Cancer incidence and survival in Lynch syndrome patients receiving colonoscopic and gynaecological surveillance : first report from the prospective Lynch syndrome database

Objective Estimates of cancer risk and the effects of surveillance in Lynch syndrome have been subject to bias, partly through reliance on retrospective studies. We sought to establish more robust estimates in patients undergoing prospective cancer surveillance. Design We undertook a multicentre study of patients carrying Lynch syndrome-associated mutations affecting MLH1, MSH2, MSH6 or PMS2. Standardised information on surveillance, cancers and outcomes were collated in an Oracle relational database and analysed by age, sex and mutated gene. Results 1942 mutation carriers without previous cancer had follow-up including colonoscopic surveillance for 13 782 observation years. 314 patients developed cancer, mostly colorectal (n=151), endometrial (n=72) and ovarian (n=19). Cancers were detected from 25 years onwards in MLH1 and MSH2 mutation carriers, and from about 40 years in MSH6 and PMS2 carriers. Among first cancer detected in each patient the colorectal cancer cumulative incidences at 70 years by gene were 46%, 35%, 20% and 10% for MLH1, MSH2, MSH6 and PMS2 mutation carriers, respectively. The equivalent cumulative incidences for endometrial cancer were 34%, 51%, 49% and 24%; and for ovarian cancer 11%, 15%, 0% and 0%. Ten-year crude survival was 87% after any cancer, 91% if the first cancer was colorectal, 98% if endometrial and 89% if ovarian. Conclusions The four Lynch syndrome-associated genes had different penetrance and expression. Colorectal cancer occurred frequently despite colonoscopic surveillance but resulted in few deaths. Using our data, a website has been established at http://LScarisk.org enabling calculation of cumulative cancer risks as an aid to genetic counselling in Lynch syndrome.Peer reviewe

Cancer risks by gene, age, and gender in 6350 carriers of pathogenic mismatch repair variants:findings from the Prospective Lynch Syndrome Database

Purpose Pathogenic variants affecting MLH1, MSH2, MSH6, and PMS2 cause Lynch syndrome and result in different but imprecisely known cancer risks. This study aimed to provide age and organ-specific cancer risks according to gene and gender and to determine survival after cancer. Methods We conducted an international, multicenter prospective observational study using independent test and validation cohorts of carriers of class 4 or class 5 variants. After validation the cohorts were merged providing 6350 participants and 51,646 follow-up years. Results There were 1808 prospectively observed cancers. Pathogenic MLH1 and MSH2 variants caused high penetrance dominant cancer syndromes sharing similar colorectal, endometrial, and ovarian cancer risks, but older MSH2 carriers had higher risk of cancers of the upper urinary tract, upper gastrointestinal tract, brain, and particularly prostate. Pathogenic MSH6 variants caused a sex-limited trait with high endometrial cancer risk but only modestly increased colorectal cancer risk in both genders. We did not demonstrate a significantly increased cancer risk in carriers of pathogenic PMS2 variants. Ten-year crude survival was over 80% following colon, endometrial, or ovarian cancer. Conclusion Management guidelines for Lynch syndrome may require revision in light of these different gene and gender-specific risks and the good prognosis for the most commonly associated cancers

Cancer risks by gene, age, and gender in 6350 carriers of pathogenic mismatch repair variants: findings from the Prospective Lynch Syndrome Database

*Shared first authorship (Dominguez-V M, Sampson J, Seppälä T)PURPOSE: Pathogenic variants affecting MLH1, MSH2, MSH6, and PMS2 cause Lynch syndrome and result in different but imprecisely known cancer risks. This study aimed to provide age and organ-specific cancer risks according to gene and gender and to determine survival after cancer. METHODS: We conducted an international, multicenter prospective observational study using independent test and validation cohorts of carriers of class 4 or class 5 variants. After validation the cohorts were merged providing 6350 participants and 51,646 follow-up years. RESULTS: There were 1808 prospectively observed cancers. Pathogenic MLH1 and MSH2 variants caused high penetrance dominant cancer syndromes sharing similar colorectal, endometrial, and ovarian cancer risks, but older MSH2 carriers had higher risk of cancers of the upper urinary tract, upper gastrointestinal tract, brain, and particularly prostate. Pathogenic MSH6 variants caused a sex-limited trait with high endometrial cancer risk but only modestly increased colorectal cancer risk in both genders. We did not demonstrate a significantly increased cancer risk in carriers of pathogenic PMS2 variants. Ten-year crude survival was over 80% following colon, endometrial, or ovarian cancer. CONCLUSION: Management guidelines for Lynch syndrome may require revision in light of these different gene and gender-specific risks and the good prognosis for the most commonly associated cancers.Peer reviewe

CHARACTERISTICS OF INDIVIDUALS UNDERGOING PANEL GENETIC TESTING FOR PRIMARY BRAIN TUMORS

Background. Currently, there are no genetic testing guidelines for patients with a primary brain tumor (PBT). This population is largely understudied in terms of the family history, tumor grade, pathology, and their relation to genetic contribution. Our aim was to describe patient-specific characteristics and family histories across mutation-positive, negative, and variant of uncertain significance (VUS) cohorts based on cancer-panel genetic test results among patients with a PBT. Methods. Subjects were referred for multi-gene panel testing between March 2012 and June 2016. Clinical data were ascertained from test requisition forms. The incidence of pathogenic mutations (including likely pathogenic) and VUS’s were calculated for each gene and patient cohort. Results. Almost all tumors were glial (n=293, 53%) or meningeal pathology (n=222, 40%). Age of diagnosis differed significantly between glial and meningeal tumors (pCHEK2 (20/104), BRCA2 (13/104), PMS2 (10/104), TP53 (8/104), and APC (8/104). Of 165 patients with available family history information, nearly all (n=157, 95%) reported a family history of some cancer. Conclusions. Our data suggest PBTs can be the primary presenting cancer in hereditary syndromes with a known PBT risk. While pathology is helpful in narrowing down the differential diagnosis, patients’ pathology can be atypical in relation to their hereditary cancer syndrome. Family history evaluations are a beneficial risk assessment modality, particularly until testing criteria are developed for PBTs. Further research is necessary for the development of genetic testing criteria in the PBT population and more robust identification of at-risk individuals

A model-based assessment of the cost-utility of strategies to identify Lynch syndrome in early-onset colorectal cancer patients.

This is a freely-available open access publication. Please cite the published version which is available via the DOI link in this record.BACKGROUND: Lynch syndrome is an autosomal dominant cancer predisposition syndrome caused by mutations in the DNA mismatch repair genes MLH1, MSH2, MSH6 and PMS2. Individuals with Lynch syndrome have an increased risk of colorectal cancer, endometrial cancer, ovarian and other cancers. Lynch syndrome remains underdiagnosed in the UK. Reflex testing for Lynch syndrome in early-onset colorectal cancer patients is proposed as a method to identify more families affected by Lynch syndrome and offer surveillance to reduce cancer risks, although cost-effectiveness is viewed as a barrier to implementation. The objective of this project was to estimate the cost-utility of strategies to identify Lynch syndrome in individuals with early-onset colorectal cancer in the NHS. METHODS: A decision analytic model was developed which simulated diagnostic and long-term outcomes over a lifetime horizon for colorectal cancer patients with and without Lynch syndrome and for relatives of those patients. Nine diagnostic strategies were modelled which included microsatellite instability (MSI) testing, immunohistochemistry (IHC), BRAF mutation testing (methylation testing in a scenario analysis), diagnostic mutation testing and Amsterdam II criteria. Biennial colonoscopic surveillance was included for individuals diagnosed with Lynch syndrome and accepting surveillance. Prophylactic hysterectomy with bilateral salpingo-oophorectomy (H-BSO) was similarly included for women diagnosed with Lynch syndrome. Costs from NHS and Personal Social Services perspective and quality-adjusted life years (QALYs) were estimated and discounted at 3.5% per annum. RESULTS: All strategies included for the identification of Lynch syndrome were cost-effective versus no testing. The strategy with the greatest net health benefit was MSI followed by BRAF followed by diagnostic genetic testing, costing £5,491 per QALY gained over no testing. The effect of prophylactic H-BSO on health-related quality of life (HRQoL) is uncertain and could outweigh the health benefits of testing, resulting in overall QALY loss. CONCLUSIONS: Reflex testing for Lynch syndrome in early-onset colorectal cancer patients is predicted to be a cost-effective use of limited financial resources in England and Wales. Research is recommended into the cost-effectiveness of reflex testing for Lynch syndrome in other associated cancers and into the impact of prophylactic H-BSO on HRQoL.NIH

Comprehensive population-wide analysis of Lynch syndrome in Iceland reveals founder mutations in MSH6 and PMS2.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked FilesLynch syndrome, caused by germline mutations in the mismatch repair genes, is associated with increased cancer risk. Here using a large whole-genome sequencing data bank, cancer registry and colorectal tumour bank we determine the prevalence of Lynch syndrome, associated cancer risks and pathogenicity of several variants in the Icelandic population. We use colorectal cancer samples from 1,182 patients diagnosed between 2000-2009. One-hundred and thirty-two (11.2%) tumours are mismatch repair deficient per immunohistochemistry. Twenty-one (1.8%) have Lynch syndrome while 106 (9.0%) have somatic hypermethylation or mutations in the mismatch repair genes. The population prevalence of Lynch syndrome is 0.442%. We discover a translocation disrupting MLH1 and three mutations in MSH6 and PMS2 that increase endometrial, colorectal, brain and ovarian cancer risk. We find thirteen mismatch repair variants of uncertain significance that are not associated with cancer risk. We find that founder mutations in MSH6 and PMS2 prevail in Iceland unlike most other populations.Ohio State University (OSU) Comprehensive Cancer Center OSU Colorectal Cancer Research fund Obrine-Weaver Fund Pelotonia Fellowship Award deCODE genetic

BRIP-1 germline mutation and its role in colon cancer: presentation of two case reports and review of literature.

BackgroundHereditary colon cancer is characterized by the inheritance of an abnormal gene mutation which predisposes to malignancy. Recent advances in genomic medicine have identified mutations in "novel" genes as conferring an increased risk of colorectal cancer. Mutations in the BRIP1 gene (BRCA1 Interacting Protein C- terminal helicase 1) are known to increase the risk of ovarian and breast cancers, but this genes association with colon cancer has not been previously reported.Case presentationWe describe two patients with colon cancer whose tumor tissue were found to harbor BRIP1 mutations on analysis by next-generation sequencing. These patients were confirmed by analysis of lymphocytes to carry the mutation in the germline as well.ConclusionsThese case reports highlight a previously unreported association of BRIP1 germline mutations with colon cancer predisposition

SNP association study in PMS2-associated Lynch syndrome

Lynch syndrome (LS) patients are at high risk of developing colorectal cancer (CRC). Phenotypic variability might in part be explained by common susceptibility loci identified in Genome Wide Association Studies (GWAS). Previous studies focused mostly on MLH1, MSH2 and MSH6 carriers, with conflicting results. We aimed to determine the role of GWAS SNPs in PMS2 mutation carriers. A cohort study was performed in 507 PMS2 carriers (124 CRC cases), genotyped for 24 GWAS SNPs, including SNPs at 11q23.1 and 8q23.3. Hazard ratios (HRs) were calculated using a weighted Cox regression analysis to correct for ascertainment bias. Discrimination was assessed with a concordance statistic in a bootstrap cross-validation procedure. Individual SNPs only had non-significant associations with CRC occurrence with HRs lower than 2, although male carriers of allele A at rs1321311 (6p21.31) may have increased risk of CRC (HR = 2.1, 95% CI 1.2–3.0). A polygenic risk score (PRS) based on 24 HRs had an HR of 2.6 (95% CI 1.5–4.6) for the highest compared to the lowest quartile, but had no discriminative ability (c statistic 0.52). Previously suggested SNPs do not modify CRC risk in PMS2 carriers. Future large studies are needed for improved risk stratification among Lynch syndrome patients

Clinical aspects of Lynch syndrome

Colorectal cancer is the second most common cancer in women and the third most common cancer in men worldwide, with 1.8 million new cases and almost 861000 deaths in 2018. Approximately 5–10% of the annual CRC burden can be attributed to inherited high risk germline mutations. The most common inherited colon cancer syndrome is Lynch syndrome, which accounts for up to 5% of all CRCs. Lynch syndrome displays both genotypic and phenotypic heterogeneity and can be suspected on the basis of a strong family history of colorectal- or endometrial cancer, but also of other tumors. Genetic counselling is recommended for families with Lynch syndrome, to provide the patient and family members with information about cancers risk and options for surveillance and management. In paper I we compared disease associated haplotypes in families from Sweden, Germany and France, all carrying the MLH1 mutation c.2059C>T, in order to elucidate if this is a founder mutation. When analyzing the haplotype in the families with Swedish descent, a shared region of approximately 0.9–2.8 Mb was identified. The MLH1 c.2059C>T mutation thus act as a founder in the Swedish population, but is also found in Europe, Asia and Australia, indicating that this is a recurring mutation globally albeit with a very low allele frequency. In paper II and III we investigated if genetic anticipation was part of the clinical picture in a Swedish cohort of Lynch syndrome families, as well as in a larger European cohort of PMS2 mutation carriers. In paper II, a total 1003 proven mutation carriers from 239 families with Lynch syndrome were included. An anticipation effect of 2,55 years and hazard rate of 1.33 between generations was seen in families with MSH2 mutation. In addition, an anticipation effect of 7.33 years and a hazard ration of 1.86 per generation was shown in families with PMS2 mutation. In paper III, 637 individuals from 123 families with PMS2 mutation were recruited from Netherlands, Norway, Germany, Denmark, Spain, including the Swedish PMS2 patients in paper II. Participants were assigned mutation probabilities in cases of unknown carrier status. As opposed to the result in paper II, an anticipation effect initially shown in a crude analysis was no longer statistically significant when corrections were made for gender and birth cohort. In paper IV we characterized the tumor spectrum, excluding colorectal- and endometrial cancers, in a nationwide cohort of 235 Swedish Lynch syndrome families. Data was stratified for gender, primary cancer, age, and mutated gene. Relative proportions of specific cancer types were compared to corresponding proportions in the reference population from the national Swedish Cancer Registry. Individuals of both sexes in our cohort had a higher proportion of gastric cancer, small bowel cancer and urinary tract cancer compared to the general population. In female mutation carriers, the proportion of ovarian cancer and non-melanoma skin cancer was increased compared to the general population