Revised guidelines for the clinical management of Lynch syndrome (HNPCC): recommendations by a group of European experts.

Lynch syndrome (LS) is characterised by the development of colorectal cancer, endometrial cancer and various other cancers, and is caused by a mutation in one of the mismatch repair genes: MLH1, MSH2, MSH6 or PMS2. In 2007, a group of European experts (the Mallorca group) published guidelines for the clinical management of LS. Since then substantial new information has become available necessitating an update of the guidelines. In 2011 and 2012 workshops were organised in Palma de Mallorca. A total of 35 specialists from 13 countries participated in the meetings. The first step was to formulate important clinical questions. Then a systematic literature search was performed using the Pubmed database and manual searches of relevant articles. During the workshops the outcome of the literature search was discussed in detail. The guidelines described in this paper may be helpful for the appropriate management of families with LS. Prospective controlled studies should be undertaken to improve further the care of these families.

Identification of a novel BRCA1 nucleotide 4803delCC/c.4684delCC mutation and a nucleotide 249T>A/c.130T>A (p.Cys44Ser) mutation in two Greenlandic Inuit families: implications for genetic screening of Greenlandic Inuit families with high risk for breast and/or ovarian cancer.

Germ-line mutations in the tumour suppressor proteins BRCA1 and BRCA2 predispose to breast and ovarian cancer. We have recently identified a Greenlandic Inuit BRCA1 nucleotide 234T>G/c.115T>G (p.Cys39Gly) founder mutation, which at that time was the only disease-causing BRCA1/BRCA2 mutation identified in this population. Here, we describe the identification of a novel disease-causing BRCA1 nucleotide 4803delCC/c.4684delCC mutation in a Greenlandic Inuit with ovarian cancer. The mutation introduces a frameshift and a premature stop at codon 1572. We have also identified a BRCA1 nucleotide 249T>A/c.130T>A (p.Cys44Ser) mutation in another Greenlandic individual with ovarian cancer. This patient share a 1-2 Mb genomic fragment, containing the BRCA1 gene, with four Danish families harbouring the same mutation, suggesting that the 249T>A/c.130T>A (p.Cys44Ser) mutation originates from a Danish ancestor. We conclude that screening of Greenlandic Inuits with high risk of breast or ovarian cancer should include sequencing of the entire BRCA1 gene.

A common Greenlandic Inuit BRCA1 RING domain founder mutation.

Germ-line mutations in the tumour suppressor proteins BRCA1 and BRCA2 predispose to breast and ovarian cancer. We examined 32 breast and/or ovarian cancer patients from Greenland for mutations in BRCA1 and BRCA2. Whereas no mutations were identified in 19 families, 13 families exhibited a BRCA1 exon 3 nucleotide 234 T > G mutation, which has not previously been reported in the breast cancer information core (BIC) database. The mutation changes a conserved cysteine 39 to a glycine in the Zn(2+) site II of the RING domain, which is essential for BRCA1 ubiquitin ligase activity. Eight of the families had members with ovarian cancer, suggesting that the RING domain may be an ovarian cancer hotspot. By SNP array analysis, we find that all 13 families share a 4.5 Mb genomic fragment containing the BRCA1 gene, showing that the mutation originates from a founder. Finally, analysis of 1152 Inuit, representing almost ~2% of the total Greenlandic Inuit population, showed that the frequency of the mutation was 1.0%. We conclude that the BRCA1 nucleotide 234 T > G is a common Greenlandic Inuit founder mutation. The relative high frequency in the general population, together with the ease of screening and possibility to reduce mortality in gene carriers, may warrant screening of the Greenlandic Inuit population. Provided screening is efficient, about 5% of breast- and 13% of ovarian cancers, respectively, may be prevented.

The risk of extra-colonic, extra-endometrial cancer in the Lynch syndrome.

Persons with the Lynch syndrome (LS) are at high risk for cancer, including cancers of the small bowel, stomach, upper urologic tract (renal pelvis and ureter), ovary, biliary tract and brain tumors, in addition to the more commonly observed colorectal and endometrial cancers. Cancer prevention strategies for these less common cancers require accurate, age-specific risk estimation. We pooled data from 4 LS research centers in a retrospective cohort study, to produce absolute incidence estimates for these cancer types, and to evaluate several potential risk modifiers. After elimination of 135 persons missing crucial information, cohort included 6,041 members of 261 families with LS-associated MLH1 or MSH2 mutations. All were either mutation carriers by test, probable mutation carriers (endometrial/colorectal cancer-affected), or first-degree relatives of these. Among mutation carriers and probable carriers, urologic tract cancer (N = 98) had an overall lifetime risk (to age 70) of 8.4% (95% CI: 6.6-10.8); risks were higher in males (p < 0.02) and members of MSH2 families (p < 0.0001). Ovarian cancer (N = 72) had an lifetime risk of 6.7% (95% CI: 5.3-9.1); risks were higher in women born after the median year of birth (p < 0.008) and in members of MSH2 families (p < 0.006). Brain tumors and cancers of the small bowel, stomach, breast and biliary tract were less common. Urologic tract cancer and ovarian cancer occur frequently enough in some LS subgroups to justify trials to evaluate promising prevention interventions. Other cancer types studied occur too infrequently to justify strenuous cancer control interventions.

Hereditary non-polyposis colorectal cancer (HNPCC): phenotype-genotype correlation between patients with and without identified mutation.

Affected members of hereditary non-polyposis colorectal cancer (HNPCC) families develop colorectal cancer at an early age (mean 45 yr) and frequently get extracolonic cancers particularly in the uterus, urinary tract, and small intestine. They have a high risk of developing more than one primary colorectal cancer if not treated with subtotal colectomy at first operation and have more frequent right-sided colon cancers and less frequent rectum cancers, compared to patients with sporadic colorectal cancer. We have screened 31 families fulfilling the Amsterdam criteria and 54 families with a colorectal cancer clustering but not fulfilling the Amsterdam criteria for mutations in MLH1 and MSH2 by direct sequencing, and detected a mutation in 61% of the Amsterdam positive families but only in 15% of the Amsterdam negative families. Genotype-phenotype correlation was compared between 141 affected individuals with an identified mutation and 78 affected individuals from Amsterdam positive families in which a mutation was not identifiable in MLH1 or MSH2. In the affected persons with identified mutations, all expected phenotypic traits were represented, whereas affected persons in whom no mutation was detected fell into two clearly distinguishable subgroups. The minor subgroup, in which no mutation was identified, generally had the same characteristics as found in affected persons with identified mutations. The major subgroup differed significantly in clinical features and exhibited phenotypic traits similar to those found in late-onset families, including abundance of rectal cancer, few HNPCC-related cancers, lower frequency of multiple colorectal cancers, and later age at onset. Finally, for six missense mutations and one single codon deletion, the pathogenic potential was evaluated by domain localization, lod score calculation or segregation analysis when possible, and mutation-induced biochemical change. The results indicate that the majority of missense mutations are pathogenic, although further characterization by functional assays is necessary before implementation in predictive testing programs.

Helicobacter pylori infection in Greenlandic patients with dyspepsia.

OBJECTIVES: The aim was to evaluate the incidence of Helicobacter pylori (HP) infection in Greenland, to assess the value of the test "Helicobacter antigen in faeces" as a diagnostic tool and to determine the level of antibiotic resistance. STUDY DESIGN: 100 consecutive patients with dyspepsia who visited for endoscopic gastric examination were included. The patients had to be born in Greenland and to be > or = 18 years old. METHODS: Samples for HP antibody in blood, HP antigen in faeces, urease test on biopsies were collected from the patients. Gastric biopsies were cultured for HP bacteria, and antibiotic resistance was tested. Patients with positive urease test and/or antigen in faeces and/or positive culture were treated simultaneously with Amoxicillin, Metronidazole and Esomeprazole for 1 week. Patients with duodenal or gastric ulcer were endoscopically re-examined 8 weeks later. Patients with proven HP infection but without ulcer submitted a faeces sample 8 weeks after the eradication. RESULTS: 77 patients were considered HP infected, and received treatment. Only 32% of them were eradicated sufficiently. CONCLUSION: HP antigen in faeces test is useful as a diagnostic tool and for control of therapy. A change in strategy of HP treatment in Greenland is a must, presumably preceded by an elucidation of microbial sensitivity.

[Prevention of colorectal cancer in families with hereditary nonpolyposis colorectal cancer]. / Forebyggelse af kolorektal cancer i hereditaer non-polyposis kolorektal cancer-familier.

INTRODUCTION: Hereditary non-polyposis colorectal cancer (HNPCC) is a dominant inherited colorectal cancer syndrome, with lifetime risk up to 90% of developing colorectal cancer (CRC) for carriers of the genes. Screening with colonoscopy can reduce the CRC-rate by 62% and prevent CRC-deaths. The HNPCC-Register was established with the aim of identification and registration of Danish HNPCC-families and coordination of surveillance. MATERIALS AND METHODS: The results of 703 colonic screenings in 396 asymptomatic individuals from 150 HNPCC-families were analysed and related to the family diagnosis. RESULTS: In 112 asymptomatic individuals, 31, colorectal cancers and 140 adenomas were diagnosed. Neoplasia was found in one fifth of the examinations and almost one third of the individuals developed an asymptomatic neoplasia which was detected by screening. At the time of the diagnosis, 77% of the colorectal cancers were localized (Dukes stage A or B). DISCUSSION: In Finland, screening for colorectal cancers in HNPCC-families prevents 25-45-fold more CRC-deaths compared to general population screening for colorectal cancer. The results of the Danish colonic HNPCC-screening reveal neoplasia in 21% of the examinations and the colorectal cancers found by screening were at a more favourable Dukes stage compared to sporadic CRC, and probably also CRC found by general population screening. The HNPCC-Register initiates surveillance together with the clinical genetic departments, but the results of the recommended colonic examinations are not automatically reported to the HNPCC-Register. To enable an in-depth investigation of the effect of CRC-screening in all Danish HNPCC-families, further financial resources should be allocated to the HNPCC-Register to collect the results.

Surveillance for urinary tract cancer in Lynch syndrome.

Hereditary non-polyposis colorectal cancer (HNPCC) is an inherited multiorgan cancer syndrome, which when caused by a germline mutation in the mismatch repair (MMR) genes is known as Lynch syndrome (LS). Mutation carriers are at risk for developing cancers primarily in the colon, rectum and endometrium, but also other extra-colonic cancers. Urinary tract cancers (UTC) have in many studies been reported increased in LS and it has been discussed among researchers and clinicians whether or not screening for urological tumours should be included in the surveillance programme and if so what screening procedures are justifiable. The aim of this review was to elucidate the present knowledge from the literature on the risk of UTC in LS and highlight the pros and cons of screening for asymptomatic neoplasia in the urinary tract. The review is based on a systematic literature search in PubMed database followed by a reference list of retrieved articles and manual searches of further relevant articles. In conclusion there is a moderate increased risk of UTC in LS, but a tremendous lack of knowledge on which screening programme, if any at all to establish, and if so what procedures and time intervals are appropriate. It is recommended that all eventually screening for UTC in LS, only should be performed in clinical trials or with a systematic reporting to a HNPCC-register for future evaluation.