Familial pancreatic cancer syndromes

Sleeping Beauty transposon mutagenesis in mouse intestinal organoids identifies genes involved in tumor progression and metastasis

To identify genes important for colorectal cancer (CRC) development and metastasis, we established a new metastatic mouse organoid model using Sleeping Beauty (SB) transposon mutagenesis. Intestinal organoids derived from mice carrying actively mobilizing SB transposons, an activating KrasG12D, and an inactivating ApcΔ716 allele, were transplanted to immunodeficient mice. While 66.7% of mice developed primary tumors, 7.6% also developed metastatic tumors. Analysis of SB insertion sites in tumors identified numerous candidate cancer genes (CCGs) identified previously in intestinal SB screens performed in vivo, in addition to new CCGs, such as Slit2 and Atxn1. Metastatic tumors from the same mouse were clonally related to each other and to primary tumors, as evidenced by the transposon insertion site. To provide functional validation, we knocked out Slit2, Atxn1, and Cdkn2a in mouse tumor organoids and transplanted to mice. Tumor development was promoted when these gene were knocked out, demonstrating that these are potent tumor suppressors. Cdkn2a knockout cells also metastasized to the liver in 100% of the mice, demonstrating that Cdkn2a loss confers metastatic ability. Our organoid model thus provides a new approach that can be used to understand the evolutionary forces driving CRC metastasis and a rich resource to uncover CCGs promoting CRC.

Pancreatic Tumorigenesis: Precursors, Genetic Risk Factors and Screening

Pancreatic cancer (PC) is a highly malignant and aggressive tumor. Despite medical advancement, the silent nature of PC results in only 20% of all cases considered resectable at the time of diagnosis. It is projected to become the second leading cause in 2030. Most pancreatic cancer cases are diagnosed in the advanced stages. Such cases are typically unresectable and are associated with a 5-year survival of less than 10%. Although there is no guideline consensus regarding recommendations for screening for pancreatic cancer, early detection has been associated with better outcomes. In addition to continued utilization of imaging and conventional tumor markers, clinicians should be aware of novel testing modalities that may be effective for early detection of pancreatic cancer in individuals with high-risk factors. The pathogenesis of PC is not well understood; however, various modifiable and non-modifiable factors have been implicated in pancreatic oncogenesis. PC detection in the earlier stages is associated with better outcomes; nevertheless, most oncological societies do not recommend universal screening as it may result in a high false-positive rate. Therefore, targeted screening for high-risk individuals represents a reasonable option. In this review, we aimed to summarize the pathogenesis, genetic risk factors, high-risk population, and screening modalities for PC.

Considerations for Germline Testing in Melanoma: Updates in Behavioral Change and Pancreatic Surveillance for Carriers of CDKN2A Pathogenic Variants

The largest proportion of hereditary melanoma cases are due to pathogenic variants (PVs) in the CDKN2A/p16 gene, which account for 20%-40% of familial melanomas and confer up to a 30%-70% lifetime risk for melanoma in individuals with these variants. In addition, PVs in the CDKN2A gene also increase risk for pancreatic cancer (~5-24% lifetime risk). Individuals with PVs in the CDKN2A gene also tend to have an earlier onset of cancer. Despite these known risks, uptake of germline testing has been limited in the past, largely due to perceptions of limited benefit for patients. Prevention recommendations have been developed for individuals with CDKN2A PVs as well the providers who care for them. On the patient level, behavioral modifications regarding melanoma prevention such as wearing sunscreen, limiting prolonged sun exposure and practicing general sun safety can help reduce risks. Germline testing can provide motivation for some individuals to adhere to these lifestyle changes. On the provider level, pancreatic cancer surveillance for individuals with CDKN2A PVs has been increasingly endorsed by expert consensus, although the efficacy of these surveillance methods remains under study. This review summarizes the updated surveillance guidelines for individuals with CDKN2A PVs and explores the impact of genetic counseling and testing in influencing behavioral changes in these individuals.

Pancreatic cancer: Current status and Challenges

PURPOSE OF THE REVIEW

The 5-year survival rate of patients with pancreatic cancer (PanCA) has remained stagnant. Unfortunately, the incidence is almost equal to mortality rates. These facts underscore the importance of concerted efforts to understand the pathology of this disease. Deregulation of multiple signaling pathways involved in a wide variety of cellular processes including proliferation, apoptosis, invasion, and metastasis contribute not only to cancer development but also to therapeutic resistance. The purpose of this review is to summarize current understanding of etiological factors including emerging evidence on the role of infectious agents, factors associated with therapeutic resistance and therapeutic options.

RECENT FINDINGS

The unique aspect of PanCA is "desmoplasia", a process that involves proliferation of stromal fibroblasts and collagen deposition in and around the filtrating cancer. Recent studies have identified pancreatic stellate cells (PSCs) as a potential source of such desmoplasia. Biphasic interactions between PSCs and cancer cells, endothelial cells, and/or myeloid derived suppressor cells in the tumor microenvironment contribute to pancreatic carcinogenesis.

SUMMARY

We summarize limitations of current therapeutic approaches and potential strategies to overcome these limitations using natural products including botanicals as adjuvant/neo-adjuvant for effective management of PanCA.

Screening for Pancreatic Cancer: Current Status and Future Directions

Pancreatic ductal adenocarcinoma is a lethal disease for a multitude of reasons, including difficulty of early detection, early metastatic spread, and absence of more effective therapies. Even with the advent of newer systemic therapies, the 1-year survival for metastatic disease ranges from 17–23% and 5-year survival is <5%. This necessitates an urgent need for the development of more effective modalities for early detection, particularly due to the long latent period between the genomic cellular changes and the development of metastatic disease. Currently available biochemical and molecular markers have significant potential; however, they require further clinical validation. Endoscopic ultrasound is one of the most sensitive modalities used to both screen and sample lesions, but is limited to use in high-risk patients due to its invasive nature and associated risks. Although clinically meaningful progress has been made in screening the high-risk cohorts in terms of detection of pancreatic ductal adenocarcinoma, intraductal papillary mucinous neoplasms, and mucinous cystic neoplasms, leading to early diagnosis and treatment, nonselective population-based screening is not yet available for widespread use. Currently there is no consensus on the most appropriate screening protocol for early pancreatic cancer detection. In this review, we focus on understanding the potential role of molecular and radiogenomic markers in the early detection of pancreatic cancer.

Management Options after Prophylactic Surgeries in Women with BRCA Mutations: A Review

Background

Although breast cancer is relatively common, only about 5% of cases are due to inheritance of highly penetrant cancer susceptibility genes. The majority of these are caused by mutations in the BRCA1 and BRCA2 genes, which are also associated with an increased risk of ovarian cancer. Increased surveillance, chemoprevention, and prophylactic surgeries are standard options for the effective medical management of mutation carriers. However, optimal management of female carriers who choose to undergo prophylactic surgeries is still poorly understood.

Methods

The authors provide an overview of the current literature regarding medical management options for women carriers of BRCA1 and BRCA2 gene mutations and the implications for those individuals who have chosen to undergo prophylactic surgeries.

Results

BRCA mutation carriers who opt for prophylactic surgeries are still at risk for development of malignancy, and appropriate monitoring is warranted.

Conclusions

There are limited data on the appropriate medical management for BRCA mutation carriers after prophylactic surgeries. However, a management plan can be extrapolated from the general management recommendations for surveillance and other risk-reducing strategies in BRCA-positive individuals.

The Role of BRCA2 Mutation Status as Diagnostic, Predictive, and Prognosis Biomarker for Pancreatic Cancer

Pancreatic cancer is one of the deadliest cancers worldwide, and life expectancy after diagnosis is often short. Most pancreatic tumours appear sporadically and have been highly related to habits such as cigarette smoking, high alcohol intake, high carbohydrate, and sugar consumption. Other observational studies have suggested the association between pancreatic cancer and exposure to arsenic, lead, or cadmium. Aside from these factors, chronic pancreatitis and diabetes have also come to be considered as risk factors for these kinds of tumours. Studies have found that 10% of pancreatic cancer cases arise from an inherited syndrome related to some genetic alterations. One of these alterations includes mutation in BRCA2 gene. BRCA2 mutations impair DNA damage response and homologous recombination by direct regulation of RAD51. In light of these findings that link genetic factors to tumour development, DNA damage agents have been proposed as target therapies for pancreatic cancer patients carrying BRCA2 mutations. Some of these drugs include platinum-based agents and PARP inhibitors. However, the acquired resistance to PARP inhibitors has created a need for new chemotherapeutic strategies to target BRCA2. The present systematic review collects and analyses the role of BRCA2 alterations to be used in early diagnosis of an inherited syndrome associated with familiar cancer and as a prognostic and predictive biomarker for the management of pancreatic cancer patients.

BRCA2 minor transcript lacking exons 4-7 supports viability in mice and may account for survival of humans with a pathogenic biallelic mutation

The breast cancer gene, BRCA2, is essential for viability, yet patients with Fanconi anemia-D1 subtype are born alive with biallelic mutations in this gene. The hypomorphic nature of the mutations is believed to support viability, but this is not always apparent. One such mutation is IVS7+2T>G, which causes premature protein truncation due to skipping of exon 7. We previously identified a transcript lacking exons 4-7, which restores the open-reading frame, encodes a DNA repair proficient protein and is expressed in IVS7+2T>G carriers. However, because the exons 4-7 encoded region contains several residues required for normal cell-cycle regulation and cytokinesis, this transcript's ability to support viability can be argued. To address this, we generated a Brca2 knock-in mouse model lacking exons 4-7 and demonstrated that these exons are dispensable for viability as well as tumor-free survival. This study provides the first in vivo evidence of the functional significance of a minor transcript of BRCA2 that can play a major role in the survival of humans who are homozygous for a clearly pathogenic mutation. Our results highlight the importance of assessing protein function restoration by premature truncating codon bypass by alternative splicing when evaluating the functional significance of variants such as nonsense and frame-shift mutations that are assumed to be clearly pathogenic. Our findings will impact not only the assessment of variants that map to this region, but also influence counseling paradigms and treatment options for such mutation carriers.

The genetic classification of pancreatic neoplasia

Cancer is caused by the accumulation of inherited and/or acquired alterations in specific genes. The recent decline in the cost of DNA sequencing has allowed tumor sequencing to be conducted on a large scale, which, in turn, has led to an unprecedented understanding of the genetic events that drive neoplasia. This understanding, when integrated with meticulous histologic analyses and with clinical findings, has direct clinical implications. The recent sequencing of all of the major types of cystic and noncystic neoplasms of the pancreas has revealed opportunities for molecular diagnoses and for personalized treatment. This review summarizes the results from these recent studies focusing on the clinical relevance of genomic data.

Risk of breast cancer and family history of other cancers in first-degree relatives in Chinese women: a case control study

Background

Few studies have systematically reported the relationship between the risk of breast cancer and family history of other cancers. This study was designed to systematically determine the relationship between breast cancer risk and family history of other cancers in first-degree relatives.

Methods

Between January 2006 and June 2011, 823 women diagnosed with breast cancer were included, and age-matched women diagnosed with benign breast disease were selected as controls. Family history of other cancers in first-degree relatives was recorded by trained reviewers. Multivariate logistic regression was applied to analyze the relationships.

Results

A family history of esophagus cancer (OR: 2.70, 95% CI: 1.11 – 6.57), lung cancer (OR: 2.49 95% CI: 1.10 – 5.65), digestive system cancer (OR: 1.79, 95% CI: 1.14 – 2.79) and any cancer (OR: 2.13, 95% CI: 1.49 – 3.04) in first-degree relatives was directly associated with increased breast cancer risk. In subgroup analysis, the risk of hormone receptor positive breast cancer was increased in subjects with a family history of lung cancer (OR: 3.37, 95% CI: 1.45 – 7.82), while the risk of hormone receptor negative breast cancer was increased in subjects with a family history of esophagus cancer (OR: 6.19, 95% CI: 2.30 – 16.71), uterus cancer (OR: 6.92, 95% CI: 1.12 – 42.89), digestive tract cancer (OR: 2.05, 95% CI: 1.03 – 4.10) and gynecology cancer (OR: 6.79, 95% CI: 1.46 – 31.65). Additionally, a significant increase in breast cancer was observed with a family history of digestive system cancer for subjects 50 y and younger (OR: 1.88, 95% CI: 1.03 – 3.43), not for subjects 50 y older (OR: 1.67, 95% CI: 0.86 – 3.25).

Conclusions

Breast cancer aggregates in families with several types of cancer especially for digestive system cancer. The influence of a family history of other cancers seems more likely to be limited to hormone receptor negative breast 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.

The analysis of microsatellite instability in extracolonic gastrointestinal malignancy

Microsatellite instability (MSI) is a genetic feature of sporadic and familial cancers of multiple sites and is related to defective mismatch repair (MMR) protein function. Lynch syndrome (LS) is a familial form of MMR deficiency that may present with a spectrum of MSI positive cancers including gastrointestinal (GI) malignancies. The incidence of high level MSI (MSI-H) in colorectal carcinoma is well defined in both familial and sporadic cases and these tumours portend a better overall prognosis in colorectal carcinoma (CRC). There are certain morphological features that suggest MSI-H CRC and international guidelines have been established for the evaluation of MSI in CRC. The prevalence and morphological features of extracolonic GI MSI-H tumours are less well documented. Furthermore, it is unclear whether the guidelines for the assessment of MSI in CRC are appropriate for application to extracolonic GI malignancies. This review aims to summarise the recent literature on MSI in extracolonic LS-related GI tract malignancies with special attention to the assessment of the MMR system by evaluation of specific microsatellite markers and/or immunohistochemical evaluation of MMR protein expression. The reported prevalence of sporadic and LS-related MSI-H tumours along with their associated unique morphological patterns and related prognostic or therapeutic implications will be discussed.

Beyond Breast and Ovarian Cancers: PARP Inhibitors for BRCA Mutation-Associated and BRCA-Like Solid Tumors

Poly(ADP-ribose) polymerase inhibitors (PARPi) have shown clinical activity in patients with germline BRCA1/2 mutation (gBRCAm)-associated breast and ovarian cancers. Accumulating evidence suggests that PARPi may have a wider application in the treatment of cancers defective in DNA damage repair pathways, such as prostate, lung, endometrial, and pancreatic cancers. Several PARPi are currently in phase I/II clinical investigation, as single-agents and/or combination therapy in these solid tumors. Understanding more about the molecular abnormalities involved in BRCA-like phenotype in solid tumors beyond breast and ovarian cancers, exploring novel therapeutic trial strategies and drug combinations, and defining potential predictive biomarkers are critical to expanding the scope of PARPi therapy. This will improve clinical outcome in advanced solid tumors. Here, we briefly review the preclinical data and clinical development of PARPi, and discuss its future development in solid tumors beyond gBRCAm-associated breast and ovarian cancers.

Hypomethylating therapy in an aggressive stroma-rich model of pancreatic carcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy that resists current treatments. To test epigenetic therapy against this cancer, we used the DNA demethylating drug 5-aza-2'-deoxycytidine (DAC) in an aggressive mouse model of stromal rich PDAC (KPC-Brca1 mice). In untreated tumors, we found globally decreased 5-methyl-cytosine (5-mC) in malignant epithelial cells and in cancer-associated myofibroblasts (CAF), along with increased amounts of 5-hydroxymethyl-cytosine (5-HmC) in CAFs, in progression from pancreatic intraepithelial neoplasia to PDAC. DAC further reduced DNA methylation and slowed PDAC progression, markedly extending survival in an early-treatment protocol and significantly though transiently inhibiting tumor growth when initiated later, without adverse side effects. Escaping tumors contained areas of sarcomatoid transformation with disappearance of CAFs. Mixing-allografting experiments and proliferation indices showed that DAC efficacy was due to inhibition of both the malignant epithelial cells and the CAFs. Expression profiling and immunohistochemistry highlighted DAC induction of STAT1 in the tumors, and DAC plus IFN-γ produced an additive antiproliferative effect on PDAC cells. DAC induced strong expression of the testis antigen deleted in azoospermia-like (DAZL) in CAFs. These data show that DAC is effective against PDAC in vivo and provide a rationale for future studies combining hypomethylating agents with cytokines and immunotherapy.

New-onset diabetes patients need pancreatic cancer screening?

OBJECTIVE

Because patients with new-onset diabetes mellitus (DM) have a significantly increased likelihood of association with pancreatic cancer, we need to select the subgroup of diabetic patients who have more chance of association with pancreatic cancer.

METHODS

We retrospectively reviewed medical records of case group (151 patients with pancreatic cancer with new-onset DM) and control group (302 patients with new-onset DM without cancer).

RESULTS

Compared with the control group, pancreatic cancer group were older, had more weight loss, lower usual body mass index (BMI), more family history of pancreatic cancer (3.3% vs. 0.7%; P=0.044), and had less family history of DM (13.9% vs. 37.4%; P<0.001). If a new-onset DM patient did not have family history of DM, he was of age older than or equal to 65 years or had weight loss of >2 kg or had premorbid usual BMI <25 kg/m(2), pancreatic cancer associated DM could be discriminated from new-onset type 2 DM with 80.8% sensitivity, 67.6% specificity, 2.5% and 99.7% of positive and negative predictability for pancreatic cancer, respectively.

CONCLUSIONS

Among patients who meet criteria for diabetes within 2 years, those who are elderly, have lower premorbid BMI, weight loss, no family history of DM, need screening of pancreatic cancer.

Hereditary pancreatic cancer: molecular bases and their application in diagnosis and clinical management: a guideline of the TTD group

Pancreatic carcinoma (PC) represents the fourth leading cause of cancer death in Spain with a death rate of 2,400 males and 2,000 females per year. Poor outcome related to its silent nature and the lack of reliable secondary prevention measures translate into advanced-stage diagnosis, 75 % of deaths within the first year of diagnosis and 5-year survival rate of <5 %. Family history was first recognized as a risk factor for PC. Further population-based and case-control studies subsequently found that 7.8 % of patients with PC have a family history of the same tumor and individuals with a first-degree relative with PC have a 3.2-fold increased risk of developing PC. Overall, it is estimated that up to 10 % of PC have a familial component. However, known genetic syndromes account for <20 % of the observed familial aggregation of PC. We review the most important aspects in epidemiology, molecular biology and clinical management of familial PC.

The pathobiological impact of cigarette smoke on pancreatic cancer development (review)

Despite extensive efforts, pancreatic cancer remains incurable. Most risk factors, such as genetic disposition, metabolic diseases or chronic pancreatitis cannot be influenced. By contrast, cigarette smoking, an important risk factor for pancreatic cancer, can be controlled. Despite the epidemiological evidence of the detrimental effects of cigarette smoking with regard to pancreatic cancer development and its unique property of being influenceable, our understanding of cigarette smoke-induced pancreatic carcinogenesis is limited. Current data on cigarette smoke-induced pancreatic carcinogenesis indicate multifactorial events that are triggered by nicotine, which is the major pharmacologically active constituent of tobacco smoke. In addition to nicotine, a vast number of carcinogens have the potential to reach the pancreatic gland, where they are metabolized, in some instances to even more toxic compounds. These metabolic events are not restricted to pancreatic ductal cells. Several studies show that acinar cells are also greatly affected. Furthermore, pancreatic cancer progenitor cells do not only derive from the ductal epithelial lineage, but also from acinar cells. This sheds new light on cigarette smoke-induced acinar cell damage. On this background, our objective is to outline a multifactorial model of tobacco smoke-induced pancreatic carcinogenesis.

The many faces of wnt and pancreatic ductal adenocarcinoma oncogenesis

Pancreatic ductal adenocarcinoma (PDAC) remains amongst the most lethal human cancers. PDAC is characterized by the tumor mass containing a paucity of malignant cells in association with a large desmoplastic reaction comprised of a variety of stromal components. Sporadic PDAC oncogenesis occurs as a result of the sequential acquisition of genetic aberrations occurring in core genetic pathways. Unfortunately, the average PDAC contains a large number of genetic aberrations that are not uniform between individual cancers. The interplay between the complex genetics and stromal component may represent a significant barrier to the development of effective therapy for this disease and ultimately be an important factor in PDAC lethality. The Wnt pathway has been identified as a one of the common pathways undergoing genetic alterations in PDAC. Wnt is a complex signal transduction pathway utilizing both a β-catenin dependent (canonical) and β-catenin independent (noncanonical) signals to affect a wide array of intracellular events. Wnt signal transduction is an integral component of pancreas organogenesis promoting the expansion and development of the exocrine pancreas. Pancreatic cancer may utilize the Wnt signaling pathway in concert with other signaling pathways such as notch during tumorigenesis. This review will focus on the role of Wnt signal transduction in pancreatic cancer biology.

Family history of cancer and tobacco exposure in index cases of pancreatic ductal adenocarcinoma

Aim. To examine interaction between history of cancer in first-degree relatives and tobacco smoking in index patients of pancreatic adenocarcinoma. Methods. We carried out a case-control involving 113 patients with pancreatic adenocarcinoma and 110 controls over a 12-month period at the Freeman Hospital, Newcastle upon Tyne, UK. They were all administered a detailed tobacco exposure questionnaire and a family history questionnaire. We calculated cumulative tobacco exposure and risk for pancreas cancer. Results. Both smokers (OR 3.01 (95% CI: 1.73 to 5.24)) and those with a family history of malignancy (OR 1.98 (95% CI: 1.15–3.38)) were more likely to develop pancreatic cancer. Having more than one first-degree relative with cancer did not significantly further increase the risk of pancreatic cancer. Amongst pancreatic cancer cases, cumulative tobacco exposure was significantly decreased (P = .032) in the group of smokers (current and ex-smokers) who had a family history of malignancy [mean (SD): 30.00 (24.77) pack-years versus 44.69 (28.47) pack-years with no such history]. Conclusions. Individuals with a family history of malignancy are at an increased risk of pancreatic cancer. Furthermore, individuals with a family history of malignancy and who smoke appear to require a lesser degree of tobacco exposure for the development of pancreatic cancer.

KRAS, Hedgehog, Wnt and the twisted developmental biology of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is characterized by near-universal mutations in KRAS and frequent deregulation of crucial embryonic signalling pathways, including the Hedgehog (Hh) and Wnt-β-catenin cascades. The creation of mouse models that closely resemble the human disease has provided a platform to better understand when and in which cell types these pathways are misregulated during PDAC development. Here we examine the central part that KRAS plays in the biology of PDAC, and how the timing and location of Hh and Wnt-β-catenin signalling dictate the specification and oncogenic properties of PDAC.

Family history of cancer and risk of pancreatic cancer: a pooled analysis from the Pancreatic Cancer Cohort Consortium (PanScan)

A family history of pancreatic cancer has consistently been associated with increased risk of pancreatic cancer. However, uncertainty remains about the strength of this association. Results from previous studies suggest a family history of select cancers (i.e., ovarian, breast and colorectal) could also be associated, although not as strongly, with increased risk of pancreatic cancer. We examined the association between a family history of 5 types of cancer (pancreas, prostate, ovarian, breast and colorectal) and risk of pancreatic cancer using data from a collaborative nested case-control study conducted by the Pancreatic Cancer Cohort Consortium. Cases and controls were from cohort studies from the United States, Europe and China, and a case-control study from the Mayo Clinic. Analyses of family history of pancreatic cancer included 1,183 cases and 1,205 controls. A family history of pancreatic cancer in a parent, sibling or child was associated with increased risk of pancreatic cancer [multivariate-adjusted odds ratios (ORs) = 1.76, 95% confidence interval (CI) = 1.19-2.61]. A family history of prostate cancer was also associated with increased risk (OR = 1.45, 95% CI = 1.12-1.89). There were no statistically significant associations with a family history of ovarian cancer (OR = 0.82, 95% CI = 0.52-1.31), breast cancer (OR = 1.21, 95% CI = 0.97-1.51) or colorectal cancer (OR = 1.17, 95% CI = 0.93-1.47). Our results confirm a moderate sized association between a family history of pancreatic cancer and risk of pancreatic cancer and also provide evidence for an association with a family history of prostate cancer worth further study.

Germline MLH1 and MSH2 mutations in Italian pancreatic cancer patients with suspected Lynch syndrome

Lynch syndrome is an inherited cancer syndrome caused by germline mutations in mismatch repair (MMR) genes MLH1, MSH2, MSH6 and PMS2. LS predisposes to high risk of early-onset colorectal, endometrial and other tumors. Patients with Lynch syndrome have also been shown to have an elevated risk for pancreatic cancer (PC). In this study, we aimed to estimate the frequency of suspected Lynch syndrome among a series of 135 PC patients. Further, we wanted to determine the frequency of MMR gene mutations in the suspected Lynch syndrome cases. We also aimed to verify the pathogenicity of any novel non-truncating variants we might detect with a functional assay. Based on personal and/or familial cancer history, 19 patients were classified as suspected Lynch syndrome cases. DNA material for mutation analysis was available for eleven of them. Four patients were found to carry a total of five MLH1 or MSH2 variants. Of these, MSH2-Q402X, MSH2-G322D, and MLH1-K618A had been previously reported, while the MSH2-E205Q and MSH2-V367I variants were novel. MSH2-Q402X is a known stop mutation and reported here for the first time here in association with PC. MLH1-K618A was found in the unaffected branch of a kindred, suggesting that it may be a polymorphism or a low penetrance variant. MSH2-G322D likely does not cause a MMR defect, although this variant has also been associated with breast cancer as indeed seen in our patient. The novel variants MSH2-E205Q and MSH2-V367I were found in the same patient. Both novel variants were however functional in the applied MMR assay. Our findings suggest that only a small subset of pancreatic cancer patients carry pathogenic MMR mutations.

The yield of first-time endoscopic ultrasonography in screening individuals at a high risk of developing pancreatic cancer

OBJECTIVES

Approximately 10-15% of all pancreatic cancers (PCs) may be hereditary in origin. We investigated the use of endoscopic ultrasonography (EUS) for the screening of individuals at high risk for developing PC. In this paper the results of first-time screening with EUS are presented.

METHODS

Those eligible for screening in this study were first-degree family members of affected individuals from familial pancreatic cancer (FPC) families, mutation carriers of PC-prone hereditary syndromes, individuals with Peutz-Jeghers syndrome, and mutation carriers of other PC-prone hereditary syndromes with clustering (> or =2 cases per family) of PC. All individuals were asymptomatic and had not undergone EUS before.

RESULTS

Forty-four individuals (M/F 18/26), aged 32-75 years underwent screening with EUS. Thirteen were from families with familial atypical multiple-mole melanoma (FAMMM), 21 with FPC, 3 individuals were diagnosed with hereditary pancreatitis, 2 were Peutz-Jeghers patients, 3 were BRCA1 and 2 were BRCA2 mutation carriers with familial clustering of PC, and 1 individual had a p53 mutation. Three (6.8%) patients had an asymptomatic mass lesion (12, 27, and 50 mm) in the body (n=2) or tail of the pancreas. All lesions were completely resected. Pathology showed moderately differentiated adenocarcinomas with N1 disease in the two patients with the largest lesions. EUS showed branch-type intraductal papillary mucinous neoplasia (IPMN) in seven individuals.

CONCLUSIONS

Screening of individuals at a high risk for PC with EUS is feasible and safe. The incidence of clinically relevant findings at first screening is high with asymptomatic cancer in 7% and premalignant IPMN-like lesions in 16% in our series. Whether screening improves survival remains to be determined, as does the optimal screening interval with EUS.

DNA repair gene polymorphisms and risk of pancreatic cancer

PURPOSE

The current research was undertaken to examine the association between genetic variations in DNA repair and pancreatic cancer risk.

EXPERIMENTAL DESIGN

We analyzed 9 single nucleotide polymorphisms of 7 DNA repair genes (LIG3, LIG4, OGG1, ATM, POLB, RAD54L, and RECQL) in 734 patients with pancreatic adenocarcinoma and 780 healthy controls using the Taqman method. Information on cigarette smoking, alcohol consumption, medical history, and other risk factors was collected by personal interview.

RESULTS

The homozygous mutant genotype of LIG3 G-39A [odds ratio (OR), 0.23; 95% confidence interval (CI), 0.06-0.82; P = 0.027] and ATM D1853N (OR, 2.55; 95% CI, 1.08-6.00; P = 0.032) was significantly associated with altered risk for pancreatic cancer. A statistically significant interaction of ATM D1853N and LIG4 C54T genotype with diabetes on the risk of pancreatic cancer was also detected. Compared with nondiabetics with the ATM D1853N GG genotype, nondiabetics with the GA/AA, diabetics with the GG, and diabetics with the GA/AA genotypes, respectively, had ORs (95% CI) of 0.96 (0.74-1.24), 1.32 (0.89-1.95), and 3.23 (1.47-7.12; P(interaction) = 0.032, likelihood ratio test). The OR (95% CI) was 0.91 (0.71-1.17), 1.11 (0.73-1.69), and 2.44 (1.34-4.46) for nondiabetics carrying the LIG4 CT/TT genotype, diabetics with the CC genotype, and diabetics carrying the CT/TT genotype, respectively, compared with nondiabetics carrying the CC genotype (P(interaction) = 0.02).

CONCLUSIONS

These observations suggest that genetic variations in DNA repair may act alone or in concert with other risk factors on modifying a patient's risk for pancreatic cancer.

Family history of various cancers and pancreatic cancer mortality in a large cohort

A family history of pancreatic cancer is associated with increased risk of pancreatic cancer, but uncertainty remains about the magnitude of this association, whether it varies by age or smoking and whether a family history of other cancers may also be associated with increased risk. We examined family history of 14 cancers and pancreatic cancer mortality among ~1.1 million men and women in Cancer Prevention Study-II (CPS-II). CPS-II participants completed a questionnaire at enrollment in 1982. During follow-up through 2006, there were 7,306 pancreatic cancer deaths. A family history of pancreatic cancer in a parent or sibling was associated with pancreatic cancer mortality [multivariable adjusted rate ratio (RR) = 1.66, 95% confidence interval (CI) 1.43-1.94]. This association was stronger among participants aged under 60 (RR = 2.89, 95% CI 1.67-5.02) than among participants aged 60 or older (RR = 1.61, 95% CI 1.37-1.88). Weaker associations were observed for family history of stomach cancer (RR = 1.23, 95% CI 1.11-1.37), liver cancer (RR = 1.25, 95% CI 1.10-1.43), and colorectal cancer (RR = 1.12, 95% CI 1.01-1.23). Results from this large prospective study indicate family history of pancreatic cancer is associated with a moderate increase in risk of pancreatic cancer, and also identify associations with the family history of certain other cancers which may be useful in generating hypotheses about shared risk factors.

Low prevalence of CDKN2A/ARF mutations among early-onset cancers of breast, pancreas and malignant melanoma in Poland

In this report the contribution of CDKN2A/ARF germline mutations to early-onset cancers of the breast, pancreas and malignant melanoma was examined. We screened 66 women with breast cancer diagnosed at age 30 and below, 72 melanoma patients with the median age at diagnosis < or = 40 years and 51 pancreatic cancer patients diagnosed under the age of 50 years. In the total set of 189 patients we found a novel change Pro48Arg (nt 143 c > g), a novel intronic change IVS1+36 g>c and two common variants A148T and IVS3+29 c>g. The results of this study revealed a paucity of mutations in CDKN2A/ARF suggesting that in the Polish population this gene does not contribute significantly to early-onset breast cancer, pancreatic cancer and malignant melanoma.

Role of the mismatch repair gene, Msh6, in suppressing genome instability and radiation-induced mutations

Mismatch repair (MMR) is critical for preserving genomic integrity. Failure of this system can accelerate somatic mutation and increase the risk of developing cancer. MSH6, in complex with MSH2, is the MMR protein that mediates DNA repair through the recognition of 1- and 2-bp mismatches. To evaluate the effects of MSH6 deficiency on genomic stability we compared the frequency of in vivo loss of heterozygosity (LOH) between MSH6-proficient and deficient, 129S2xC57BL/6 F1 hybrid mice that were heterozygous for our reporter gene Aprt. We recovered mutant cells that had functionally lost APRT protein activity and categorized the spectrum of mutations responsible for the LOH events. We also measured the mutant frequency at the X-linked gene, Hprt, as a second reporter for point mutation. In Msh6-/-Aprt+/- mice, mutation frequency at Aprt was elevated in both T cells and fibroblasts by 2.5-fold and 5.7-fold, respectively, over Msh6+/+Aprt+/- littermate controls. While a modest increase in mitotic recombination (MR) was observed in MSH6-deficient fibroblasts compared to wild type controls, point mutation was the predominant mechanism leading to APRT deficiency in both cell types. Base substitution, consisting of multiple types of transitions, accounted for all of the point mutations identified within the Aprt coding region. We also assessed the role of MSH6 in preventing mutations caused by a common environmental mutagen, ionizing radiation (IR). In Msh6-/-Aprt+/- mice, 4Gy of X-irradiation induced a significant increase in point mutations at both Aprt and Hprt in T cells, but not in fibroblasts. These findings indicate that MutS alpha reduces spontaneous and IR-induced mutation in a cell type-dependant manner.

Tumor M2-pyruvate kinase as tumor marker in exocrine pancreatic cancer a meta-analysis

OBJECTIVES

Tumor M2-pyruvate kinase, a tumor-associated dimeric form of enzyme pyruvate kinase, is commonly elevated in pancreatic cancers. This meta-analysis aimed to evaluate its diagnostic utility in comparison to carbohydrate antigen 19-9 (CA19-9) in pancreatic cancer.

METHODS

A literature search was conducted for entries from 1951 to 2006 using PubMed, Embase, Central, and SCI Expanded databases using M2 pyruvate kinase AND pancreatic cancer/s OR tumor/s as keywords. A total of 258 references were retrieved. Of these, 118 duplicates were removed and 132 references were excluded. All studies comparing TuM2-PK with CA19-9 in pancreatic cancer were included. Full text was obtained for 8 references of 7 included studies. Diagnostic odds ratio (DOR) and 95% confidence interval (CI) was calculated from the available specificity and sensitivity for each study and were pooled to give overall DOR and 95% CI for TuM2-PK and CA19-9. Receiver operator characteristic curve was calculated to give overall specificity and sensitivity for TuM2-PK.

RESULTS

The diagnostic performance of TuM2-PK (DOR, 35; 95% CI, 19.7-62.3) was similar to those of CA19-9 (DOR, 44; 95% CI, 26.5-73.1). The overall specificity for TuM2-PK was 60% with corresponding sensitivity of 95%.

CONCLUSION

Efficacy of TuM2-PK as a tumor marker is similar to that of CA19-9. Further trials are needed to use it alone or in combination with CA19-9 in patients with suspected pancreatic cancer.

Allogeneic transplantation and the risk for transmission of genetic disease: the heritable cancer disorders

With the development of new approaches to transplantation therapy, such as those building upon the potential found in stem cells, it is vital to pursue a clear understanding of transplantation risks. Allogeneic transplantation presents risk for the transmission of disease of various types, including genetic disease. Predisposition to develop cancer is a feature of numerous genetic disorders, and it may be transmissible by transplantation. Some genetic disorders predisposing to cancer are remarkably common, either worldwide or in specific populations, and they could pose significant risk. Hence, to reduce risk to recipients, there is reason to exclude from donation those potential donors (including embryos) harboring certain germ-line mutations. However, the frequent absence of readily identifiable features might confound the effort to exclude those who harbor mutation. Thus, it is also important to consider the magnitude of risk that they represent. For some disorders, life-threatening cancer is highly likely to develop in those individuals born with germ-line mutation, but whether recipients would face the same risk from transplanted mutation is not always evident. Given the diversity of pathways that lead to cancer, there may be diverse factors that impact the likelihood for cancer to develop in the recipient, with some factors decreasing and others increasing the risk. One factor of special concern is the possibility that manipulation of donor cells, prior to transplantation, might introduce additional genetic or epigenetic abnormality, thereby increasing the risk.

Precursor lesions of pancreatic cancer: molecular pathology and clinical implications

BACKGROUND

Pancreatic cancer is a lethal disease, with near uniform 5-year mortality rates. The key to improving survival of pancreatic cancer rests upon early detection of this neoplasm at a resectable, and hence potentially curable, stage.

METHODS

We review the current state of the literature vis-à-vis the three common precursor lesions of pancreatic adenocarcinoma: pancreatic intraepithelial neoplasia, intraductal papillary mucinous neoplasm, and mucinous cystic neoplasm. We also discuss two clinical scenarios of emerging importance, namely asymptomatic pancreatic cysts ('pancreatic incidentalomas') and the significance of precursor lesions in familial pancreatic cancer kindreds.

RESULTS

Pancreatic intraepithelial neoplasias are the microscopic precursor lesions of pancreatic adenocarcinomas, while intraductal papillary mucinous neoplasms and mucinous cystic neoplasms are macroscopic, cystic precursor lesions. All three noninvasive entities demonstrate a multistep morphologic and genetic progression that culminates in frank invasive adenocarcinoma. Despite these commonalities, each precursor lesion harbors a unique repertoire of clinicopathologic and genetic characteristics that has an impact on natural history and prognosis of these lesions. Due to improvements in radiological techniques, asymptomatic pancreatic cysts are being increasingly discovered in the general population; intraductal papillary mucinous neoplasms and mucinous cystic neoplasms are the most common underlying histology in resected incidentalomas of the pancreas. Pancreatic asymptomatic cysts present an enormous challenge in terms of accurate diagnosis and management stratification. Incorporating molecular signatures of cystic precursor lesions into the diagnostic algorithm will likely become a standard of care for asymptomatic pancreatic cysts. High-risk individuals from familial pancreatic cancer kindreds are another group of individuals where knowledge of precursor lesions has had a therapeutic impact; sensitive imaging technologies have enabled the identification and subsequent resection of pancreatic cancer precursors in these high-risk individuals, preventing the progression to invasive cancer.

CONCLUSIONS

Precursor lesions of pancreatic adenocarcinomas represent a unique opportunity for diagnosis and intervention for a malignancy with near uniform lethality. Further studies on these precursors will enable the development of rational early detection and therapeutic strategies in order to ameliorate pancreatic cancer survival.

An update on familial pancreatic cancer and the management of asymptomatic relatives

Families of patients with pancreatic adenocarcinoma (PC) often ask about their own risk of developing this disease. There is now a sufficient body of evidence to inform relatives of their relative risk of developing PC. The purpose of this review is to provide practical advice for the clinician when confronted with questions about the risk of PC in relatives, and the role of genetic testing and screening in high-risk individuals.