Lessons in Integrating Shared Decision-Making Into Cancer Care.

The benefits of shared decision-making (SDM) in health care delivery are well documented, but implementing SDM at the institutional level is challenging, particularly when patients have complex illnesses and care needs, as in cancer. Denmark's Lillebaelt Hospital, in creating The Patient's Cancer Hospital in Vejle, has learned key lessons in implementing SDM so that the organization's culture is actually being transformed. In short, SDM is becoming part of the fabric of care, not a mere add-on to it. Specifically, the hospital chose and structured its leadership to ensure that SDM is constantly championed. It organized multiple demonstration projects focused on use of decision aids, patient-reported outcome measures, and better communication tools and practices. It designed programs to train clinicians in the art of doctor-patient communication. It used research evidence to inform development of the decision aids that its clinicians use with their patients. And it rigorously measured SDM performance in an ongoing fashion so that progress could be tracked and refined to ensure continuous improvement. Initial data on the institution's SDM initiatives from the Danish national annual survey of patients' experiences show substantial progress, thereby motivating Lillebaelt to reassert its commitment to the effort, to share what it has learned, and to invite dialogue among all cancer care organizations as they seek to fully integrate SDM in daily clinical practice.

A Novel Locus Harbouring a Functional CD164 Nonsense Mutation Identified in a Large Danish Family with Nonsyndromic Hearing Impairment.

Nonsyndromic hearing impairment (NSHI) is a highly heterogeneous condition with more than eighty known causative genes. However, in the clinical setting, a large number of NSHI families have unexplained etiology, suggesting that there are many more genes to be identified. In this study we used SNP-based linkage analysis and follow up microsatellite markers to identify a novel locus (DFNA66) on chromosome 6q15-21 (LOD 5.1) in a large Danish family with dominantly inherited NSHI. By locus specific capture and next-generation sequencing, we identified a c.574C>T heterozygous nonsense mutation (p.R192*) in CD164. This gene encodes a 197 amino acid transmembrane sialomucin (known as endolyn, MUC-24 or CD164), which is widely expressed and involved in cell adhesion and migration. The mutation segregated with the phenotype and was absent in 1200 Danish control individuals and in databases with whole-genome and exome sequence data. The predicted effect of the mutation was a truncation of the last six C-terminal residues of the cytoplasmic tail of CD164, including a highly conserved canonical sorting motif (YXXФ). In whole blood from an affected individual, we found by RT-PCR both the wild-type and the mutated transcript suggesting that the mutant transcript escapes nonsense mediated decay. Functional studies in HEK cells demonstrated that the truncated protein was almost completely retained on the plasma cell membrane in contrast to the wild-type protein, which targeted primarily to the endo-lysosomal compartments, implicating failed endocytosis as a possible disease mechanism. In the mouse ear, we found CD164 expressed in the inner and outer hair cells of the organ of Corti, as well as in other locations in the cochlear duct. In conclusion, we have identified a new DFNA locus located on chromosome 6q15-21 and implicated CD164 as a novel gene for hearing impairment.

Regulation of MLH1 mRNA and protein expression by promoter methylation in primary colorectal cancer: a descriptive and prognostic cancer marker study.

BACKGROUND: In colorectal cancer MLH1 deficiency causes microsatellite instability, which is relevant for the patient's prognosis and treatment, and its putative heredity. Dysfunction of MLH1 is caused by sporadic gene promoter hypermethylation or by hereditary mutations as seen in Lynch Syndrome. The aim of this study was to determine in detail how DNA methylation regulates MLH1 expression and impacts clinical management. METHODS: Colorectal cancer samples were collected from 210 patients. The laboratory methods used to study these samples included methylation specific multiplex ligation-dependent probe amplification (MS-MLPA), real-time quantitative PCR (qPCR), and immunohistochemistry (IHC). RESULTS: We found that the MLH1 mRNA and protein expression levels were highly related. MS-MLPA was successful in tumors from 195 patients. In these tumors, hypermethylation was observed in promoter regions A (n = 57), B (n = 30), C (n = 28), and D (n = 47), and in intron 1 (n = 25). The promoter region C and intron 1 methylation levels were found to be excellently suited for discriminating between low and high gene expression levels, whereas those of promoter regions A, B and D were less specific. Hypermethylation in any region (n = 77) served as an independent prognostic factor (hazard ratio 0.56, 95 % confidence interval 0.36-0.89, p = 0.01). CONCLUSIONS: MLH1 inactivation through hypermethylation was found to be related to improved survival. Hypermethylation in promoter region C and intron 1 served as the most specific markers for this inactivation.

A BAP1 mutation in a Danish family predisposes to uveal melanoma and other cancers.

Truncating germline mutations in the tumor suppressor gene BRCA-1 associated protein-1 (BAP1) have been reported in families predisposed to developing a wide range of different cancer types including uveal melanoma and cutaneous melanoma. There has also been an association between amelanotic tumor development and germline BAP1 mutation suggesting a possible phenotypic characteristic of BAP1 mutation carriers. Though there have been many types of cancer associated with germline BAP1 mutation, the full spectrum of disease association is yet to be ascertained. Here we describe a Danish family with predominantly uveal melanoma but also a range of other tumor types including lung, neuroendocrine, stomach, and breast cancer; as well as pigmented skin lesions. Whole-exome sequencing identified a BAP1 splice mutation located at c.581-2A>G, which leads to a premature truncation of BAP1 in an individual with uveal melanoma. This mutation was carried by several other family members with melanoma or various cancers. The finding expands on the growing profile of BAP1 as an important uveal and cutaneous melanoma tumor suppressor gene and implicates its involvement in the development of lung, and stomach cancer.

Gene expression of the mismatch repair gene MSH2 in primary colorectal cancer.

Microsatellite instability (MSI) is caused by defective mismatch repair (MMR) and is one of the very few molecular markers with proven clinical importance in colorectal cancer with respect to heredity, prognosis, and treatment effect. The gene expression of the MMR gene MSH2 may be a quantitative marker for the level of MMR and a potential molecular marker with clinical relevance. The aim was to investigate the gene expression of MSH2 in primary operable colorectal cancer in correlation with MSI, protein expression, and promoter hypermethylation. In a cohort of 210 patients, the primary tumor and lymphnode metastases were analyzed with immunohistochemistry, methylation and MSI analyses, and quantitative polymerase chain reaction (PCR). The median gene expression of MSH2 was 1.00 (range 0.16-11.2, quartiles 0.70-1.51) and there was good agreement between the gene expression in primary tumor and lymph node metastasis (Spearman's rho = 0.57, p < 0.001, n = 73). The validity of gene expression analysis was made probable by a significant correlation to protein expression (p = 0.005). MSI was most often caused by deficient MLH1 and was not correlated to MSH2 expression. Hypermethylation of the MSH2 gene promoter was only detected in 14 samples and only at a low level with no correlation to gene expression. MSH2 gene expression was not a prognostic factor for overall survival in univariate or multivariate analysis. The gene expression of MSH2 is a potential quantitative marker ready for further clinical validation.

Common alleles at 6q25.1 and 1p11.2 are associated with breast cancer risk for BRCA1 and BRCA2 mutation carriers.

Two single nucleotide polymorphisms (SNPs) at 6q25.1, near the ESR1 gene, have been implicated in the susceptibility to breast cancer for Asian (rs2046210) and European women (rs9397435). A genome-wide association study in Europeans identified two further breast cancer susceptibility variants: rs11249433 at 1p11.2 and rs999737 in RAD51L1 at 14q24.1. Although previously identified breast cancer susceptibility variants have been shown to be associated with breast cancer risk for BRCA1 and BRCA2 mutation carriers, the involvement of these SNPs to breast cancer susceptibility in mutation carriers is currently unknown. To address this, we genotyped these SNPs in BRCA1 and BRCA2 mutation carriers from 42 studies from the Consortium of Investigators of Modifiers of BRCA1/2. In the analysis of 14 123 BRCA1 and 8053 BRCA2 mutation carriers of European ancestry, the 6q25.1 SNPs (r(2) = 0.14) were independently associated with the risk of breast cancer for BRCA1 mutation carriers [hazard ratio (HR) = 1.17, 95% confidence interval (CI): 1.11-1.23, P-trend = 4.5 × 10(-9) for rs2046210; HR = 1.28, 95% CI: 1.18-1.40, P-trend = 1.3 × 10(-8) for rs9397435], but only rs9397435 was associated with the risk for BRCA2 carriers (HR = 1.14, 95% CI: 1.01-1.28, P-trend = 0.031). SNP rs11249433 (1p11.2) was associated with the risk of breast cancer for BRCA2 mutation carriers (HR = 1.09, 95% CI: 1.02-1.17, P-trend = 0.015), but was not associated with breast cancer risk for BRCA1 mutation carriers (HR = 0.97, 95% CI: 0.92-1.02, P-trend = 0.20). SNP rs999737 (RAD51L1) was not associated with breast cancer risk for either BRCA1 or BRCA2 mutation carriers (P-trend = 0.27 and 0.30, respectively). The identification of SNPs at 6q25.1 associated with breast cancer risk for BRCA1 mutation carriers will lead to a better understanding of the biology of tumour development in these women.

Identification of chromosome aberrations in sporadic microsatellite stable and unstable colorectal cancers using array comparative genomic hybridization.

Colorectal cancer (CRC) is one of the most common cancers in Denmark and in the western world in general, and the prognosis is generally poor. According to the traditional molecular classification of sporadic colorectal cancer, microsatellite stable (MSS)/chromosome unstable (CIN) colorectal cancers constitute approximately 85% of sporadic cases, whereas microsatellite unstable (MSI) cases constitute the remaining 15%. In this study, we used array comparative genomic hybridization (aCGH) to identify genomic hotspot regions that harbor recurrent copy number changes. The study material comprised fresh samples from 40 MSS tumors and 20 MSI tumors obtained from 60 Danish CRC patients. We identified five small genomic regions (<15 megabases) exhibiting recurrent copy number loss, which, to our knowledge, have not been reported in previously published aCGH studies of CRC: 3p25.3, 3p21.2-p21.31, 5q13.2, 12q24.23-q24.31, and 12q24.23-q24.31. These regions contain several potentially important tumor suppressor genes that may play a role in a significant proportion of both sporadic MSS CRC and MSI CRC. Furthermore, the generated aCGH data are in support of the recently proposed classification of sporadic CRC into MSS CIN+, MSI CIN-, MSI CIN+, and MSS CIN- cancers.

Identification of BRCA1-deficient ovarian cancers.

OBJECTIVE: It is believed that 24-40% of ovarian cancers have dysfunction in the BRCA1 or BRCA2 (BRCAness) genes, due to either inherited or somatic mutations or due to epigenetic inactivation. Demonstration of ovarian cancers with BRCAness is becoming important both due to the possibility of offering genetic counseling and due to beneficial effects of polyadenosine diphosphate ribose polymerase inhibitor treatment in this group. As DNA sequencing is expensive and time consuming, efforts have been devoted to develop more indirect methods for BRCA screening that can improve the selection of patients for sequence-based BRCA testing. DESIGN: BRCA1 immunohistochemistry, fluorescence in situ hybridization (FISH) and methylation analyses were performed on formalin-fixed, paraffin-embedded ovarian cancer tissue. SAMPLE: Fifty-four ovarian cancers; 15 BRCA1 cancers, four BRCA2 cancers, 10 cancers from patients with a family history but no mutation detected, and 25 ovarian cancers with unknown BRCA1 status. RESULTS: Abnormal BRCA1 immunohistochemistry was found to indicate BRCA mutations with a sensitivity of 80%, a specificity of 93% and an estimated positive predictive value of 73%. The FISH analyses supported the diagnosis in most cases. Methylation analyses could indicate BRCA deficiency in combination with one of the other methods. CONCLUSIONS: BRCA1 immunohistochemistry is a promising screening method for BRCA1 mutation detection.

Genetic variation at 9p22.2 and ovarian cancer risk for BRCA1 and BRCA2 mutation carriers.

BACKGROUND: Germline mutations in the BRCA1 and BRCA2 genes are associated with increased risks of breast and ovarian cancers. Although several common variants have been associated with breast cancer susceptibility in mutation carriers, none have been associated with ovarian cancer susceptibility. A genome-wide association study recently identified an association between the rare allele of the single-nucleotide polymorphism (SNP) rs3814113 (ie, the C allele) at 9p22.2 and decreased risk of ovarian cancer for women in the general population. We evaluated the association of this SNP with ovarian cancer risk among BRCA1 or BRCA2 mutation carriers by use of data from the Consortium of Investigators of Modifiers of BRCA1/2. METHODS: We genotyped rs3814113 in 10,029 BRCA1 mutation carriers and 5837 BRCA2 mutation carriers. Associations with ovarian and breast cancer were assessed with a retrospective likelihood approach. All statistical tests were two-sided. RESULTS: The minor allele of rs3814113 was associated with a reduced risk of ovarian cancer among BRCA1 mutation carriers (per-allele hazard ratio of ovarian cancer = 0.78, 95% confidence interval = 0.72 to 0.85; P = 4.8 × 10(-9)) and BRCA2 mutation carriers (hazard ratio of ovarian cancer = 0.78, 95% confidence interval = 0.67 to 0.90; P = 5.5 × 10(-4)). This SNP was not associated with breast cancer risk among either BRCA1 or BRCA2 mutation carriers. BRCA1 mutation carriers with the TT genotype at SNP rs3814113 were predicted to have an ovarian cancer risk to age 80 years of 48%, and those with the CC genotype were predicted to have a risk of 33%. CONCLUSION: Common genetic variation at the 9p22.2 locus was associated with decreased risk of ovarian cancer for carriers of a BRCA1 or BRCA2 mutation.

A BRCA2 mutation incorrectly mapped in the original BRCA2 reference sequence, is a common West Danish founder mutation disrupting mRNA splicing.

Inherited mutations in the tumor suppressor genes BRCA1 and BRCA2 predispose carriers to breast and ovarian cancer. The authors have identified a mutation in BRCA2, 7845+1G>A (c.7617+1G>A), not previously regarded as deleterious because of incorrect mapping of the splice junction in the originally published genomic reference sequence. This reference sequence is generally used in many laboratories and it maps the mutation 16 base pairs inside intron 15. However, according to the recent reference sequences the mutation is located in the consensus donor splice sequence. By reverse transcriptase analysis, loss of exon 15 in the final transcript interrupting the open reading frame was demonstrated. Furthermore, the mutation segregates with a cancer phenotype in 18 Danish families. By genetic analysis of more than 3,500 Danish breast/ovarian cancer risk families, the mutation was identified as the most common BRCA2 mutation in West Denmark, while it is rare in Central and East Denmark and not identified in South Sweden. Haplotype analysis using dense SNP arrays indicated a common founder of the mutation approximately 1,500 years ago.

International distribution and age estimation of the Portuguese BRCA2 c.156_157insAlu founder mutation.

The c.156_157insAlu BRCA2 mutation has so far only been reported in hereditary breast/ovarian cancer (HBOC) families of Portuguese origin. Since this mutation is not detectable using the commonly used screening methodologies and must be specifically sought, we screened for this rearrangement in a total of 5,443 suspected HBOC families from several countries. Whereas the c.156_157insAlu BRCA2 mutation was detected in 11 of 149 suspected HBOC families from Portugal, representing 37.9% of all deleterious mutations, in other countries it was detected only in one proband living in France and in four individuals requesting predictive testing living in France and in the USA, all being Portuguese immigrants. After performing an extensive haplotype study in carrier families, we estimate that this founder mutation occurred 558 ± 215 years ago. We further demonstrate significant quantitative differences regarding the production of the BRCA2 full length RNA and the transcript lacking exon 3 in c.156_157insAlu BRCA2 mutation carriers and in controls. The cumulative incidence of breast cancer in carriers did not differ from that of other BRCA2 and BRCA1 pathogenic mutations. We recommend that all suspected HBOC families from Portugal or with Portuguese ancestry are specifically tested for this rearrangement.

Common breast cancer susceptibility alleles and the risk of breast cancer for BRCA1 and BRCA2 mutation carriers: implications for risk prediction.

The known breast cancer susceptibility polymorphisms in FGFR2, TNRC9/TOX3, MAP3K1, LSP1, and 2q35 confer increased risks of breast cancer for BRCA1 or BRCA2 mutation carriers. We evaluated the associations of 3 additional single nucleotide polymorphisms (SNPs), rs4973768 in SLC4A7/NEK10, rs6504950 in STXBP4/COX11, and rs10941679 at 5p12, and reanalyzed the previous associations using additional carriers in a sample of 12,525 BRCA1 and 7,409 BRCA2 carriers. Additionally, we investigated potential interactions between SNPs and assessed the implications for risk prediction. The minor alleles of rs4973768 and rs10941679 were associated with increased breast cancer risk for BRCA2 carriers (per-allele HR = 1.10, 95% CI: 1.03-1.18, P = 0.006 and HR = 1.09, 95% CI: 1.01-1.19, P = 0.03, respectively). Neither SNP was associated with breast cancer risk for BRCA1 carriers, and rs6504950 was not associated with breast cancer for either BRCA1 or BRCA2 carriers. Of the 9 polymorphisms investigated, 7 were associated with breast cancer for BRCA2 carriers (FGFR2, TOX3, MAP3K1, LSP1, 2q35, SLC4A7, 5p12, P = 7 × 10(-11) - 0.03), but only TOX3 and 2q35 were associated with the risk for BRCA1 carriers (P = 0.0049, 0.03, respectively). All risk-associated polymorphisms appear to interact multiplicatively on breast cancer risk for mutation carriers. Based on the joint genotype distribution of the 7 risk-associated SNPs in BRCA2 mutation carriers, the 5% of BRCA2 carriers at highest risk (i.e., between 95th and 100th percentiles) were predicted to have a probability between 80% and 96% of developing breast cancer by age 80, compared with 42% to 50% for the 5% of carriers at lowest risk. Our findings indicated that these risk differences might be sufficient to influence the clinical management of mutation carriers.

Incidence, etiology and prognosis of first-time acute pancreatitis in young patients: a population-based cohort study.

BACKGROUND/AIMS: The etiology of acute pancreatitis (AP) seems to have changed during the last two decades, and since detection of mutations in the gene for cationic trypsinogen(PRSS1) causing hereditary pancreatitis some patients formerly diagnosed with idiopathic AP (IAP) turn out to have a genetic cause. METHODS: Data on patients <30 years of age, diagnosed with AP identified in the Danish National Registry of Patients, were retrieved. Patients previously diagnosed with IAP were offered genetic counseling and testing for mutations in the PRSS1, the Serine Protease Inhibitor Kazal type1 (SPINK1) and the Cystic Fibrosis Transmembrane Conductance Regulator gene (CFTR). RESULTS: The standardized incidence ratio (SIR) of AP increased from 3.56 per 100,000 person-years in the period 1980-1984 to 6.43 in 2000-2004 (p < 0.01). The SIR of women surpassed that of men in 1999. Among patients with former IAP, 3 had hereditary pancreatitis, 3 CFTR and 4 SPINK1 mutations after re-evaluation. CONCLUSION: The incidence of AP, especially in women, increased over time. More patients had gallstone-related and less alcohol-related AP in the period 1999-2004 compared to 1980-1999. Genetic causes of AP were found in 32% of those tested with IAP and as a minimum estimation in 4% of the total cohort. and IAP.

Genetic, epidemiological, and clinical aspects of hereditary pancreatitis: a population-based cohort study in Denmark.

OBJECTIVES: In a population-based, well-defined group of patients first regarded as having pancreatitis of unknown origin (PUO), we identified, described, and compared the clinical and genetic aspects of patients with hereditary pancreatitis (HP) and with cystic fibrosis transmembrane conductance regulator gene (CFTR) and serine protease inhibitor Kazal type 1 gene (SPINK1) mutations with patients who retained the diagnosis of true idiopathic pancreatitis (tIP) after genetic testing for HP, SPINK1, and CFTR mutations. METHODS: Patients with PUO were identified in the Danish National Registry of Patients or were referred by clinicians. DNA from blood was analyzed for cationic trypsinogen (PRSS1), SPINK1, and CFTR mutations. Considering the diagnosis of HP, a pedigree was drawn for each patient. RESULTS: A genetic mutation was found in 40% of 122 patients with PUO. After testing first-degree relatives of the 18 initially identified HP patients, 38 HP patients in total were identified, and 28 patients had SPINK1-CFTR mutations. Among HP patients, no p.N29I mutations were found and the p.A16V mutation was more frequent than previously reported, 45 and 32% had exocrine and endocrine insufficiency, respectively, and among tIP patients 9 and 12%, respectively. Pancreatic cancer was diagnosed in 5% of the HP families. CONCLUSIONS: The genotype of the Danish population with HP differs from that of previously described cohorts. The occurrence of exocrine and endocrine insufficiency is higher among patients with HP than in patients with SPINK1-CFTR mutations and tIP, and more HP families develop pancreatic cancer. Genetic testing thus helps to predict the prognosis of the pancreatitis.

Molecular biology from bench-to-bedside - which colorectal cancer patients should be referred for genetic counselling and risk assessment.

Lynch syndrome is associated with deficiency of the mismatch repair genes MLH1, MSH2, MSH6 or PMS2. However, most MLH1 deficient tumours are sporadic in origin, and they can be identified if harbouring a BRAF V600E mutation or hypermethylation of the MLH1 gene promoter. The aim of this study was to validate our previously suggested clinically applicable strategy based on molecular characteristics for identifying which patients to refer for genetic counselling. The strategy was validated in an unselected cohort of 287 colorectal cancer patients. All tumours were tested for MLH1, PMS2, MSH2 and MSH6 protein expression with immunohistochemistry. DNA from MLH1 negative tumours was sequenced for BRAF mutations. If BRAF was wild-type, MLH1 promoter was subsequently analyzed for promoter hypermethylation. Most tumours, 251 (88%), stained positive for all four proteins. Six (2%) had negative MSH2 and one (<1%) isolated loss of MSH6. MLH1 and PMS2 were negative in 29 cases (10%). DNA quality allowed BRAF analysis in 27 of these with 14 mutations and 13 wild-type. DNA quality allowed methylation analysis in 11 of the 13 BRAF wild-type, and all but one were methylated. Subsequently, Lynch syndrome could not be ruled out in 12 patients. A follow-up at 8-10 years revealed four definite cases of Lynch syndrome and three highly suspicious. An easy and clinically applicable step-wise approach with immunohistochemistry (100%), BRAF sequencing (10%) and methylation analysis (5%) identified several patients with hereditary cancer. It is feasible to perform a molecular screening to select patients for genetic counselling.

Incidence, prevalence, etiology, and prognosis of first-time chronic pancreatitis in young patients: a nationwide cohort study.

BACKGROUND/AIMS: Publications on etiology of chronic pancreatitis (CP) are infrequent. Etiologies today encompass genetic disorders. We wanted to describe etiologies of today and identify patients with genetic disorders like hereditary pancreatitis (HP), mutations in Serine Protease Inhibitor Kazal type1 (SPINK1), and the Cystic Fibrosis Transmembrane Conductance Regulator gene (CFTR) among patients formerly considered to have idiopathic CP. METHODS: Data on patients diagnosed with first-time CP < 30 years of age in Denmark identified in the Danish National Registry of Patients were retrieved. Patients previously considered to have idiopathic pancreatitis were offered genetic counseling and evaluation for HP, SPINK1, and CFTR mutations. RESULTS: In the period 1980-2004, 580 patients < 30 years of age presented with CP, the standardized prevalence ratio of CP increased from 11.7 per 100,000 person years in 1980-1984 to 17.0 per 100,000 in 2000-2004 (p < 0.001). The odds ratio (OR) having gallstone-related CP increased in the latter time period, especially in women, that of alcohol-induced CP decreased over time. OR having idiopathic CP increased in the latter period; 50% of patients with idiopathic pancreatitis accepted genetic reevaluation; 28 patients had a genetic mutation that totally or partly could explain their pancreatitis, nine of these had two, and 11 patients had HP. CONCLUSION: The prevalence of CP, especially in women, increased over time. Genetic causes that partly or totally could explain the CP were found in 54.90% (95% CI (40.45-68.62)) of those with idiopathic CP, as a minimum estimation 1.9% (95% CI (1.00-3.47)) of the total cohort had HP.

Population-based survey of cancer risks in chromosome 3 translocation carriers.

Familial renal cell carcinoma (RCC) is genetically heterogeneous and may be associated with germline mutations in a number of genes. Twelve different constitutional translocations involving chromosome 3 have also been described in association with inherited RCC. In some families the lifetime risk of RCC in chromosome 3 translocation carriers has been estimated to be more than 80%; however the cancer risks in patients with chromosome 3 translocations not ascertained because of a family history of RCC are not well defined. We report a retrospective population-based study using Danish national cytogenetic and cancer registries to clarify tumor risks associated with constitutional translocations involving chromosome 3. We identified 222 (105 females, 117 males) individuals with a constitutional chromosome 3 translocation and compared their cancer risks to those of the Danish population. None of the chromosome 3 translocation carriers had developed RCC at the time of study (female 95% CIs 0.000-0.042, male 95% CIs 0.000-0.038) (P = 1.0 and P = 0.498 for females and males compared to Danish population). Fourteen translocation carriers had developed cancer but there was no evidence of an excess of early onset disease and lifetime cancer risks in chromosome 3 translocation carriers were similar that in the Danish population. There was no association between cancer risk and location of the chromosome 3 breakpoint (HR = 1.322, P = 0.673). These findings suggest that, in the absence of a family history of RCC or evidence of disruption of a specific tumor suppressor gene, chromosome 3 translocations carriers are not at high risk of developing RCC.

Major contribution from recurrent alterations and MSH6 mutations in the Danish Lynch syndrome population.

An increasing number of mismatch-repair (MMR) gene mutations have been identified in hereditary nonpolyposis colorectal cancer (HNPCC) or Lynch syndrome. This study presents the population-based Danish MMR gene mutation profile, which contains 138 different MMR gene alterations. Among these, 88 mutations in 164 families are considered pathogenic and an additional 50 variants from 76 families are considered to represent variants of unknown pathogenicity. The different MMR genes contribute to 40% (MSH2), 29% (MLH1), and 22% (MSH6) of the mutations and the Danish population thus shows a considerably higher frequency of MSH6 mutations than previously described. Although 69/88 (78%) pathogenic mutations were present in a single family, previously recognized recurrent/founder mutations were causative in 75/137 (55%) MLH1/MSH2 mutant families. In addition, the Danish MLH1 founder mutation c.1667+2_1667_+8TAAATCAdelinsATTT was identified in 14/58 (24%) MLH1 mutant families. The Danish Lynch syndrome population thus demonstrates that MSH6 mutations and recurrent/founder mutations have a larger contribution than previously recognized, which implies that the MSH6 gene should be included in routine diagnostics and suggests that directed analysis of recurrent/founder mutations may be feasible e.g. in families were diagnostic material is restricted to archival tissue.

Microsatellite instability and the association with plasma homocysteine and thymidylate synthase in colorectal cancer.

The possible associations between microsatellite instability, homocysteine and thymidylate synthase were investigated in tumors and plasma from 130 patients with colorectal cancer. Other analyses included thymidylate synthase and 5,10-methylene-tetrahydrofolate reductase gene polymorphisms, carcinoembryonic antigen, vitamin B12, and folate. Microsatellite instability of tumors was associated with higher levels of plasma homocysteine (p = 0.008) and higher protein expression of thymidylate synthase (p < 0.001). Supplemental analyses ruled out that the finding could be explained by the other analyzed factors. CEA was not associated with neither homocysteine nor microsatellite instability. The data suggests that there is a more pronounced methyl unit deficiency in microsatellite instable tumors.