Mercedes Sina-Frey

Anticipation in familial pancreatic cancer

Background: Previous studies of anticipation in familial pancreatic cancer have been small and subject to ascertainment bias. Our aim was to determine evidence for anticipation in a large number of European families. Patients and methods: A total of 1223 individuals at risk from 106 families (264 affected individuals) were investigated. Generation G3 was defined as the latest generation that included any individual aged over 39 years; preceding generations were then defined as G2 and G1. Results: With 80 affected child-parent pairs, the children died a median (interquartile range) of 10 (7, 14) years earlier. The median (interquartile range) age of death from pancreatic cancer was 70 (59, 77), 64 (57, 69), and 49 (44, 56) years for G1, G2, and G3, respectively. These indications of anticipation could be the result of bias. Truncation of Kaplan-Meier analysis to a 60 year period to correct for follow up time bias and a matched test statistic indicated significant anticipation (p = 0.002 and p<0.001). To minimise bias further, an iterative analysis to predict cancer numbers was developed. No single risk category could be applied that accurately predicted cancer cases in every generation. Using three risk categories (low with no pancreatic cancer in earlier generations, high with a single earlier generation, and very high where two preceding generations were affected), incidence was estimated without significant error. Anticipation was independent of smoking. Conclusion: This study provides the first strong evidence for anticipation in familial pancreatic cancer and must be considered in genetic counselling and the commencement of secondary screening for 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.

Evaluation of the 4q32-34 Locus in European Familial Pancreatic Cancer

Background: Familial pancreatic cancer (FPC) describes a group of families where the inheritance of pancreatic cancer is consistent with an autosomal-dominant mode of inheritance. The 4q32-34 region has been previously identified as a potential locus for FPC in a large American family. Methods: The region was allelotyped in 231 individuals from 77 European families using nine microsatellite markers, and haplotyping was possible in 191 individuals from 41 families. Families were selected based on at least two affected first-degree relatives with no other cancer syndromes. Results: Linkage to most of the locus was excluded based on LOD scores less than −2.0. Eight families were excluded from linkage to 4q32-34 based on haplotypes not segregating with the disease compared with a predicted six to seven families. Two groups of families were identified, which seem to share common alleles within the minimal disease-associated region of 4q32-34, one group with an apparently earlier age of cancer death than the other pancreatic cancer families. Four genes were identified with potential tumor suppressor roles within the locus in regions that could not be excluded based on the LOD score. These were HMGB2, PPID, MORF4, and SPOCK3. DNA sequence analysis of exons of these genes in affected individuals and in pancreatic cancer cell lines did not reveal any mutations. Conclusion: This locus is unlikely to harbor a FPC gene in the majority of our European families. (Cancer Epidemiol Biomarkers Prev 2006;15(10):1948–55)

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.

Update of Familial Pancreatic Cancer in Germany

Background/Aims: The prevalence of familial pancreatic cancer (FPC) and the characteristics of FPC have not yet been well investigated in the German population. Therefore, a German case collection for FPC was established in July 1999 to collect and evaluate data on FPC families. Methods: The prevalence of pancreatic cancer (PC) as well as other tumours and diseases was studied in families with at least 2 first-degree relatives with histologically confirmed PC, and in families of patients with PC and a first-degree relative with malignant melanoma. All participating family members were genetically counselled and evaluated by a standardised questionnaire. Results: In an 18-month period, 73 independent kindreds with potential FPC contacted the national case collection. So far, 20 kindreds have fulfilled the criteria for FPC and have undergone complete workups. Most families revealed an autosomal dominant pattern of inheritance. Twelve families revealed an isolated accumulation of PC. Importantly, in 8 of 20 (35%) families, additional tumour types such as melanoma, breast and prostate cancer occurred. Conclusion: The observed phenotypic heterogeneity indicates an association with predisposing tumour suppressor genes p16 and BRCA2 in up to 30% of FPC families. Mutation analysis of these candidate genes might lead to the identification of the predisposing gene defect in a proportion of FPC families.

German national case collection of familial pancreatic cancer - clinical-genetic analysis of the first 21 families.

Background: The observation of a familial accumulation of ductal pancreatic adenocarcinoma (PC) and the increased risk for PC in certain hereditary tumor syndromes point to a genetic predisposition for PC. In order to evaluate the characteristics of familial PC, a German national case collection for familial pancreas cancer (FaPaCa) was established. Patients and Methods: In FaPaCa, families of patients with PC are being collected, who have at least 1 first-degree relative with PC or with malignant melanoma. Histopathologic verification of tumor diagnoses, acquisition of clinical data, and full genetic counselling are prerequisites for the enrollment of PC families in FaPaCa. Results: So far, 21 families fulfilled the criteria for partaking in FaPaCa. In 11 families, PC represented the sole tumor entity. Additional tumors included malignant melanoma in 5, breast cancer in 3, and prostatic, colon or lung cancer in 2 families. Compared to the preceding generation, a younger age at diagnosis of PC was observed in the offspring of PC patients (offspring median 53 years vs. parents median 75.5 years). Conclusion: The association of PC and breast cancer, and of PC and malignant melanoma suggests predisposing mutations in the BRCA2 or CDKN2A genes in about one third of the FaPaCa families. Mutational analyses in both candidate genes may help to identify individuals who are at an increased risk for developing PC. A shift towards a younger age at diagnosis in our PC families may indicate genetic anticipation and/or changes of patterns of exogenous risk factors.

The NOD2 3020insC Mutation and The Risk of Familial Pancreatic Cancer

Dear Sirs, Pancreatic cancer is an aggressive disease with a poor prognosis but despite much investigation little is known about genetic susceptibilities to this cancer [1-4]. There are several studies showing pancreatic abnormalities in patients with Crohns disease, a chronic inflammatory condition of the digestive tract. It has been suggested that pancreatitis could be an extrahepatic manifestation of inflammatory bowel disease, since its incidence in this disease is greater than that in the general population and in many cases no aetiological factor has been found [5]. It has been recently identified in Japan that over 6% of Crohns disease patients had morphological abnormalities of the pancreas [6]. There is also a notion that Crohns-associated pancreatitis could be a premalignant state for cystadenocarcinoma of the pancreas [7]. Recently in patients with Crohns disease mutations in CARD15/NOD2 have been found. NOD2 encodes a protein involved in bacterial recognition by monocytes. The NOD2 gene is localized to chromosome 16 and is comprised of 12 exons that encode a protein of 1040 amino acids [8]. Several mutations have been identified in the NOD2 gene, which appear with a significantly higher frequency in patients with Crohns disease. One such mutation (3020insC) is believed to be clearly causative because it is the only common variant which results in a prematurely truncated protein predicted to reduce its functional efficiency. It has been recognized recently that the presence of this particular NOD2 mutation increases the risk of developing colorectal cancer characterized by a later average age of disease diagnosis [9]. Since the risk of cancers at various sites has been characteristic among patients with Crohns disease, it was considered justified to study the relationship between the 3020insC mutation and other cancer risks. Here, we report the analyses of the 3020insC mutation in the NOD2 gene in patients with pancreatic cancer. Initially, we have examined the frequency of the 3020insC mutation in a series of 158 patients divided into 3 groups: 1. 127 consecutive pancreatic cancers; 2. 4 familial cases - pancreatic cancer patients from families with at least two pancreatic cancers on the one side of the family; 3. 27 healthy children of pancreatic cancer patients from families with at least two pancreatic cancer cases where DNA samples from affected individuals were not available. Individuals from the last group were younger than 46 years. In the consecutive group peripheral blood samples were available from 58 cases. DNA from the remaining patients was isolated from paraffin embedded tissues. In all familial cases and the group of healthy children DNA samples were obtained from the peripheral blood lymphocytes. The control group consisted of 300 consecutive newborns from the clinical hospitals of Szczecin. DNA samples were obtained from umbilical cord blood. The method described by Ogura et al [8] was used to identify the 3020insC mutation. The sequence of the PCR products was confirmed by DNA sequencing. The frequency of the 3020insC mutation in the control group was 7%. In the group of consecutive cases six C-insertion mutations were identified (4.7%). In the four independent familial pancreatic cancer patients no mutation was found, but four changes (14.8%; 4/27) were detected in the group of healthy children of pancreatic cancer patients derived from families with aggregations of these tumours (Fig. ​(Fig.11). Figure 1 Pedigree of the family with 3020insC mutation. Since our results indicated that there was an increased frequency of the 3020insC mutation in familial pancreatic cancer cases we decided to enlarge this group. 30 additional histologically confirmed familial pancreatic cancer patients of independent families from the German National Case Collection for Familial Pancreatic Cancer of the Deutsche Krebshilfe (FaPaCa) were included in this study [10]. The frequency of the mutant allele in this group did not confirm our initial result since only two changes were found (6.7%; 2/30). However, even if Polish and German familial cases are combined it is still an open question whether 3020insC is related to a predisposition to familial pancreatic cancer. Further investigations on a larger number of cases are needed. In summary we cannot conclude that NOD2 is not involved in familial pancreatic cancer but it appears not to be associated with sporadic cases of disease.

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.

Keimbahnmutationen des RNASEL Gens bei Patienten mit sporadischem und familiärem Pankreaskarzinom

RNASEL (encoding ribonuclease L) has been proposed as a candidate for the hereditary prostate cancer gene. Recent studies have shown that the RNASEL variant 1385 G→A (Arg462Gln) has three times less enzymatic activity than non-mutated RNASEL and is significant associated with prostate cancer risk. Here, for the first time, we screened for RNASEL mutations in patients with sporadic and familial pancreatic cancer. In patients with sporadic pancreatic cancer we found wild type in 22% (G/G), 66% were heterozygous (G/A) and 12% were homozygous (A/A). This was significant higher than in controls (45% G/G, 45% G/A and 10% A/A; p: 0,02). In patients with familial pancreatic cancer even 45% were heterozygous (G/A), 23% were homozygous (A/A), while in only 32% of the patients wild type was identified. These results suggest that germline mutations of RNASEL gene may be associated with sporadic and familial pancreatic cancer.