permanent histology demonstrated well-differentiated thyroid cancer in 6 of these 28 patients (21%). Of the 31 patients in the non-frozen-section group, 3 (10%) showed well-differentiated thyroid carcinoma on permanent histology. Complications were limited to one transient unilateral vocal cord dysfunction. All but one patient had a 1-day hospital stay. There were no significant differences between the groups in surgical time or total hospital charges; however, the charge per informative frozen section was approximately $12,470. CONCLUSIONS: For the vast majority of patients (96.4%) with follicular neoplasms of the thyroid, frozen section is neither informative nor cost-effective.

Renal cell carcinoma metastatic to the pancreas: results of surgical management.

Metastatic tumors to the pancreas are uncommon. Renal cell carcinoma is one of the few tumors known to metastasize to the pancreas. The purpose of the current report is to evaluate the surgical management and long-term outcome of patients with metastatic renal cell carcinoma. A retrospective review of patients undergoing pancreatic resection for renal cell carcinomas metastatic to the pancreas or periampullary region between April 1989 and May 1999, inclusive, was performed. Time from initial presentation, other metastatic sites, surgical outcomes, and long-term survival were evaluated. During the 10-year time period, 10 patients underwent pancreatic resection for renal cell carcinoma metastases. Of those, six underwent pancreaticoduodenectomy and two underwent distal pancreatectomy, whereas the two remaining patients underwent total pancreatectomy for extensive tumor involvement throughout the entire gland. The mean time from nephrectomy for resection of the primary tumor to reoperation for periampullary recurrence was 9.8 years (median 8.5 years). The range was 0 to 28 years, with one patient presenting with a synchronous metastasis. The mean age of the patients was 61.2 years with 60% of patients being male and 90% being white. Pathologic findings included histologically negative lymph nodes and negative surgical margins in all patients. One patient had tumor involving the retroperitoneal soft tissue, but final margins were negative. The mean live patient follow-up was 30 months (median = 15 months), with eight patients remaining alive. The Kaplan-Meier actuarial 5-year survival was 75%, with the longest survivor still alive 117 months following resection. The patient with retroperitoneal soft tissue involvement died 4 months after resection. The pancreas is an uncommon site of metastasis for renal cell carcinoma, typically occurring years after treatment of the primary tumor. When the metastatic focus is isolated and the tumor can be resected in its entirety, patients can experience excellent 5-year survival rates. The current report suggests that pancreatic metastases from renal cell carcinoma should be managed aggressively with complete resection when possible.

Immunohistochemical labeling for the Dpc4 gene product is a specific marker for adenocarcinoma in biopsy specimens of the pancreas and bile duct.

We immunohistochemically labeled 72 biopsy specimens from the extrahepatic biliary tree and pancreas for Dpc4 protein and correlated expression with histologic diagnosis and patient follow-up. Specimens were classified histologically as follows: nonneoplastic, 35; neoplastic, 22; atypical, 15. Loss of expression of Dpc4 protein was identified in 12 specimens; 11 were histologically diagnostic of carcinoma. The 12th specimen was from a patient whose biopsy specimen initially was diagnosed as "atypical," but clinical follow-up revealed adenocarcinoma. Of the 12 atypical biopsy specimens with intact expression for Dpc4, follow-up later revealed that 10 were adenocarcinoma. Loss of expression of Dpc4 protein was never identified in a benign specimen. Immunohistochemical labeling for the Dpc4 gene product is a specific marker of carcinoma in biopsy specimens of the pancreas and extrahepatic bile ducts and is marginally helpful in classifying atypical specimens. The sensitivity for carcinoma is low. This latter finding is not unexpected, because the DPC4 tumor suppressor gene is inactivated in only about half of pancreatic and biliary malignant neoplasms. Importantly, loss of Dpc4 expression has been reported in in situ carcinomas, suggesting that loss of expression should not be equated with invasive carcinoma.

Quality of life and long-term survival after surgery for chronic pancreatitis.

The objective of this study was to evaluate the short-term and long-term outcome as well as quality of life in patients undergoing surgical management of chronic pancreatitis. Between January 1980 and December 1996, a total of 255 patients underwent surgery for chronic pancreatitis at The Johns Hopkins Hospital. The etiology of the disease, indications for surgery, patient characteristics, and long-term survival were analyzed. A visual analog quality-of-life questionnaire containing 23 items graded on a scale of 0 to 10 (0 = worst and 10 = best) was sent to patients postoperatively. Visual analog responses relating to before and after the chronic pancreatitis surgery were compared using a paired t test. During the17-year review period, 263 operations were performed for chronic pancreatitis in 255 patients. The most common presenting symptoms were abdominal pain (88%), weight loss (36%), nausea/vomiting (30%), jaundice (14%), and diarrhea (12%). The cause of the pancreatitis was resumed to be alcohol in 43%, idiopathic in 38%, pancreas divisum in 5%, ampullary abnormality in 4%, and gallstones in 3%. Pancreaticoduodenectomy was the most common procedure in 96 patients (37%), followed by distal pancreatectomy in 67 (25%), Puestow procedure in 52 (19%), sphincteroplasty in 37 (14%), and Duval procedure in five (2%). The overall mortality and morbidity rates were 1.9% and 35%, respectively. Two hundred twenty-seven (89%) of the 255 patients were alive at last follow-up. For the entire cohort of patients, the 5- and 10-year actuarial survivals were 88% and 82%, respectively. One hundred six (47%) of the 227 living patients responded to the visual analog quality-of-life questionnaire. Patients reported improvements in all aspects of the quality-of-life survey including enjoyment out of life, satisfaction with life, pain, number of hospitalizations, feelings of usefulness, and overall health (P < 0.005). In addition to improved quality of life after surgery, narcotic use was decreased (41% vs. 21%, P < 0.01) and alcohol use was decreased (59% vs. 33%, P < 0.001). However, patients often became insulin-dependent diabetics (12% vs. 41%, P < 0.0001) and required pancreatic enzyme supplementation (34% vs. 55%, P < 0.01) after surgical intervention. These data suggest that surgery for patients with chronic pancreatitis can be performed safely with minimal morbidity and excellent long-term survival. Moreover, this study evaluates quality of life in a standardized analog fashion, with highly significant improvement reported in all quality-of-life measures. We conclude that surgery remains an excellent option for patients with chronic pancreatitis.

Dpc-4 protein is expressed in virtually all human intraductal papillary mucinous neoplasms of the pancreas: comparison with conventional ductal adenocarcinomas.

DPC4 (MADH4, SMAD4) encodes a nuclear transcription factor shown to be genetically inactivated in over one-half of conventional infiltrating ductal adenocarcinomas of the pancreas. Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas have been suggested to be distinct neoplasms with a significantly less aggressive course than conventional ductal adenocarcinomas of the pancreas, but molecular comparisons of these tumor types have previously been impaired by technical difficulties. Recently, immunohistochemical labeling for the DPC4 gene product has been shown to be an extremely sensitive and specific marker for DPC4 gene alterations in pancreatic adenocarcinomas. Therefore, we analyzed the immunohistochemical expression of Dpc4 protein in 79 IPMNs using a previously characterized monoclonal antibody. Twenty-nine of the IPMNs also had an associated infiltrating adenocarcinoma available for analysis. The labeling patterns observed were compared to those we have previously reported for conventional ductal carcinomas. All 79 of the intraductal components of the IPMNs strongly expressed Dpc4 protein. In 77 of the 79 cases (97%), the labeling was diffusely positive, and in 2 of the 79 (3%) the labeling was focally positive. Dpc4 expression was seen in 28 (97%) of the associated 29 invasive cancers. The one infiltrating carcinoma that showed loss of Dpc4 expression was associated with an intraductal component which showed focal loss of Dpc4 expression. The strong and almost universal expression of Dpc4 in IPMNs contrasts sharply with the loss of Dpc4 expression seen in approximately 30% of in situ adenocarcinomas of the pancreas (so-called pancreatic intraepithelial neoplasms, grade 3; P: < 0.001) and in 55% of pancreatic duct carcinomas (P: < 0.0001). Differences in Dpc4 expression between IPMNs and ductal carcinomas suggest a fundamental genetic difference in tumorigenesis, which may relate to the significantly better clinical outcomes observed for IPMNs.

Does prophylactic octreotide decrease the rates of pancreatic fistula and other complications after pancreaticoduodenectomy? Results of a prospective randomized placebo-controlled trial.

OBJECTIVE: To evaluate the endpoints of complications (specifically pancreatic fistula and total complications) and death in patients undergoing pancreaticoduodenectomy. SUMMARY BACKGROUND DATA: Four randomized, placebo-controlled, multicenter trials from Europe have evaluated prophylactic octreotide (the long-acting synthetic analog of native somatostatin) in patients undergoing pancreatic resection. Each trial reported significant decreases in overall complication rates, and two of the four reported significantly lowered rates of pancreatic fistula in patients receiving prophylactic octreotide. However, none of these four trials studied only pancreaticoduodenal resections, and all trials had high pancreatic fistula rates (>19%) in the placebo group. A fifth randomized trial from the United States evaluated the use of prophylactic octreotide in patients undergoing pancreaticoduodenectomy and found no benefit to the use of octreotide. Prophylactic use of octreotide adds more than $75 to the daily hospital charge in the United States. In calendar year 1996, 288 patients received octreotide on the surgical service at the authors' institution, for total billed charges of $74,652. METHODS: Between February 1998 and February 2000, 383 patients were recruited into this study on the basis of preoperative anticipation of pancreaticoduodenal resection. Patients who gave consent were randomized to saline control versus octreotide 250 microg subcutaneously every 8 hours for 7 days, to start 1 to 2 hours before surgery. The primary postoperative endpoints were pancreatic fistula, total complications, death, and length of hospital stay. RESULTS: Two hundred eleven patients underwent pancreaticoduodenectomy with pancreatic-enteric anastomosis, received appropriate saline/octreotide doses, and were available for endpoint analysis. The two groups were comparable with respect to demographics (54% male, median age 66 years), type of pancreaticoduodenal resection (60% pylorus-preserving), type of pancreatic-enteric anastomosis (87% end-to-side pancreaticojejunostomy), and pathologic diagnosis. The pancreatic fistula rates were 9% in the control group and 11% in the octreotide group. The overall complication rates were 34% in the control group and 40% in the octreotide group; the in-hospital death rates were 0% versus 1%, respectively. The median postoperative length of hospital stay was 9 days in both groups. CONCLUSIONS: These data demonstrate that the prophylactic use of perioperative octreotide does not reduce the incidence of pancreatic fistula or total complications after pancreaticoduodenectomy. Prophylactic octreotide use in this setting should be eliminated, at a considerable cost savings.

A novel histone deacetylase inhibitor identified by high-throughput transcriptional screening of a compound library.

Libraries of compounds are increasingly becoming commercially available for the use of individual academic laboratories. A high-throughput system based on a stably integrated transcriptional reporter was used to screen a library of random compounds to identify agents that conferred robust augmentation of a signal transduction pathway. A novel histone deacetylase (HDAC) inhibitor, termed scriptaid, conferred the greatest effect, a 12- to 18-fold augmentation. This facilitation of transcriptional events was generally applicable to exogenous gene constructs, including viral and cellular promoters, different cell lines and reporter genes, and stably integrated and transiently introduced sequences. Scriptaid did not interfere with a further induction provided by stimulation of the cognate signal transduction pathway (transforming growth factor beta/Smad4), which implied the functional independence of ligand-stimulated transcriptional activation and histone acetylation states in this system. Additional insights into this and other signal transduction systems are likely to be afforded through the application of compound screening technologies.

Genetic, immunohistochemical, and clinical features of medullary carcinoma of the pancreas: A newly described and characterized entity.

Medullary carcinomas of the pancreas are a recently described, histologically distinct subset of poorly differentiated adenocarcinomas that may have a unique pathogenesis and clinical course. To further evaluate these neoplasms, we studied genetic, pathological, and clinical features of 13 newly identified medullary carcinomas of the pancreas. Nine (69%) of these had wild-type K-ras genes, and one had microsatellite instability (MSI). This MSI medullary carcinoma, along with three previously reported MSI medullary carcinomas, were examined immunohistochemically for Mlh1 and Msh2 expression, and all four expressed Msh2 but did not express Mlh1. In contrast, all of the medullary carcinomas without MSI expressed both Msh2 and Mlh1. Remarkably, the MSI medullary carcinoma of the pancreas in the present series arose in a patient with a synchronous but histologically distinct cecal carcinoma that also had MSI and did not express Mlh1. The synchronous occurrence of two MSI carcinomas suggests an inherited basis for the development of these carcinomas. Indeed, the medullary phenotype, irrespective of MSI, was highly associated with a family history of cancer in first-degree relatives (P < 0.001). Finally, one medullary carcinoma with lymphoepithelioma-like features contained Epstein-Barr virus-encoded RNA-1 by in situ hybridization. Therefore, because of medullary carcinoma's special genetic, immunohistochemical, and clinical features, recognition of the medullary variant of pancreatic adenocarcinoma is important. Only by classifying medullary carcinoma as special subset of adenocarcinoma can we hope to further elucidate its unique pathogenesis.

Quality of life and outcomes after pancreaticoduodenectomy.

OBJECTIVE: To assess the quality of life (QOL) and functional outcome of patients after pancreaticoduodenectomy. SUMMARY BACKGROUND DATA: Pancreaticoduodenectomy is gaining acceptance and is being performed in increasing numbers for various malignant and benign diseases of the pancreas and periampullary region. There is a general impression that pancreaticoduodenectomy can severely impair QOL and alter normal activities. Only a few small studies have evaluated QOL after pancreaticoduodenectomy. METHODS: A standard QOL questionnaire was sent to 323 patients surviving pancreaticoduodenectomy who had undergone surgery at The Johns Hopkins Hospital between 1981 and 1997. Thirty items on a visual analog scale were categorized into three domains: physical (15 items), psychological (10 items), and social (5 items). Scores are reported as a percentile, with 100% being the highest possible score. The same QOL questionnaire was also sent to laparoscopic cholecystectomy patients and healthy controls. A separate component of the questionnaire asked about functional outcomes and disabilities. RESULTS: Overall QOL scores for the 192 responding pancreaticoduodenectomy patients in the three domains (physical, psychological, social) were 78%, 79%, and 81%, respectively. These QOL scores were comparable to those of the 37 laparoscopic cholecystectomy patients and the 31 healthy controls. The pancreaticoduodenectomy patients were subgrouped into chronic pancreatitis, other benign disease, pancreatic adenocarcinoma, and other cancers. Patients who underwent resection for chronic pancreatitis and pancreatic adenocarcinoma had significantly lower QOL scores in the physical and psychological domains compared with the laparoscopic cholecystectomy patients and the healthy controls. Common problems after pancreaticoduodenectomy were weight loss, abdominal pain, fatigue, foul stools, and diabetes. CONCLUSIONS: This is the largest single-institution experience assessing QOL after pancreaticoduodenectomy. These data demonstrate that as a group, patients who survive pancreaticoduodenectomy have near-normal QOL scores. Many patients report weight loss and symptoms consistent with pancreatic exocrine and endocrine insufficiency. Most patients have QOL scores comparable to those of control patients and can function independently in daily activities.

Do preoperative biliary stents increase postpancreaticoduodenectomy complications?

It has been suggested that the placement of endoscopic or percutaneous biliary stents prior to pancreaticoduodenectomy increases postoperative morbidity. A retrospective review of a prospectively collected database was performed. Patients undergoing preoperative biliary stenting were compared with patients who did not undergo stenting. In addition, outcomes after endoscopic and percutaneous stenting were compared. Patients who had undergone operative biliary bypass prior to pancreaticoduodenectomy were excluded from the analysis. Between January 1994 and December 1997, 567 patients underwent pancreaticoduodenectomy without prior operative biliary bypass. Preoperative biliary stenting was performed in 408 patients (72%), whereas the remaining 159 patients (28%) did not undergo biliary stenting. In the stented group, 64% had stents placed via a percutaneous approach and 36% had stents placed endoscopically. The stented patients were older (mean 63.1 years vs. 61.4 years; P = 0.05) and were more likely to be white (92% vs. 82%; P = 0.005). Those who had stents placed were more likely to have jaundice (67% vs. 38%; P <0.0001) and fever (5% vs. 1%; P = 0.03) as presenting symptoms. There were no differences in multiple intraoperative parameters when the two groups were compared. Patients who had stents placed had a perioperative mortality rate of 1.7% compared to 2.5% in those who did not (P = 0.3). Although the overall complication rates were 35% in those who had stents placed and 30% in those who did not (P = NS), patients with stents experienced a significantly increased incidence of pancreatic fistula (10% vs. 4%; P = 0.02) and wound infection (10% vs. 4%; P = 0.02). The incidences of other postoperative complications were similar between the stented and unstented groups. Eight patients (3%) in the percutaneously stented group developed significant hemobilia after stent placement, whereas none of the patients undergoing endoscopic stent placement developed hemobilia (P = 0.03). There were no statistical differences in other complications between the percutaneously and endoscopically stented groups. Preoperative biliary stenting did not increase the overall complication rate or mortality rate in patients undergoing pancreaticoduodenectomy. Stenting does appear to increase the rate of pancreatic fistula formation, possibly as a result of pancreatic inflammation related to the stenting procedure. Stenting also increases the rate of wound infection, likely secondary to contaminated bile (bactibilia) after instrumentation of the biliary tree. Preoperative biliary stenting is safe but should be used selectively because of the above-mentioned risks. The method of stenting should be based on local expertise.

Immunohistochemical labeling for dpc4 mirrors genetic status in pancreatic adenocarcinomas : a new marker of DPC4 inactivation.

DPC4 (MADH4, SMAD4) is a tumor suppressor gene inactivated by allelic loss in approximately 55% of pancreatic adenocarcinomas. Unfortunately, it can be technically very difficult to detect the inactivation of DPC4 at the genetic level because genetic analyses require the microdissection of relatively pure samples of neoplastic and normal tissues. This is especially true for pancreatic adenocarcinomas, which elicit vigorous, non-neoplastic, stromal responses. Immunohistochemical labeling can overcome this hurdle because it preserves morphological information. We therefore studied the expression of the DPC4 gene product in 46 cancers, including 5 cancer cell lines by Western blot analysis and 41 primary periampullary adenocarcinomas by immunohistochemistry. The status of exons 1-11 of the DPC4 gene in all 46 of the cancers had been previously characterized at the molecular level, allowing us to correlate Dpc4 expression directly with gene status. Three cell lines had wild-type DPC4 genes, and Dpc4 expression was detected in all three by Western blot. The two cell lines with homozygously deleted DPC4 genes did not show Dpc4 protein by Western blot analysis. Immunohistochemical labeling revealed that 17 (94%) of the 18 primary adenocarcinomas with wild-type DPC4 genes expressed the DPC4 gene product, whereas 21 (91%) of 23 primary adenocarcinomas with inactivated DPC4 genes did not. Cases in which there was discordance between the immunohistochemical labeling and the genetic analyses were reanalyzed genetically, and we identified a deletion in exon 0 of DPC4 in one of these cases. This is the first report of a mutation in exon 0 of DPC4 in a pancreatic cancer. The contrast between the strong expression of Dpc4 by normal tissues and the loss of expression in the carcinomas was highlighted in several cases in which an infiltrating cancer was identified growing into a benign duct. These observations suggest that immunohistochemical labeling for the DPC4 gene product is an extremely sensitive and specific marker for DPC4 gene alterations in pancreatic carcinomas. The sensitivity and specificity of immunohistochemical labeling for Dpc4 in other periampullary carcinomas has yet to be determined.

The molecular genetics of pancreatic ductal carcinoma: a review.

In the last several years, numerous advances in the field of molecular genetics have been applied to pancreatic ductal carcinoma- the 5th leading cause of cancer death in the United States. This review summaries the current knowledge about adenocarcinoma of the pancreas.

Resected adenocarcinoma of the pancreas-616 patients: results, outcomes, and prognostic indicators.

This large-volume, single-institution review examines factors influencing long-term survival after resection in patients with adenocarcinoma of the head, neck, uncinate process, body, or tail of the pancreas. Between January 1984 and July 1999 inclusive, 616 patients with adenocarcinoma of the pancreas underwent surgical resection. A retrospective analysis of a prospectively collected database was performed. Both univariate and multivariate models were used to determine the factors influencing survival. Of the 616 patients, 526 (85%) underwent pancreaticoduodenectomy for adenocarcinoma of the head, neck, or uncinate process of the pancreas, 52 (9%) underwent distal pancreatectomy for adenocarcinoma of the body or tail, and 38 (6%) underwent total pancreatectomy for adenocarcinoma extensively involving the gland. The mean age of the patients was 64.3 years, with 54% being male and 91% being white. The overall perioperative mortality rate was 2.3%, whereas the incidence of postoperative complications was 30%. The median postoperative length of stay was 11 days. The mean tumor diameter was 3.2 cm, with 72% of patients having positive lymph nodes, 30% having positive resection margins, and 36% having poorly differentiated tumors. Patients undergoing distal pancreatectomy for left-sided lesions had larger tumors (4.7 vs. 3.1 cm, P < 0.0001), but fewer node-positive resections (59% vs. 73%, P = 0.03) and fewer poorly differentiated tumors (29% vs. 36%, P < 0.001), as compared to those undergoing pancreaticoduodenectomy for right-sided lesions. The overall survival of the entire cohort was 63% at 1 year and 17% at 5 years, with a median survival of 17 months. For right-sided lesions the 1- and 5-year survival rates were 64% and 17%, respectively, compared to 50% and 15% for left-sided lesions. Factors shown to have favorable independent prognostic significance by multivariate analysis were negative resection margins (hazard ratio [HR] = 0.64, confidence interval [CI] = 0.50 to 0.82, P = 0.0004), tumor diameter less than 3 cm (HR = 0.72, CI = 0.57 to 0.90, P = 0.004), estimated blood loss less than 750 ml (HR = 0.75, CI = 0.58 to 0.96, P = 0.02), well/moderate tumor differentiation (HR = 0.71, CI = 0.56 to 0.90, P = 0.005), and postoperative chemoradiation (HR = 0.50, CI = 0.39 to 0.64, P < 0.0001). Tumor location in head, neck, or uncinate process approached significance in the final multivariate model (HR = 0.60, CI = 0.35 to 1.0, P = 0.06). Pancreatic resection remains the only hope for long-term survival in patients with adenocarcinoma of the pancreas. Completeness of resection and tumor characteristics including tumor size and degree of differentiation are important independent prognostic indicators. Adjuvant chemoradiation is a strong predictor of outcome and likely decreases the independent significance of tumor location and nodal status.

Is prophylactic gastrojejunostomy indicated for unresectable periampullary cancer? A prospective randomized trial.

OBJECTIVE: This prospective, randomized, single-institution trial was designed to evaluate the role of prophylactic gastrojejunostomy in patients found at exploratory laparotomy to have unresectable periampullary carcinoma. SUMMARY BACKGROUND DATA: Between 25% and 75% of patients with periampullary cancer who undergo exploratory surgery with intent to perform a pancreaticoduodenectomy are found to have unresectable disease. Most will undergo a biliary-enteric bypass. Whether or not to perform a prophylactic gastrojejunostomy remains unresolved. Retrospective reviews of surgical series and prospective randomized trials of endoscopic palliation have demonstrated that late gastric outlet obstruction, requiring a gastrojejunostomy, develops in 10% to 20% of patients with unresectable periampullary cancer. METHODS: Between May 1994 and October 1998, 194 patients with a periampullary malignancy underwent exploratory surgery with the purpose of performing a pancreaticoduodenectomy and were found to have unresectable disease. On the basis of preoperative symptoms, radiologic studies, or surgical findings, the surgeon determined that gastric outlet obstruction was a significant risk in 107 and performed a gastrojejunostomy. The remaining 87 patients were thought by the surgeon not to be at significant risk for duodenal obstruction and were randomized to receive either a prophylactic retrocolic gastrojejunostomy or no gastrojejunostomy. Short- and long-term outcomes were determined in all patients. RESULTS: Of the 87 patients randomized, 44 patients underwent a retrocolic gastrojejunostomy and 43 did not undergo a gastric bypass. The two groups were similar with respect to age, gender, procedure performed (excluding gastrojejunostomy), and surgical findings. There were no postoperative deaths in either group, and the postoperative morbidity rates were comparable (gastrojejunostomy 32%, no gastrojejunostomy 33%). The postoperative length of stay was 8.5+/-0.5 days for the gastrojejunostomy group and 8.0+/-0.5 days for the no gastrojejunostomy group. Mean survival among those who received a prophylactic gastrojejunostomy was 8.3 months, and during that interval gastric outlet obstruction developed in none of the 44 patients. Mean survival among those who did not have a prophylactic gastrojejunostomy was 8.3 months. In 8 of those 43 patients (19%), late gastric outlet obstruction developed, requiring therapeutic intervention (gastrojejunostomy 7 patients, endoscopic duodenal stent 1 patient; p < 0.01). The median time between initial exploration and therapeutic intervention was 2 months. CONCLUSION: The results from this prospective, randomized trial demonstrate that prophylactic gastrojejunostomy significantly decreases the incidence of late gastric outlet obstruction. The performance of a prophylactic retrocolic gastrojejunostomy at the initial surgical procedure does not increase the incidence of postoperative complications or extend the length of stay. A retrocolic gastrojejunostomy should be performed routinely when a patient is undergoing surgical palliation for unresectable periampullary carcinoma.

Intensified adjuvant therapy for pancreatic and periampullary adenocarcinoma: survival results and observations regarding patterns of failure, radiotherapy dose and CA19-9 levels.

PURPOSE: Primary endpoints were 1. To determine if, in the context of postoperative adjuvant therapy of pancreatic and nonpancreatic periampullary adenocarcinoma, continuous infusion (C.I.) 5-fluorouracil (5-FU) and leucovorin (Lv), combined with continuous-course external-beam radiotherapy (EBRT) to liver (23.4-27.0 Gy), regional lymph nodes (50.4-54.0 Gy) and tumor bed (50.4-57.6 Gy), followed by 4 months of C.I. 5-FU/Lv without EBRT could be given with acceptable toxicity. 2. To determine an estimate of disease-free and overall survival (DFS, OS) with this treatment in this context. Secondary endpoints were 1. To observe the effects of therapy at two different dose levels of irradiation, and 2. To observe for correlations among DFS, OS and CA 19-9 levels during therapy. METHODS: Patients received C.I. 5-FU 200 mg/m2 and Lv 5 mg/m2 Monday through Friday during EBRT, and 4 cycles of the same chemotherapy without EBRT were planned for each 2 weeks of 4, beginning 1 month following the completion of EBRT. Therapy was to begin within 10 weeks of surgery and patients were monitored for disease recurrence, toxicity, and CA 19-9 levels before the start of EBRT/5-FU/Lv, before each cycle of C.I. 5-FU/Lv, and periodically after the completion of therapy. There were two EBRT dosage groups: Low EBRT, 23.4 Gy to the whole liver, 50.4 Gy to regional nodes and 50.4 Gy to the tumor bed; High EBRT, 27.0 Gy to the whole liver, 54.0 Gy to regional nodes, and 57.6 Gy to the tumor bed. RESULTS: 29 patients were enrolled and treated (23 with pancreatic cancer, and 6 with nonpancreatic periampullary cancer). Of these, 18 had tumor sizes > or = 3 cm and 23 had at least one histologically involved lymph node; 6 had histologically positive resection margins. Mean time to start of EBRT/5-FU/Lv was 53 +/- 2 days following surgery. The first 18 patients were in the Low EBRT Group and the last 11 in the High EBRT Group. Toxicity was moderate and manageable, including a possible case of late radiation hepatitis. Median DFS was 8.3 months (pancreatic cancer patients 8.5 months) and OS was 14.1 months (pancreatic cancer patients 15.9 months). Among patients with pancreatic cancer, results were similar for the Low and High EBRT Groups (DFS: 8.3 vs. 8.6 months; OS: 14.4 vs. 16.9 months, respectively). With a mean follow up of 2.6 +/- 0.3 years for the surviving patients and a minimal follow-up of 2.5 years, 27 of 29 pts have relapsed and 25 pts have died. A rise in CA 19-9 levels preceded clinical relapse by 9.1 +/- 1.5 months. Time to first relapse by site showed inverse correlation with dose of radiotherapy to that site: peritoneal (5 +/- 1 month), hepatic (7 +/- 0.9 months), regional nodes/tumor bed (9.6 +/- 1.8 months). Mean postresection CA 19-9 level was 63.3 +/- 16.2 U/ml. Postresection CA 19-9 values did not correlate with survival, margin status, or with the identification of metastatic carcinoma in resected lymph nodes. However, among patients with histologically involved nodes in the resected specimen, postresection CA 19-9 values did correlate with the number of positive nodes identified (p = 0.05). CONCLUSIONS: Although toxicity was acceptable, survival results were not improved over those seen with standard adjuvant treatment. Most patients relapsed before the planned chemotherapy cycles were completed, or within 100 days thereof, suggesting disease resistance to C.I. 5-FU/Lv as used in this study. Although this regimen is not recommended for further study, the doses of EBRT utilized may be suitable for evaluation with other chemotherapy combinations. Postoperative CA 19-9 levels did not correlate with survival, but did correlate with the number of histologically involved lymph nodes found in the resected specimen among node-positive patients. Moreover, rising CA 19-9 levels anticipated ultimate clinical failure by 9 months.