Update of familial pancreatic cancer in Germany

Joint Linkage and Association Analysis Using GENEHUNTER-MODSCORE with an Application to Familial Pancreatic Cancer

INTRODUCTION

Joint linkage and association (JLA) analysis combines two disease gene mapping strategies: linkage information contained in families and association information contained in populations. Such a JLA analysis can increase mapping power, especially when the evidence for both linkage and association is low to moderate. Similarly, an association analysis based on haplotypes instead of single markers can increase mapping power when the association pattern is complex.

METHODS

In this paper, we present an extension to the GENEHUNTER-MODSCORE software package that enables a JLA analysis based on haplotypes and uses information from arbitrary pedigree types and unrelated individuals. Our new JLA method is an extension of the MOD score approach for linkage analysis, which allows the estimation of trait-model and linkage disequilibrium (LD) parameters, i.e., penetrance, disease-allele frequency, and haplotype frequencies. LD is modeled between alleles at a single diallelic disease locus and up to three diallelic test markers. Linkage information is contributed by additional multi-allelic flanking markers. We investigated the statistical properties of our JLA implementation using extensive simulations, and we compared our approach to another commonly used single-marker JLA test. To demonstrate the applicability of our new method in practice, we analyzed pedigree data from the German National Case Collection for Familial Pancreatic Cancer (FaPaCa).

RESULTS

Based on the simulated data, we demonstrated the validity of our JLA-MOD score analysis implementation and identified scenarios in which haplotype-based tests outperformed the single-marker test. The estimated trait-model and LD parameters were in good accordance with the simulated values. Our method outperformed another commonly used JLA single-marker test when the LD pattern was complex. The exploratory analysis of the FaPaCa families led to the identification of a promising genetic region on chromosome 22q13.33, which can serve as a starting point for future mutation analysis and molecular research in pancreatic cancer.

CONCLUSION

Our newly proposed JLA-MOD score method proves to be a valuable gene mapping and characterization tool, especially when either linkage or association information alone provide insufficient power to identify the disease-causing genetic variants.

Proteomics biomarker discovery for individualized prevention of familial pancreatic cancer using statistical learning

BACKGROUND

The low five-year survival rate of pancreatic ductal adenocarcinoma (PDAC) and the low diagnostic rate of early-stage PDAC via imaging highlight the need to discover novel biomarkers and improve the current screening procedures for early diagnosis. Familial pancreatic cancer (FPC) describes the cases of PDAC that are present in two or more individuals within a circle of first-degree relatives. Using innovative high-throughput proteomics, we were able to quantify the protein profiles of individuals at risk from FPC families in different potential pre-cancer stages. However, the high-dimensional proteomics data structure challenges the use of traditional statistical analysis tools. Hence, we applied advanced statistical learning methods to enhance the analysis and improve the results' interpretability.

METHODS

We applied model-based gradient boosting and adaptive lasso to deal with the small, unbalanced study design via simultaneous variable selection and model fitting. In addition, we used stability selection to identify a stable subset of selected biomarkers and, as a result, obtain even more interpretable results. In each step, we compared the performance of the different analytical pipelines and validated our approaches via simulation scenarios.

RESULTS

In the simulation study, model-based gradient boosting showed a more accurate prediction performance in the small, unbalanced, and high-dimensional datasets than adaptive lasso and could identify more relevant variables. Furthermore, using model-based gradient boosting, we discovered a subset of promising serum biomarkers that may potentially improve the current screening procedure of FPC.

CONCLUSION

Advanced statistical learning methods helped us overcome the shortcomings of an unbalanced study design in a valuable clinical dataset. The discovered serum biomarkers provide us with a clear direction for further investigations and more precise clinical hypotheses regarding the development of FPC and optimal strategies for its early detection.

Combinations of Low-Frequency Genetic Variants Might Predispose to Familial Pancreatic Cancer

Familial pancreatic cancer (FPC) is an established but rare inherited tumor syndrome that accounts for approximately 5% of pancreatic ductal adenocarcinoma (PDAC) cases. No major causative gene defect has yet been identified, but germline mutations in predisposition genes BRCA1/2, CDKN2A and PALB2 could be detected in 10–15% of analyzed families. Thus, the genetic basis of disease susceptibility in the majority of FPC families remains unknown. In an attempt to identify new candidate genes, we performed whole-genome sequencing on affected patients from 15 FPC families, without detecting BRCA1/2, CDKN2A or PALB2 mutations, using an Illumina based platform. Annotations from CADD, PolyPhen-2, SIFT, Mutation Taster and PROVEAN were used to assess the potential impact of a variant on the function of a gene. Variants that did not segregate with pancreatic disease in respective families were excluded. Potential predisposing candidate genes ATM, SUFU, DAB1, POLQ, FGFBP3, MAP3K3 and ACAD9 were identified in 7 of 15 families. All identified gene mutations segregated with pancreatic disease, but sometimes with incomplete penetrance. An analysis of up to 46 additional FPC families revealed that the identified gene mutations appeared to be unique in most cases, despite a potentially deleterious ACAD9 Ala326Thr germline variant, which occurred in 4 (8.7%) of 46 FPC families. Notably, affected PDAC patients within a family carried identical germline mutations in up to three different genes, e.g., DAB1, POLQ and FGFBP3. These results support the hypothesis that FPC is a highly heterogeneous polygenetic disease caused by low-frequency or rare variants.

Gress T, Langer P, P. Slater E. The German National Case Collection for Familial Pancreatic Carcinoma (FaPaCa)—Knowledge Gained in 20 Years

BACKGROUND

Familial pancreatic carcinoma (FPC) is a rare hereditary tumor syndrome with a heterogeneous clinical phenotype. The study of FPC also contributes to a better understanding of the more common sporadic pancreatic ductal adenocarcinoma (PDAC). We report on the past 20 years' experience of the German National Case Collection for Familial Pancreatic Carcinoma (FaPaCa) of the German Cancer Aid (Deutsche Krebshilfe).

METHODS

From 1999 onward, families in which at least two first-degree relatives had PDAC, and which did not meet the criteria for any other tumor syndrome, have been entered into the FaPaCa registry and analyzed both clinically and with molecular genetic techniques. Persons at risk are offered the opportunity to participate in an early detection program.

RESULTS

From June 1999 to June 2019, 227 families (a total of 2579 persons) met the criteria for entry into the FaPaCa registry. PDAC was the sole tumor entity present in 37% of the families (95% confidence interval [31.1; 44.1]); in the remaining 63% [55.9; 68.9], other tumor types were present as well, particularly breast cancer (70 families, 31% [24.9; 37.3]), colon carcinoma (25 families, 11% [7.3; 15.8]) , and melanoma (22 families, 9.7% [6.2; 14.3]). The mode of inheritance of PDAC was autosomal dominant in 72% [65.5; 77.6] of the families. Predisposing germ-line mutations were found in 25 of the 150 (16.7%) families studied, in the following genes: BRCA2 (9 families), CDKN2A (5 families), PALB2 (4 families), BRCA1 (3 families), ATM (2 families), and CHEK2 (2 families). The early detection program revealed high-grade cancer precursor lesions or a PDAC in 5 of the participating 110 persons at risk (4.5%, [1.5; 10.3] during a period of observation of at least five years.

CONCLUSION

The care of families with FPC is complex and should be provided in centers with the necessary expertise. Prospective, controlled longitudinal studies are needed to determine whether the screening of persons at risk for PDAC truly lessens mortality and is cost-effective.

Italian registry of families at risk of pancreatic cancer: AISP Familial Pancreatic Cancer Study Group

Pancreatic cancer is one of the main causes of cancer-related death worldwide, with a survival rate around 9%. In Italy 13,500 new cases of pancreatic cancer occurred in 2019. It is estimated that at least 5% have a hereditary background. Surveillance is advisable for healthy individuals with specific genetic syndromes with or without family history of pancreatic cancer or members of families with multiple cases of pancreatic cancer, irrespective of genetic syndromes. In 2010 the Italian Association for the Study of the Pancreas (AISP) defined criteria to include individuals in such surveillance programs with the first-round results published in 2019. In order to include other categories at high-risk and increase the diagnostic yield of surveillance, these criteria have recently been modified. The present position paper presents the updated criteria of the Italian Registry of Families at Risk of Pancreatic Cancer (IRFARPC) with their diagnostic yield calculation. Also, AISP priority projects concerning: (a) increasing awareness of citizens and primary care physicians through a dedicated App; (b) increasing access to germline testing to personalize surveillance; (c) measuring psychological impact of surveillance; (d) investigating the role of risk-modifiers and (e) evaluating the cost-effectiveness and ability to save lives of the program are briefly presented.

[Hereditary cutaneous tumor syndromes]

Skin tumors can manifest solitarily and sporadically but can also be multiple and familial. Beside the skin, hereditary cutaneous tumor syndromes also affect extracutaneous organs and are clinically and genetically heterogeneous. Taking the medical history, a clinical examination and dermatopathological characterization of the respective neoplasia will help the dermatologist to reach a diagnosis at an early stage. Subsequently, this diagnosis can be unambiguously confirmed by molecular genetic analysis. Here, we provide an overview and update on selected hereditary cutaneous tumor syndromes.

German National Case Collection for familial pancreatic Cancer (FaPaCa) - acceptance and psychological aspects of a pancreatic cancer screening program

Background

Pancreatic cancer screening is recommended to individuals at risk (IAR) of familial pancreatic cancer (FPC) families, but little is known about the acceptance of such screening programs. Thus, the acceptance and psychological aspects of a controlled FPC screening program was evaluated.

Methods

IAR of FPC families underwent comprehensive counseling by a geneticist and pancreatologist prior to the proposed screening. Participating IAR, IAR who discontinued screening and IAR who never participated in the screening program were invited to complete questionnaires to assess the motivation for participating in surveillance, cancer worries, structural distress and experiences with participation. Questionnaires were completed anonymously to receive most accurate answers.

Results

Of 286 IAR to whom pancreatic ductal adenocarcinoma (PDAC) screening was recommended, 139 (48.6%) IAR regularly participated (group 1), 49 (17.1%) IAR (group 2) discontinued screening after median 1 (1–10) screening visits and 98 (34.2%) IAR (group 3) never underwent screening. The overall response rate of questionnaires was 67% (189/286) with rates of 100% (139 of 139 IAR), 49% (29 of 49 IAR) and 23.4% (23 of 98 IAR) for groups 1, 2 and 3, respectively. At least 93% of IAR felt adequately informed about the screening program after initial counseling. However, only 38.8% received knowledge of or the recommendation for PDAC screening by physicians. The reported cancer-related distress and the fear of investigations were highest in group 1, but acceptably low in all three groups. The main reasons to discontinue or not to participate in screening were the time efforts and travel costs (groups 2 and 3 48,7%).

Conclusion

Less than 50% of IAR regularly participate in a proposed PDAC screening program, although the associated psychological burden is quite low. Physicians should be educated about high risk PDAC groups and screening recommendations. Time and travel efforts must be reduced to encourage more IAR to participate in a recommended screening.

Benefit of Surveillance for Pancreatic Cancer in High-Risk Individuals: Outcome of Long-Term Prospective Follow-Up Studies From Three European Expert Centers

PURPOSE

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis. Hereditary factors play a role in the development of PDAC in 3% to 5% of all patients. Surveillance of high-risk groups, may facilitate detection of PDAC at an early stage. The aim of this study was to assess whether surveillance aids detection of early-stage PDAC or precursor lesions (PRLs) and improves the prognosis.

PATIENTS AND METHODS

Screening outcomes were collected from three European centers that conduct prospective screening in high-risk groups including families with clustering of PDAC (familial pancreatic cancer [FPC]) or families with a gene defect that predisposes to PDAC. The surveillance program consisted of annual magnetic resonance imaging, magnetic resonance cholangiopancreatography, and/or endoscopic ultrasound.

RESULTS

Four hundred eleven asymptomatic individuals participated in the surveillance programs, including 178 CDKN2A mutation carriers, 214 individuals with FPC, and 19 BRCA1/2 or PALB2 mutation carriers. PDAC was detected in 13 (7.3%) of 178 CDKN2A mutation carriers. The resection rate was 75%, and the 5-year survival rate was 24%. Two CDKN2A mutation carriers (1%) underwent surgical resection for low-risk PRL. Two individuals (0.9%) in the FPC cohort had a pancreatic tumor, including one advanced PDAC and one early grade 2 neuroendocrine tumor. Thirteen individuals with FPC (6.1%) underwent surgical resection for a suspected PRL, but only four (1.9%) had high-risk lesions (ie, high-grade intraductal papillary mucinous neoplasms or grade 3 pancreatic intraepithelial neoplasms). One BRCA2 mutation carrier was found to have PDAC, and another BRCA2 mutation carrier and a PALB2 mutation carrier underwent surgery and were found to have low-risk PRL. No serious complications occurred as consequence of the program.

CONCLUSION

Surveillance of CDNK2A mutation carriers is relatively successful, detecting most PDACs at a resectable stage. The benefit of surveillance in families with FPC is less evident.

Familial pancreatic cancer--status quo

INTRODUCTION

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

FPC SCREENING

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

SCOPE OF THE REVIEW

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

Multiple small "imaging" branch-duct type intraductal papillary mucinous neoplasms (IPMNs) in familial pancreatic cancer: indicator for concomitant high grade pancreatic intraepithelial neoplasia?

Most screening programs for familial pancreatic cancer are currently based on endoscopic ultrasonography and/or magnetic resonance imaging (MRI). Cystic lesions, especially those suspicious for small intraductal pancreatic mucinous neoplasms (IPMNs) of the branch ducts, can be visualized in up to 40 % of individuals at risk, but their pathological importance in the setting of FPC is yet not well established. Individuals at risk from a prospective screening program for familial pancreatic cancer with small "imaging" IPMNs of the branch-duct type (BD-IPMN) who underwent pancreatic resection were analysed regarding clinico-pathological data and the locations of pancreatic lesions. Five of 125 individuals at risk who underwent screening had multiple small (size 2-10 mm) unicystic lesions and/or multicystic single lesions in the pancreatic body and tail suspicious for BD-IPMNs upon MRI imaging and decided to undergo surgical resection after interdisciplinary counselling, although none fulfilled the consensus criteria for IPMN resection. Histological examination revealed BD-IPMNs with low or moderate dysplasia of the gastric type in combination with multifocal PanIN2 and PanIN3 lesions in 4 individuals. The remaining patient had only tiny ductectasias in the pancreatic tail with multifocal PanIN 2 lesions in the entire gland and one PanIN3 lesion in the pancreatic head. Intriguingly, the location of the most dysplastic histological lesions (PanIN3) did not correspond to the preoperatively detected lesions and were not visible in preoperative imaging. In the setting of FPC, the presence of multiple small "imaging" BD-IPMNs may indicate the presence of high-grade PanIN lesions elsewhere in the pancreas.

Familial pancreatic cancer: current status

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

Familial pancreatic cancer--current knowledge

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

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.

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

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

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

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

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

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

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.

[Hereditary pancreatic cancer]

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

Early prediction of severity in acute pancreatitis using infrared spectroscopy of serum

BACKGROUND

One of the main problems in the management of acute pancreatitis (AP) is the scarcity of accurate predictors of disease severity.

METHODS

In a prospective design, we compared APACHE II score, C-reactive protein (CRP) level, and infrared (IR) spectral absorption of serum (wavelength 940 nm) in 167 consecutive patients with AP, 34 with predicted severe and 133 with mild form.

RESULTS

The IR spectral absorption levels on admission and at 24 h after admission were significantly (p < 0.05) lower in patients with severe AP. On admission, the sensitivity was 74, 56, and 44%; the specificity was 82, 83, and 81%; the positive predictive value was 51, 45, and 37%, and the negative predictive value was 92, 88, and 85%, for IR spectroscopy, APACHE II, and CRP, respectively. At 24 h, the sensitivity, specificity, positive predictive value, and negative predictive value was 82, 74, 44, and 94%; 65, 72, 37, and 89%; 68, 73, 39, and 90%, for IR spectroscopy, CRP, and APACHE II, respectively.

CONCLUSIONS

IR spectroscopy seems to be useful for early detection of severe AP and, in turn, for identifying patients requiring treatment in the intensive care unit and who can benefit from novel therapies.

Low frequency of CHEK2 mutations in familial pancreatic cancer

Familial pancreatic cancer (FPC) is a rare tumour syndrome and its underlying major gene defect is still unknown. Recently, CHEK2 has been identified as multi-organ cancer susceptibility gene associated with a predisposition to breast, prostate and colon cancer. Since these cancers also are associated with some FPC families, we have analysed 35 index patients of German FPC families for CHEK2 mutations. The CHEK2 * 1100delC mutation was found in 1 (3%) of 35 FPC families. Given the low expected mutation rate of up to 1.4% for CHEK2 * 1100delC in the European population our data are suggestive for possible contribution of CHEK2 mutations to a small subset of FPC.

Low Frequency of CHEK2 Mutations in Familial Pancreatic Cancer

Familial pancreatic cancer (FPC) is a rare tumour syndrome and its underlying major gene defect is still unknown. Recently, CHEK2 has been identified as multi-organ cancer susceptibility gene associated with a predisposition to breast, prostate and colon cancer. Since these cancers also are associated with some FPC families, we have analysed 35 index patients of German FPC families for CHEK2 mutations. The CHEK2 * 1100delC mutation was found in 1 (3%) of 35 FPC families. Given the low expected mutation rate of up to 1.4% for CHEK2 * 1100delC in the European population our data are suggestive for possible contribution of CHEK2 mutations to a small subset of FPC.

Familial pancreatic cancer syndromes

Hereditary pancreatic cancer (PC) is rare and extremely heterogeneous, and it accounts for approximately 2% of all PC cases. The major component of hereditary PC is the familial pancreatic cancer syndrome. Although up to 20% of hereditary PC cases are associated with germline mutations in the BRCA2, CDKN2A, PRSS1,STKI1, or MMR genes, the major underlying gene defect(s) is still unknown. Although hereditary PC is rare, the data on PC families that have been collected by various study groups worldwide provide a unique opportunity to evaluate the natural history, causative gene alterations, new diagnosis and chemoprevention strategies as well as treatment modalities.

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.

RNASEL germline variants are associated with pancreatic cancer

The RNASEL (encoding ribonuclease L) gene Glu265X mutation has been implicated in familial prostate cancer, and an association between the RNASEL Arg462Gln variant and sporadic and familial prostate cancer, has also been suggested. Because prostate cancer occurs in some familial pancreatic cancer families, we evaluated the role of the RNASEL gene variants Glu265X and Arg462Gln in the etiology of pancreatic cancer. Exon 2 of the RNASEL gene was directly sequenced in the germline of 36 familial and 75 sporadic pancreatic cancer patients and in 108 controls. The Glu265X mutation was identified in one (2.8%) familial and one (1.3%) sporadic pancreatic cancer case, but not in any of the controls. Arg462Gln variants were identified in 61 (56%) controls and in 55 (73%) sporadic pancreatic cancer cases with 8 (7%) and 12 (16%) homozygotes, respectively (p = 0.009). For homozygous carriers the increased risk for pancreatic cancer was 3.5 (odds ratio [OR] = 3.53, 95% confidence interval [CI] = 1.11-11.46, p = 0.03). The population attributable fraction (PAF) was 38.7% (95% CI = 0.08-0.80). In familial pancreatic cancer no association between Arg462Gln genotypes and pancreatic cancer risk was evident. In sporadic pancreatic cancer there were no significant differences between Arg462Gln genotypes regarding clinical characteristics. In familial pancreatic cancer, however, patients with Arg462Gln variants had more aggressive tumors with more high grade cancers (OR = 15.40, p = 0.009) and more distant metastases (OR = 7.00, p = 0.04) than patients with the wild-type genotype. Our results suggest that RNASEL variants Glu265X and Arg462Gln may contribute to the tumorigenesis of sporadic and familial pancreatic cancer, which has to be proven in large scale studies.

Prophylaktische Chirurgie des Pankreas

The goal of prophylactic surgery is to prevent malignant growth in patients with hereditary tumor predisposition. The pancreas presents as particularly challenging, due to the difficulty of operation and comparatively high risk of morbidity and even mortality. In addition, partial operative procedures and, more significantly, total resection lead to exocrine pancreas insufficiency and secondary diabetes, with grave consequences for the patient. Hereditary tumor predisposition syndromes that can result in pancreaticoduodenal endocrine tumors (PET) include multiple endocrine neoplasia type 1 syndrome and von Hippel-Lindau syndrome. As penetrance is maximally 70-80% and the 10-year survival rate over 80%, prophylactic pancreatic resection without evidence of a tumor is not indicated. However, prophylactic extension of a resection would be advised, should a PET be diagnosed. Patients predisposed to developing ductal pancreatic carcinoma (PC) are at risk of familial pancreatic cancer syndrome (FPC), hereditary pancreatitis, and other hereditary tumor predisposition syndromes such as Peutz-Jeghers syndrome and familial atypical multiple mole-melanoma syndrome. As the gene defect responsible for FPC has yet to be identified and the penetrance of PC in the other tumor predisposition syndromes is low or unknown, a prophylactic pancreatectomy based on today's knowledge is not indicated. Prophylactic extension of the resection is advisable should PC or high-grade PanIN lesions be diagnosed, as these patients often present with multifocal dysplasia and even carcinoma.

Genetics of hereditary pancreatic carcinoma

Several tumor syndromes are known to have an increased incidence of pancreatic carcinoma. Unfortunately, the incidence of pancreatic carcinoma almost equals its mortality. Because of intense research activities in the past decade, several genetic alterations have been identified that are responsible for the so-called sporadic pancreatic carcinoma development. National and international research activities only recently have begun focusing on the molecular pathogenesis of hereditary risk factors for pancreatic carcinoma. It is hoped that these genetic studies will aid the development of clinical management strategies for pancreatic carcinoma prevention.

Genetics of hereditary pancreatic carcinoma

Several tumor syndromes are known to have an increased incidence of pancreatic carcinoma. Unfortunately, the incidence of pancreatic carcinoma almost equals its mortality. Because of intense research activities in the past decade, several genetic alterations have been identified that are responsible for the so-called sporadic pancreatic carcinoma development. National and international research activities only recently have begun focusing on the molecular pathogenesis of hereditary risk factors for pancreatic carcinoma. It is hoped that these genetic studies will aid the development of clinical management strategies for pancreatic carcinoma prevention.

No evidence for germline mutations of the LKB1/STK11 gene in familial pancreatic carcinoma

Familial pancreatic cancer (FPC) (approximately 3% of all cases) has not been linked to defects in any specific gene. Germline inactivation of the gene LKB1/STK11 have been shown to cause Peutz-Jeghers syndrome (PJS) associated with a approximately 100-fold higher risk for the development of pancreatic cancer. We have analysed 39 index patients from European FPC families for mutations of LKB1/STK11 by sequencing of their DNA. No germline mutation was found within the complete coding region. Therefore, our results indicate that LKB1/STK11 is not altered in the germline of patients with hereditary pancreatic cancer.

Prevalence of familial pancreatic cancer in Germany

Based on several case-control studies, it has been estimated that familial aggregation and genetic susceptibility play a role in up to 10% of patients with pancreatic cancer, although conclusive epidemiologic data are still lacking. Therefore, we evaluated the prevalence of familial pancreatic cancer and differences to its sporadic form in a prospective multicenter trial. A total of 479 consecutive patients with newly diagnosed, histologically confirmed adenocarcinoma of the pancreas were prospectively evaluated regarding medical and family history, treatment and pathology of the tumour. A family history for pancreatic cancer was confirmed whenever possible by reviewing the tumour specimens and medical reports. Statistical analysis was performed by calculating odds ratios, regression analysis with a logit-model and the Kaplan-Meier method. Twenty-three of 479 (prevalence 4.8%, 95% CI 3.1-7.1) patients reported at least 1 first-degree relative with pancreatic cancer. The familial aggregation could be confirmed by histology in 5 of 23 patients (1.1%, 95% CI 0.3-2.4), by medical records in 9 of 23 patients (1.9%, 95% CI 0.9-3.5) and by standardized interviews of first-degree relatives in 17 of 23 patients (3.5%, 95% CI 2.1-5.6), respectively. There were no statistical significant differences between familial and sporadic pancreatic cancer cases regarding sex ratio, age of onset, presence of diabetes mellitus and pancreatitis, tumour histology and stage, prognosis after palliative or curative treatment as well as associated tumours in index patients and families, respectively. The prevalence of familial pancreatic cancer in Germany is at most 3.5% (range 1.1-3.5%) depending on the mode of confirmation of the pancreatic carcinoma in relatives. This prevalence is lower than so far postulated in the literature. There were no significant clinical differences between the familial and sporadic form 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.

Management of Patients at High Risk for Pancreatic Cancer

Because pancreatic cancer patients seldom exhibit disease-specific symptoms until the cancer is at an advanced stage, its diagnosis is a virtual death sentence. Therefore, to make a significant impact on long-term survival for subjects with pancreatic cancer, asymptomatic individuals would have to be screened for premalignant precursors of pancreatic cancer or for asymptomatic pancreatic cancer. A number of formidable obstacles limit the ability of healthcare providers to screen for early neoplastic changes and to make a very early and specific diagnosis of pancreatic cancer. These include lack of a high-risk population for sporadic pancreatic cancer and lack of a simple, noninvasive test sensitive enough to detect small cancers. However, progress is being made in defining various high-risk groups for pancreatic cancer, and improvements in imaging modalities make detection of premalignant lesions and small cancers possible in such individuals. The protocols currently being studied, including use of endoscopic ultrasound and endoscopic retrograde cholangiopancreatography to detect precancerous lesions and small pancreatic cancer in high-risk patients, are still in the research arena and not yet ready for clinical practice.

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.