Hereditary pancreatitis and the risk of pancreatic cancer. International Hereditary Pancreatitis Study Group

Hereditary pancreatitis: a model for understanding the genetic basis of acute and chronic pancreatitis

Progress in understanding pancreatic diseases has been limited by a number of factors. Primary problems include the absence of good animal models, and difficulty in understanding the origin of pancreatic disease since the disease is usually manifest by the progressive destruction of the gland itself. Beginning in 1995, our laboratory, with the support of the Midwest Multicenter Pancreatic Study Group, began investigating the genetic basis of hereditary pancreatitis. Utilization of information becoming available through the human genome project allowed us to map and identify the hereditary pancreatitis gene as cationic trypsinogen (PRSS1). Molecular modeling, and subsequent experimental evidence, has solved key elements of the mysteries surrounding the origin of acute pancreatitis and the progression of acute pancreatitis to chronic pancreatitis. The availability of new genetic information and genomic tools should produce a revolution in our understanding of pancreatic diseases.

Pancreatic cancer genetics

Cancer is a multi-stage process resulting from accumulation of genetic changes in the somatic DNA of normal cells. Although in the majority of cases the changes occur only in the cancer cells there is a small proportion of cancers where a germline mutation confers an increased risk for cancer. Cancer susceptibility genes have effects that range from high to low penetrance with a corresponding high to lower likelihood for cancer in the carriers. Pancreatic cancer-prone families have been identified and some of the germline mutations responsible elucidated. Germline mutations in the BRCA2, CDKN2A/p16, hMSH2, hMLH1, hPMS1, hPMS2, LKB1/STK1, and PRSS1 genes have been associated with increased risk for pancreatic cancer. The concept of screening high-risk groups for pancreatic cancer is emerging, preferably in specialised centres with a multidisciplinary team approach.

Cyclooxygenase 2 expression in pancreatic adenocarcinoma and pancreatic intraepithelial neoplasia: an immunohistochemical analysis with automated cellular imaging

We immunohistochemically examined material from 36 pancreata (adenocarcinomas, 30 lesions; pancreatic intraepithelial neoplasia [PanIN], 65; normal pancreatic ducts, 30) for cyclooxygenase 2 (COX-2) with an automated platform. We analyzed 7 to 10 discrete foci and generated an average percentage of positive cells and average staining intensity for each lesion. These 2 values were then multiplied to create an overall "HistoScore" for each lesion. COX-2 demonstrated considerable heterogeneity of expression between and within cases. The overall average percentage of positive cells in adenocarcinomas was 47.3%; in PanINs, 36.3%; and in normal ducts, 19.2%. COX-2 was expressed in more than 20% of cells in 23 adenocarcinomas (77%), 42 PanINs (65%), and 12 normal ducts (40%). The overall average HistoScore for adenocarcinomas was 6.1; for PanINs, 5.4; and for normal ducts, 3.5. Significant differences in COX-2 expression were demonstrable in adenocarcinomas vs normal ducts, PanINs vs normal ducts, and PanIN 2/3 vs PanIN 1a/1b. In general, the pattern of COX-2 expression increased from normal to PanIN to adenocarcinoma. The up-regulation of COX-2 in a subset of noninvasive precursor lesions makes it a potential target for chemoprevention with selective COX-2 inhibitors.

Human aspartyl (asparaginyl) beta-hydroxylase monoclonal antibodies: potential biomarkers for pancreatic carcinoma

INTRODUCTION

Pancreatic adenocarcinoma is among the top 10 leading causes of death due to cancer in the United States. The lack of reliable and sensitive biomarkers for this disease makes it difficult to render an early diagnosis.

AIMS

To evaluate carcinoma-associated monoclonal antibodies (MoAbs), including AF-20, SF-25, and FB-50, for their binding specificity to pancreatic adenocarcinoma relative to normal pancreatic tissue. In addition, binding of the Th9 MoAb to human Reg 1 protein was studied because of its potential role in cell growth.

METHODOLOGY

Adjacent histologic sections were immunostained with each of the MoAbs and graded on a scale of 0 to 4+, corresponding to the relative distribution and intensity of immunoreactivity within the tumor and normal adjacent tissue.

RESULTS

Intense levels (grade 3 or 4) of FB50 immunoreactivity were detected in 19 of 19 tumors but not in normal adjacent pancreatic tissue. In addition, increased levels of FB50 immunoreactivity were detected in at least 75% of the tumor cells in 18 of the 19 cases. SF-25 immunoreactivity similarly distinguished pancreatic adenocarcinoma from normal pancreas in 14 of 19 cases. In contrast, AF20 immunoreactivity was detected in 6 of 19 pancreatic adenocarcinomas, and for the most part, the labeling was focal and of a low level. TH9 immunoreactivity was detected in 5 of 19 tumors but also in normal as well as inflamed adjacent pancreatic tissue.

CONCLUSION

These results suggest that the FB50 and SF25 MoAbs represent excellent potential biomarkers of pancreatic adenocarcinoma and could be configured in an immunoassay for detecting pancreatic adenocarcinoma cells in biologic fluids.

Pancreatitis as a risk for pancreatic cancer

Chronic pancreatitis clearly predisposes to pancreatic cancer, with early onset-long duration chronic pancreatitis from cystic fibrosis, TP, and HP conferring the highest risk. Chronic pancreatitis is not a critical step, however, but rather one of several conditions that accelerate the accumulation of critical genetic mutations and chromosomal losses necessary for carcinogenesis. Indeed, other germline mutations, environmental factors such as tobacco smoking and alcohol consumption, or dietary factors may also accelerate the pathway to carcinogenesis, and may be synergistic with the conditions created by chronic pancreatitis. Because patients with chronic pancreatitis are at high risk of pancreatic cancer, the physician is faced with decisions on how to manage this risk. Discontinuing smoking and alcohol consumption, and perhaps dietary modification are obvious recommendations for risk reduction. If, however, the patient is older and already in a very high-risk category (e.g., long-standing HP), then screening for cancers must be considered. Inclusion in multicenter trials is recommended, and information on ongoing studies can be obtained through the office of Dr. Whitcomb, or as posted on www.pancreas.org.

Inflammation and the development of pancreatic cancer

OBJECTIVE

Pancreatic cancer has an extremely poor prognosis and the cellular mechanisms contributing to pancreatic cancer are relatively unknown. The goals of this review are to present the epidemiological and experimental data that supports inflammation as a key mediator of pancreatic cancer development, to explain how inflammatory pathways may create an environment that supports tumor formation, and to discuss how the use of novel agents directed at these pathways may be used for the treatment of pancreatic malignancy.

SUMMARY BACKGROUND DATA

Inflammation has been identified as a significant factor in the development of other solid tumor malignancies. Both hereditary and sporadic forms of chronic pancreatitis are associated with an increased risk of developing pancreatic cancer. The combined increase in genomic damage and cellular proliferation, both of which are seen with inflammation, strongly favors malignant transformation of pancreatic cells. Cytokines, reactive oxygen species, and mediators of the inflammatory pathway (e.g., NF-kappaB and COX-2) have been shown to increase cell cycling, cause loss of tumor suppressor function, and stimulate oncogene expression; all of which may lead to pancreatic malignancy. Anti-cytokine vaccines, inhibitors of pro-inflammatory NF-kappaB and COX-2 pathways, thiazolidinediones, and anti-oxidants are potentially useful for the prevention or treatment of pancreatic cancer. Redirection of experimental interests toward pancreatic inflammation and mechanisms of carcinogenesis may identify other novel anti-inflammatory agents or other ways to screen for or prevent pancreatic cancer.

CONCLUSION

Pancreatic inflammation, mediated by cytokines, reactive oxygen species, and upregulated pro-inflammatory pathways, may play a key role in the early development of pancreatic malignancy.

Update on pancreatic cancer

Pancreatic cancer is one of the commonest causes of cancer death worldwide. Patients with pancreatic cancer benefit from resectional surgery (improved quality of life) and adjuvant treatment (enhanced survival). This review covers advances in the understanding of the development of pancreatic cancer, state-of-the-art clinical management and, finally, novel treatment and screening techniques.

A new susceptibility locus for autosomal dominant pancreatic cancer maps to chromosome 4q32-34

Pancreatic cancer is the fifth leading cause of cancer death in the United States. Nearly every person diagnosed with pancreatic cancer will die from it, usually in <6 mo. Familial clustering of pancreatic cancers is commonly recognized, with an autosomal dominant inheritance pattern in approximately 10% of all cases. However, the late age at disease onset and rapid demise of affected individuals markedly hamper collection of biological samples. We report a genetic linkage scan of family X with an autosomal dominant pancreatic cancer with early onset and high penetrance. For the study of this family, we have developed an endoscopic surveillance program that allows the early detection of cancer and its precursor, before family members have died of the disease. In a genomewide screening of 373 microsatellite markers, we found significant linkage (maximum LOD score 4.56 in two-point analysis and 5.36 in three-point analysis) on chromosome 4q32-34, providing evidence for a major locus for pancreatic cancer.

Chronic pancreatitis: Asia-Pacific consensus report

Current knowledge about chronic pancreatitis (CP) is limited and there is a particular dearth of information about the entity known as tropical pancreatitis. A consensus working party was convened by the Trustees of the Journal of Gastroenterology and Hepatology Foundation to conduct a systematic investigation into available evidence about the epidemiology, etiopathogenesis, diagnosis and management of CP. A literature search and formal survey of international experts in the field were used to assemble reliable evidence about these issues. The present review summarizes the results of the working party's findings and presents a series of practice guidelines to improve diagnosis, investigation and treatment of patients with CP, particularly those in the Asia-Pacific region. Areas for further research have also been identified.

A syndrome of hereditary pancreatic adenocarcinoma and cysts of the liver and kidneys

Pancreatic adenocarcinoma is the fifth leading cause of cancer death in developed countries. Several family and population studies have suggested that there is a genetic predisposition in about 10% of cases. Despite this, pedigrees showing a definite Mendelian inheritance pattern are quite rare. Recently, a family came to our attention with several cases of pancreatic adenocarcinoma. A detailed family medical history was obtained from the index patient. Medical records, including death certificates, histopathology, radiology, and laboratory reports from several family members were reviewed. Computerized tomography scans and CA19-9 serum assays were performed on selected family members. The family seems to have a syndrome of autosomal dominant adenocarcinoma of the pancreas, accompanied by multiple cysts of the liver and kidneys. Affected family members without pancreatic cancer have elevated serum CA19-9 levels. This seems to be a previously undescribed syndrome. The family may be carrying a tumor suppressor gene mutation specific for pancreatic adenocarcinoma.

Hereditary pancreatitis caused by a novel PRSS1 mutation (Arg-122 --> Cys) that alters autoactivation and autodegradation of cationic trypsinogen

Hereditary pancreatitis has been found to be associated with germline mutations in the cationic trypsinogen (PRSS1) gene. Here we report a family with hereditary pancreatitis that carries a novel PRSS1 mutation (R122C). This mutation cannot be diagnosed with the conventional screening method using AflIII restriction enzyme digest. We therefore propose a new assay based on restriction enzyme digest with BstUI, a technique that permits detection of the novel R122C mutation in addition to the most common R122H mutation, and even in the presence of a recently reported neutral polymorphism that prevents its detection by the AflIII method. Recombinantly expressed R122C mutant human trypsinogen was found to undergo greatly reduced autoactivation and cathepsin B-induced activation, which is most likely caused by misfolding or disulfide mismatches of the mutant zymogen. The K(m) of R122C trypsin was found to be unchanged, but its k(cat) was reduced to 37% of the wild type. After correction for enterokinase activatable activity, and specifically in the absence of calcium, the R122C mutant was more resistant to autolysis than the wild type and autoactivated more rapidly at pH 8. Molecular modeling of the R122C mutant trypsin predicted an unimpaired active site but an altered stability of the calcium binding loop. This previously unknown trypsinogen mutation is associated with hereditary pancreatitis, requires a novel diagnostic screening method, and, for the first time, raises the question whether a gain or a loss of trypsin function participates in the onset of pancreatitis.

Early detection of pancreatic carcinoma

The poor prognosis and late presentation of pancreatic cancer patients emphasize the importance of an effective early detection strategy for patients at risk of developing pancreatic cancer. In current practice, the use of CA 19-9 levels and imaging techniques is not optimal for detecting small pancreatic lesions. It is hoped that the understanding of genetic alterations in combination with the development of high-throughput sensitive techniques will lead to the rapid discovery of a panel of biomarkers that will save lives by enabling aggressive therapy at the time when tumors are curable.

Novel cationic trypsinogen (PRSS1) N29T and R122C mutations cause autosomal dominant hereditary pancreatitis

Hereditary pancreatitis (HP) is usually caused by mutations in the cationic trypsinogen (PRSS1) gene, especially R122H or N29I. We sequenced the PRSS1 gene in the proband of families without these common mutations. Novel R122C and N29T mutations were detected in independent families that segregated with the disease in an autosomal dominant fashion. The R122C mutation eliminates the arginine autolysis site as with R122H mutations. The N29T mutation may also enhance intrapancreatic trypsin activity as has been demonstrated in vitro. Identification of these new mutations requires special attention as commonly used detection methods may fail.

Clinical characterization of patients with hereditary pancreatitis and mutations in the cationic trypsinogen gene

PURPOSE

We determined the clinical manifestations of hereditary pancreatitis in nearly 30 families.

PATIENTS AND METHODS

The two trypsinogen mutations N29I and R122H were identified in a group of 550 patients with chronic pancreatitis of unclear origin. The following criteria were used to characterize the severity of chronic pancreatitis (one point each): calcifications, cysts, dilation of the pancreatic duct, diabetes, hospital treatment, and operation. Stages were defined as stage 0 (no points), stage 1 (one to two points), stage 2 (three to four points), and stage 3 (more than four points). Smoking and drinking habits were also recorded.

RESULTS

Six families with the N29I mutation (25 subjects with the mutation) and 21 families with the R122H mutation (76 subjects with the mutation) were identified. The median ages for the onset of disease were 11 years in N29I and 10 years in R122H patients. The severity of chronic pancreatitis and symptoms were similar for both mutations. About 26% (n = 26) of the 101 subjects carrying a mutation were asymptomatic, and 42% (n = 42) had mild disease (stage 1). Twenty-nine percent (n = 29) had moderate disease (stage 2), and only 4% (n = 4) had severe disease (stage 3).

CONCLUSIONS

Symptoms of patients with the N29I or R122H trypsinogen mutation were generally similar. The majority of subjects with trypsinogen mutations had mild disease or was asymptomatic.

Cystic fibrosis gene mutations and pancreatitis risk: relation to epithelial ion transport and trypsin inhibitor gene mutations

BACKGROUND & AIMS

Nonalcoholic chronic pancreatitis is usually idiopathic and often associated with cystic fibrosis gene (CFTR) mutations. It is unknown whether pancreatitis risk correlates with having 1 or 2 CFTR mutations, abnormal epithelial ion transport, or mutations of other genes.

METHODS

We tested 39 patients with idiopathic chronic pancreatitis (mean age at diagnosis, 33 years) for common mutations of CFTR and of genes encoding a trypsin inhibitor (PSTI) and trypsinogen (PRSS1). To exclude hereditary pancreatitis, we initially relied on family history and subsequently tested for PRSS1 mutations. Twenty subjects were tested for rare CFTR mutations (DNA sequencing) and 11 were tested for extrapancreatic CFTR function (clinical and physiologic evaluation).

RESULTS

Mutations were identified in 24 of 39 subjects. Nine patients had cystic fibrosis-causing mutations, 8 of whom also had mild-variable mutations. Eight others had only mild-variable mutations. Nine subjects had the N34S PSTI mutation and 1 had hereditary pancreatitis (R122H, PRSS1). Pancreatitis risk was increased approximately 40-fold by having 2 CFTR mutations (P < 0.0001), 20-fold by having N34S (P < 0.0001), and 900-fold by having both (P < 0.0001). Subjects with 2 CFTR mutations had abnormal nasal epithelial ion transport and clinical findings suggesting residual CFTR function between that in cystic fibrosis and in carriers. By contrast, subjects with only PSTI mutations had normal CFTR function.

CONCLUSIONS

CFTR-related pancreatitis risk correlates with having 2 CFTR mutations and reduced extrapancreatic CFTR function. The N34S PSTI mutation increased risk separately. Testing for pancreatitis-associated CFTR and PSTI genotypes may be useful in nonalcoholic pancreatitis.

Previous cholecystectomy, gastrectomy, and diabetes mellitus are not crucial risk factors for pancreatic cancer in patients with chronic pancreatitis

INTRODUCTION

In the general population, cholecystectomy, diabetes, and chronic pancreatitis seem to be associated with an increased risk of developing pancreatic cancer.

AIMS

We assessed whether previous cholecystectomy, gastrectomy, or diabetes mellitus may be risk factors for pancreatic cancer in patients with chronic pancreatitis.

METHODOLOGY

We analyzed 853 patients with chronic pancreatitis (110 women, 743 men) with a median follow-up period of 14 years with particular reference to establishing which patients had previously undergone cholecystectomy or distal gastric resection (Billroth II anastomosis) or had diabetes or gallstone disease and the respective time scales involved.

RESULTS

Pancreatic cancer developed in 17 patients with chronic pancreatitis after a median period of 8 years from onset of pancreatitis symptoms (range, 3-38 years). Excluding two cholecystectomies performed 1 year before diagnosis of cancer, cholecystectomy was performed in 7/17 (41%) patients with pancreatic cancer and in 381/836 (46%) of the other patients with chronic pancreatitis. Forty-nine (10%) patients with chronic pancreatitis and no pancreatic cancer had undergone cholecystectomy during the years before the onset of chronic pancreatitis, whereas none of the patients in whom a pancreatic malignancy developed had undergone cholecystectomy before the onset of chronic pancreatitis symptoms. Gastrectomies were performed in 116 patients (14%), 47 before the onset of chronic pancreatitis. Only 2/17 patients with pancreatic cancer had undergone previous gastrectomy, though in both cases only shortly before diagnosis of the cancer. Diabetes was diagnosed in 353 patients, but only in 30 (4%) before onset of chronic pancreatitis. Only 1/17 patients (6%) with pancreatic cancer had long-standing diabetes, whereas diabetes developed in 3/17 shortly before diagnosis of pancreatic cancer.

CONCLUSIONS

Cholecystectomy, gastrectomy, and diabetes are not major risk factors for the development of pancreatic cancer in patients with chronic pancreatitis.

Low serum levels of CD44, CD44v6, and neopterin indicate immune dysfunction in chronic pancreatitis

INTRODUCTION

In autoimmune diseases, malignancies, and inflammatory conditions, a correlation of serum levels of CD44, interleukin-2 receptor (IL-2r), and neopterin with disease activity could be shown.

AIMS

To assess the immune parameters in chronic pancreatitis in correlation to clinical data to evaluate the potential role of immune dysfunction as a risk factor.

METHODOLOGY

Levels of IL-2r, sCD44, sCD44v6, and neopterin were measured using the enzyme-linked immunosorbent assay in 63 patients with chronic pancreatitis who underwent surgery between 1992 and 1995 in our institution. Clinical data were evaluated prospectively before surgery, and a follow-up investigation was conducted in 1997.

RESULTS

Mean serum levels of CD44, CD44v6, and neopterin were significantly lower in patients with chronic pancreatitis compared with the control group. The mean level of IL-2r was also lower in chronic pancreatitis, but this difference was not significant. However, no influence of immunosuppressive factors such as alcohol consumption, cigarette smoking, or diabetes could be detected on the levels of IL-2r, CD44, CD44v6, and neopterin.

CONCLUSION

In accordance with other diseases of reduced immunoreactivity, depressed serum levels of biomarkers in chronic pancreatitis are caused by reduced T-lymphocyte and macrophage activation. By ruling out a significant influence of concomitant immunosuppressive factors, we conclude that the inflammatory process itself is the source of the depressed immune function, which might be restored by surgical resection.

Idiopathic acute recurrent pancreatitis

Acute recurrent pancreatitis (ARP) results most commonly from alcohol abuse or gallstone disease. Initial evaluation fails to detect the cause of ARP in 10-30% of patients, and as a result the diagnosis of "idiopathic" ARP is given. In these patients, a more extensive evaluation including specialized labs, ERCP, endoscopic ultrasound, or magnetic resonance cholangiopancreatography typically leads to a diagnosis of microlithiasis, sphincter of Oddi dysfunction, or pancreas divisum. Less commonly, hereditary pancreatitis, cystic fibrosis, a choledochocele, annular pancreas, an anomalous pancreatobiliary junction, pancreatobiliary tumors, or chronic pancreatitis are diagnosed. Determining the etiology is important, as it helps to direct therapy, limits further unnecessary evaluation, and may improve a patient's long term prognosis.

Molecular pathogenesis of pancreatic ductal adenocarcinoma and clinical implications

Pancreatic ductal adenocarcinoma (PDAC) is a significant cause of cancer death worldwide. PDAC is also one of the best-studied cancers with regard to molecular pathogenesis. The chief risk factors associated with PDAC are smoking and pancreatitis, in addition genetic predisposition seems to play a major role. This genetic predisposition may in some cases be indirect, for example via the elevated risk of pancreatitis seen in patients with hereditary pancreatitis (HP). The elucidation of the molecular causes of PDAC has enabled the provision of secondary screening for PDAC in conditions such as HP. This review is concerned with the molecular pathogenesis of PDAC and the application of this basic scientific understanding into state-of-the-art clinical practice.

Cancer genetics

Cancer genetics has for many years focused on mutational events that have their primary effect within the cancer cell. Recently that focus has widened, with evidence of the importance of epigenetic events and of cellular interactions in cancer development. The role of common genetic variation in determining the range of individual susceptibility within the population is increasingly recognized, and will be addressed using information from the Human Genome Project. These new research directions will highlight determinants of cancer that lie outside the cancer cell, suggest new targets for intervention, and inform the design of strategies for prevention in groups at increased risk.

The genetics of pancreatic adenocarcinoma: a roadmap for a mouse model

Pancreatic cancer is among the leading causes of cancer death. Although a genetic profile for pancreatic cancer is emerging, many biological aspects of this disease are poorly understood. Indeed, fundamental questions regarding progenitor cell lineages, host stromal milieu, and the role of specific genetic alterations in tumor progression remain unresolved. A mouse model engineered with signature mutations would provide a powerful ally in the study of pancreatic cancer biology and may guide improved prognostic assessment and treatment for the human disease. In this review, we discuss the molecular basis for normal pancreatic development and the genetics of human pancreatic adenocarcinoma in the hope of charting a course for the development of a faithful mouse model for this lethal cancer.

p53 and K-ras mutations in pancreatic juice samples from patients with chronic pancreatitis

BACKGROUND

Mutations in p53 and ras genes are frequent in pancreatic carcinoma. Several ras mutations are consistently detected in the pancreatic juice from patients with chronic pancreatitis. The p53 gene mutations have been detected occasionally in chronic pancreatitis tissue. It was the aim of this study to evaluate the presence and clinical significance of p53 and ras mutations in clinical pancreatic juice samples from patients with chronic pancreatitis.

METHODS

Pancreatic juice was obtained from 66 patients with chronic pancreatitis and no evidence of pancreatic carcinoma (51 men, 15 women; age 17-86 years [mean 49.6 +/- 12.9]). Patients were followed prospectively for 26 +/- 3 (4-54) months. Detection of p53 gene mutations was by temperature gradient gel electrophoresis (TGGE) and single strand conformation polymorphism (SSCP) for exons 5-8. Analysis of ras mutations was performed by SSCP/polymerase chain reaction, restriction fragment length polymorphism/polymerase chain reaction. All mutations were confirmed by sequencing.

RESULTS

Five of 66 (7.5%) pancreatic juice samples contained p53 mutations, and ras mutations were detected in 6 cases (9%). Cytology was negative in all cases. No pancreatic carcinoma developed during follow-up and neither cancer cells nor preneoplastic lesions could be detected histologically in resected specimens. Although no correlation between p53 mutations and duration of pancreatitis or drinking habits was found, K-ras mutations correlated with both heavy smoking and severity of the disease.

CONCLUSION

p53 and ras mutations can be detected in a minority of pancreatic juice samples from patients with chronic pancreatitis in the absence of malignancy.

Motivations and concerns of patients with access to genetic testing for hereditary pancreatitis

OBJECTIVES

Direct DNA testing is now available for hereditary pancreatitis (HP). This study aimed to identify the factors that motivated individuals to participate in research and to determine how research participants used their genetic test results.

METHODS

A survey was mailed to 247 participants (110 male, 137 female) who were > or =18 yr of age and living in the US. Data analysis was primarily a description of frequency distribution of the responses.

RESULTS

Ninety-one of 247 participants (37%) completed the survey. Of the 55 female and 36 male respondents, 60% were 31-55 yr old, and a total of 54% tested positive for HP. The most common reason for participating in research was "to help a relative/family member" (61%), and genetic testing was pursued because of "the disturbance of seeing affected relatives" (48%) and "the desire to help future generations" (33%). Perceived risk of developing HP in the future was the least important motivating factor in seeking genetic testing. Sixty-two percent of respondents had received their genetic test results. All but one chose to share their results with at least one person: most often with family members (96%) and physicians (62%), and least often with insurance companies (4%). The most common influential factor in withholding information was "the fear of insurance discrimination" (23%).

CONCLUSIONS

The major motivations to participate in the HP genetic research study were to obtain genetic testing and to help current family members and future generations. The major concern was insurance discrimination. Participants clearly appreciate the availability of genetic testing for HP. These results suggest that a mechanism to disclose results to research participants should be considered, and effective ways to protect at-risk individuals from insurance discrimination must remain a genetics health care priority.

The role of genetic factors in the etiology of pancreatic adenocarcinoma: an update

Pancreatic cancer is a disease with a very poor prognosis and its etiology is still largely elusive. The only consistent environmental risk factor is cigarette smoking. A previous history of pancreatitis or diabetes mellitus is also considered to be a risk factor. Epidemiological studies have confirmed that relatives of those with pancreatic cancer have an increased risk of this malignancy, and it has been evaluated that 3-5% of all pancreatic cancer cases are caused by genetic predisposition to the disease. Usually this occurs in the setting of a known inherited cancer syndrome caused by mutations in genes such as BRCA1/2 and CDKN2A. Whether or not a true site-specific pancreatic adenocarcinoma syndrome exists is not known. The real challenge for the management of high risk patients is to develop new screening methods than can identify pre-neoplastic or early neoplastic lesions in a timely manner.

Dietary and other methyl-group availability factors and pancreatic cancer risk in a cohort of male smokers

The authors examined prospectively whether dietary folate and other factors known to influence methyl-group availability were associated with the development of exocrine pancreatic cancer within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort. Of the 27,101 healthy male smokers aged 50--69 years who completed a self-administered dietary questionnaire at baseline, 157 developed pancreatic cancer during up to 13 years of follow-up from 1985 to 1997. Cox proportional hazards models were used to estimate the hazards ratios and 95% confidence intervals. The adjusted hazards ratio comparing the highest with the lowest quintile of dietary folate intake was 0.52 (95% confidence interval: 0.31, 0.87; p-trend = 0.05). Dietary methionine, alcohol intake, and smoking history did not modify this relation. No significant associations were observed between dietary methionine, vitamins B(6) and B(12), or alcohol intake and pancreatic cancer risk. Consistent with prior studies, this study shows that cigarette smoking was associated with an increased risk (highest compared with lowest quintile, cigarettes per day: hazards ratio = 1.82; 95% confidence interval: 1.10, 3.03; p-trend = 0.05). These results support the hypothesis that dietary folate intake is inversely associated with the risk of pancreatic cancer and confirm the risk associated with greater cigarette smoking.

Surveillance of pre-malignant disease of the pancreatico-biliary system

Technical advancements in ultrasonography, contrast-enhanced computed tomography and magnetic resonance imaging, as well as the wider availability of these ultramodern imaging techniques, have resulted in the early detection and a better classification of various asymptomatic and symptomatic pancreatico-biliary lesions. Pre-malignant biliary and pancreatic lesions are rare disorders, and no clear data are available to define their malignant potential. Because of the lack of controlled epidemiological data, the time span for malignant transformation and its frequency cannot be defined in the majority of these lesions. Adenomyomatosis of the gallbladder and gallbladder polyps larger than 10 mm should be treated by cholecystectomy even in asymptomatic patients because of an increased risk of malignant transformation. Chronic cholangitis, primary sclerosing cholangitis and choledochal cysts are also pre-malignant conditions. The timing of surgery, once it is advised for a pre-malignant condition that is still benign, should, however, be individualized to the particular patient situation. In patients with chronic pancreatitis, surgery may be indicated for disease-related complications. In as much as chronic pancreatitis predisposes to a higher risk of pancreatic cancer, any suspicion of malignancy should warrant a surgical exploration. Intraductal papillary tumours and mucin-producing pancreatic tumours are other pre-malignant pancreatic lesions whose malignant potential cannot be precisely determined pre-operatively. They should be resected in situations where there is a high degree of suspicion even without a clear objective diagnosis. In conclusion, pre-malignant hepato-biliary and pancreatic lesions of uncertain pathology should undergo early resection in view of treatment limitations and the dismal prognosis of established cancers. While hepato-biliary and pancreatic surgery is nowadays performed in specialized centres, with a low post-operative morbidity and mortality, it is equally important to understand that observation alone with regular computed tomography or magnetic resonance imaging control can no longer be recommended in the management of these lesions.

Genetic testing in acute and chronic pancreatitis

Hereditary pancreatitis (HP) is clinically indistinguishable from pancreatitis with other causes. Patients with HP have an increased chance of developing pancreatitis. Mutations in the cationic trypsinogen gene appear to cause most HP, although there is evidence for mild genetic heterogeneity with defects in other genes. Trypsin stabilization and protection from autolysis appear to play a central role in the pathogenesis of pancreatitis. The role of mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) as well as the pancreatic secretory trypsin inhibitor (PSTI) in patients with pancreatitis is intriguing but as yet incompletely understood. Genetic testing may help to identify and manage patients with HP. Healthcare professionals should understand the elements necessary for obtaining informed consent for patients undergoing these tests, the limits in interpreting test results, and the psychosocial issues that may arise from genetic testing.

Distributional and functional alterations of immunocompetent peripheral blood lymphocytes in patients with chronic pancreatitis

OBJECTIVE

To investigate whether the chronic inflammatory process in patients with chronic pancreatitis affects their immune function.

SUMMARY BACKGROUND DATA

Chronic pancreatitis is a chronic inflammatory disease of the exocrine pancreas. In approximately 30% of patients, an inflammatory mass of the pancreatic head is found, representing an indication for surgery.

METHODS

This study comprised 28 patients with chronic pancreatitis. Sixteen patients were also reevaluated 1 year after resection of the pancreatic head for chronic pancreatitis.

RESULTS

Compared with an age- and gender-matched control group, the number of CD3(+) cells was significantly increased in patients with chronic pancreatitis, with an increase of both CD3(+)CD4(+) and CD3(+)CD8(+) cells. The number of natural killer cells or B lymphocytes did not differ between the patients and the control group. After stimulation with phytohemagglutinin or anti-CD3 antibodies, the blastogenic response was significantly attenuated in the patients with chronic pancreatitis. One year after resection of the pancreatic head for chronic pancreatitis, the distribution and the blastogenic response to phytohemagglutinin and anti-CD3 antibodies had returned to normal compared with preoperative values.

CONCLUSION

The chronic inflammatory process in chronic pancreatitis markedly affects the distribution and function of peripheral immunocompetent blood cells, and elimination of the chronic inflammatory focus by pancreatic head resection restores the suppressed immune function in these patients.

Chronic pancreatitis: diagnosis, classification, and new genetic developments

The utilization of recent advances in molecular and genomic technologies and progress in pancreatic imaging techniques provided remarkable insight into genetic, environmental, immunologic, and pathobiological factors leading to chronic pancreatitis. Translation of these advances into clinical practice demands a reassessment of current approaches to diagnosis, classification, and staging. We conclude that an adequate pancreatic biopsy must be the gold standard against which all diagnostic approaches are judged. Although computed tomography remains the initial test of choice for the diagnosis of chronic pancreatitis, the roles of endoscopic retrograde pancreatography, endoscopic ultrasonography, and magnetic resonance imaging are considered. Once chronic pancreatitis is diagnosed, proper classification becomes important. Major predisposing risk factors to chronic pancreatitis may be categorized as either (1) toxic-metabolic, (2) idiopathic, (3) genetic, (4) autoimmune, (5) recurrent and severe acute pancreatitis, or (6) obstructive (TIGAR-O system). After classification, staging of pancreatic function, injury, and fibrosis becomes the next major concern. Further research is needed to determine the clinical and natural history of chronic pancreatitis developing in the context of various risk factors. New methods are needed for early diagnosis of chronic pancreatitis, and new therapies are needed to determine whether interventions will delay or prevent the progression of the irreversible damage characterizing end-stage chronic pancreatitis.

Hereditary Chronic Pancreatitis: Implications for Surgical Treatment and Follow-Up

Hereditary pancreatitis is an uncommon cause of chronic pancreatitis in Western society. It should be suspected when chronic pancreatitis presents in young adults. The diagnosis is made when chronic pancreatitis is present in several members of the same family who are determined not to have other risk factors for chronic pancreatitis. Molecular research focusing on mutations in the tripsinogen gene has uncovered the genetic defects associated with hereditary pancreatitis, and this knowledge has suggested the possible pathophysiologic mechanism of this disease. Because patients with hereditary pancreatitis develop their disease early in life they are very likely to require treatment for complications. As in patients with chronic pancreatitis of other etiologies those with hereditary pancreatitis should be treated medically for acute exacerbations. When complications occur or when the disease causes intractable pain surgery is recommended. Surgical therapy is tailored to the patient's pancreatic anatomy based on endoscopic retrograde cholangiopancreatography or CT scan. The two patients described in this report underwent successful longitudinal pancreaticojejunostomy (Puestow procedure) with good results. Finally it has been shown that patients with hereditary pancreatitis are at increased risk for developing pancreatic adenocarcinoma. Although not widely used pancreatic cancer screening programs have been suggested for surveillance of these patients.

Neoplasms in neurofibromatosis 1 are related to gender but not to family history of cancer

The risk of malignancies among persons with neurofibromatosis 1 (NF1) is higher than in the general population, but the excess risk has not been precisely estimated. The effects of gender and inheritance pattern on cancer risk are unclear. Therefore, we conducted a historical cohort study to determine cancer risk factors by contacting 138 Caucasian NF1 patients originally seen at Baylor College of Medicine (BCM) in Houston between 1978 and 1984. A total of 304 patients of all ethnic groups were evaluated at BCM during this period. We successfully located 173 patients, 138 of who were Caucasian. We computed standardized incidence ratios (SIRs) with the age-, gender-, and time period-specific rates from the Connecticut Tumor Registry for 2,094 person-years of observation (median follow-up = 16 years). Eleven incident tumors were reported. Females were at much higher risk of cancer than males (SIR = 5.6, 95% confidence interval (CI) 2.7-10.3 and SIR = 0.6; 95% CI, 0.0-3.0, respectively). We found no elevated cancer risk in unaffected first-degree relatives, regardless of whether the proband had cancer or not (SIR = 1.1 95% CI, 0.6-1.8 and SIR = 1.0, 95% CI, 0.6-1.5, respectively). Our results suggest that malignancy in the proband is not the result of a modifying gene that has a significant impact on general cancer risk.

Molecular technology and pancreatic cancer

BACKGROUND

Pancreatic cancer is the fifth leading cause of cancer death in the Western world. Despite improvement in operative mortality rates, little impact has been made on overall 5-year survival. This review discusses the molecular changes peculiar to pancreatic cancer and how the use of molecular technology might affect detection, screening, diagnosis and treatment of the disease.

METHODS

A literature review was performed using the National Library of Medicine's Pubmed database; this was combined with ongoing work within the Queen Elizabeth Hospital, Birmingham.

RESULTS

Over the past 20 years great strides have been made in our understanding of the molecular basis of disease. Advances in molecular biology are now reshaping how diseases are screened for, diagnosed, investigated and treated. In recent years collaboration between clinicians and basic scientists has revealed a unique pattern of genetic and molecular events in pancreatic cancer. This review discusses how these advances may impact on patients with this disease.

CONCLUSION

The past decade has seen some improvement in outlook for patients with pancreatic cancer, but the 'molecular age' promises to deliver even better results.

Mutations of the cationic trypsinogen in hereditary pancreatitis

Hereditary pancreatitis (OMIM 167800) is thought to be associated with a mutation of the exon 3 of cationic trypsinogen (Nature Genet (1996): 14:141-145). This paper reports sequence data of two independent families suffering from this disease. PCR amplificates from leukocyte or buccal swab DNA showed no mutation of exon 3 of cationic trypsinogen. Instead, in exon 2, an A-to-T tranversion was found that led to the substitution of Asn by Ile in the sixth amino acid of the active trypsin. In exons 4 and 5, silent mutations were found. In the other expressed trypsinogens, several homozygous alterations not associated to hereditary pancreatitis were identified. As a model of pathogenesis, we hypothesize that mutation of trypsinogen in exon 2 could lead to premature cleavage of the activation peptide of trypsinogen or to altered intracellular transport.

Chronic pancreatitis

Chronic pancreatitis causes destruction of the pancreatic gland which leads to diabetes and malabsorption. Its principal cause is alcohol abuse, and intractable pain is the main clinical feature. The incidence of pancreatic carcinoma is increased among patients with chronic pancreatitis.

Hereditary pancreatitis and mutations of the cationic trypsinogen gene

BACKGROUND

Mutations of the cationic trypsinogen gene have been detected in hereditary pancreatitis. This article reviews current understanding of their function and clinical significance.

METHODS

An unrestricted Medline search was conducted using the key words hereditary pancreatitis and 'cationic trypsinogen . Additional material was obtained from references cited in original papers and recently published abstracts of meetings.

RESULTS AND CONCLUSION

Cationic trypsinogen mutations have been identified in most, but not all, families with hereditary pancreatitis. This confirms existing evidence that premature trypsinogen activation plays a central role in the pathogenesis of human pancreatitis. Patients currently clinically defined as having hereditary pancreatitis should be screened for the presence of cationic trypsinogen mutations. A subgroup of patients with non-hereditary pancreatitis may also benefit from being screened for these mutations. Patients with hereditary pancreatitis should be entered into prospective, multicentre trials investigating secondary screening for pancreatic cancer. Gene therapy for hereditary pancreatitis is beyond current technological capability but remains a future therapeutic prospect for this often debilitating condition.

Ductal lesions in patients with chronic pancreatitis show K-ras mutations in a frequency similar to that in the normal pancreas and lack nuclear immunoreactivity for p53

BACKGROUND

Chronic pancreatitis (CP) is considered to be a risk factor for the development of pancreatic carcinoma. The detection of K-ras mutations in the duodenal or pancreatic juice has been held to be a reliable tool for its early diagnosis. However, K-ras mutations also occur in hyperplastic ductal epithelium, making it difficult to interpret their role in pancreatic carcinogenesis.

METHODS

The study included 30 resection specimens, 15 from patients with alcoholic CP, and 15 from patients with idiopathic CP. The mean duration of disease was 6.8 years. A total of 429 ductal lesions were classified according to the World Health Organization classification (1996) and microdissected. K-ras analysis was performed by means of polymerase chain reaction (45 cycles), constant denaturing gel electrophoresis, and sequencing. Immunostaining was performed with antibodies against p53, Ki-S5, carcinoembryonic antigen, and two types of mucins.

RESULTS

The 30 specimens demonstrated all types of ductal lesions. Severe cellular atypia was not observed. A total of 429 ductal lesions were analyzed. Approximately 4.4% of the lesions (19 of 429) from 27% of the patients (8 of 30) showed K-ras mutations, but they were unrelated to the duration or type of CP. Immunostaining for mutated p53 protein always was negative. Increased proliferative activity was noted only in patients with papillary hyperplasia. No patient developed pancreatic carcinoma within a follow-up period of at least 3 years.

CONCLUSIONS

Ductal lesions in patients with CP exhibit K-ras mutations without additional indications of neoplastic transformation such as severe dysplasia or mutated p53 protein. Therefore, for diagnostic and therapeutic purposes, the detection of K-ras mutations should be supplemented by the demonstration of additional genetic alterations or clinical signs of malignancy.

Genetic testing. Counseling, laboratory, and regulatory issues and the EUROPAC protocol for ethical research in multicenter studies of inherited pancreatic diseases

This article highlights several of the important issues and illustrates a European protocol that should be considered when offering genetic testing on a research or clinical basis for HP, as well as for other inherited disorders of the pancreas.

Pancreatic cancer surveillance in a high-risk cohort. Is it worth the cost?

Pancreatic adenocarcinoma is the 10th most common malignancy and 4th largest cancer killer in adults. Earlier tumor detection through screening of high risk groups, presumably to increase the percentage of cases resectable for cure in these cohorts, has emerged as a prominent strategy to combat this disease. This article examines the feasibility of this strategy in patients with hereditary pancreatic cancer (HPC) and hereditary pancreatitis (HP). Because of a variety of factors, specific cost projections for screening with HPC kindreds are problematic at best. Patients with HP exhibit a 53-fold increased risk of pancreatic cancer, with a cumulative risk of 40% by age 70. The authors discuss the modalities available to screen this cohort and subsequently perform a theoretical cost analysis. The authors' findings suggest that screening has the potential to be cost-effective only in hereditary pancreatitis patients = 50 years-of-age. The most cost-effective option will likely combine an initial serologic test with high sensitivity and a subsequent serologic or pancreatic juice test with sufficient specificity to act as a "gatekeeper" to imaging with endoscopic ultrasound (EUS). Banking of blood and pancreatic juice samples should be mandatory in any screening protocol. The lower tumor yield in other high-risk groups (e.g., non-hereditary chronic pancreatitis) will effectively preclude the use of such screening protocols. The vast majority of patients will continue to present with unresectable disease.

Cancer surveillance of patients from familial pancreatic cancer kindreds

The family history can be used to determine which family members warrant surveillance and when to start it. Surveillance should be started at least 1 decade before the earliest age of pancreatic cancer in the family. EUS is the basic, least-invasive surveillance tool; however, findings are similar to those seen in chronic pancreatitis. All patients who have a positive EUS or who have symptoms warrant ERCP. Changes on ERCP of ductal stricturing and clubbed or saccular side branches are suggestive of patients who may need pancreatectomy in the setting of hereditary pancreatic cancer. The goal for surveillance of familial pancreatic cancer patients is to diagnose them before the development of cancer, when they have dysplasia or carcinoma in situ, and to perform a complete pancreatectomy. Timing is crucial for determining when a patient warrants surgery; if performed too early, the patient is put at risk for the morbidity and mortality of a total pancreatectomy, which is not inconsequential. If the patient survives the operation, he or she is often left a brittle diabetic. The alternative of diagnosing too late is more worrisome because the patient dies of pancreatic cancer. An essential ingredient to a good patient outcome is a team approach to these patients, using gastroenterologists, surgeons, and pathologists who have expertise and interest in pancreatic disease.

Hereditary pancreatitis. Historical perspectives

Clinically, hereditary pancreatitis was not distinguishable from any other cause of pancreatitis. But astute clinical observations demonstrated an evolution toward chronic pancreatitis that could develop into carcinoma in some patients. A chromosomal abnormality was identified on chromosome 7q35, and then three separate genetic abnormalities were identified. It is now understood that a defect in trypsinogen is at the basis of the anomaly, and further developments should help identify new therapeutic approaches.

Molecular genetic alterations in ductal pancreatic adenocarcinomas

Pancreatic ductal adenocarcinomas are known to harbor a distinct variety of genetic alterations in oncogenes, tumor-suppressor genes, and occasionally genes that carry out DNA mismatch repair. Although this malignancy occurs at an elevated frequency in patients with familial recurrent acute pancreatitis, the genetic alterations of these particular tumors have not been reported. The changes are likely to be similar to those of sporadic pancreatic cancer; if so, this would provide useful clues for studying the progression of early and advanced neoplasia in such pancreatitis patients to aid their clinical monitoring and provision of therapeutic recommendations.