Systemic cancer and the FAMMM syndrome

Twenty-five years of surveillance for familial and hereditary pancreatic ductal adenocarcinoma: Historical perspectives and introduction to the special issue

In the 1990s, as prevention became a central strategy in the battle against cancer and the molecular genetics revolution uncovered the genetic basis of numerous hereditary cancer syndromes, there were no options available for patients at increased risk of developing pancreatic cancer. When surveillance efforts for those at familial and hereditary risk of pancreatic cancer emerged in the late 1990s, it was uncertain if early detection was achievable.In this introduction to the special issue, we offer an overview of the history of surveillance for pancreatic cancer, including the first reports of familial pancreatic cancer in the medical literature, the initial results of surveillance in the United States and the initiation of surveillance programs for hereditary pancreatic cancer in the Netherlands.This special issue features a collection of 18 articles written by prominent experts in the field, focusing specifically on refining surveillance methodologies with the primary objective of improving care of high-risk individuals. Several reviews in this collection highlight improved survival rates associated with pancreas surveillance, underlying the potential of early detection and improved management in the continuing fight against pancreatic cancer.

High-Grade Endometrial Stromal Sarcomas With YWHAE::NUTM2 Gene Fusion Exhibit Recurrent CDKN2A Alterations and Absence of p16 Staining is a Poor Prognostic Marker

High-grade endometrial stromal sarcomas (HGESSs) are aggressive uterine tumors harboring oncogenic fusion proteins. We performed a molecular study of 36 HGESSs with YWHAE::NUTM2 gene fusion, assessing co-occurring genetic events, and showed that these tumors frequently harbor recurrent events involving the CDKN2A locus on chromosome 9p. Using array-based copy number profiling and CDKN2A fluorescence in situ hybridization, we identified homozygous and hemizygous deletions of CDKN2A in 18% and 14% of tumors (n = 22 analyzed), respectively. While all YWHAE-rearranged HGESSs with retained disomy for CDKN2A were immunohistochemically positive for p16INK4 (p16), all tumors with homozygous deletion of CDKN2A showed complete absence of p16 staining. Of the 2 tumors with a hemizygous deletion of CDKN2A, 1 showed diffuse and strong p16 positivity, whereas the other showed complete absence of staining. In the p16-negative case, we did not find intragenic mutations or DNA promoter methylation to explain the p16 protein loss, implicating other mechanisms in the regulation of protein expression. In our cohort, subclonal or complete absence of p16 staining was associated with worse overall survival compared with positive p16 staining (1-year overall survival: 28.6% vs 90.7%, respectively; n = 32; P < .001), with all 7 patients in the p16-negative group having succumbed to their disease within 2 years of diagnosis. Our results suggested CDKN2A alterations as a cooperative driver of tumorigenesis in a subset of HGESSs with the YWHAE::NUTM2 gene fusion and showed p16 to be a potential prognostic marker.

Genetics, Genomics and Emerging Molecular Therapies of Pancreatic Cancer

The number of cases of pancreatic cancers in 2019 in Poland was 3852 (approx. 2% of all cancers). The course of the disease is very fast, and the average survival time from the diagnosis is 6 months. Only <2% of patients live for 5 years from the diagnosis, 8% live for 2 years, and almost half live for only about 3 months. A family predisposition to pancreatic cancer occurs in about 10% of cases. Several oncogenes in which somatic changes lead to the development of tumours, including genes BRCA1/2 and PALB2, TP53, CDKN2A, SMAD4, MLL3, TGFBR2, ARID1A and SF3B1, are involved in pancreatic cancer. Between 4% and 10% of individuals with pancreatic cancer will have a mutation in one of these genes. Six percent of patients with pancreatic cancer have NTRK pathogenic fusion. The pathogenesis of pancreatic cancer can in many cases be characterised by homologous recombination deficiency (HRD)-cell inability to effectively repair DNA. It is estimated that from 24% to as many as 44% of pancreatic cancers show HRD. The most common cause of HRD are inactivating mutations in the genes regulating this DNA repair system, mainly BRCA1 and BRCA2, but also PALB2, RAD51C and several dozen others.

Identification of high-risk germline variants for the development of pancreatic cancer: Common characteristics and potential guidance to screening guidelines

Pancreatic cancer (PC) is a product of a variety of environmental and genetic factors. Recent work has highlighted the influence of hereditary syndromes on pancreatic cancer incidence. The purpose of this review is to identify the high-risk syndromes, common variants, and risks associated with PC. The study also elucidates common characteristics of patients with these mutations, which is used to recommend potential changes to current screening protocols for greater screening efficacy. We analyzed 8 syndromes and their respective variants: Hereditary Breast and Ovarian Cancer (BRCA1/2), Familial Atypical Multiple Mole Melanoma Syndrome (CDKN2A), Peutz-Jeghers Syndrome (STK11), Lynch Syndrome (PMS2, MLH1, MSH2, MSH6, EPCAM), Ataxia Telangiectasia (ATM), Li-Fraumeni Syndrome (TP53), Fanconi Anemia (PALB2), and Hereditary Pancreatitis (PRSS1, SPINK1, CFTR). Of 587 studies evaluated, 79 studies fit into our inclusion criteria. Information from each study was analyzed to draw conclusions on these variants as well as their association with pancreatic cancer. Information from this review is intended to improve precision medicine and improve criteria for screening.

Dysplastic nevus syndrome and pancreatic cancer: A case report

Multiple primary cancers may occur in the same patient, with a prevalence that follows an ascendant trend. Their development is dictated by a complex interplay between a variety of factors, both patient-dependent and external. The case of a 38-year-old female patient diagnosed and treated for pancreatic cancer (PC) is presented in whom the digital dermoscopic monitoring of melanocytic nevi revealed a marked change of two nevi that acquired rapidly highly atypical features. They were surgically excised and the histopathological examination revealed two completely excised dysplastic compound nevi. Clinicians should be aware of the strong association between dysplastic nevus syndrome and PC, a malignancy associated with an extremely poor prognosis. Familial atypical multiple mole melanoma syndrome (FAMMM) predisposes to the development of melanoma, pancreatic cancer and other neoplasms. The common genetic background of PC and hereditary melanoma is discussed and the importance of regular skin checkup and screening for PC in these patients is underlined.

CDKN2A-Mutated Pancreatic Ductal Organoids from Induced Pluripotent Stem Cells to Model a Cancer Predisposition Syndrome

Patient-derived induced pluripotent stem cells (iPSCs) provide a unique platform to study hereditary disorders and predisposition syndromes by resembling germline mutations of affected individuals and by their potential to differentiate into nearly every cell type of the human body. We employed plucked human hair from two siblings with a family history of cancer carrying a pathogenic CDKN2A variant, P16-p.G101W/P14-p.R115L, to generate patient-specific iPSCs in a cancer-prone ancestry for downstream analytics. The differentiation capacity to pancreatic progenitors and to pancreatic duct-like organoids (PDLOs) according to a recently developed protocol remained unaffected. Upon inducible expression of KRAS^G12Dusing a piggyBac transposon system in CDKN2A-mutated PDLOs, we revealed structural and molecular changes in vitro, including disturbed polarity and epithelial-to-mesenchymal (EMT) transition. CDKN2A-mutated KRAS^G12DPDLO xenotransplants formed either a high-grade precancer lesion or a partially dedifferentiated PDAC-like tumor. Intriguingly, P14/P53/P21 and P16/RB cell-cycle checkpoint controls have been only partly overcome in these grafts, thereby still restricting the tumorous growth. Hereby, we provide a model for hereditary human pancreatic cancer that enables dissection of tumor initiation and early development starting from patient-specific CDKN2A-mutated pluripotent stem cells.

The Role of Inherited Pathogenic CDKN2A Variants in Susceptibility to Pancreatic Cancer

ABSTRACT

CDKN2A is cell cycle negative regulator, and the role of CDKN2A in the development of pancreatic ductal adenocarcinoma, which continues to be a lethal cancer, is well-established. Somatic loss of CDKN2A is considered one of the major drivers of pancreatic tumorigenesis. CDKN2A gene is one of the pancreatic cancer susceptibility gene; in addition to melanoma, pathogenic germline CDKN2A variants have been identified in up to 3.3% patients with pancreatic ductal adenocarcinoma depending on family history of disease. Carriers of a known pathogenic germline CDKN2A variant have up to a 12.3-fold increased risk of developing pancreatic cancer. Recently, several studies have demonstrated the benefit of clinical surveillance in patients with pathogenic germline CDKN2A variants. Therefore, identification of patients with a pathogenic germline CDKN2A variant is important for screening of at-risk relatives for pancreatic cancer. It has the potential to lead to the detection of early, potentially curable pancreatic cancer and precursor neoplasms, and reduce mortality. Furthermore, patients with a germline pathogenic CDKN2A variant and somatic loss of CDKN2A may benefit in the future from treatment with targeted therapies, such as a CDK4/6 inhibitor.

Development of esophageal squamous cell cancer in patients with FAMMM syndrome: Two clinical reports

Familial atypical multiple mole melanoma (FAMMM) syndrome is a hereditary syndrome characterized by multiple dysplastic nevi and melanoma. Patients with FAMMM may have a heterozygous, inactivating, pathogenic germline variant in the CDKN2A gene, especially the NM_000077.4: c.225_243del19 (p.p75fs) variant, also known as p16-Leiden variant. Patients with this variant are at high risk for developing melanomas and pancreatic cancer due to somatic inactivation of the wild-type CDKN2A allele. The combination of an inactivating germline CDKN2A mutation and somatic inactivation of the wild-type CDKN2A allele in the same cell results in tumor formation. It has been suggested that carriers of a germline CDKN2A mutation are also at increased risk for several other cancer types, including esophageal cancer. Here, we describe two unrelated patients with the p16-Leiden variant who developed esophageal squamous cell cancer. Evidence of loss of the wild-type CDKN2A allele was obtained in the tumor tissue of both patients indicating biallelic inactivation of p16 in the tumor cells. These results suggest that these patients developed esophageal squamous cell cancer in the context of FAMMM syndrome.

CDKN2A germline alterations in melanoma patients with personal or familial history of pancreatic cancer

CDKN2A germline mutations increase the risk of melanoma development and are present in 20 and 10% of familial and multiple melanoma cases, respectively. Pancreatic cancer has been associated with CDKN2A in some populations and, accordingly, its presence in first-degree or second-degree relatives of a melanoma patient is considered as a criterion for genetic testing. In this study, we show that in an area with low melanoma incidence, CDKN2A germline mutations in patients with melanoma and personal or family history of pancreatic cancer are mainly present in the setting of familial or multiple melanoma cases. In addition, a relatively young age (≤52 years) at pancreatic diagnosis is an additional single criterion that might also be considered.

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

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

Pancreatic Cancer Genetics

Although relatively rare, pancreatic tumors are highly lethal [1]. In the United States, an estimated 48,960 individuals will be diagnosed with pancreatic cancer and 40,560 will die from this disease in 2015 [1]. Globally, 337,872 new pancreatic cancer cases and 330,391 deaths were estimated in 2012 [2]. In contrast to most other cancers, mortality rates for pancreatic cancer are not improving; in the US, it is predicted to become the second leading cause of cancer related deaths by 2030 [3, 4]. The vast majority of tumors arise in the exocrine pancreas, with pancreatic ductal adenocarcinoma (PDAC) accounting for approximately 95% of tumors. Tumors arising in the endocrine pancreas (pancreatic neuroendocrine tumors) represent less than 5% of all pancreatic tumors [5]. Smoking, type 2 diabetes mellitus (T2D), obesity and pancreatitis are the most consistent epidemiological risk factors for pancreatic cancer [5]. Family history is also a risk factor for developing pancreatic cancer with odds ratios (OR) ranging from 1.7-2.3 for first-degree relatives in most studies, indicating that shared genetic factors may play a role in the etiology of this disease [6-9]. This review summarizes the current knowledge of germline pancreatic cancer risk variants with a special emphasis on common susceptibility alleles identified through Genome Wide Association Studies (GWAS).

Multiple primary cutaneous melanomas in patients with FAMMM syndrome and sporadic atypical mole syndrome (AMS): what's worse?

Atypical Mole Syndrome is the most important phenotypic risk factor for cutaneous melanoma, a malignancy that accounts for about 80% of deaths from skin cancer. Since early diagnosis of melanoma is of great prognostic relevance, the identification of Atypical Mole Syndrome carriers (sporadic and familial) is essential, as well as the recommendation of preventative measures that must be undertaken by these patients.We report two rare cases concerning patients with multiple primary skin melanomas in the setting of a familial and a sporadic syndrome of dysplastic nevi: the first patient is a 67-year-old patient with a history of multiple superficial spreading melanomas localized on his back. The second patient presented with multiple primary melanomas in advanced stage in the context of the so-called sporadic form of the syndrome of dysplastic nevi-AMS (atypical mole syndrome). In the first case, excision of the melanomas was carried out with an uneventful post-operative period. In the second case, disseminated metastases were detected, involving the right fibula, the abdominal cavity as well as multiple lesions in the brain. The patient declined BRAF mutation tests as well as chemotherapy or targeted therapies, and suffered a rapid deterioration in his general condition leading to death. We classified the second case as a sporadic form of the atypical mole syndrome, associated with one nodular and two superficial spreading melanomas.There are no data in the literature to allow us to understand if, in patients with multiple primary melanomas, there is any difference in terms of prognosis between those with and without a family history of a similar phenotype. To answer this and other questions related to these rare cases, further studies with a significant number of patients should be carried out.

Epidemiology of pancreatic cancer and the role of family history

Pancreatic cancer is a lethal disease for which only a small number of risk factors have been identified. In addition to older age, male gender, and black race, risk factors include smoking, obesity, long-standing diabetes and pancreatitis, and heavy alcohol use; allergies such as hay fever are related to lowered risk. Several genetic syndromes increase risk of pancreatic cancer. Work on more common genetic variants promises to reveal more potentially important genetic associations.

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.

Hereditary pancreatic and hepatobiliary cancers

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

Upper gastrointestinal cancer predisposition syndromes

Malignancies of the upper gastrointestinal tract form a heterogeneous group of cancers characterized by unique epidemiology and biology. Despite these differences, survival for advanced disease remains poor across the panel of diseases, from cancers of the esophagus, stomach, pancreas, and, until recently, even gastrointestinal stromal tumors. Genetic predisposition syndromes associated with these diseases comprise an emerging subset of these diseases that may provide valuable information on cause and etiology. They may provide insight into molecular drivers for the disease, or disease subtypes, and also insights into novel gene/environment interactions. This review summarizes the current understanding of genetic predisposition syndromes of cancers of the upper gastrointestinal tract.

Clinical characteristics of cutaneous melanoma and second primary malignancies in a dutch hospital-based cohort of cutaneous melanoma patients

The increasing number of living cutaneous melanoma patients and the increased risk of developing a second primary tumour incited us to analyse the clinical characteristics of cutaneous melanoma and define the frequency, site, and type of second primary cancers in cutaneous melanoma patients. We collected data on patients who visited the Department of Dermatology at the Radboud University Nijmegen Medical Centre and were newly diagnosed with cutaneous melanoma or metastasis of melanoma with unknown primary localization between 2002 and 2006. A total of 194 cases were included; eleven patients developed a subsequent melanoma, 24 had at least one basal cell carcinoma, three had at least one squamous cell carcinoma, and 21 patients had a second non-cutaneous primary malignancy. In conclusion, 48 patients developed a subsequent malignancy. As nonmelanoma skin cancer is the most frequent second malignancy, our results subscribe to the necessity of follow-up by a dermatologist.

Clinical and genetic analysis of 18 pancreatic carcinoma/melanoma-prone families

Families with both melanoma and pancreatic cancer are extremely rare and some are affected with the autosomal dominant inherited familial atypical multiple mole melanoma-pancreatic cancer (FAMMM-PC) syndrome. The phenotypic and genotypic expressions of such pancreatic cancer-melanoma prone families are not well defined. The National Case Collection of Familial Pancreatic Cancer of the Deutsche Krebshilfe includes 110 pancreatic cancer families, 18 of which (16%) show an association of pancreatic cancer and melanoma. These 18 families were analysed regarding their phenotype and the prevalence of germline mutations in the candidate genes CDKN2A, BRCA2, CHEK2, NOD2, ARL11 and Palladin (PALLD). There were two types of families: five families with the FAMMM-PC phenotype and 13 PC/melanoma families without the multiple mole phenotypes (PCMS). The prevalences of PC and melanoma in the two types of families were similar. The prevalence of other tumour types, especially breast carcinoma, was higher (11%) in PCMS- than in FAMMM-PC families (2.4%, p = 0.02). CDKN2A mutations were identified in 2 of 18 (11%) PCMS families. A cosegregating BRCA2 mutation was detected in one PCMS family without breast cancer. None of the reported germline mutations in the NOD2, Palladin, ARL11 or CHEK2 genes were detected in either type of family. In conclusion, families with an accumulation of PC and melanoma show a large variety of phenotypic expression, which is not always consistent with the FAMMM-PC phenotype. More PC/melanoma-prone families need to be analysed to clarify whether such families represent variations of the FAMMM-PC syndrome or two distinct hereditary cancer syndromes.

BRCA germline mutations in Jewish patients with pancreatic adenocarcinoma

PURPOSE

The prognostic significance of germline BRCA1 and BRCA2 mutations in Jewish patients with pancreatic adenocarcinoma (PAC) is unknown. Our objective was to define the prevalence of BRCA1 and BRCA2 in an unselected group of Jewish patients and to compare the clinical characteristics and overall survival (OS) of patients with resected BRCA mutation-associated PAC to PAC patients without mutations.

PATIENTS AND METHODS

Jewish patients with PAC resected between January 1986 and January 2004 were identified. DNA was extracted from the archived material, anonymized, and genotyped for founder mutations in BRCA1 (185delAG, 5382insC) and BRCA2 (6174delT). Standard two-sided statistical tests were utilized.

RESULTS

Of the 187 Jewish patients who underwent resection for PAC, tissue was available for 145 patients. Eight subjects (5.5%) had a BRCA founder mutation (two with BRCA1 [1.3%], six with BRCA2 [4.1%]). The BRCA2 founder mutation was identified in 4.1% of patients with pancreatic adenocarcinoma compared with only 1.1% of cancer-free Washington, DC,-area controls (4.1% v 1.1%; P = .007; odds ratio, 3.85; 95% CI, 2.1 to 10.8). Patients with and without BRCA1 or BRCA2 mutations did not differ in age (mean, 66 v 73 years; P = .6) or other clinicopathologic features. OS was not significantly different (median, 6 v 16 months; P = .35). A previous cancer was reported by 24% (35 of 145) of patients with the most common sites being breast cancer (9 of 35; 74%) and prostate cancer (8 of 35; 23%).

CONCLUSION

Founder mutations for BRCA1 and BRCA2 were identified in 5.5% of Ashkenazi patients operated on for PAC. BRCA2 mutations were more prevalent than documented by population studies. Consistent with previous reports, BRCA2 mutations are associated with an increased risk of PAC.

Artificial neural networks in pancreatic disease

BACKGROUND

An artificial neural network (ANNs) is a non-linear pattern recognition technique that is rapidly gaining in popularity in medical decision-making. This study investigated the use of ANNs for diagnostic and prognostic purposes in pancreatic disease, especially acute pancreatitis and pancreatic cancer.

METHODS

PubMed was searched for articles on the use of ANNs in pancreatic diseases using the MeSH terms 'neural networks (computer)', 'pancreatic neoplasms', 'pancreatitis' and 'pancreatic diseases'. A systematic review of the articles was performed.

RESULTS

Eleven articles were identified, published between 1993 and 2007. The situations that lend themselves best to analysis by ANNs are complex multifactorial relationships, medical decisions when a second opinion is needed and when automated interpretation is required, for example in a situation of an inadequate number of experts.

CONCLUSION

Conventional linear models have limitations in terms of diagnosis and prediction of outcome in acute pancreatitis and pancreatic cancer. Management of these disorders can be improved by applying ANNs to existing clinical parameters and newly established gene expression profiles.

Familial pancreatic cancer: from genes to improved patient care

Pancreatic cancer is essentially a disease caused by inherited and acquired mutations in cancer-causing genes. A number of the genes responsible for the aggregation of pancreatic cancer in families have been discovered, including BRCA2, p16/CDKN2A, STK11 and PRSS1. Individuals can be tested for germline mutations in these genes; however, until recently, little could be done about the risk of pancreatic cancer if a patient was found to carry a mutation. Currently, new approaches are being developed to screen at-risk individuals for curable precancerous pancreatic lesions and laboratory studies have led to novel therapies that specifically target some of these genetic defects. This review focuses on the genetic basis for the familial aggregation of pancreatic cancer, with emphasis placed on the implications of the genetic alterations on clinical patient care.

Detecting early pancreatic cancer: problems and prospects

Pancreatic cancer has a poor prognosis. Improving survival will require diagnosis of early pancreatic cancer, which can be defined based on resectability, size, or curability. Pancreatic cancer progresses from noninvasive precursor lesions to invasive cancer over a variable time period. Retrospective review of computed tomography (CT) scans performed prior to diagnosis suggests that pancreatic cancer resectability may be significantly improved if detected as few as 6 months before clinical diagnosis. Since pancreatic cancer is relatively uncommon, to allow cost-effective screening the populations will have to be enriched for the disease using two "sieves." The first sieve would identify a population of subjects at higher than average risk of pancreatic cancer and the second sieve could be a characteristic phenotype among the members of the high-risk group, an abnormality seen on noninvasive imaging or a serologic marker of early pancreatic cancer. So far two high-risk groups have been targets of screening for pancreatic cancer: hereditary pancreatic cancer kindreds and new-onset diabetes. There is no serologic marker of early pancreatic cancer. Confirmation of diagnosis usually requires invasive procedures such as endoscopic ultrasonography (EUS). Although much work still needs to be done, the developments in the field provide us with hope that screening for early pancreatic cancer could become a reality in the not-so-distant future.

Peutz-Jeghers syndrome and screening for pancreatic cancer

BACKGROUND

Cancer risk, including pancreatic, is high in those with Peutz-Jeghers syndrome (PJS). It has been suggested that such patients should undergo screening for pancreatic cancer.

METHODS

The risk of pancreatic cancer in PJS, pancreatic screening and potential screening strategies were reviewed. Cost-effectiveness was assessed according to American Gastroenterology Association guidelines and a risk stratification model proposed by the European Registry of Hereditary Pancreatitis and Familial Pancreatic Cancer.

RESULTS

The risk of pancreatic cancer is increased in PJS but screening would cost over US 35,000 dollars per life saved. Risk stratification reduces cost by 100,000 dollars and costs fall to 50,000 dollars per life saved if deaths from other forms of cancer are avoided.

CONCLUSION

Screening should be performed only on a research basis to evaluate the benefit and cost-effectiveness in high-risk groups.

Management of familial melanoma

Relatives of patients with melanoma are at increased risk of melanoma. We review the evidence that this risk may be attributed both to shared susceptibility genes (both high-penetrance and lower-penetrance genes) and shared environment. The most frequent high-penetrance susceptibility gene is CDKN2A, and environmental effects on the risk to gene carriers are evident in that CDKN2A penetrance is higher in CDKN2A-mutation-positive families living in Australia than those in Europe. We review the approaches to managing melanoma families, in which the likelihood of there being detectable CDKN2A mutations is positively correlated with the number of cases of melanoma in the family. Within families, risk that an individual carries a germline mutation can be estimated by pedigree analysis for autosomal dominant genes with incomplete penetrance. Prevention advice to families relates to moderation of sun exposure and self-examination of naevi, although there are few supportive data.

High-risk melanoma susceptibility genes and pancreatic cancer, neural system tumors, and uveal melanoma across GenoMEL

GenoMEL, comprising major familial melanoma research groups from North America, Europe, Asia, and Australia has created the largest familial melanoma sample yet available to characterize mutations in the high-risk melanoma susceptibility genes CDKN2A/alternate reading frames (ARF), which encodes p16 and p14ARF, and CDK4 and to evaluate their relationship with pancreatic cancer (PC), neural system tumors (NST), and uveal melanoma (UM). This study included 466 families (2,137 patients) with at least three melanoma patients from 17 GenoMEL centers. Overall, 41% (n = 190) of families had mutations; most involved p16 (n = 178). Mutations in CDK4 (n = 5) and ARF (n = 7) occurred at similar frequencies (2-3%). There were striking differences in mutations across geographic locales. The proportion of families with the most frequent founder mutation(s) of each locale differed significantly across the seven regions (P = 0.0009). Single founder CDKN2A mutations were predominant in Sweden (p.R112_L113insR, 92% of family's mutations) and the Netherlands (c.225_243del19, 90% of family's mutations). France, Spain, and Italy had the same most frequent mutation (p.G101W). Similarly, Australia and United Kingdom had the same most common mutations (p.M53I, c.IVS2-105A>G, p.R24P, and p.L32P). As reported previously, there was a strong association between PC and CDKN2A mutations (P < 0.0001). This relationship differed by mutation. In contrast, there was little evidence for an association between CDKN2A mutations and NST (P = 0.52) or UM (P = 0.25). There was a marginally significant association between NST and ARF (P = 0.05). However, this particular evaluation had low power and requires confirmation. This GenoMEL study provides the most extensive characterization of mutations in high-risk melanoma susceptibility genes in families with three or more melanoma patients yet available.

Features associated with germline CDKN2A mutations: a GenoMEL study of melanoma-prone families from three continents

BACKGROUND

The major factors individually reported to be associated with an increased frequency of CDKN2A mutations are increased number of patients with melanoma in a family, early age at melanoma diagnosis, and family members with multiple primary melanomas (MPM) or pancreatic cancer.

METHODS

These four features were examined in 385 families with > or =3 patients with melanoma pooled by 17 GenoMEL groups, and these attributes were compared across continents.

RESULTS

Overall, 39% of families had CDKN2A mutations ranging from 20% (32/162) in Australia to 45% (29/65) in North America to 57% (89/157) in Europe. All four features in each group, except pancreatic cancer in Australia (p = 0.38), individually showed significant associations with CDKN2A mutations, but the effects varied widely across continents. Multivariate examination also showed different predictors of mutation risk across continents. In Australian families, > or =2 patients with MPM, median age at melanoma diagnosis < or =40 years and > or =6 patients with melanoma in a family jointly predicted the mutation risk. In European families, all four factors concurrently predicted the risk, but with less stringent criteria than in Australia. In North American families, only > or =1 patient with MPM and age at diagnosis < or =40 years simultaneously predicted the mutation risk.

CONCLUSIONS

The variation in CDKN2A mutations for the four features across continents is consistent with the lower melanoma incidence rates in Europe and higher rates of sporadic melanoma in Australia. The lack of a pancreatic cancer-CDKN2A mutation relationship in Australia probably reflects the divergent spectrum of mutations in families from Australia versus those from North America and Europe. GenoMEL is exploring candidate host, genetic and/or environmental risk factors to better understand the variation observed.

Impact of E27X, a novel CDKN2A germ line mutation, on p16 and p14ARF expression in Italian melanoma families displaying pancreatic cancer and neuroblastoma

Mutations in the CDKN2A gene underlie melanoma susceptibility in as many as 50% of melanoma kindreds in selected populations, and several CDKN2A founder mutations have been described. Inherited mutations in CDKN2A have been found to be associated with other, non-melanoma cancers including pancreatic cancer (PC) and neural system tumors (NST). Here we report a novel germline mutation in exon 1 of the CDKN2A gene, E27X, which we first detected in melanoma patients living in or originally from a small geographic area bordering Liguria in north-western Italy. A subset of melanoma kindreds positive for this mutation displayed PC and neuroblastoma. E27X generates a premature stop codon, leading to dramatically reduced protein levels of p16 and leaving p14ARF unaltered. As PC and NSTs have been postulated to be preferentially associated with CDKN2A mutations located in exon 2 and/or affecting p14ARF alone, the position of E27X in exon 1alpha provides interesting insights towards clarifying the mechanisms by which the CDKN2A/ARF locus is involved in cancer predisposition.

Genotype/phenotype of familial pancreatic cancer

It is estimated that 5% to 10% of pancreatic cancer cases are attributable to hereditary factors. We believe that the number of cases that are genetic in etiology are even greater, however, based not on a classic autosomal dominant pattern of inheritance but rather when one takes into account low-penetrant inherited susceptibility factors. There is also a growing recognition that the development of pancreatic cancer in pancreatic cancer-prone families is dependent not only on genetic variables but on nongenetic factors. The aim of this article is to review the challenges in identifying pancreatic cancer-prone families and how environmental factors interact with genetic factors in these families.

The genetics of melanoma

Melanoma is an increasingly common cancer and in order to direct preventative advice at those at risk, an understanding of susceptibility is crucial. This review summarizes what is known about common low-risk genes (such as those controlling red hair) and rare high-risk genes.

Predisposición genética en el melanoma cutáneo

The incidence of cutaneous melanoma has increased worldwide in the last 20 years. Research on potential risk factors, both environmental and genetic, has led us to some new and interesting conclusions. Ultraviolet radiation is clearly the main environmental risk factor for melanoma, but its relationship is complex and controversial. With regard to genetic factors, the discovery of two types of genes was a great advance in further understanding the biology of the melanocyte. CDKN2A (p16) is the prototype of the high-penetrance, low-prevalence gene related to melanoma. This gene has been studied in some families in which several members have been diagnosed with melanoma. In the general population with non-familial melanoma, low-penetrance, high-prevalence genes such as MC1R seem to be more interesting. Studies on the MC1R gene have not only shown its importance in skin and hair pigmentation, but also in the development of melanoma. Functional studies on CDKN2A and MC1R have led us to new and important conclusions. The analysis of data from studies on families, twins and control cases, with the collaboration of several countries, will lead us to new discoveries. For the primary and secondary prevention of this tumor, we must promote public health campaigns on the dangers of sun exposure and the identification of individuals at high risk.

The inherited genetics of pancreatic cancer and prospects for secondary screening

It is estimated that pancreatic cancer has a familial component in approximately 5-10% of cases. Some of these cases are part of a defined cancer syndrome with a known gene mutation but in the remaining the causative gene remains unknown. In recent years, a better understanding of the molecular events that occur in the progression model of pancreatic cancer has lead to the development of secondary screening programmes with the aim of identifying early precursor lesions or pre-invasive cancer at a stage amenable to curative resection. High-risk groups who have an inherited predisposition for pancreatic cancer form the ideal group to study in developing a robust screening programme. Multimodality screening using computed tomography and endoluminal ultrasound in combination with molecular analysis of pancreatic juice are proving promising as diagnostics tools or at least serving as predictors of risk over a defined period.

Molecular pathogenesis of pancreatic cancer

Pancreatic cancer is fundamentally a disease of inherited and acquired mutations in cancer-related genes. The genes targeted in pancreatic cancer include tumor-suppressor genes (p16/CDKN2A, TP53 and SMAD4), oncogenes (KRAS, BRAF, AKT2, MYB, and AIB1), and genome-maintenance genes (MLH1, MSH2, BRAC2 and other Fanconi anemia genes). An understanding of the cancer-related genes that are altered in pancreatic cancer has a number of clinical applications including genetic counseling for individuals with a family history of cancer, early detection of pancreatic neoplasia, and mechanism-based therapies for patients with advanced disease. This chapter will provide an overview of the molecular pathogenesis of pancreatic cancer with emphasis on clinical applications.

Risk factors for pancreatic adenocarcinoma: are we ready for screening and surveillance?

Of all common malignancies, pancreatic cancer has the lowest survival rate. According to estimates by the American Cancer Society, in 2004, 31,860 Americans were diagnosed, and 31,270 died from this near universally lethal disease. Unfortunately, only a small minority of patients are diagnosed when the extent of disease is still localized and thus potentially curable. These dismal survival results could be improved by developing successful screening and prevention strategies. Routine screening is not currently suggested for pancreatic cancer; however, there may be a benefit in a select group of patients identified to be at high risk for developing this disease. It is recommended that surveillance be performed on these high-risk individuals in a research setting to allow for the development of a successful detection strategy.

Hereditary cancer syndromes of the skin

Hereditary cancer syndromes are a group of disorders characterized by a genetic susceptibility to the development of malignant tumors. Multiple cancers in the family or an abnormally early onset for the given cancer may suggest an underlying inherited predisposition. Awareness of their associated dermatologic manifestations can facilitate early detection of risk for neoplasms. This article provides an update on the clinical features, diagnostic criteria, and the use of genetic analysis in the detection of causative mutations of those hereditary cancer syndromes with cutaneous manifestations.

Identification of high-risk pancreatic cancer-prone families

Pancreatic cancer-prone families provide a unique resource for studying the etiology, natural history, genetics, and treatment of pancreatic cancer. The only effective way of identifying these families is by obtaining a complete family history, since it is not possible to differentiate sporadic pancreatic cancer cases from hereditary cases based on either clinical presentation or features. These families also would benefit greatly from early detection or prevention strategies. Ultimately, this knowledge could be applied to the more common sporadic form of pancreatic cancer, where diagnosis is almost always late, and prognosis remains quite grim.

INK4/ARF germline alterations in pancreatic cancer patients

BACKGROUND

Roughly 40% of germinal mutations in melanoma families (MF) affect p16(INK4a) and p14(ARF). We investigated the association between INK4/ARF alterations and the occurrence of pancreatic cancer in MF and in sporadic pancreatic cancer (SPC) patients.

PATIENTS AND METHODS

Forty-nine MF, 66 SPC cases and 54 controls were enrolled. The INK4/ARF locus was screened.

RESULTS

As compared with the general population, the risk of pancreatic cancer (PC) was increased 9.4-fold [95% confidence interval (CI) 2.7-33.4] and 2.2-fold (95% CI 0.8-5.7) in G101W-positive and -negative MF, respectively, while mean ages at onset were 61 and 77 years, respectively. A 1.7 (95% CI 1.06-2.79) increased risk of cancer at any site was observed among first-degree relatives of SPC cases as compared with controls. The G101W founder mutation was detected in 4% of SPC cases but the rate increased to 13% when tumor clustering in either branch of families was taken into account. One G101W-positive PC patient with a melanoma in a first-degree relative harbored a germline deletion of the second allele, including exon 1B.

CONCLUSIONS

The presence of a deletion including exon 1B in two PC patients points to the involvement of p14(ARF) in the development of PC and may suggest that the increased risk of PC in MF is caused by impairment of both loci.

Familial melanoma: a complex disorder leading to controversy on DNA testing

The initial enthusiasm generated by the discovery of the first susceptibility gene found for melanoma has slightly dampened over recent years. For the majority of melanoma families the underlying gene defect is still not known, so the search for other melanoma genes is continuing. Also, the increased risk of melanoma does not seem to be restricted to mutation carriers, but is present even in non-mutation carriers in melanoma families. The underlying defect of familial melanoma is less straightforward than previously thought; both environmental and hereditary risk modifiers intermingle in a perplexing way. This makes familial melanoma a complex disorder which deserves the close attention of both clinicians and researchers, especially as the opinion on gene testing in familial melanoma has not yet achieved consensus. On the one hand, there is a rising demand from families for genetic testing; on the other hand, there is the clinicians' concern about the value of such testing.

Epidemiology of pancreatic cancer: an overview

INTRODUCTION

The incidence of pancreatic cancer worldwide appears to correlate with increasing age, and it is slightly more common among men and Jewish people. There is evidence that the incidence rate is higher among blacks than among whites.

METHODS

The published literature was reviewed for preparation of an overview on epidemiology of pancreatic cancer.

RESULTS

A possible role of diabetes in the etiology of pancreatic cancer has been suggested by different epidemiological studies. Several investigations indicate that a history of pancreatitis may increase the risk of pancreas cancer, and it appears that people with a history of pernicious anemia or partial gastrectomy for ulcer as well as cholecystectomy may be at higher risk. Individuals with familial adenomatous polyposis (FAP) also have a high risk of developing this cancer. Pancreatic cancer is seen in some breast cancer families with BRCA1 and BRCA2 mutations. Epidemiological studies have confirmed that relatives of individuals with pancreatic cancer have an increased risk of this malignancy. Affected family members of the familial atypical multiple-mole melanoma (FAMMM) as well as those with a positive family history of ataxia-telangiectasia (AT) have much higher risk of developing pancreatic cancer, compared with the general population. A positive association has been reported between pancreatic cancer risk and dietary intake such as fat and oil, meat, and dairy products, as well as with high intake of energy, fried foods, carbohydrates, cholesterol, and salt. The risk is found to decrease with increased consumption of fresh fruits and vegetables, fiber, natural foods, and Vitamin C. Cigarette smoking has shown the strongest positive association with risk of pancreatic cancer.

CONCLUSION

Some diseases and medical conditions such as diabetes, chronic pancreatitis, AP, family aggregation of pancreatic cancer, FAMMM, AT, as well as nutrition and lifestyle factors, like smoking may play important role in the etiology of pancreatic cancer.

Familial pancreatic carcinoma in Jews

Pancreatic cancer (PC) is the most fatal of all gastrointestinal cancers, wherein its mortality compares strikingly with its incidence. Unfortunately, 80-90% of PCs are diagnosed in the nonresectable stage. While the lifetime risk of PC in developed countries is approximately 1-3%, it is the fifth most common cause of cancer deaths among both males and females in Western countries. It occurs in excess in Jews. Approximately 5-10% of PC shows familial clustering. Examination of such familial clusters must take into consideration cancers of diverse anatomic sites, such as malignant melanoma in the familial atypical multiple melanoma (FAMMM) syndrome due to the CDKN2A (p16) germline mutation, and combinations of colorectal and endometrial carcinoma, ovarian carcinoma, and several other cancers in hereditary nonpolyposis colorectal cancer (HNPCC), which are due to mismatch repair germline mutations, the most common of which are MSH2 and MLH1 . Other hereditary disorders predisposing to PC include Peutz-Jeghers syndrome, due to the STK11 mutation, familial pancreatitis due to the cationic trypsinogen gene, site-specific familial pancreatic cancer which may be due to the 4q32-34 mutation, hereditary breast-ovarian cancer (HBOC) syndrome that is due to BRCA2 and possibly some families with HBOC that is due to BRCA1 , familial adenomatous polyposis due to the ATP gene, and ataxia telangiectasia due to the ATM germline mutation. This extant heterogeneity mandates that the physician be knowledgeable about these PC-prone syndromes which play such an important role when considering the differential diagnosis of hereditary PC. Unfortunately, there are no PC screening programs with acceptable sensitivity and specificity. However, the gold standard for screening at this time is endoscopic ultrasound. Clearly, there is a great need for the development of novel screening approaches with acceptable sensitivity and specificity. Further research is needed to elucidate those etiologic factors that contribute to the apparent excess of PC in Ashkenazi Jews. Attention should also be given to the search for mutations predisposing to PC in Jews so that opportunities to learn more about the disease's pathogenesis, as well as screening and control, may take place.

Genetic epidemiology of melanoma

Melanoma incidence has risen in many Caucasians populations over the last 20 years and research on the potential environmental and genetic risk factors has led to some interesting new findings but also to many more questions. The relationship between melanoma and ultraviolet radiation is complex and this area of research is controversial especially regarding the use of sunbeds and sunscreens. In terms of genetic factors, the discovery of two genes CDKN2A and CDK4 has been a great advance with more understanding of melanocyte biology in relation to defects in senescence. For phenotypic risk factors such as fair skin and high numbers of naevi, the role of genetic factors is clearly evident but these traits are complex and the discovery of genes involved in skin pigmentation and naevi formation is not an easy task. Research on the MC1R gene has not only shown the importance of this gene in hair and skin pigmentation but also in senescence and immunity. Functional studies involving CDKN2A and MC1R are leading to important new findings. There is also some hope regarding the use of micro-arrays in helping to dissect many genetic events in melanoma. The collection of large datasets including family, twin and case-control studies as well as tumour banks with collaborations between countries will hopefully lead to more discoveries. For the primary and secondary prevention of this tumour, efforts need to be sustained in public health campaigns on sun exposure and the recognition of individuals at high risk.

BRCA2 germline mutations in familial pancreatic carcinoma

BACKGROUND

Although as many as 10% of pancreatic cancer cases may have an inherited component, familial pancreatic cancer has not been linked to defects in any specific gene. Some studies have shown that families with germline mutations in the breast cancer susceptibility gene BRCA2 have an increased risk of breast and ovarian cancers, as well as a modestly increased risk of pancreatic cancer. To study these relationships in more detail, we examined whether BRCA2 germline mutations are associated with familial pancreatic cancer.

METHODS

We identified 26 European families in which at least two first-degree relatives had a histologically confirmed diagnosis of pancreatic ductal adenocarcinoma. We sequenced genomic DNA isolated from peripheral blood lymphocytes obtained from participating family members to identify germline mutations in BRCA2.

RESULTS

Three (12%, exact 95% confidence interval [CI] = 2% to 30%) families carried germline frameshift mutations in the BRCA2 gene that are predicted to result in a truncated BRCA2 protein. Two additional families harbored mutations previously designated as unclassified variants of BRCA2. Thus, 19% (exact 95% CI = 7% to 39%) of the families in our study had either a frameshift mutation or an unclassified variant of BRCA2. None of the families in our study met the criteria for familial breast or ovarian cancer.

CONCLUSIONS

Our data support an important role for BRCA2 germline mutations in a subpopulation of families with familial pancreatic cancer. BRCA2 mutation analysis should be included in molecular genetic testing and counseling strategies in families with at least two first-degree relatives affected with ductal adenocarcinoma of the pancreas.

CDKN2A germline mutations in familial pancreatic cancer

OBJECTIVE

To evaluate the prevalence of mutations in the CDKN2A gene encoding p16 and p14 in familial pancreatic cancer (FPC).

SUMMARY BACKGROUND DATA

The genetic basis of FPC is still widely unknown. Recently, it has been shown that germline mutations in the p16 tumor suppressor gene can predispose to pancreatic cancer. The presence of p14 germline mutations has yet not been determined in this setting.

METHODS

Eighteen families with at least two first-degree relatives with histologically confirmed pancreatic cancer and five families with at least one patient with pancreatic cancer and another first-degree relative with malignant melanoma of the German National Case Collection for Familial Pancreatic Cancer were analyzed for CDKN2A germline mutations including p16 and p14 by direct DNA sequencing. All participating family members were genetically counseled and evaluated by a three-generation pedigree.

RESULTS

None of 18 FPC families without malignant melanoma revealed p16 mutations, compared to 2 of 5 families with pancreatic cancer and melanoma. Truncating p16 germline mutations Q50X and E119X were identified in the affected patients of pancreatic cancer plus melanoma families. None of the 23 families revealed p14 germline mutations.

CONCLUSIONS

CDKN2A germline mutations are rare in FPC families. However, these data provide further evidence for a pancreatic cancer-melanoma syndrome associated with CDKN2A germline mutations affecting p16. Thus, all members of families with combined occurrence of pancreatic cancer and melanoma should be counseled and offered screening for p16 mutations to identify high-risk family members who should be enrolled in a clinical screening program.