Polymorphisms of SPINK1 N34S and CFTR in patients with sporadic and familial pancreatic cancer

Evaluation of inherited germline mutations in cancer susceptibility genes among pancreatic cancer patients: a single-center study

BACKGROUND

Germline mutations in cancer susceptibility genes were identified in pancreatic cancer (PanC) patients with a sporadic disease and in those unselected for family cancer history.

METHODS

With the aim to determine the prevalence of germline predisposition genes mutations in PanC, and to evaluate whether they were associated with the presence of PanC, we profiled a custom AmpliSeq panel of 27 cancer susceptibility genes in 47 PanC patients and 51 control subjects by using the Ion Torrent PGM system.

RESULTS

Multigene panel testing identified a total of 31 variants in 27 PanC (57.4%), including variants with pathogenic/likely pathogenic effect, those of uncertain significance, and variants whose clinical significance remains currently undefined. Five patients carried more than one variant in the same gene or in different genes. Eight patients (17.0%) had at least one pathogenic/likely pathogenic variant in four main genes: CFTR (10.6%), BRCA2 (8.5%), ATM and CHEK2 (2.1%). Pathogenic/likely pathogenic mutation were identified in patients with positive PanC family history (20%) or in patients without first-degree relatives affected by PanC (13.6%). All the BRCA2 mutation carriers were unselected PanC patients. The presence of mutations in BRCA2 was significantly associated with an increased occurrence of PanC and with positive family history for endometrial cancer (p = 0.018).

CONCLUSIONS

This study confirmed the potential remarkable contribution of BRCA2 in assessing the presence of PanC. Overall our findings supported the recommendation of offering the germline testing to all the PanC patients with the intent to reduce the number of underdiagnosed carriers of mutations in predisposition genes, and not to preclude their relatives from the opportunity to benefit from surveillance programs.

The Evolving Paradigm of Germline Testing in Pancreatic Ductal Adenocarcinoma and Implications for Clinical Practice

Identification of deleterious germline mutations in pancreatic ductal adenocarcinoma (PDAC) patients can have therapeutic implications for the patients and result in cascade testing and prevention in their relatives. Universal testing for germline mutations is now considered standard of care in patients with PDAC, regardless of family history, personal history, or age. Here, we highlight the commonly identified germline mutations in PDAC patients as well as the impact of multigene panel testing. We further discuss therapeutic implications of germline testing on the index cases, and the impact of cascade testing on cancer early detection and prevention in relatives.

New Screening System Using Forward-Viewing Radial Endoscopic Ultrasound and Magnetic Resonance Imaging for High-Risk Individuals With Familial History of Pancreatic Cancer

Background and Aims

Attention is increasingly being paid to family history of pancreatic cancer (PC) as a risk factor for developing PC. It is mandatory to develop a screening system for early detection of PC; however, the relationship between a family history of PC and the incidence of pancreatic abnormalities, such as pancreatic cyst and chronic pancreatitis (CP), in the Japanese population remains unknown.

Patients and Methods

Individuals with a family history of PC were prospectively enrolled in a screening program using forward-viewing radial endoscopic ultrasound (FR-EUS) and magnetic resonance imaging (MRI) with magnetic resonance cholangiopancreatography (MRCP) as the diagnostic modalities.

Results

In total, forty-three individuals in 37 families were enrolled (mean age, 54 years). All individuals underwent FR-EUS and MRI with no complications. FR-EUS revealed resectable PC (n = 1, 2.3%), pancreatic cysts (n = 24, 55.8%), intraductal papillary mucinous neoplasm (IPMN; n = 13, 30.2%), and early CP-like appearance (n = 15, 34.9%). The detection rate of early CP-like appearance was significantly higher by EUS than by MRI. Pancreatic cysts and IPMN detected by FR-EUS were significantly correlated to age (≥60 years) and less correlated to men (hazard ratio [HR] 22.4; 95% confidence interval [CI], 2.10–236.0; p < 0.01 and HR 0.092; 95% CI, 0.01–0.83; p = 0.033, respectively). Early CP-like appearance detected by FR-EUS was significantly correlated with men and smoking (HR 5.0; 95% CI, 1.3–19.3; p = 0.02 and HR 4.02; 95% CI, 0.991–16.3; p = 0.05, respectively).

Conclusion

A screening system using FR-EUS and MRI/MRCP for individuals with a family history of PC was useful for identifying curable PC and pancreatic abnormalities. The incidence of pancreatic cysts, such as IPMN and early CP-like appearance, was also high in the Japanese cohort.

SPINK1 mutations and risk of pancreatic cancer in a Chinese cohort

OBJECTIVE

The relationship between SPINK1 and pancreatic cancer (PC) remains controversial. The current study aimed to determine the effect of SPINK1 mutations on PC development among patients with chronic pancreatitis (CP).

METHODS

This is a prospective observational study including a large cohort of 965 CP patients with 11-year follow-up. Patients' demographic characteristics and clinical CP outcomes were documented in detail. Genetic testing was performed. The effect of SPINK1 mutations on the clinical development of PC was explored using Cox proportional hazards regression. Subgroup analyses conducted included the consideration of gender, onset age of CP (early- and late-onset), etiologies of CP, smoking, and alcoholic drinking status.

RESULTS

PC was diagnosed in 2.5% (24/965) of patients, and the cumulative incidence rates were 0.2%, 0.8%, and 1.5% at 3, 5, and 10 years since the onset of CP, respectively. In this cohort, SPINK1 c.194+2T > C was the most common variant with a proportion of 39.1%. And the risk of PC development varied marginally between patients with and without SPINK1 mutations (Cox HR 0.39(0.14-1.04), P = 0.059). In the subgroup analyses, patients carrying SPINK1 mutations had a significantly lower risk of PC (Cox HR 0.18(0.04-0.80), P = 0.025) in the non-smoking group. SPINK1 mutations showed no significant effect in the other subgroups considered.

CONCLUSIONS

CP patients harboring SPINK1 mutations do not have an elevated risk of PC development compared to mutation-negative CP patients. On the contrary, SPINK1 mutations may be a protective factor in non-smoking patients with CP.

Pancreatic cancer epidemiology: understanding the role of lifestyle and inherited risk factors

Pancreatic cancer is a leading cause of cancer death worldwide and its global burden has more than doubled over the past 25 years. The highest incidence regions for pancreatic cancer include North America, Europe and Australia, and although much of this increase is due to ageing worldwide populations, there are key modifiable risk factors for pancreatic cancer such as cigarette smoking, obesity, diabetes and alcohol intake. The prevalence of these risk factors is increasing in many global regions, resulting in increasing age-adjusted incidence rates for pancreatic cancer, but the relative contribution from these risk factors varies globally due to variation in the underlying prevalence and prevention strategies. Inherited genetic factors, although not directly modifiable, are an important component of pancreatic cancer risk, and include pathogenic variants in hereditary cancer genes, genes associated with hereditary pancreatitis, as well as common variants identified in genome-wide association studies. Identification of the genetic changes that underlie pancreatic cancer not only provides insight into the aetiology of this cancer but also provides an opportunity to guide early detection strategies. The goal of this Review is to provide an up-to-date overview of the established modifiable and inherited risk factors for pancreatic cancer.

International consensus guidelines on surveillance for pancreatic cancer in chronic pancreatitis. Recommendations from the working group for the international consensus guidelines for chronic pancreatitis in collaboration with the International Association of Pancreatology, the American Pancreatic Association, the Japan Pancreas Society, and European Pancreatic Club

BACKGROUND

Patients with chronic pancreatitis (CP) have an increased risk of pancreatic cancer. We present the international consensus guidelines for surveillance of pancreatic cancer in CP.

METHODS

The international group evaluated 10 statements generated from evidence on 5 questions relating to pancreatic cancer in CP. The GRADE approach was used to evaluate the level of evidence available per statement. The working group voted on each statement for strength of agreement, using a nine-point Likert scale in order to calculate Cronbach's alpha reliability coefficient.

RESULTS

In the following domains there was strong consensus: (1) the risk of pancreatic cancer in affected individuals with hereditary pancreatitis due to inherited PRSS1 mutations is high enough to justify surveillance; (2) the risk of pancreatic cancer in patients with CP associated with SPINK1 p. N34S is not high enough to justify surveillance; (3) surveillance should be undertaken in pancreatic specialist centers; (4) surveillance should only be introduced after the age of 40 years and stopped when the patient would no longer be suitable for surgical intervention. All patients with CP should be advised to lead a healthy lifestyle aimed at avoiding risk factors for progression of CP and pancreatic cancer. There was only moderate or weak agreement on the best methods of screening and surveillance in other types of environmental, familial and genetic forms of CP.

CONCLUSIONS

Patients with inherited PRSS1 mutations should undergo surveillance for pancreatic cancer, but the best methods for cancer detection need further investigation.

Natural history of SPINK1 germline mutation related-pancreatitis

BACKGROUND

The aim was to describe genetic, clinical and morphological features in a large, multicentre European cohort of patients with SPINK1 related pancreatitis, in comparison with patients with idiopathic pancreatitis (IP).

METHODS

All SPINK1 mutation carriers with pancreatic symptoms from two French and one English centers were included. Patients with IP were included in a control group. Genetic, clinical, radiological and biochemical data were collected.

FINDINGS

209 and 302 patients were included in the SPINK1 and control groups (median follow-up: 8.3 years (3.7-17.4) vs 5.3 (2.5-8.8)). The median age at onset of symptoms was 20.1 years (17.5-22.8) in the SPINK1 group versus 41.2 (35.2-45.2). The age of exocrine pancreatic insufficiency (EPI) onset in the SPINK1 group was 49.5 (44.5-54.6) years vs. 65.2 (62.1-68.3), p < 0.001. SPINK1 patients with EPI were 5.3%, 14.7%, 28.3% and 52.4% at 20, 30, 40 and 50 years. Diabetes occurred 37.7 (33.3-42.1) years following the onset of symptoms in the SPINK1 group vs. 30.6 (17.3-43.8) (p = 0.002). SPINK1 patients with diabetes were 7.8%, 13.4%, 26.3% and 43.4% at 30, 40, 50 and 60 years. Seven patients (3.3%) developed pancreatic cancer in the SPINK1 group (versus 3 (0.99%), p = 0.1), at a median age of 60 vs 66 years. The cancer risk was 0.8% before 50 years, 11.9%, 27.7%, 51.8% at 60, 70 and 80 years and was 12 times higher than in controls (Cox HR 12.0 (3.0-47.8), p < 0.001).

INTERPRETATION

SPINK1 related pancreatitis is associated with earlier onset and pancreatic insufficiencies. p.N34S SPINK1 may well be associated with cancer.

Cystic fibrosis transmembrane conductance regulator-emerging regulator of cancer

Mutations of cystic fibrosis transmembrane conductance regulator (CFTR) cause cystic fibrosis, the most common life-limiting recessive genetic disease among Caucasians. CFTR mutations have also been linked to increased risk of various cancers but remained controversial for a long time. Recent studies have begun to reveal that CFTR is not merely an ion channel but also an important regulator of cancer development and progression with multiple signaling pathways identified. In this review, we will first present clinical findings showing the correlation of genetic mutations or aberrant expression of CFTR with cancer incidence in multiple cancers. We will then focus on the roles of CFTR in fundamental cellular processes including transformation, survival, proliferation, migration, invasion and epithelial-mesenchymal transition in cancer cells, highlighting the signaling pathways involved. Finally, the association of CFTR expression levels with patient prognosis, and the potential of CFTR as a cancer prognosis indicator in human malignancies will be discussed.

Mutations in the pancreatic secretory enzymes CPA1 and CPB1 are associated with pancreatic cancer

To evaluate whether germline variants in genes encoding pancreatic secretory enzymes contribute to pancreatic cancer susceptibility, we sequenced the coding regions of CPB1 and other genes encoding pancreatic secretory enzymes and known pancreatitis susceptibility genes (PRSS1, CPA1, CTRC, and SPINK1) in a hospital series of pancreatic cancer cases and controls. Variants in CPB1, CPA1 (encoding carboxypeptidase B1 and A1), and CTRC were evaluated in a second set of cases with familial pancreatic cancer and controls. More deleterious CPB1 variants, defined as having impaired protein secretion and induction of endoplasmic reticulum (ER) stress in transfected HEK 293T cells, were found in the hospital series of pancreatic cancer cases (5/986, 0.5%) than in controls (0/1,045, P = 0.027). Among familial pancreatic cancer cases, ER stress-inducing CPB1 variants were found in 4 of 593 (0.67%) vs. 0 of 967 additional controls (P = 0.020), with a combined prevalence in pancreatic cancer cases of 9/1,579 vs. 0/2,012 controls (P < 0.01). More ER stress-inducing CPA1 variants were also found in the combined set of hospital and familial cases with pancreatic cancer than in controls [7/1,546 vs. 1/2,012; P = 0.025; odds ratio, 9.36 (95% CI, 1.15-76.02)]. Overall, 16 (1%) of 1,579 pancreatic cancer cases had an ER stress-inducing CPA1 or CPB1 variant, compared with 1 of 2,068 controls (P < 0.00001). No other candidate genes had statistically significant differences in variant prevalence between cases and controls. Our study indicates ER stress-inducing variants in CPB1 and CPA1 are associated with pancreatic cancer susceptibility and implicate ER stress in pancreatic acinar cells in pancreatic cancer development.

Meta-analysis of the impact of SPINK1 p.N34S gene variation in Caucasic patients with chronic pancreatitis. An update

BACKGROUND

SPINK1 p.N34S gene variation is one of the endogenous factors which seem to be associated with chronic pancreatitis (CP). However, in literature there is no clear agreement regarding its contribution in different ethnicity and CP etiologies.

AIM

To investigate the role of SPINK1 p.N34S gene variation in CP patients with European origin by means of meta-analysis.

METHODS

Literature search was conducted and case-control studies evaluating Caucasian population, published between May 2007 and May 2015, were included. We also included Caucasian selected studies analyzed in previous meta-analysis. We carried out meta-analysis including all selected studies. After that, we performed two additional meta-analyses considering the incidence of SPINK1 p.N34S gene variation in alcoholic or in idiopathic CP patients vs control group.

RESULTS

Twenty-five studies were included and the total number of subjects was 8800 (2981 cases and 5819 controls). The presence of p.N34S variation increased nine times the overall CP risk in population of European origin [OR 9.695 (CI 95% 7.931-11.851)]. Also, the contribution of SPINK1 in idiopathic pancreatitis [OR 13.640 (CI 95% 8.858-21.002)] was found to be higher than in alcoholic CP [5.283 (CI 95% 3.449-8.092)].

CONCLUSION

The association between SPINK1 p.N34S gene variation and CP is confirmed. Also, we confirmed that the idiopathic etiology needs a better definition by means of genetic analysis.

Copy number variants and VNTR length polymorphisms of the carboxyl-ester lipase (CEL) gene as risk factors in pancreatic cancer

BACKGROUND/OBJECTIVES

We have recently described copy number variants (CNVs) of the human carboxyl-ester lipase (CEL) gene, including a recombined deletion allele (CEL-HYB) that is a genetic risk factor for chronic pancreatitis. Associations with pancreatic disease have also been reported for the variable number of tandem repeat (VNTR) region located in CEL exon 11. Here, we examined if CEL CNVs and VNTR length polymorphisms affect the risk for developing pancreatic cancer.

METHODS

CEL CNVs and VNTR were genotyped in a German family with non-alcoholic chronic pancreatitis and pancreatic cancer, in 265 German and 197 Norwegian patients diagnosed with pancreatic adenocarcinoma, and in 882 controls. CNV screening was performed using PCR assays followed by agarose gel electrophoresis whereas VNTR lengths were determined by DNA fragment analysis.

RESULTS

The investigated family was CEL-HYB-positive. However, an association of CEL-HYB or a duplication CEL allele with pancreatic cancer was not seen in our two patient cohorts. The frequency of the 23-repeat VNTR allele was borderline significant in Norwegian cases compared to controls (1.2% vs. 0.3%; P = 0.05). For all other VNTR lengths, no statistically significant difference in frequency was observed. Moreover, no association with pancreatic cancer was detected when CEL VNTR lengths were pooled into groups of short, normal or long alleles.

CONCLUSIONS

We could not demonstrate an association between CEL CNVs and pancreatic cancer. An association is also unlikely for CEL VNTR lengths, although analyses in larger materials are necessary to completely exclude an effect of rare VNTR alleles.

Metastatic pancreatic adenocarcinoma associated with chronic calcific pancreatitis and a heterozygous SPINK1 N34S mutation

Contrary to patients with a cationic trypsinogen gene (PRSS1) mutations, Serine protease inhibitor Kazal-type 1 (SPINK1) heterozygote gene mutation carriers have a very low penetrance for acute, acute recurrent and/or chronic pancreatitis. Despite this, heterozygote SPINK 1 gene mutation patients have a similar age of onset of pancreatitis as PRSS 1 gene mutation patients. While the substantially elevated risk of pancreatic cancer in patients with PRSS1 gene mutations with chronic pancreatitis has been well established, little is known about the risk of pancreatic cancer in SPINK 1 gene mutation carriers with pancreatitis. We describe a case of malignant pancreatic cancer diagnosed in a young patient with chronic pancreatitis who is a SPINK 1 heterozygote gene mutation carrier. The risk of pancreatic cancer in gene mutation patients with chronic pancreatitis, in addition to screening options and management options for these patients is discussed.

SPINK1 Promoter Variants in Chronic Pancreatitis

OBJECTIVES

Serine protease inhibitor Kazal type 1 (SPINK1) provides an important line of defense against premature trypsinogen activation within the pancreas. Our aim was to identify pathogenic SPINK1 promoter variants associated with chronic pancreatitis (CP).

METHODS

One hundred CP patients (cases) and 100 controls with no pancreatic disease from the Hungarian National Pancreas Registry were enrolled. Direct sequencing of SPINK1 promoter region was performed. Functional characterization of variants was carried out using luciferase reporter gene assay.

RESULTS

Two common polymorphisms (c.-253T>C and c.-807C>T) were found in both cases and controls. Variant c.253T>C was enriched in cases relative to controls (odds ratio, 2.1; 95% confidence interval, 1.2-3.8; P = 0.015). Variant c.-215G>A was detected in 3 of 100 cases; always linked with the pathogenic variant c.194+2T>C. Novel promoter variants c.-14G>A, c.-108G>T, and c.-246A>G were identified in 1 case each. Functional analysis showed decreased promoter activity for variants c.-14G>A (80%), c.-108G>T (31%), and c.-246A>G (47%) whereas activity of variant c.-215G>A was increased (201%) and variant c.-253T>C was unchanged compared with wild type.

CONCLUSIONS

The common promoter variant c.-253T>C was associated with CP in this cohort. Two of 3 newly identified SPINK1 promoter variants seem to exhibit significant functional defects and should be considered potential risk factors for CP.

Hereditary Pancreatic Cancer Syndromes

Despite decades of scientific and clinical research, pancreatic ductal adenocarcinoma (PDAC) remains a lethal malignancy. The clinical and pathologic features of PDAC, specifically the known environmental and genetic risk factors, are reviewed here with special emphasis on the hereditary pancreatic cancer (HPC) syndromes. For these latter conditions, strategies are described for their identification, for primary and secondary prevention in unaffected carriers, and for disease management in affected carriers. Nascent steps have been made toward personalized medicine based on the rational use of screening, tumor subtyping, and targeted therapies; these have been guided by growing knowledge of HPC syndromes in PDAC.

CFTR, SPINK1, PRSS1, and CTRC mutations are not associated with pancreatic cancer in German patients

OBJECTIVE

Mutations in the cationic trypsinogen (PRSS1), cystic fibrosis transmembrane conductance regulator (CFTR), serine protease inhibitor Kazal type 1 (SPINK1), and chymotrypsin C (CTRC) genes are associated with an elevated risk for chronic pancreatitis, which is a known risk factor for pancreatic cancer (PC). Therefore, we analyzed whether PRSS1, CFTR, SPINK1, and/or CTRC mutations are associated with pancreatic adenocarcinoma.

METHODS

The study cohort was composed of 121 PC patients, of whom 74 were classified as having chronic pancreatitis, 102 patients with idiopathic chronic pancreatitis, and 130 as healthy controls. Mutation analyses for the CFTR, SPINK1, PRSS1, and CTRC genes were performed for the presence of the most common mutations.

RESULTS

The frequency of CFTR mutations in patients with PC was not significantly different in comparison with healthy controls and controls with pancreatitis. The SPINK1 mutation frequency was significantly decreased in patients with PC in comparison with patients with idiopathic pancreatitis but varied not significantly in comparison with healthy controls. None of the selected 121 PC samples showed a pancreatitis-predisposing mutation in the PRSS1 or CTRC gene.

CONCLUSIONS

Mutations in the genes CFTR, SPINK1, PRSS1, and CTRC do not seem to significantly increase the risk for pancreatic adenocarcinoma.

Strategies for early detection of resectable pancreatic cancer

Pancreatic cancer is difficult to diagnose at an early stage and generally has a poor prognosis. Surgical resection is the only potentially curative treatment for pancreatic carcinoma. To improve the prognosis of this disease, it is essential to detect tumors at early stages, when they are resectable. The optimal approach to screening for early pancreatic neoplasia has not been established. The International Cancer of the Pancreas Screening Consortium has recently finalized several recommendations regarding the management of patients who are at an increased risk of familial pancreatic cancer. In addition, there have been notable advances in research on serum markers, tissue markers, gene signatures, and genomic targets of pancreatic cancer. To date, however, no biomarkers have been established in the clinical setting. Advancements in imaging modalities touch all aspects of the clinical management of pancreatic diseases, including the early detection of pancreatic masses, their characterization, and evaluations of tumor resectability. This article reviews strategies for screening high-risk groups, biomarkers, and current advances in imaging modalities for the early detection of resectable pancreatic cancer.

Endoscopic ultrasonography for surveillance of individuals at high risk for pancreatic cancer

Pancreatic cancer is a highly lethal disease with a genetic susceptibility and familial aggregation found in 3%-16% of patients. Early diagnosis remains the only hope for curative treatment and improvement of prognosis. This can be reached by the implementation of an intensive screening program, actually recommended for individuals at high-risk for pancreatic cancer development. The aim of this strategy is to identify pre-malignant precursors or asymptomatic pancreatic cancer lesions, curable by surgery. Endoscopic ultrasound (EUS) with or without fine needle aspiration (FNA) seems to be the most promising technique for early detection of pancreatic cancer. It has been described as a highly sensitive and accurate tool, especially for small and cystic lesions. Pancreatic intraepithelial neoplasia, a precursor lesion which is highly represented in high-risk individuals, seems to have characteristics chronic pancreatitis-like changes well detected by EUS. Many screening protocols have demonstrated high diagnostic yields for pancreatic pre-malignant lesions, allowing prophylactic pancreatectomies. However, it shows a high interobserver variety even among experienced endosonographers and a low sensitivity in case of chronic pancreatitis. Some new techniques such as contrast-enhanced harmonic EUS, computer-aided diagnostic techniques, confocal laser endomicroscopy miniprobe and the detection of DNA abnormalities or protein markers by FNA, promise improvement of the diagnostic yield of EUS. As the resolution of imaging improves and as our knowledge of precursor lesions grows, we believe that EUS could become the most suitable method to detect curable pancreatic neoplasms in correctly identified asymptomatic at-risk patients.

Frequency of CFTR, SPINK1, and cathepsin B gene mutation in North Indian population: connections between genetics and clinical data

Objectives. Genetic mutations and polymorphisms have been correlated with chronic pancreatitis (CP). This study aims to investigate the association of genetic variants of cystic fibrosis transmembrane conductance regulator (CFTR) and serine protease inhibitor Kazal type 1 (SPINK-1) genes and Cathepsin B gene polymorphisms with CP and to associate genetic backgrounds with clinical phenotypes. Methods. 150 CP patients and 150 normal controls were enrolled consecutively. We analyzed SPINK-1 N34S and IVS3+2T>C gene mutations by PCR-restriction-fragment length polymorphism (RFLP). The identification of DF508, G551D, G542X, R117H, and W1282X mutations was carried out by ARMS-PCR. S549N mutation, IVS8 polyTn polymorphism, and Cathepsin B Lec26Val were analysed by PCR-RFLP, nested PCR, and PCR-RFLP plus sequencing, respectively. Results. We found a significant association of SPINK1 (N34S) gene polymorphism. IVS1−37T>C polymorphism shows linkage with 101A>G. 300 chromosomes belonging to the CFTR subgroup exhibited minor allele frequency of 0.04, 0.03, 0.03, 0.013, 0.006, and 0.02 for DF508, G452X, G551D, S549N, R117H, and IVS8 T5, respectively. Except for R117H and IVS8 T5 polymorphisms, all other mutations showed significant variation. Conclusion. Analysis of potential susceptibility variants is needed to support nature of the genes and environment in pancreatitis. This data may help establish genetic screening and prenatal setup for Indian population.

Early diagnosis of pancreatic cancer: challenges and new developments

Pancreatic cancer is a lethal malignancy with its incidence almost equivalent to mortality. The complex pathophysiology, absence of early diagnostic and prognostic markers and unresponsiveness to radiation and chemotherapies are major barriers against successful therapy. Poor performance of therapeutic agents, even in the initial stage of invasive cases, emphasizes the importance of early detection for improved survival. The present review discusses the challenges and advances in biomarkers including serological signatures, circulating tumor cells, autoantibodies, epigenetic markers and miRNAs that are being explored to detect this cancer at early stages. Considering the long time gap between the development of malignant lesions and full-blown primary and metastatic pancreatic cancer, unique opportunities are being contemplated for the development of potential diagnostic and prognostic markers.

Proteomic analysis of formalin-fixed paraffin-embedded pancreatic tissue using liquid chromatography tandem mass spectrometry

OBJECTIVES

FFPE tissue is a standard method of specimen preservation for hospital pathology departments. Formalin-fixed paraffin-embedded tissue banks are a resource of histologically characterized specimens for retrospective biomarker investigation. We aim to establish liquid chromatography coupled with tandem mass spectrometry analysis of FFPE pancreatic tissue as a suitable strategy for the study of the pancreas proteome.

METHODS

We investigated the proteomic profile of FFPE pancreatic tissue specimens, using liquid chromatography coupled with tandem mass spectrometry, from 9 archived specimens that were histologically classified as normal (n = 3), chronic pancreatitis (n = 3), and pancreatic cancer (n = 3).

RESULTS

We identified 525 nonredundant proteins from 9 specimens. Implementing our filtering criteria, 78, 15, and 21 proteins were identified exclusively in normal, chronic pancreatitis, and pancreatic cancer specimens, respectively. Several proteins were identified exclusively in specimens with no pancreatic disease: spink 1, retinol dehydrogenase, and common pancreatic enzymes. Similarly, proteins were identified exclusively in chronic pancreatitis specimens: collagen α1 (XIV), filamin A, collagen α3 (VI), and SNC73. Proteins identified exclusively in pancreatic cancer included annexin 4A and fibronectin.

CONCLUSIONS

We report that differentially expressed proteins can be identified among FFPE tissue specimens originating from individuals with different pancreatic histologic findings. The mass spectrometry-based method used herein has the potential to enhance biomarker discovery and chronic pancreatitis research.

Is the SPINK1 variant p.N34S overrepresented in patients with acute pancreatitis?

OBJECTIVES

Serine Protease Inhibitor Kazal type 1 (SPINK1) protects against premature intracellular activation of trypsinogen and development of acute pancreatitis. Our aim was to determine the prevalence of SPINK1 mutations (a) in unselected patients with first-time acute pancreatitis and (b) in the Danish background population (c) in a meta-analysis to combine the results with findings in similar investigations worldwide and (d) to evaluate whether patients with SPINK1 mutations had a more severe clinical course.

METHODS

A total of 75 consecutive patients admitted to a surgical department with first-time acute pancreatitis were prospectively included. In addition, 188 healthy controls were tested for the SPINK1 variants: p.N34S, p.P55S, p.R65Q, p.R67C, and IVS3+2 T>C, in order to calculate the prevalence of SPINK1 mutations in the Danish background population. A meta-analysis was conducted on previous studies on acute pancreatitis and SPINK1 mutations.

RESULTS

Two patients (2.7%) and two controls (1.1%) were heterozygous for the p.N34S variant. The meta-analysis confirmed that the p.N34S variant is overrepresented in patients with acute pancreatitis compared with the background population (OR=3.16, P<0.001). But this analysis did not clarify whether this was only true for patients with first-time acute pancreatitis or recurrent pancreatitis as the present studies do not provide this information, and those who do not have enough patients to reach levels of statistic significance, even if data are pooled.

CONCLUSION

The SPINK1 variant p.N34S is overrepresented in patients with acute pancreatitis, but more studies distinguishing between first-time and recurrent acute pancreatitis have to be done to determine whether this is only true for patients with recurrent acute pancreatitis.

Genetic susceptibility to pancreatic cancer

Pancreatic cancer is the fourth leading cause of cancer death in both men and women in the United States. However, it has the poorest prognosis of any major tumor type, with a 5-yr survival rate of approximately 5%. Cigarette smoking, increased body mass index, heavy alcohol consumption, and a diagnosis of diabetes mellitus have all been demonstrated to increase risk of pancreatic cancer. A family history of pancreatic cancer has also been associated with increased risk suggesting inherited genetic factors also play an important role, with approximately 5-10% of pancreatic cancer patients reporting family history of pancreatic cancer. While the genetic basis for the majority of the familial clustering of pancreatic cancer remains unclear, several important pancreatic cancer genes have been identified. These consist of high penetrance genes including BRCA2 or PALB2, to more common genetic variation associated with a modest increase risk of pancreatic cancer such as genetic variation at the ABO blood group locus. Recent advances in genotyping and genetic sequencing have accelerated the rate at which novel pancreatic cancer susceptibility genes have been identified with several genes identified within the past few years. This review addresses our current understanding of the familial aggregation of pancreatic cancer, established pancreatic cancer susceptablity genes and how this knowledge informs risk assessment and screening for high-risk families.

Subject review: pancreatic ductal adenocarcinoma in the setting of mutations in the cystic fibrosis transmembrane conductance regulator gene: case report and review of the literature

BACKGROUND

Cystic fibrosis (CF) is the most commonly inherited lethal autosomal recessive genetic disease amongst Caucasians. CF results from mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Patients with homozygous or compound heterozygous CFTR mutations have a risk of pancreatitis, but typically do not live long enough to develop pancreatic ductal adenocarcinoma (PDA), a disease that has an average age at diagnosis of 65 years. Little is known about the risk of the development of PDA in people who are heterozygous for mutations in the CFTR gene.

PATIENTS AND METHODS

We report a case of a patient with PDA who underwent resection, who is a carrier for the W1282X nonsense mutation in the CFTR gene. The patient is of Ashkenazi Jewish ethnicity and has a family history of CF, but no family history of PDA. We reviewed the English language literature for the prevalence of PDA in CF patients (and CFTR mutations in the setting of PDA) and their significance in terms of screening, and the use of this mutation as a biomarker for an increased risk of the development of PDA.

CONCLUSION

We conclude that patients with CFTR mutations, who also have other risks for the development of PDA such as a family history of the disease, should undergo screening and be educated about their risks.

Familial pancreatic cancer and hereditary syndromes: screening strategy for high-risk individuals

Globally, and almost evenly across nations, a familial disposition can be found in 4-10% of patients with pancreatic cancer (PC). A family history of PC is a risk for this disease and the risk level changes in correlation with the number of affected relatives. Several hereditary syndromes with potential germline mutation also have a high risk for PC; however, little is yet known regarding the genes responsible for familial pancreatic cancer (FPC). Characteristics of FPC cases are similar to those of other familial tumors, including younger onset than in sporadic cases and an ethnic difference (Ashkenazi Jewish > other Caucasian). Other risks resemble those of sporadic cases and include smoking and diabetes mellitus. People with several genetic syndromes, including Peutz-Jeghers syndrome, hereditary pancreatitis, breast-ovarian cancer syndrome, hereditary nonpolyposis colorectal cancer, and familial adenomatous polyposis also have an increased risk of PC. In many countries, but not yet in Japan, screening of these high-risk individuals is now ongoing for the detection of early PC under established familial pancreatic cancer registries. In addition to the ordinary risk factors, such as smoking, diabetes, pancreatitis, cysts, duct ectasia, and intraductal papillary mucinous neoplasm (IPMN), individuals with a family history of PC and hereditary syndromes are expected to be entered into the screening protocol.

Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations and risk for pancreatic adenocarcinoma

BACKGROUND

Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene are common in white persons and are associated with pancreatic disease. The purpose of this case-control study was to determine whether CFTR mutations confer a higher risk of pancreatic cancer.

METHODS

In a case-control study, the authors compared the rates of 39 common cystic fibrosis-associated CFTR mutations between 949 white patients with pancreatic adenocarcinoma and 13,340 white controls from a clinical laboratory database for prenatal testing for CFTR mutations. The main outcome measure was the CFTR mutation frequency in patients and controls.

RESULTS

Overall, 50 (5.3%) of 949 patients with pancreatic cancer carried a common CFTR mutation versus 510 (3.8%) of 13,340 controls (odds ratio [OR], 1.40; 95% confidence interval [CI], 1.04-1.89; P = .027). Among patients who were younger when their disease was diagnosed (<60 years), the carrier frequency was higher than in controls (OR, 1.82; 95% CI, 1.14-2.94; P = .011). In patient-only analyses, the presence of a mutation was associated with younger age (median 62 vs 67 years; P = .034). In subgroups, the difference was seen only among ever-smokers (60 vs 65 years, P = .028). Subsequent sequencing analysis of the CFTR gene detected 8 (16%) compound heterozygotes among the 50 patients initially detected to have 1 mutation.

CONCLUSIONS

Carrying a disease-associated mutation in CFTR is associated with a modest increase in risk for pancreatic cancer. Those affected appear to be diagnosed at a younger age, especially among smokers. Clinical evidence of antecedent pancreatitis was uncommon among both carriers and noncarriers of CFTR mutations.

[From the chronic pancreatitis to chronic pancreatites]

Chronic alcohol intake accounts for 60-90% of the cases of chronic pancreatitis, but other etiologies have been recognized and described in the very recent years. Genetic causes include mutations of the cationic trypsinogen gene PRSS1 (100 families in France), of its inhibitor SPINK1 and of the CFTR gene involved in cystic fibrosis. Auto-immune pancreatitis is often part of an "IgG4-related systemic disease" involving the biliary tract, the salivary glands, the retroperitoneum and/or the kidneys. Diagnostic criteria are now well-defined (HISORt of the Mayo Clinic), with ductal and parenchymal lesions on imaging that may mimick pancreatic adenocarcinoma. Corticoids are efficacious but recurrences are frequent and long-term outcome is still poorly known.

The inherited genetic component of sporadic pancreatic adenocarcinoma

Pancreatic cancer, like many other complex diseases, has genetic and environmental components to its etiology. It is likely that relatively common genetic variants with modest effects on pancreatic cancer risk play an important role in both familial and sporadic forms of the disease, either individually or in interaction with environmental factors. The relatively high frequency of such variants means that they could potentially explain a substantial portion of disease risk. Here we summarize the findings published to date from genetic association studies. In general, very few low-penetrance variants have been identified and those that have require replication in independent studies. Possible gene-environment interactions arising from these studies also require replication. More comprehensive approaches are needed to make progress, including global analyses of biologically sound pathways and genome-wide association studies. Large sample sizes are required to do this appropriately and multi-study consortia make this possible. A number of consortia of pre-existing studies have already been formed, and these will facilitate the identification of further low-penetrance variants and gene-environment interaction. However, these approaches do not substitute for the design of novel, sufficiently powered studies that apply uniform criteria to case selection, the acquisition of environmental exposure information, and to biological sample collection.

Pathways to injury in chronic pancreatitis: decoding the role of the high-risk SPINK1 N34S haplotype using meta-analysis

Background

The complex interactions between recurrent trypsin-mediated pancreatic injury, alcohol-associated pancreatic injury and SPINK1 polymorphisms in chronic pancreatitis (CP) are undefined. We hypothesize that CP occurs as a result of multiple pathological mechanisms (pathways) that are initiated by different metabolic or environmental factors (etiologies) and may be influenced differentially by downstream genetic risk factors. We tested this hypothesis by evaluating the differences in effect size of the high risk SPINK1 N34S haplotype on CP from multiple etiologies after combining clinical reports of SPINK1 N34S frequency using meta-analysis.

Methods and Findings

The Pubmed and the Embase databases were reviewed. We studied 24 reports of SPINK1 N34S in CP (2,421 cases, 4,857 controls) using reported etiological factors as surrogates for pathways and multiple meta-analyses to determine the differential effects of SPINK1 N34S between alcoholic and non-alcoholic etiologies. Using estimates of between-study heterogeneity, we sub-classified our 24 studies into four specific clusters. We found that SPINK1 N34S is strongly associated with CP overall (OR 11.00; 95% CI: 7.59–15.93), but the effect of SPINK1 N34S in alcoholic CP (OR 4.98, 95% CI: 3.16–7.85) was significantly smaller than in idiopathic CP (OR 14.97, 95% C.I. = 9.09–24.67) or tropical CP (OR 19.15, 95% C.I. = 8.83–41.56). Studies analyzing familial CP showed very high heterogeneity suggestive of a complex etiology with an I² = 80.95%.

Conclusion

The small effect of SPINK1 N34S in alcoholic subjects suggests that CP is driven through a different pathway that is largely trypsin-independent. The results also suggest that large effect sizes of SPINK1 N34S in small candidate gene studies in CP may be related to a mixture of multiple etiologic pathways leading to the same clinical endpoint.

Cystic fibrosis transmembrane conductance regulator (CFTR) gene 5T allele may protect against prostate cancer: a case-control study in Chinese Han population

BACKGROUND

Cystic fibrosis transmembrane conductance regulator (CFTR) is expressed in a wide variety of epithelial cells including the prostate subglandular epithelia. Previous studies have suggested that CFTR mutations and polymorphisms may be associated with several cancers. Mutations and polymorphisms in the CFTR gene are responsible for cystic fibrosis (CF), and the incidence of prostate cancer in CF patients seemed to be lower than expected.

METHODS

A hospital-based case-control study was conducted including 230 prostate cancer patients and 230 age-matched controls. We used nested PCR to analysis the IVS8-poly(T) tract and PCR-RFLP method to analysis the M470V polymorphism in CFTR gene.

RESULTS

We observed an association of the low expression allele, IVS8-5T with prostate cancer protection (P=0.002; OR=0.281, 95%CI 0.120-0.658). Logistic regression analysis confirmed the 5T/7T genotype was in protective association with prostate cancer risk (P=0.003; OR=0.232, 95%CI 0.090-0.599). Linkage disequilibrium between IVS8-poly(T) and M470V existed among prostate cancer patients (D'=0.701). The low expression haplotype, "5T-V470" was found to be associated with protection against prostate cancer risk (P=0.010; OR=0.324, 95%CI 0.132-0.796).

CONCLUSIONS

Our results indicate that the low expression CFTR polymorphisms may contribute to a reduced risk of prostate cancer in Chinese Han population.

Genetics and biology of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer death in the United States with a median survival of <6 mo and a dismal 5-yr survival rate of 3%-5%. The cancer's lethal nature stems from its propensity to rapidly disseminate to the lymphatic system and distant organs. This aggressive biology and resistance to conventional and targeted therapeutic agents leads to a typical clinical presentation of incurable disease at the time of diagnosis. The well-defined serial histopathologic picture and accompanying molecular profiles of PDAC and its precursor lesions have provided the framework for emerging basic and translational research. Recent advances include insights into the cancer's cellular origins, high-resolution genomic profiles pointing to potential new therapeutic targets, and refined mouse models reflecting both the genetics and histopathologic evolution of human PDAC. This confluence of developments offers the opportunity for accelerated discovery and the future promise of improved treatment.

Mutations N34S and P55S of the SPINK1 gene in patients with chronic pancreatitis or pancreatic cancer and in healthy subjects: a report from Finland

OBJECTIVE

Mutations in the Kazal type 1 serine protease inhibitor (SPINK1) gene have recently been associated with chronic pancreatitis (CP), an established risk factor for pancreatic cancer. The aim of this study was to investigate the frequency of the SPINK1 gene mutations (N34S and P55S) in patients with CP, or pancreatic cancer, and in healthy subjects in Finland.

MATERIAL AND METHODS

The N34S and P55S mutations were determined by PCR amplification followed by solid-phase minisequencing in 116 patients with CP and in 188 with pancreatic cancer. In patients with CP, alcohol was the aetiological factor in 87 (75%), pancreas divisum in 4 (3%), gallstones in 5 (5%) and 20 patients (17%) had an idiopathic disease; 459 healthy individuals were enrolled as controls.

RESULTS

The frequency of the N34S mutation was significantly higher in patients with CP (14/116, 12%) than in controls (12/459, 2.6%) (p<0.0001). There was no difference in the frequency of the P55S mutation between patients with CP (1/116, 0.9%) and controls (6/459, 1.3%). The N34S mutation was present in 9 (10%) out of 87 patients with alcoholic CP, and in 5 (25%) patients with idiopathic CP. No SPINK1 mutations were found in patients with CP caused by anatomical variations or gallstones. Among the 188 patients with a pancreatic malignant tumour, the N34S mutation was present in 7 cases (3.7%). The frequency of the N34S mutation in healthy controls in this study was significantly higher than earlier reported in other countries (p=0.03).

CONCLUSIONS

The SPINK1 N34S mutation was significantly associated with an increased risk of CP. The association of the N34S mutation with alcoholic CP was marginally stronger than in earlier studies, whereas in the Finnish population in general, this mutation was significantly more frequent than reported elsewhere.

Screening for pancreatic neoplasia in high-risk individuals: an EUS-based approach

BACKGROUND & AIMS

Relatives of patients with pancreatic cancer and persons with certain inherited syndromes are at increased risk for developing pancreatic cancer. We prospectively evaluated the feasibility of screening for pancreatic neoplasia in high-risk individuals.

METHODS

Individuals from familial pancreatic cancer kindreds and a patient with Peutz-Jeghers syndrome underwent screening endoscopic ultrasound (EUS). If the EUS was abnormal, EUS-guided fine-needle aspiration, endoscopic retrograde cholangiopancreatography (ERCP), and spiral computed tomography (CT) were performed. Patients with abnormalities suggesting neoplasia had surgery.

RESULTS

Thirty-eight patients were studied; 31 (mean age, 58 yr; 42% men) from kindreds with > or =3 affected with pancreatic cancer; 6 from kindreds with 2 affected relatives, 1 was a patient with Peutz-Jeghers syndrome. None had symptoms referable to the pancreas or suggestive of malignancy. Six pancreatic masses were found by EUS: 1 invasive ductal adenocarcinoma, 1 benign intraductal papillary mucinous neoplasm, 2 serous cystadenomas, and 2 nonneoplastic masses. Hence, the diagnostic yield for detecting clinically significant pancreatic neoplasms was 5.3% (2 of 38). The 1 patient with pancreatic cancer was treated and still is alive and disease-free >5 years after surgery. EUS changes similar to those associated with chronic pancreatitis were found, which were more common in patients with a history of regular alcohol intake (P = 0.02), but also occurred in patients who did not consume alcohol. Screening also led to a new diagnosis and treatment of symptomatic upper-gastrointestinal conditions in 18.4% of patients.

CONCLUSIONS

EUS-based screening of asymptomatic high-risk individuals can detect prevalent resectable pancreatic neoplasia but false-positive diagnoses also occur.