Genetics of Pancreatic Cancer

Risk of Syndrome-Associated Cancers Among First-Degree Relatives of Patients With Pancreatic Ductal Adenocarcinoma With Pathogenic or Likely Pathogenic Germline Variants

Importance

Increased cancer risk in first-degree relatives of probands with pancreatic ductal adenocarcinoma (PDAC probands) who carry pathogenic or likely pathogenic germline variants (PGVs) in cancer syndrome-associated genes encourages cascade genetic testing. To date, unbiased risk estimates for the development of cancers on a gene-specific basis have not been assessed.

Objective

To quantify the risk of development of PDAC and extra-PDAC among first-degree relatives of PDAC probands who carry a PGV in 1 of 9 cancer syndrome-associated genes-ATM, BRCA1, BRCA2, PALB2, MLH1, MSH2, MSH6, PMS2, and CDKN2A.

Design, Setting, and Participants

This case series focused on first-degree relatives of PDAC probands carrying PGVs in specific cancer syndrome-associated genes. The cohort comprised clinic-ascertained patients enrolled in the Mayo Clinic Biospecimen Resource for Pancreas Research registry with germline genetic testing. In total, 234 PDAC probands carrying PGVs were drawn from the prospective research registry of 4562 participants who had undergone genetic testing of cancer syndrome-associated genes. Demographic and cancer-related family histories were obtained by questionnaire. The data were collected from October 1, 2000, to December 31, 2021.

Main Outcomes and Measures

For the PDAC probands, the genetic test results of the presence of PGVs in 9 cancer syndrome-associated genes were obtained by clinical testing. Cancers (ovary, breast, uterus or endometrial, colon, malignant melanoma, and pancreas) among first-degree relatives were reported by the probands. Standardized incidence ratios (SIRs) were used to estimate cancer risks among first-degree relatives of PDAC probands carrying a PGV.

Results

In total, 1670 first-degree relatives (mean [SD] age, 58.1 [17.8] years; 853 male [51.1%]) of 234 PDAC probands (mean [SD] age, 62.5 [10.1] years; 124 male [53.0%]; 219 [94.4%] White; 225 [98.7%] non-Hispanic or non-Latino]) were included in the study. There was a significantly increased risk of ovarian cancer in female first-degree relatives of probands who had variants in BRCA1 (SIR, 9.49; 95% CI, 3.06-22.14) and BRCA2 (SIR, 3.72; 95% CI, 1.36-8.11). Breast cancer risks were higher with BRCA2 variants (SIR, 2.62; 95% CI, 1.89-3.54). The risks of uterine or endometrial cancer (SIR, 6.53; 95% CI, 2.81-12.86) and colon cancer (SIR, 5.83; 95% CI, 3.70-8.75) were increased in first-degree relatives of probands who carried Lynch syndrome mismatch repair variants. Risk of PDAC was also increased for variants in ATM (SIR, 4.53; 95% CI, 2.69-7.16), BRCA2 (SIR, 3.45; 95% CI, 1.72-6.17), CDKN2A (SIR, 7.38; 95% CI, 3.18-14.54), and PALB2 (SIR, 5.39; 95% CI, 1.45-13.79). Melanoma risk was elevated for first-degree relatives of probands with CDKN2A variants (SIR, 7.47; 95% CI, 3.97-12.77).

Conclusions and Relevance

In this case series, the presence of PGVs in 9 cancer syndrome-associated genes in PDAC probands was found to be associated with increased risk of 6 types of cancers in first-degree relatives. These gene-specific PDAC and extra-PDAC cancer risks may provide justification for clinicians to counsel first-degree relatives about the relevance and importance of genetic cascade testing, with the goal of higher uptake of testing.

Integrated transcriptional analysis reveals macrophage heterogeneity and macrophage-tumor cell interactions in the progression of pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease harboring significant microenvironment heterogeneity, especially for the macrophages. Tumor-associated macrophages (TAMs) orchestrate PDAC malignancy, but their dynamics during disease progression remains poorly understood. There is a pressing need to identify the molecular mechanism underlying tumor-macrophage interactions and thus design novel therapeutic strategies.

METHODS

Herein, we developed an insilico computational method incorporating bulk and single-cell transcriptome profiling to characterize macrophage heterogeneity. CellPhoneDB algorithm was applied to infer macrophage-tumor interaction networks, whereas pseudotime trajectory for dissecting cell evolution and dynamics.

RESULTS

We demonstrated myeloid compartment was an interactive hub of tumor microenvironment (TME) essential for PDAC progression. Dimensionality reduction classified seven clusters within the myeloid cells wherein five subsets of macrophages were characterized by diverse cell states and functionality. Remarkably, tissue-resident macrophages and inflammatory monocyte were identified as potential sources of TAMs. Further, we uncovered several ligand-receptor pairs lining tumor cells and macrophages. Among them, HBEGF-CD44, HBEGF-EGFR, LGALS9-CD44, LGALS9-MET, and GRN-EGFR were correlated with worse overall survival. Notably, as in vitro experiments indicated, TAM-derived HBEGF promoted proliferation and invasion of the pancreatic cancer cell line.

CONCLUSION

Together, our work deciphered a comprehensive single-cell atlas of the macrophage compartment of PDAC and provided novel macrophage-tumor interaction features with potential value in developing targeted immunotherapies and molecular diagnostics for predicting patient outcome.

The role of microbiome in pancreatic cancer

Recent studies of the human microbiome have offered new insights into how the microbiome can impact cancer development and treatment. Specifically, in pancreatic ductal adenocarcinoma (PDAC), the microbiota has been shown to modulate PDAC risk, contribute to tumorigenesis, impact the tumor microenvironment, and alter treatment response. These findings provide rationale for further investigations into leveraging the microbiome to develop new strategies to diagnose and treat PDAC patients. There is growing evidence that microbiome analyses have the potential to become easily performed, non-invasive diagnostic, prognostic, and predictive biomarkers in pancreatic cancer. More excitingly, there is now emerging interest in developing interventions based on the modulation of microbiota. Fecal microbiota transplantation, probiotics, dietary changes, and antibiotics are all potential strategies to augment the efficacy of current therapeutics and reduce toxicities. While there are still challenges to overcome, this is a rapidly growing field that holds promise for translation into clinical practice and provides a new approach to improving patient outcomes.

Germline sequence analysis of RABL3 in a large series of pancreatic ductal adenocarcinoma patients reveals no evidence of deleterious variants

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease with a 5-year survival rate of less than 10%. Individuals with a pathogenic germline variant in a pancreatic cancer susceptibility gene are at an increased risk of developing pancreatic cancer. Understanding the inherited genetic basis of pancreatic tumor development provides a unique opportunity to improve patient care and outcomes. For example, relatives of a patients with PDAC who have a pathogenic germline variant in a pancreatic cancer susceptibility gene are eligible for disease surveillance where cancers may be detected early, and 5-year survival greatly improved. Furthermore, for some patients with PDAC and a pathogenic germline variant in a pancreatic cancer susceptibility gene, their tumors may be susceptible to specific anti-cancer therapies. Recently, RABL3 was identified as a pancreatic cancer susceptibility gene. To validate these findings and inform clinical translation, we determined the prevalence of deleterious RABL3 variants in a large cohort of 1037 patients with PDAC that had undergone either whole genome or whole exome germline sequencing. We identified two synonymous variants and four missense variants classified as variants of unknown significance. We found no pathogenic RABL3 variants, indicating that the maximum prevalence of such variants in patients with PDAC is less than 0.36% (minor allele frequency 0, 97.5% one-sided confidence interval: 0-0.0036). This finding has important implications for germline genetic testing of patients with PDAC.

Cohort profile and heritability assessment of familial pancreatic cancer: a nation-wide study

BACKGROUND

Familial Pancreatic Cancer (FPC) is responsible for up to 10% of all cases of pancreatic ductal adenocarcinoma (PDAC). Individuals predisposed for FPC have an estimated lifetime risk of 16-39% of developing PDAC. While heritability of PDAC has been estimated to be 36% in a Nordic twin study, no heritability estimate specific on FPC has been reported.

METHODS

A national cohort of Danish families with predisposition for FPC is currently included in a screening program for PDAC at Odense University Hospital. Family members included in the screening program were interviewed for pedigree data including: cases of PDAC among first-degree relatives (FDRs) and number of affected/unaffected siblings. Heritability for FPC in the predisposed families was assessed by doubling the estimated intra-class correlation coefficient (ICC) from a random intercept logistic model fitted to data on FDRs.

RESULTS

Among families with predisposition for FPC, 83 cases of PDAC were identified. The median age at diagnosis of PDAC was 66 years, and median time from diagnosis to death was 7.6 months. A total of 359 individuals were found as unaffected FDRs of the 83 PDAC cases. The retrieved FDRs included a total of 247 individuals in sibship and 317 individuals in parent-offspring relatedness. We estimated an ICC of 0.25, corresponding to a narrow sense additive heritability estimate of 0.51 in the FPC family cohort.

CONCLUSION

We have established a nation-wide cohort of FPC families to facilitate clinical and genetic studies on FPC. The estimated heritability of 51% prominently underlines a strong genetic background of FPC.

Outcomes of endoscopic ultrasound as a one-off pancreatic cancer screening tool for 122 high- and moderate-risk patients

Background and Aim

Pancreatic cancer (PC) carries a poor prognosis and is often detected at later stages. Screening programs for moderate- and high-risk people are still under debate. We present the results from a prospective study on endoscopic ultrasound (EUS) as a one-off screening tool for pancreatic cancer screening.

Methods

Asymptomatic patients with moderate- or high-risk of PC were invited to participate. Moderate risk consisted of one first-degree and at least one second-degree relative with PC and no PC-associated genetic mutations. High risk consisted of >1 first-degree relatives with PC or PC-associated mutations (i.e. BRCA2, Lynch Syndrome, Familial Atypical Multiple Mole Melanoma Syndrome, STK11, or PALB2). All included patients had genetic counseling and a screening EUS done. Primary outcome was the detection of PC on EUS. Secondary outcomes assessed the evolution of psychological symptoms based on the Impact of Events Scale (IES) and Personal Consequences Questionnaire (PCQ) before and after the screening took place.

Results

A total of 122 patients had a screening EUS performed between 2013 and 2019; 60 were male, 55.8 years was the mean age, 78 were at high risk for PC, and 25 had PC-associated mutations. No pancreatic cancers were identified at the one-off EUS screening. Overall, patients' IES/PCQ scores did not change after screening and feedback of no malignancy, with the exception of females (less concerned about PC after screening EUS).

Conclusions

EUS did not detect any PCs in either a moderate- or high-risk population as a one-off screening method. The EUS procedure and genetic counseling improved psychological symptoms for the female subset of this population.

The significance of gene mutations across eight major cancer types

Mutations occur spontaneously, which can be induced by either chemicals (e.g. benzene) or biological factors (e.g. virus). Not all mutations cause noticeable changes in cellular functions. However, mutation in key cellular genes leads to developmental disorders. It is one of the main ways in which proto-oncogenes can be changed into their oncogenic state. The progressive accumulation of multiple mutations throughout life leads to cancer. In the past few decades, extensive research on cancer biology has discovered many genes and pathways having role in cancer development. In this review, we tried to summarize the current knowledge of mutational effect on different cancer types and its consequences in brief for future reference and guidance of researchers in cancer biology.

Analysis of Kras gene from induced pancreatic cancer rats administered with Momordicacharantia and Ocimumbasilicum leaf extracts

OBJECTIVE

To analyze K-ras gene from induced pancreatic cancer rats administered with Momordicacharantia and Ocimumbasilicum leaf extracts.

METHODS

Twenty-five (25) adult rats weighing between 90-120 g were divided into 5 groups namely RA, RB, RC, NC and PC, each group had 5 rats. The PC which served as the control was fed with normal fish meal and water ad libitum; the NC which is the negative control received 20 mg/ml/week of Nitrosamines only while other groups received different concentrations of aqueous extract of both M.charantia and O.basilicum (200 mg, 100 mg, 50 mg) and Nitrosamine. Qualitative phytochemical screening of the aqueous extract of both M.charantia and O.basilicum was carried out. The extraction of DNA was done using Jena Bioscience DNA preparation kit and the protocol was based on the spin column based genomic DNA purification from blood, animal and plant cells. Agarose gel electrophoresis was used to analyze the K-ras gene extracted from the pancreas tissues of experimental rats while hematoxylinand eosin staining was used for histological assay.

RESULTS

Phytochemical screening revealed the presence of alkaloids, tannins, flavonoids, saponins and glycosides in M.charantia while saponins, tannins and glycosides were discovered in O.basilicum. Significant reduction in the weight of rats treated with 200 mg of aqueous extracts of M.charantia and O.basilicum while rats that were dosed with nitrosamines only showed a slight increase in weight in the first three weeks when compared to the positive control. Histological studies revealed that there is both enlargement and reduction in the islet cell size, with one of the sections showing a normal islet cell size. While the agarose gel electrophoresis revealed that there may be possibility of prevention of damage to k-ras gene as a result of the effect of plants extract.

CONCLUSION

This work has shown that the leaf extracts of both M.charantia and O.basilicum will serve as a measure against induced pancreatic cancer in rats.

Current Molecular and Genetic Aspects of Pancreatic Cancer, the Role of Metastasis Associated Proteins (MTA): A Review

Purpose/aim: To focus on current molecular and genetic aspects and MTA proteins, since pancreatic cancer is a lethal malignant with poor prognosis. Early diagnosis is essential step, contributing to potential curative resection.

MATERIALS AND METHODS

A PubMed search of relevant articles published up to August 2016 was performed to identify current information about pancreatic cancer regarding molecular biomarkers, with emphasis on carcinogenesis, novel therapeutic targets, and MTA proteins.

RESULTS

Understanding the mechanisms involved in the process of carcinogenesis at the molecular level and the recognition of various oncogenes has opened new horizons for both diagnosis and targeted therapy. Metastasis associated (MTA) proteins (MTA1, MTA2, MTA3) comprise a well-established family of biomarkers. The oncogene MTA1 and its expression product MTA1 protein are the most important and adequately studied in the current research. It defines the growth, local invasiveness, lymphatic spread, and metastatic capacity of various malignancies such as colorectal or gastric cancer including also pancreatic cancer. This protein is associated with malignant potential and biological behavior. Consequently, it could contribute to cancer detection since the first stages of carcinogenesis, as well as in prediction of its malignant differentiation grade. The pre-operative information of the possibility of lymph node involvement may also affect the attempt and the extent of curative resection and lymphadenectomy.

CONCLUSIONS

Carcinogenesis and implicated oncogenes, either activators or repressors, concentrate much research interest, as well as being useful as biomarkers and for targeted therapy. MTA proteins could become useful diagnostic and prognostic biomarkers in current management of pancreatic cancer.

LITAF is a potential tumor suppressor in pancreatic cancer

Early diagnosis of pancreatic cancer, one of the most deadly cancers with low survival rates, is difficult, and effective biomarkers are urgently needed. Lipopolysaccharide-induced tumor necrosis factor-α factor (LITAF) has been recently proposed as a potential tumor suppressor gene in several types of cancer. Here, we analyzed the biological function of LITAF in pancreatic cancer. The LITAF gene and protein levels were decreased in pancreatic tumor tissues compared with their paired adjacent non-cancerous tissues. In addition, patients with the lower LITAF protein expression had lower disease-free survival rates. The decreased LITAF expression correlated with LITAF promoter hypermethylation in pancreatic cancer cells and tissues. Moreover, promoter demethylation dose-dependently increased the LITAF transcription. Importantly, LITAF demethylation suppressed proliferation and cell cycle progression, and enhanced apoptosis of pancreatic cancer cells. Together, our results indicate that LITAF functions as a tumor suppressor gene in pancreatic cancer cells, and might serve as a novel biomarker for early diagnosis of pancreatic cancer.

A network-based pathway-expanding approach for pathway analysis

Background

Pathway analysis combining multiple types of high-throughput data, such as genomics and proteomics, has become the first choice to gain insights into the pathogenesis of complex diseases. Currently, several pathway analysis methods have been developed to study complex diseases. However, these methods did not take into account the interaction between internal and external genes of the pathway and between pathways. Hence, these approaches still face some challenges. Here, we propose a network-based pathway-expanding approach that takes the topological structures of biological networks into account.

Results

First, two weighted gene-gene interaction networks (tumor and normal) are constructed integrating protein-protein interaction(PPI) information, gene expression data and pathway databases. Then, they are used to identify significant pathways through testing the difference of topological structures of expanded pathways in the two weighted networks. The proposed method is employed to analyze two breast cancer data. As a result, the top 15 pathways identified using the proposed method are supported by biological knowledge from the published literatures and other methods. In addition, the proposed method is also compared with other methods, such as GSEA and SPIA, and estimated using the classification performance of the top 15 expanded pathways.

Conclusions

A novel network-based pathway-expanding approach is proposed to avoid the limitations of existing pathway analysis approaches. Experimental results indicate that the proposed method can accurately and reliably identify significant pathways which are related to the corresponding disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s12859-016-1333-x) contains supplementary material, which is available to authorized users.

Hereditary melanoma: Update on syndromes and management: Genetics of familial atypical multiple mole melanoma syndrome

Malignant melanoma is considered the most lethal skin cancer if it is not detected and treated during its early stages. About 10% of melanoma patients report a family history of melanoma; however, individuals with features of true hereditary melanoma (ie, unilateral lineage, multigenerational, multiple primary lesions, and early onset of disease) are in fact quite rare. Although many new loci have been implicated in hereditary melanoma, CDKN2A mutations remain the most common. Familial melanoma in the presence of multiple atypical nevi should raise suspicion for a germline CDKN2A mutation. These patients have a high risk of developing multiple primary melanomas and internal organ malignancies, especially pancreatic cancer; therefore, a multidisciplinary approach is necessary in many cases. The value of dermoscopic examination and total body photography performed at regular intervals has been suggested by a number of studies, and should therefore be considered for these patients and their first-degree relatives. In addition, genetic counseling with the possibility of testing can be a valuable adjunct for familial melanoma patients. This must be performed with care, however, and only by qualified individuals trained in cancer risk analysis.

Clinical importance of Familial Pancreatic Cancer Registry in Japan: a report from kick-off meeting at International Symposium on Pancreas Cancer 2012

Pancreatic cancer is still a highly lethal disease with a 5-year survival rate of approximately 5 %. Early detection offers one of the best hopes for improving survival. Previous cohort studies and case-control studies showed that 4-10 % of pancreatic cancers have a hereditary basis, and individuals with a family history have an increased risk of developing pancreatic and extra-pancreatic malignancies. Since individuals with a family history of pancreatic cancer and those with a known genetic syndrome that predisposes to pancreatic cancer will be the first to benefit from early detection tests as they become available, familial pancreatic cancer (FPC) registries have been established in the US and Europe, but not yet in Japan. Such registries form the basis for epidemiological studies, clinical trials, and basic research on familial pancreatic cancer. There is a need for FPC registries in Japan as cancer risk varies among different populations and discoveries made in Western populations may not translate to the Japanese population. These registries in Japan will align with ongoing international efforts and add to a better understanding of the natural history, risk factors, screening strategies, and responsible genes, for improving survival of this dismal disease.

Familial and sporadic pancreatic cancer share the same molecular pathogenesis

Pancreatic ductal adenocarcinoma (PDAC) is nearly uniformly lethal, with a median overall survival in 2014 of only 6 months. The genetic progression of sporadic PDAC (SPC) is well established, with common somatic alterations in KRAS, p16/CDKN2A, TP53, and SMAD4/DPC4. Up to 10 % of all PDAC cases occur in families with two or more affected first-degree relatives (familial pancreatic cancer, FPC), but these cases do not appear to present at an obviously earlier age of onset. This is unusual because most familial cancer syndrome patients present at a substantially younger age than that of corresponding sporadic cases. Here we collated the reported age of onset for FPC and SPC from the literature. We then used an integrated approach including whole exomic sequencing, whole genome sequencing, RNA sequencing, and high density SNP microarrays to study a cohort of FPC cell lines and corresponding germline samples. We show that the four major SPC driver genes are also consistently altered in FPC and that each of the four detection strategies was able to detect the mutations in these genes, with one exception. We conclude that FPC undergoes a similar somatic molecular pathogenesis as SPC, and that the same gene targets can be used for early detection and minimal residual disease testing in FPC patients.

PanGen-Fam: Spanish registry of hereditary pancreatic cancer

PURPOSE

To describe the organisation of the registry and the preliminary results in terms of characteristics of high-risk pancreatic ductal adenocarcinoma (PDAC) families recruited to date and findings of the screening programme. To compare early onset sporadic cases (⩽50 years), sporadic cases (>50 years) and cases with family history of cancer, for PDAC possible risk factors.

METHODS/PATIENTS

Families with hereditary cancer syndromes predisposing to PDAC were recruited from two main sources: Spanish hospitals participating in PanGenEU, a pan-European multicentre case-control study, and their genetic counseling unit. Individuals at high-risk of PDAC were enrolled into a screening programme, consisting of Endoscopic ultrasound, computerised tomography, magnetic resonance imaging. Genetic testing of candidate genes was offered according to each patient's risk.

RESULTS

Among 577 consecutive PDAC cases, recruited via PanGenEU, 36 (6%) had ⩾2 first-degree relative with PDAC: Familial pancreatic cancer (FPC). So far PanGen-Fam has recruited 42 high-risk PDAC families; 25 (60%) had FPC. Five index cases with cancer were positive for BRCA2 and one for BRCA1 germline mutations. In the second year of prospective PDAC screening, one neuroendocrine tumour and a high-grade dysplasia lesion suspicious of carcinoma were diagnosed among 41 high-risk individuals. Furthermore EUS detected chronic-pancreatitis-like parenchymal changes in 15 patients.

CONCLUDING STATEMENT

The identification and recruitment of PDAC high-risk families into the PanGen-Fam registry provides an opportunity to detect early onset cancer and precursor pancreatic cancer lesions at a potentially curative stage and to increase the knowledge of the natural history of the disease.

Demographics, epidemiology, and inheritance of pancreatic ductal adenocarcinoma

Pancreatic cancer (PC) will affect 48,960 persons in the United States and will result in 40,560 deaths in 2015, according to the American Cancer Society. On a global basis, at least 337,000 persons will be diagnosed with PC. The incidence of PC has increased slightly in the United States, though worldwide cases are likely to increase substantially due to the influence of cigarette smoking, rising obesity and type II diabetes. The development of PC is related to a state of chronic inflammation and insulin resistance. Well-established environmental and personal risk factors for PC include advancing age, cigarette smoking, second-hand tobacco smoke exposure, obesity, inherited familial cancer syndromes, Ashkenazi Jewish heritage, chronic pancreatitis, dietary factors, and diabetes. Other identified associations are human immunodeficiency virus infection, ABO blood group polymorphisms, hepatitis B virus, and Helicobacter pylori.

Identification of dysregulated pathways associated with pancreatic cancer by survival analysis

In order to identify the dysregulated pathways associated with pancreatic cancer, the fourth leading cause of cancer mortality in the United States, tumor and non-tumor samples were systematically analyzed in the present study. Initially, dysregulated genes in pancreatic cancer were identified using paired t-test. Subsequently, dysregulated biological pathways involved in the development of pancreatic cancer were identified by enrichment analysis. Finally, individual survival analysis of the significantly dysregulated functions was conducted at the pathway level. Our results indicated that the pathway named ̔Pathways in cancer was significantly correlated with survival time. In addition, the mean survival time of individual and genetic variation demonstrated a significantly negative correlation, that is, the lower the genetic variation, the longer the survival time. Furthermore, detailed analysis of genes on the pathway named ̔Pathways in cancer denoted that this pathway involved multiple cancer hallmark signals and several dysregulated cancer genes, including tumor protein p53, myelocytomatosis, Kirsten rat sarcoma, phosphatidylinositol 3-kinase, v-raf murine sarcoma viral oncogene homolog B1 and cyclin-dependent kinase inhibitor 2A. According to the DrugBank database, certain oncogenes have been validated to be the targets of drugs, including Sorafenib, Trastuzumab, Imatinib and Paclitaxel or were under investigation. An improved understanding of the pathophysiology of pancreatic cancer has been achieved based on our results and the present study aimed to provide guidance for the development of drugs to treat pancreatic cancer.

The clinical utility of biomarkers in the management of pancreatic adenocarcinoma

Pancreatic cancer is the fourth leading cause of cancer-related deaths in the United States and survival rates have seen minimal improvement over the past few decades. Although results are poor, surgical resection is considered the only curative therapeutic intervention for pancreatic cancer, thereby emphasizing the significance of effective diagnostic and prognostic tools to improve outcomes. As such, biomarkers play a promising role in the development of personalized treatments for patients with pancreatic cancer. Prognostic biomarkers, such as serum carbohydrate antigen 19-9 in particular, as well as cancer stem cell markers, provide valuable insight into the biological processes of an individual and their likely course of disease. This, consequently, allows for the assessment of optimal therapeutic intervention. Furthermore, current efforts target putative predictive biomarkers such as BRCA2, PALB2, and SPARC so as to determine their influence on tumor response on targeted therapies. As research progresses, more evidence will provide clinicians with guidelines on the utilization of biomarkers to accurately stage and tailor personalized treatment to the needs of specific patients with pancreatic cancer.

Familial pancreatic cancer--status quo

INTRODUCTION

Familial pancreatic cancer (FPC) is defined by families with at least two first-degree relatives with confirmed pancreatic ductal adenocarcinoma (PDAC) that do not fulfill the criteria of other inherited tumor syndromes with an increased risk for the development of PDAC, such as hereditary pancreatitis or hereditary breast and ovarian cancer. FPC is mostly autosomal dominant inherited and presents with a heterogeneous phenotype. Although the major gene defect has not yet been identified, some important germline mutations in the BRCA2-, PALB2-, and ATM-genes are causative in some FPC families.

FPC SCREENING

It is suggested by experts to include high-risk individuals in a screening program with a multidisciplinary approach under research protocol conditions. However, neither biomarkers nor reliable imaging modalities for the detection of high-grade precursor lesions are yet available. Most screening programs are currently based on endoscopic ultrasound and magnetic resonance imaging, and first data demonstrated that precursor lesions (pancreatic intraepithelial neoplasia, intraductal papillary mucinous neoplasm) of PDAC can be identified. Timing and extent of surgery are still a matter of debate.

SCOPE OF THE REVIEW

The present review focuses on the clinical phenotype of FPC, its histopathological characteristics, known underlying genetic changes, genetic counseling, and screening.

Demographics and epidemiology of pancreatic cancer

Pancreatic cancer affects 44,000 Americans and at least 250,000 individuals worldwide annually. The incidence is slowly increasing after a recent period of decline. Cases are predicted to increase globally because of increased longevity and the widespread adoption of cancer-causing behaviors, such as cigarette smoking, dietary indiscretion, and a global increase in diabetes. Well-known risk factors for pancreatic cancer are advancing age, tobacco smoking, obesity, certain inherited familial disorders, second-hand smoke exposure, chronic pancreatitis, and diabetes. Associations with human immunodeficiency virus, ABO blood group, hepatitis B virus, human immunodeficiency virus, and Helicobacter pylori have also been identified.

Familial pancreatic cancer: current status

The term 'familial pancreatic cancer (FPC) defines families with at least two first-degree relatives with confirmed pancreatic cancer that do not fulfill the criteria of other inherited cancer syndromes with an increased risk for the development of PC, such as Peutz-Jeghers syndrome, hereditary pancreatitis and hereditary breast and ovarian cancer. FPC is a mostly autosomal dominant inherited tumor syndrome with a heterogeneous phenotype. The major genetic defect has not been identified yet, although mutations, for example in the BRCA2 gene, could be identified in some FPC families. Nevertheless, most experts recommend participation in screening and surveillance programs to high-risk individuals. Most board-approved screening programs are based on endoscopic ultrasound. The first data on the prospective screening of high-risk individuals have demonstrated that precursor lesions of PC can be identified, but false-positive findings do occur.

The prevention and genetics of pancreatic cancer: a programmatic approach

Pancreatic cancer (PC) is typically a fatal disease due to its rapid growth and the lack of early diagnostic -techniques. Because approximately 10% of PCs are attributable to a hereditary susceptibility, identifying and studying patients with a family history of PC or known genetic predisposition to PC can improve the prevention, diagnosis, and treatment of PC. A skilled team of study investigators, physicians, genetic counselors, and data managers must work with patients and families to confidentially store and organize data from PC patients and high-risk patients. This data, collected in conjunction with patients' tissue and blood specimens, will contribute to the understanding of the biology, etiology, and epidemiology of PC, and can ultimately improve screening and management for patients with an underlying hereditary predisposition to PC.

Identifying people at a high risk of developing pancreatic cancer

Pancreatic cancer is a leading cause of cancer death, and it has the poorest prognosis of any major tumour type. Familial pancreatic cancer registries are important for investigating the genetic aetiology of this devastating disease. Using data from our familial pancreatic cancer registry and other registries, this Review discusses the usefulness of family registries in the study of pancreatic and other cancers, and also how such registries provide a unique opportunity for laboratory, population and clinical research.

Familial pancreatic cancer--current knowledge

Familial pancreatic cancer (FPC) describes families with at least two first-degree relatives with confirmed exocrine pancreatic cancer that do not fulfil the criteria of other inherited tumour syndromes with increased risks of pancreatic cancer, such as Peutz-Jeghers syndrome, hereditary pancreatitis, and hereditary breast and ovarian cancer. The inheritance of FPC is mostly autosomal dominant and with a heterogeneous phenotype. The major gene defect is yet to be identified, although germline mutations in BRCA2, PALB2 and ATM are causative in some FPC families. Expert consensus conferences considered it appropriate to screen for pancreatic cancer in high-risk individuals using a multidisciplinary approach under research protocol conditions. However, neither biomarkers nor reliable imaging modalities for the detection of high-grade precursor lesions are yet available. Most screening programmes are currently based on findings from endoscopic ultrasonography and MRI, and data has demonstrated that precursor lesions of pancreatic cancer can be identified. No consensus exists regarding the age to initiate or stop screening and the optimal intervals for follow-up. Timing and extent of surgery as a treatment for FPC are debated. This Review focuses on the clinical phenotype of FPC, its histopathological characteristics, known underlying genetic changes and associated genetic counselling and screening.

Individuals at high-risk for pancreatic cancer development: management options and the role of surgery

Pancreatic cancer (PC) is a highly lethal disease. Despite advances regarding the safety and long-term results of pancreatectomies, early diagnosis remains the only hope for cure. This necessitates the implementation of an intensive screening program (based mainly on modern imaging), which - given the incidence of PC - is not cost effective for the general population. However, this screening program is recommended for individuals at high-risk for PC development. Indications for screening include the following three clinical settings: hereditary cancer predisposition syndromes associated with PC, hereditary pancreatitis and familial pancreatic cancer syndrome. The aim of this strategy is to identify pre-invasive (precursor) lesions, which are curable. Surgery is recommended in the presence of recognizable lesion on imaging lesions. Partial (anatomic) pancreatectomy - depending on the location of the suspicious lesion - is the most widely accepted type of surgical intervention in this setting; occasionally, however, total pancreatectomy may be required, in carefully selected patients. Despite that experience still remains limited, there is evidence that this aggressive strategy allows early detection of neoplastic lesions, thereby improving the effectiveness of surgery and prognosis.

German national case collection for familial pancreatic cancer (FaPaCa): ten years experience

Familial pancreatic cancer (FPC) is a rare hereditary tumor syndrome. The 10-years experience of the national case collection for familial pancreatic cancer of Germany (FaPaCa) is reported. Since 1999 FaPaCa has collected families with at least two first-degree relatives with confirmed pancreatic cancer (PC), who did not fulfill the criteria of other hereditary tumor syndromes. Histopathological verification of tumor diagnoses, and genetic counseling were prerequisites for enrollment of families in FaPaCa. 94 of 452 evaluated families fulfilled the criteria for partaking in FaPaCa. PC represented the sole tumor entity in 38 (40%) families. In 56 families additional tumor types occurred, including breast cancer (n = 28), colon cancer (n = 20) and lung cancer (n = 11). In 70 (74%) families the pattern of inheritance was consistent with an autosomal dominant trait. Compared to the preceding generation, a younger age of onset was observed in the offspring of PC patients (median: 57 vs. 69 years), indicating anticipation. Mutation analyses of BRCA2, PALB2, CDKN2a, RNASEL, STK11, NOD2, CHEK2 and PALLD, revealed deleterious causative germline mutations of BRCA2 and PALB2 in 2 of 70 (3%) and 2 of 41 (4.9%) German FPC families, respectively. Prospective PC screening with EUS, MRI and MRCP detected precancerous lesions (IPMN, multifocal PanIN2/3) or carcinoma in 5.5% (4 of 72) to 12.5% (9 of 72) of individuals at risk, depending on histological verification. Appropriate inclusion of families at high risk for PC in registries, such as FaPaCa, provides a unique and excellent tool to gain clinical and genetic knowledge of FPC. Focused research projects can be conducted most efficiently, when data of different FPC registries are combined.

Moderators of cancer-related distress and worry after a pancreatic cancer genetic counseling and screening intervention

OBJECTIVES

Although the hereditary breast and ovarian cancer literature has demonstrated short-term gains in psychological adjustment following genetic counseling, there has been limited research examining long-term outcomes and moderators. Moreover, there has been minimal research into the psychological effects of this intervention in populations at high risk for pancreatic cancer. This study examines the long-term effects of pancreatic cancer screening and genetic counseling on cancer-related distress and cancer worry in a high-risk population at 1-year follow-up. Additionally, this study explores potential moderators of the effectiveness of this intervention.

METHODS

One hundred twenty-nine participants with familial pancreatic cancer or with the BRCA2 gene mutation completed a baseline questionnaire prior to their first pancreatic cancer screening and genetic counseling session. Participants also completed questionnaires at 3- and 12-month follow-up.

RESULTS

Cancer-related intrusive thoughts decreased significantly over time, whereas cancer-related worry decreased at 3 months and showed a small but significant increase at 1 year. Age and baseline distress exhibited moderator effects. Younger individuals showed a significant decrease in cancer-related intrusive thoughts, cancer-related avoidant thoughts, and cancer worry. Additionally, individuals with greater baseline distress showed a significant decrease in cancer-related intrusive thoughts over time.

CONCLUSIONS

Analysis of the long-term effects of pancreatic cancer screening and genetic testing reveal psychological gains that are maintained at 1-year follow-up. This intervention is particularly effective for younger participants and individuals with greater baseline distress.

Hereditary pancreatic and hepatobiliary cancers

Hereditary etiologies of pancreatic and hepatobiliary cancers are increasingly recognized. An estimated >10% of pancreatic and increasing number of hepatobiliary cancers are hereditary. The cumulative risk of hereditary pancreatic cancer ranges from measurable but negligible in cystic fibrosis to a sobering 70% in cases of hereditary pancreatitis. Candidates for pancreatic cancer surveillance are those with a risk pancreatic cancer estimated to be >10-fold that of the normal population. Screening for pancreatic cancer in high-risk individuals is typically performed by endoscopic ultrasound and should begin at least 10 years prior to the age of the youngest affected relative. Disease states known to be associated with increased risk of hepatocellular cancer include hereditary hemochromatosis, autoimmune hepatitis, porphyria, and α1-antitrypsin deficiency, with relative risks as high as 36-fold. Although much less is known about hereditary bile-duct cancers, Muir-Torre syndrome and bile salt export pump deficiency are diseases whose association with hereditary carcinogenesis is under investigation.

Prevalence of BRCA2 and CDKN2a mutations in German familial pancreatic cancer families

Previous small scale studies reported that deleterious BRCA2 and CDKN2a germline mutations contribute to a subset of families with inherited pancreatic cancer. As the prevalence of those mutations in the setting of familial pancreatic cancer is still not well defined for the German population, we evaluated the presence of BRCA2 and CDKN2a germline mutations in a large cohort of familial pancreatic cancer (FPC) families from the German National Case Collection for Familial Pancreatic Cancer (FaPaCa). Fifty-six FPC families with at least two-first-degree relatives with confirmed pancreatic cancer that did not fulfill the criteria of other tumor predisposition syndromes, were analyzed for BRCA2 and CDKN2a germline mutations by DHPLC and/or direct sequencing. No deleterious CDKN2a mutations were identified in our families suggesting that CDKN2a mutations are unlikely to predispose PC in FPC families without melanoma. No deleterious BRCA2 mutations, but 6 unclassified variants, were detected in our FPC collection. Combining the prevalence of deleterious BRCA2 germline mutations from our previous separate study with the data from this study we were able to much more accurately estimate the BRCA2 carrier frequency for FPC families in the German population. A total of two mutations and 6 unclassified variants (mutation range: 2.8-11.4%) were thus identified in 70 German FPC families, indicating that the prevalence of BRCA2 mutations in the German FPC population is less frequent than previously reported.

Intraductal papillary mucinous neoplasm: a clinicopathologic review

Intraductal papillary mucinous neoplasm (IPMN) is an intraductal mucin-producing epithelial neoplasm that arises from the main pancreatic duct (MD-IPMN), secondary branch ducts (BD-IPMN), or both (mixed type; Mix-IPMN). Neoplastic progression from benign adenoma to invasive adenocarcinoma has not been proven but is generally thought to occur. With increasing recognition of IPMN, our understanding of the diagnosis and management of the tumors is evolving. At present, treatment options for patients with IPMN range from observation to pancreatic resection depending on the natural history of the lesion. This review focuses on currently available data that guide management decisions for patients with IPMN.

Adjuvant chemoradiotherapy after pancreatic resection for invasive carcinoma associated with intraductal papillary mucinous neoplasm of the pancreas

PURPOSE

Intraductal papillary mucinous neoplasms are mucin-producing cystic neoplasms of the pancreas. One-third are associated with invasive carcinoma. We examined the benefit of adjuvant chemoradiotherapy (CRT) for this cohort.

METHODS AND MATERIALS

Patients who had undergone pancreatic resection at Johns Hopkins Hospital between 1999 and 2004 were reviewed. Of these patients, 83 with a resected pancreatic mass were found to have an intraductal papillary mucinous neoplasm with invasive carcinoma, 70 of whom met inclusion criteria for the present analysis.

RESULTS

The median age at surgery was 68 years. The median tumor size was 3.3 cm, and invasive carcinoma was present at the margin in 16% of the patients. Of the 70 patients, 50% had metastases to the lymph nodes and 64% had Stage II disease. The median survival was 28.0 months, and 2- and 5-year survival rate was 57% and 45%, respectively. Of the 70 patients, 40 had undergone adjuvant CRT. Those receiving CRT were more likely to have lymph node metastases, perineural invasion, and Stage II-III disease. The 2-year survival rate after surgery with vs. without CRT was 55.8% vs. 59.3%, respectively (p = NS). Patients with lymph node metastases or positive surgical margins benefited significantly from CRT (p = .047 and p = .042, respectively). On multivariate analysis, adjuvant CRT was associated with improved survival, with a relative risk of 0.43 (95% confidence interval, 0.19-0.95; p = .044) after adjusting for major confounders.

CONCLUSION

Adjuvant CRT conferred a 57% decrease in the relative risk of mortality after pancreaticoduodenectomy for intraductal papillary mucinous neoplasms with an associated invasive component after adjusting for major confounders. Patients with lymph node metastases or positive margins appeared to particularly benefit from CRT after definitive surgery.

Assessment of "gene-environment" interaction in cases of familial and sporadic pancreatic cancer

INTRODUCTION

Pancreatic cancer (PC) is the fourth leading cause of cancer death in the United States. This study characterizes one of the largest national registries of familial PC (FPC) and sporadic PC (SPC), focusing on demographics, clinical factors, self-reported environmental and occupational lifetime exposures, and survival status.

BACKGROUND

Reported risk factors for PC include advancing age, a family history of PC, high-risk inherited syndromes, cigarette, cigar, and pipe smoking, exposure to occupational and environmental carcinogens, African-American race, high fat/high cholesterol diet, obesity, chronic pancreatitis, and diabetes mellitus.

PATIENTS AND METHODS

This retrospective cross-sectional, case-only analysis includes cases of FPC (n = 569) and SPC (n = 689) from the Johns Hopkins National Familial Pancreas Tumor Registry (NFPTR) enrolled between 1994 and 2005.

RESULTS

FPC smokers with environmental tobacco smoke (ETS) exposure were diagnosed at a significantly younger mean age (63.7 years) as compared to FPC non-smokers without ETS exposure (66.6 years; p = 0.05). Non-smoker ETS-exposed cases were diagnosed with PC at a significantly younger mean age (64.0 years) compared to non-smoker non-ETS-exposed cases (66.5 years) (p < 0.0004). The mean age at diagnosis for Ashkenazi Jewish SPC subjects was significantly younger (by 2.1 years) than Ashkenazi Jewish FPC cases (p = 0.05). In addition, Ashkenazi Jewish FPC subjects who smoked were diagnosed 5.9 years earlier than Ashkenazi Jewish FPC non-smokers (p = 0.05). The median length of survival for unresected FPC cases was significantly shorter (168 days) as compared to unresected SPC cases (200 days) (p = 0.04). Survival was improved in resected cases, 713 days for FPC cases and 727 days for SPC cases, but was not significantly different between the groups (p = 0.4). Mild to moderate multiplicative interaction was found between a family history of PC and exposure to asbestos, environmental radon, and environmental tobacco smoke (ETS), as evidenced by odds ratios >1.0.

CONCLUSIONS

These are the first data to show that occupational and environmental exposures may act synergistically with inherited or acquired genetic polymorphisms, resulting in earlier occurrence of PC. Exposure to cigarette smoking and ETS exposure in non-smokers when younger than 21 years of age are associated with a younger mean age of diagnosis in FPC and SPC cases and Ashkenazi Jewish smokers, when compared to non-exposed cases. Risk prediction models which take into account environmental exposures as well as family history may more accurately predict the risk of PC. High-risk individuals will likely benefit from early identification of pre-malignant lesions and molecular profiling, as methods of early detection, prevention, and personalized therapy.

Pancreatic cancer surveillance among high-risk populations: knowledge and intent

Pancreatic cancer is the fourth most common cancer in both men and women in the United States. It has the lowest survival rate of all cancers, largely due to the presence of non-specific symptoms, leading to diagnosis at advanced stages. While the majority of cases of pancreatic cancer are sporadic, up to 10% may be associated with an inherited predisposition. Currently, there is no standard screening protocol for pancreatic cancer, although this will change in the future as technology improves. Additionally, there is little information regarding the perceptions and intent to screen for pancreatic cancer among those with an increased risk due to a hereditary cancer predisposition syndrome, which was the objective of this study. Focus groups and individual telephone interviews were conducted, with questions focused on knowledge about pancreatic cancer and screening, perceived motivators, and perceived barriers related to each of the screening techniques currently available. Participants were recruited from the High Risk Breast Cancer and Pancreatic Cancer Registries at Huntsman Cancer Institute. The findings of this study indicated that individuals from these high-risk groups have low knowledge levels of pancreatic cancer screening, despite their desire for this information. Motivation to undergo a particular screening technique is related to whether the test is recommended by a physician, cost, degree of invasiveness, and comfort level. This information is useful to genetics professionals who counsel at-risk individuals, physicians who formulate patient care plans, and translational researchers who are developing pancreatic screening methods.

Multidisciplinary approach to diagnosis and management of intraductal papillary mucinous neoplasms of the pancreas

Intraductal papillary mucinous neoplasms have gained recognition in recent years as premalignant precursors to pancreatic cancer that enable early detection and often are found incidentally at imaging. Accurate diagnosis and optimal, finely tuned management of these lesions are important and require collaboration across various disciplines, including radiology, endoscopy, surgery, and pathology. Several imaging modalities can visualize these lesions adequately, each with specific advantages and disadvantages. Multidetector computed tomography and magnetic resonance cholangiopancreatography are generally the first-line imaging modalities; endoscopic imaging such as endoscopic ultrasound and endoscopic retrograde cholangiopancreatography are beneficial when the former 2 modalities are equivocal. Surgical candidates generally include patients with main duct lesions or branch duct lesions greater than 3 cm or any possessing a solid component. A management algorithm indicating when surgery should be pursued is proposed. For nonsurgical and postsurgical patients, follow-up management is important to monitor growth and recurrence, and risks from repeated radiation exposure should be taken into account. Furthermore, issues of multifocality and increased predisposition of the pancreas to ductal adenocarcinoma must be addressed at follow-up evaluation. A follow-up management algorithm also is proposed in this review.

Pancreatic intraepithelial neoplasia revisited and updated

Most pancreatic neoplasms are classified as ductal adenocarcinoma because they show a ductal phenotype, making a ductal origin very likely. The duct lesions that may give rise to pancreatic ductal adenocarcinoma have been called pancreatic intraepithelial neoplasia (PanIN). A classification system for these lesions distinguishes between three grades of PanIN. Molecular studies revealed that PanIN-2 and PanIN-3 lesions represent a distinct step towards invasive carcinoma. While high-grade PanINs are extremely rare in the normal pancreas, low-grade PanINs are common in individuals older than 40 years and may be associated with lobular fibrosis and intraductal papillary mucinous neoplasms of the gastric type. This disease spectrum has also been described in members of kindreds with familial pancreatic cancer. The natural history and cause of PanINs are unknown. As PanIN-1 lesions entail little risk, while PanIN-3 lesions are high-risk lesions, it would be of interest to target PanIN-2 lesions, which can be regarded as the starting point of progressive neoplastic changes that lead to invasive pancreatic ductal adenocarcinoma. Global gene expression analysis identified several differentially expressed genes which show enhanced expression in PanINs and may be used as potential biomarkers to facilitate diagnosis and therapy.

[Hereditary pancreatic cancer]

An inherited predisposition to pancreatic cancer (PC) is prevalent in about 3% of PC cases and is currently believed to occur in three distinct clinical settings, (1) hereditary tumour predisposition syndromes with an increased risk of PC such as Peutz-Jeghers syndrome and familial atypical multiple mole melanoma, (2) hereditary pancreatitis and cystic fibrosis, in which genetically determined early-age changes of the pancreas can predispose to the development of PC, and (3) familial pancreatic cancer syndrome (FPC). According to a recent consensus conference, high-risk individuals from PC-prone families should be enrolled in board-approved, prospective, controlled screening programs at expert centres. Based on the available data, prophylactic pancreatectomy is not indicated, since the underlying causative gene defect of the FPC syndrome is still unknown and the penetrance of PC in other tumour predisposition syndromes is either low or yet undetermined. In case of the diagnosis of a PC or high-grade precursor lesions, a prophylactic extension of the resection can be considered, since patients with hereditary PC often develop multifocal pancreatic lesions.

Family history is a significant risk factor for pancreatic cancer: results from a systematic review and meta-analysis

Epidemiologic evidence suggests a family history of pancreatic cancer (PC) is a risk factor for the disease, yet the magnitude of risk varies between studies. We performed a systematic review of studies that quantified familial risks of PC, and through a meta-analysis, obtained more precise estimates of familial risk. A MEDLINE search identified published studies that reported relative risks (RR) of PC associated with a family history of the disease. A random effects model was used to summarize study-specific RRs and 95% confidence intervals (CI). Sensitivity and sub-group analyzes were performed. Seven case-control and two cohort studies involving 6,568 PC cases were identified. There was no evidence of statistical heterogeneity between studies (I(2) = 0%; P = 0.483). Results from case-control (RR = 2.82; 95% CI: 1.99-3.66) and cohort (RR = 1.62; 95% CI: 1.28-1.97) studies showed a significant increase in PC risk associated with having an affected relative, with an overall summary RR = 1.80 (95% CI: 1.48-2.12). Similar RR were observed for early (RR = 2.69; 95% CI: 0.56-4.82) and later (RR = 3.41; 95% CI: 0.79-6.03) onset disease in the index case. Data was too sparse to generate an overall summary RR based on the number or type of affected relatives. Individuals with a family history of PC have nearly a two-fold increased risk for developing PC compared to those without such a history. Families with two or more PC cases may benefit from comprehensive risk assessment that involves collection of detailed family history information and data regarding various risk factors for PC, especially smoking history. Those at highest risk may be referred to screening programs and studies; these are important steps toward early detection and greater odds of surviving this disease.

Identifying molecular markers for the early detection of pancreatic neoplasia

Pancreatic cancer is the fourth most common cause of cancer death in the United States. There is a great need for better diagnostic markers of pancreatic neoplasia. Better markers would improve the early diagnosis of pancreatic cancer and allow more patients to undergo curative surgical resection. Identifying individuals at high risk of developing pancreatic cancer and applying markers that could identify precancerous lesions of the pancreas in these individuals could allow such lesions to be resected before the development of pancreatic cancer. As we continue to characterize the genetic, epigenetic, and proteomics alterations that occur in pancreatic cancers and their percursors, better diagnostic markers of pancreatic cancer are expected to follow.

Cystic lesions of the pancreas

Although cystic tumors of the pancreas are relatively rare, they constitute an increasingly important category. Advances in imaging and interventional techniques and the sharp drop in the mortality rate of pancreatic surgery have rendered pancreatic biopsies and resections commonplace specimens. Consequently, in the past two decades, the nature of many cystic tumors in this organ has been better characterized. The names of some existing entities were revised; for example, what was known as papillary-cystic tumor is now regarded as solid-pseudopapillary tumor. New entities, in particular, intraductal papillary mucinous neoplasm and its variants, such as oncocytic and intestinal subtypes were recognized. The importance of clinical and pathologic correlation in the evaluation of these lesions was appreciated, in particular, with regards to the multifocality of these lesions, their association with invasive carcinomas, and thus their 'preinvasive' nature. Consensus criteria for the distinction of these from the ordinary precursors of adenocarcinoma, the pancreatic intraepithelial neoplasia, were established. The definition of mucinous cystic neoplasms was refined; ovarian-like stroma has now become almost a requirement for the diagnosis of mucinous cystic neoplasia, and defined as such, the propensity of these tumors to occur in perimenopausal women became even more striking. The validity and clinical value of classifying the pancreatic cysts of mucinous type as adenoma, borderline, CIS and invasive have been established. Related to this, the importance of thorough sampling in accurate classification of these mucinous lesions was recognized. Greater accessibility of the pancreas afforded by improved invasive as well as noninvasive modalities has also increased the detection of otherwise clinically silent cystic tumors, which has led to the recognition of more innocuous entities such as acinar cell cystadenoma and squamoid cyst of pancreatic ducts. As the significance of the cystic lesions emerged, cystic forms of otherwise typically solid tumors were also better characterized. Thus, significant developments have taken place in the classification and our understanding of pancreatic cystic tumors in the past few years, and experience with these lesions is likely to grow exponentially in the coming years.

Pancreatic cancer genetic epidemiology consortium

We have organized the Pancreatic Cancer Genetic Epidemiology (PACGENE) Consortium to identify susceptibility genes in familial pancreatic cancer (FPC). The Consortium comprises seven data collection centers, a statistical genetics core, and a pathology/archival genotyping core. We recruit kindreds containing two or more affected blood relatives ascertained through incident pancreatic adenocarcinoma cases, physician referrals, and/or through Internet recruitment. Accrual to a database containing core clinical, demographic, lifestyle, and family history information from questionnaires is ongoing, along with biospecimen collection. To date, 13,147 patients have been screened for family history, of whom 476 (50% male) probands and 1,912 of their adult (99% unaffected) relatives have been enrolled. Of these, 379 kindreds meet criteria for FPC, having at least two first-degree relatives with pancreatic cancer. Cumulative incidence curves using available age of diagnosis (onset) among and affected relatives were compared with those for incident pancreatic cancer cases reported to 13 U.S. Surveillance Epidemiology and End Results (SEER) sites from 1973 to 2000 (N = 72,700). The mean age +/- SD at diagnosis among 466 PACGENE probands and 670 affected relatives was 64.1 +/- 11.8 and was 65.4 +/- 11.6 for the subset of 369 FPC probands and 429 relatives. Both samples were significantly younger than the mean age at diagnosis in the SEER population (70.0 +/- 12.1 years; differences in curves versus SEER, P < 0.001). Age at diagnosis (excluding probands) in FPC kindreds does not decrease with increasing number of affected individuals. In our sample, younger age at diagnosis was observed whether we grouped probands by recruitment sites that predominantly recruited through high-risk referrals, or through screening all pancreatic cancer patients for family history. Linkage studies are ongoing. The PACGENE Consortium will be a valuable family-based resource that will greatly enhance genetic epidemiology research in pancreatic cancer.

Pancreatic cancer mortality in Egypt: comparison to the United States pancreatic cancer mortality rates

OBJECTIVES

Little is known about the descriptive epidemiology of pancreatic cancer in many developing countries, such as Egypt. It is believed to be rare in developing countries, but this may reflect lack of systematic cancer registration. Mortality may serve as a surrogate for incidence, since the disease is lethal. Because of availability of reliable mortality registration in Egypt, we used the national mortality data to estimate pancreatic cancer mortality in 2765 deaths from 2000 to 2004, and to gain insights into the disease incidence.

METHODS

Mortality data in Egypt was obtained from the electronic national mortality records of the Ministry of Health. We calculated population-based age-specific and age-standardized pancreatic cancer mortality rates for Egypt, and compared them with the Surveillance, Epidemiology, and End Results (SEER) mortality data of the United States.

RESULTS

Comparisons of age-specific mortality demonstrated higher rates in Egypt compared to the United States for subjects under age 20 years (relative risks (RR) of 7.7 and 4.2, for the age groups 0-15 and 15-20, respectively), and significantly higher rates in the United States compared to Egypt for subjects 40 years and older (RR 1.8-80.5 for the age groups of 40-45 to 75+). For the majority of age groups in Egypt and the United States, mortality in males was higher than in females. Analysis of regional distribution of pancreatic cancer mortality in Egypt showed significant variations in rates among provinces (p<0.0001) with Northern provinces having average rate that is 2.85 times the rate of Southern provinces. The highest mortality rates were observed in the Nile Delta compared to southern Egypt and the oasis.

CONCLUSIONS

The findings of this study demonstrate both international and regional variation in pancreatic cancer mortality, and highlight the importance of further investigation to explore the possible factors that may contribute to the observed epidemiological patterns.

Molecular biology of exocrine pancreatic cancer

Exocrine pancreatic cancer is one of the neoplasias with a worse prognosis, with conventional treatments having little impact on disease outcome. Research and genomic high-throughput technology is continuously expanding our knowledge of pancreas cancer biology. Characterization of genetic and epigenetic alterations in pancreatic tumors has allowed a better understanding of the progression model of the disease at the molecular level. The development of new therapeutic approaches with target- oriented agents is been tested in the preclinical and clinical settings. This review updates the current available data on pancreatic cancer molecular biology.

Differential gene expression in patients genetically predisposed to pancreatic cancer

BACKGROUND

Nearly 10% of all pancreatic cancer (PCA) results from genetic predisposition. Although abnormalities in sporadic PCA have been described, little is known about the genetics of heritable PCA. The purpose of this study was to identify novel genes expressed in patients with a presumed genetic predisposition or "familial" PCA.

PATIENTS AND METHODS

We defined "familial" PCA as patients having one or more first-degree relatives with biopsy-proven adenocarcinoma of the pancreas. Using a PCR-based subtractive and enrichment procedure, representational difference analysis (RDA), pancreatic tumor cDNA was reverse-transcribed from pooled poly(A)+ mRNA from six such patients (tester) and compared to pooled cDNA from five normal pancreata (driver). Tumor-specific gene fragments were identified and confirmed to be overexpressed in familial PCA by comparative RT-PCR. Six PCA cell lines, 11 sporadic tumors, 5 neuroendocrine tumors, and 3 chronic pancreatitis tissues were screened to determine the specificity of these genes.

RESULTS

Sequence analysis revealed several sequences of unknown significance and six genes previously described in neoplasia/carcinogenesis: Apolipoprotein A4, CEA, Keratin 19, Stratifin (14-3-3 sigma), Trefoil Factor, and Calcium Binding Protein S100 A6. Screening of cell lines and pancreatic tissue types showed varying degrees of specificity for familial and sporadic PCA. The APO-A4 gene was up-regulated in familial PCA.

CONCLUSIONS

The pattern of frequency in all screened tissue suggests that these genes are associated with conditions that produce significant desmoplastic responses and are difficult to differentiate from chronic inflammatory processes. Apolipoprotein A4 is preferentially expressed in familial patients, suggesting that the importance of fatty acid synthesis in carcinogenesis be investigated further.