Evaluating Lynch syndrome in very early onset colorectal cancer probands without apparent polyposis

To characterize the frequency of germline mutations associated with Lynch syndrome and review the potential expanded differential diagnoses in very early onset colorectal cancer (CRC) cases without apparent polyposis. Retrospectively reviewed medical records of 96 probands with CRC diagnosed prior to age 36 from three cancer centers. Determined the frequency of germline mutations in probands meeting different clinical criteria used to identify Lynch syndrome. Three of 46 (6.5%) single case indicators (probands without additional personal or family history suspicious for Lynch syndrome) were identified to carry a deleterious or suspected deleterious mismatch repair (MMR) mutation compared with 10 of 19 (52.6%) in the cases meeting at least one additional revised Bethesda guideline, and 11 of 15 (73.3%) in the cases meeting Amsterdam criteria. Two families without MMR mutations were documented to have a germline APC or TP53 mutation after additional clinical features were identified. Our results suggest that single cases of CRC (those without additional personal or family history suspicious of Lynch syndrome) diagnosed prior to age 36 infrequently have identifiable MMR mutations, especially when compared to cases meeting additional criteria. Careful attention to evolving or additional clinical features is warranted and may lead to an alternate genetic diagnosis in families with early onset CRC.     

Lynch 综合征的诊治进展和家系管理*

Lynch 综合征（Lynch syndrome,LS）是遗传性结直肠癌中最常见（约占5%）的一类常染色体显性遗传病,错配修复基因的种系突变和微卫星不稳定是其区别于其他遗传性结直肠癌的两大特点。近年来,研究发现在诊断和治疗上,LS与散发性结直肠癌有一定的区别;此外除了患者本人的诊断和治疗,整个家系的管理也至关重要。此类疾病应当引起临床高度重视。本文对LS的最初定义、诊断标准和筛查标准的变迁、最新治疗进展和家系管理进行综述,旨在帮助临床了解LS,给予患者合理的治疗,以及对其家系成员适当的干预和监控,尽可能降低患癌风险。      

Comprehensive characterization of CRC with germline mutations reveals a distinct somatic mutational landscape and elevated cancer risk in the Chinese population

Objective: Hereditary colorectal cancer(CRC) accounts for approximately 5%–10% of all CRC cases. The full profile of CRC-related germline mutations and the corresponding somatic mutational profile have not been fully determined in the Chinese population.Methods: We performed the first population study investigating the germline mutation status in more than 1,000(n = 1,923) Chinese patients with CRC and examined their relationship with the somatic mutational landscape. Germline alterations were e...     

Clinical and histomolecular endometrial tumor characterization of patients at-risk for Lynch syndrome in South of Brazil

Lynch syndrome is an autosomal dominant cancer predisposition syndrome caused by germline mutations in one of the mismatch repair (MMR) genes: MLH1, MSH2, MSH6 and PMS2. Clinically, Lynch syndrome is characterized by early onset (45 years) of colorectal cancer (CRC), as well as extra-colonic cancer. Male and female carriers of Lynch syndrome-associated mutations have different lifetime risks for CRC and in women endometrial cancer (EC) may be the most common tumor. Whenever Amsterdam criteria are not fulfilled, the currently recommended laboratory screening strategies involve microsatellite instability testing and immunohistochemistry staining of the tumor for the major MMR proteins. The aim of this study was to estimate the frequency of MMR deficiencies in women diagnosed with EC who are at-risk for Lynch syndrome. Thirty women diagnosed with EC under the age of 50 years and/or women with EC and a first degree relative diagnosed with a Lynch syndrome-associated tumor were included. To assess MMR deficiencies four methods were used: multiplex PCR, Single Strand Conformation Polymorphism, Immunohistochemistry and Methylation Specific–Multiplex Ligation-dependent Probe Amplification. Twelve (40%) patients with EC fulfilling one of the inclusion criteria had results indicative of MMR deficiency. The identification of 5 women with clear evidence of MMR deficiency and absence of either Amsterdam or Bethesda criteria among 10 diagnosed with EC under the age of 50 years reinforces previous suggestions by some authors that these women should be considered at risk and always screened for Lynch syndrome after informed consent.     

Lynch syndrome and cervical cancer

Carriers of germline mutations in DNA mismatch repair (MMR) genes are at increased risk of several cancers including colorectal and gynecologic cancers (Lynch syndrome). There is no substantial evidence that these mutations are associated with an increased risk of cervical cancer. A total of 369 families with at least one carrier of a mutation in a MMR gene (133 MLH1, 174 MSH2, 35 MSH6 and 27 PMS2) were ascertained via population cancer registries or via family cancer clinics in Australia, New Zealand, Canada, and USA. Personal and family histories of cancer were obtained from participant interviews. Modified segregation analysis was used to estimate the hazard ratio (incidence rates for carriers relative to those for the general population), and age‐specific cumulative risks of cervical cancer for carriers. A total of 65 cases of cervical cancer were reported (including 10 verified by pathology reports). The estimated incidence was 5.6 fold (95% CI: 2.3–13.8; p = 0.001) higher for carriers than for the general population with a corresponding cumulative risk to 80 years of 4.5% (95% CI: 1.9–10.7%) compared with 0.8% for the general population. The mean age at diagnosis was 43.1 years (95% CI: 40.0–46.2), 3.9 years younger than the reported USA population mean of 47.0 years (p = 0.02). Women with MMR gene mutations were found to have an increased risk of cervical cancer. Due to limited pathology verification we cannot be certain that a proportion of these cases were not lower uterine segment endometrial cancers involving the endocervix, a recognized cancer of Lynch syndrome.     

What the physician needs to know about Lynch syndrome: an update

The Lynch syndrome (hereditary nonpolyposis colorectal cancer [HNPCC]), is the most common form of hereditary colorectal cancer (CRC), accounting for 2% to 7% of all CRC cases. The next most common hereditary CRC syndrome is familial adenomatous polyposis (FAP), which accounts for less than 1% of all CRC. Lynch syndrome is of crucial clinical importance due to the fact that it predicts the lifetime risk for CRC and a litany of extra-CRC cancers (of the endometrium, ovary, stomach, small bowel, hepatobiliary tract, upper uroepithelial tract, and brain) through assessment of a well-orchestrated family history. A Lynch syndrome diagnosis is almost certain when a mutation in a mismatch repair gene--most commonly MSH2, MLHI, or, to a lesser degree, MSH6--is identified. Once diagnosed, the potential for significant reduction in cancer-related morbidity and mortality through highly targeted surveillance may be profound. Particularly important is colonoscopy initiated at an early age (ie, 25 years) and repeated annually due to accelerated carcinogenesis. In women, endometrial aspiration biopsy and transvaginal ultrasound are important given the extraordinarily high risk for endometrial and ovarian carcinoma. These cancer control strategies have a major impact on at-risk family members once they have been counseled and educated thoroughly about Lynch syndrome's natural history and their own hereditary cancer risk.     

Young age and a positive family history of colorectal cancer are complementary selection criteria for the identification of Lynch syndrome

Families at high risk for Lynch syndrome can effectively be recognised by microsatellite instability (MSI) testing. The aim of the present study is to compare the effectiveness of a MSI test for the identification of Lynch syndrome in patients selected by a pathologist mainly based on young age at diagnosis (MSI-testing-indicated-by-a-Pathologist; MIPA), with that of patients selected by a clinical geneticist mainly based on family history (MSI-testing-indicated-by-Family-History; MIFH).Patients with a Lynch syndrome associated tumour were selected using MIPA (n = 362) or MIFH (n = 887). Germline DNA mutation testing was performed in 171 out of 215 patients (80%) with a MSI positive tumour.MSI was tested positive in 20% of the MIPA-group group compared to 16% in the MIFH-group (P = 0.291). In 91 of 171 patients with MSI positive tumours tested for germline mutations were identified as Lynch syndrome patients: 42% in the MIPA-group and 56% in the MIFH-group (P = 0.066). Colorectal cancer (CRC) or endometrial cancer (EC) presenting at an age below 50 years would have led to the diagnosis of Lynch syndrome in 89% of these families (CRC below 50 years: 88% and EC below 50 years: 12%). Families detected by MIPA were characterised more often by extracolonic Lynch syndrome associated malignancies, especially EC (P < 0.001).Our results indicate that recognition of Lynch syndrome by CRC or EC below 50 years is as effective as a positive family history. Families from patients selected by individual criteria more often harbour extracolonic Lynch syndrome associated malignancies.     

Population‐based detection of Lynch syndrome in young colorectal cancer patients using microsatellite instability as the initial test

Approximately 1–2% of colorectal cancers (CRC) arise because of germline mutations in DNA mismatch repair genes, referred to as Lynch syndrome. These tumours show microsatellite instability (MSI) and loss of expression of mismatch repair proteins. Pre‐symptomatic identification of mutation carriers has been demonstrated to improve survival; however, there is concern that many are not being identified using current practices. We evaluated population‐based MSI screening of CRC in young patients as a means of ascertaining mutation carriers. CRC diagnosed in patients aged <60 years were identified from pathology records. No prior information was available on family history of cancer. PCR techniques were used to determine MSI in the BAT‐26 mononucleotide repeat and mutation in the BRAF oncogene. Loss of MLH1, MSH2, MSH6 and PMS2 protein expression was evaluated in MSI+ tumours by immunohistochemistry. MSI+ tumours were found in 105/1,344 (7.8%) patients, of which 7 were excluded as possible Lynch syndrome because of BRAF mutation. Of the 98 “red flag” cases that were followed up, 25 were already known as mutation carriers or members of mutation carrier families. Germline test results were obtained for 35 patients and revealed that 22 showed no apparent mutation, 11 showed likely pathogenic mutations and 2 had unclassified variants. The proportion of MSI+ cases in different age groups that were estimated to be mutation carriers was 89% (<30 years), 83% (30–39), 68% (40–49) and 17% (50–59). We recommend MSI as the initial test for population‐based screening of Lynch syndrome in younger CRC patients, regardless of family history. © 2008 Wiley‐Liss, Inc.     

No evidence of genetic anticipation in a large family with Lynch syndrome

Lynch syndrome is the commonest inherited cause of colorectal cancer (CRC). Genetic anticipation occurs when the age of onset of a disorder decreases in successive generations. It is controversial whether this occurs in Lynch syndrome. Previous studies have included heterogenous groups of subjects from multiple families, including subjects with a clinical diagnosis (based on family history) as well as those with proven germline mismatch repair gene mutations. The purpose of this study was to determine whether genetic anticipation occurs in mismatch repair gene carriers from a single Lynch syndrome family. This study includes members of a single family known to carry an MLH1 gene mutation who are proven germline mutation carriers or obligate carriers (based on their offspring’s mutation status). Evidence of genetic anticipation (determined by age of onset of first CRC) was sought in two ways: Firstly, subjects were grouped as parent-child pairs and individuals were compared with their own offspring; secondly they were grouped by generation within the family tree. The Kaplan–Meier technique was used to adjust for variable follow up times. The family tree consisted of 714 subjects. Ninety-two subjects over five generations were included in the study. There was no evidence of genetic anticipation over the generations. (P = 0.37). Similarly, in the 75 parent–child pairs identified, age of onset of CRC was similar for parents and children (P = 0.51). We could not identify any evidence of genetic anticipation in mutation carriers from a single family with Lynch syndrome.     

Risk factors for metachronous colorectal cancer following a primary colorectal cancer: A prospective cohort study

Individuals diagnosed with colorectal cancer (CRC) are at risk of developing a metachronous CRC. We examined the associations between personal, tumour‐related and lifestyle risk factors, and risk of metachronous CRC. A total of 7,863 participants with incident colon or rectal cancer who were recruited in the USA, Canada and Australia to the Colon Cancer Family Registry during 1997‐2012, except those identified as high‐risk, for example, Lynch syndrome, were followed up approximately every 5 years. We estimated the risk of metachronous CRC, defined as the first new primary CRC following an interval of at least one year after the initial CRC diagnosis. Observation time started at the age at diagnosis of the initial CRC and ended at the age at diagnosis of the metachronous CRC, last contact or death whichever occurred earliest, or were censored at the age at diagnosis of any metachronous colorectal adenoma. Cox regression was used to derive hazard ratios (HRs) and 95% confidence intervals (CIs). During a mean follow‐up of 6.6 years, 142 (1.81%) metachronous CRCs were diagnosed (mean age at diagnosis 59.8; incidence 2.7/1,000 person‐years). An increased risk of metachronous CRC was associated with the presence of a synchronous CRC (HR = 2.73; 95% CI: 1.30–5.72) and the location of cancer in the proximal colon at initial diagnosis (compared with distal colon or rectum, HR = 4.16; 95% CI: 2.80–6.18). The presence of a synchronous CRC and the location of the initial CRC might be useful for deciding the intensity of surveillance colonoscopy for individuals diagnosed with CRC.     

Risk of breast cancer in Lynch syndrome: a systematic review

Introduction

Lynch syndrome is an autosomal dominantly inherited disorder of cancer susceptibility caused by germline mutations in the DNA mismatch repair (MMR) genes. Mutation carriers have a substantial burden of increased risks of cancers of the colon, rectum, endometrium and several other organs which generally occur at younger ages than for the general population. The issue of whether breast cancer risk is increased for MMR gene mutation carriers has been debated with evidence for and against this association.

Methods

Using the PUBMED, we identified all relevant studies of breast cancer associated with Lynch syndrome that were published by 15 December 2012. In the review, we included: (i) molecular studies that reported microsatellite instability and/or immunohistochemistry in breast cancer tumors of MMR gene mutation carriers; and (ii) risk studies that investigated risk of breast cancer for confirmed MMR gene mutation carriers or families or clinically and/or pathologically defined Lynch syndrome families.

Results

We identified 15 molecular studies and, when combined, observed 62 of 122 (51%; 95% CI 42 to 60%) breast cancers in MMR gene mutation carriers were MMR-deficient. Of the 21 risk studies identified, 13 did not observe statistical evidence for an association of breast cancer risk with Lynch syndrome while 8 studies found an increased risk of breast cancer ranging from 2- to 18-fold compared with the general population (or non-carriers). There is only one prospective study demonstrating an elevated risk of breast cancer for MMR gene mutation carriers compared with the general population (standardized incidence ratio 3.95; 95% CI 1.59, 8.13).

Conclusions

Since breast cancer is a relatively common disease in the general population, more precise estimates of risk and gene-specific risks will need to utilize large prospective cohort studies with a long follow-up. While current data are inconclusive at a population level, individual tumor testing results suggest that MMR deficiency is involved with breast cancers in some individuals with Lynch syndrome.     

Gynecologic cancers associated with Lynch syndrome/HNPCC

Lynch syndrome/hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal dominant inherited cancer susceptibility syndrome caused by a germline mutation in one of the deoxyribonucleic acid (DNA) mismatch repair genes. It is associated with early onset of cancer (age younger than 50 years) and the development of multiple cancer types, particularly colon and endometrial cancer. Women with Lynch syndrome have a 40-60% risk of endometrial cancer, which equals or exceeds their risk of colorectal cancer. In addition, they have a 12% risk of ovarian cancer. Despite limited information on the efficacy of surveillance in reducing endometrial and ovarian cancer risk in women with Lynch syndrome, the current gynecologic cancer screening guidelines include annual endometrial sampling and transvaginal ultrasonography beginning at age 30-35 years. In addition, risk-reducing surgery consisting of prophylactic hysterectomy and bilateral salpingooophorectomy should be offered to women aged 35 years or older who do not wish to preserve their fertility.     

Evaluation of predictive models in daily practice for the identification of patients with Lynch syndrome

The optimal strategy for identifying patients with Lynch syndrome among patients with newly diagnosed colorectal cancer (CRC) is still debated. Several predictive models (e.g., MMRpredict, PREMM1,2 and MMRpro) combining personal and familial data have recently been developed to quantify the risk that a given patient with CRC carries a Lynch syndrome-causing mutation. Their clinical applicability to patients with CRC from the general population requires evaluation. We studied a consecutive series of 214 patients with newly diagnosed CRC characterized for tumor microsatellite instability (MSI), somatic BRAF mutation, MLH1 promoter methylation and mismatch repair (MMR) gene germline mutation status. The performances of the models for identifying MMR mutation carriers (8/214, 3.7%) were evaluated and compared to the revised Bethesda guidelines and a molecular strategy based on MSI testing in all patients followed by the exclusion of MSI-positive sporadic cases from mutational testing by screening for BRAF mutation and MLH1 promoter methylation. The sensitivities of the three models, at the lowest thresholds proposed, were identical (75%), with similar numbers of probands eligible for further MSI testing (almost half the patients). In our dataset, the prediction models gave no better discrimination than the revised Bethesda guidelines. Both approaches failed to identify two of the eight mutation carriers (the same two patients, aged 67 and 81 years, both with no family history). Thus, like the revised Bethesda guidelines, predictive models did not identify all patients with Lynch syndrome in our series of consecutive CRC. Our results support systematic screening for MMR deficiency in all new CRC cases.     

Three molecular pathways model colorectal carcinogenesis in Lynch syndrome

Lynch syndrome is caused by germline mutations of DNA mismatch repair (MMR) genes. MMR deficiency has long been regarded as a secondary event in the pathogenesis of Lynch syndrome colorectal cancers. Recently, this concept has been challenged by the discovery of MMR‐deficient crypt foci in the normal mucosa. We aimed to reconstruct colorectal carcinogenesis in Lynch syndrome by collecting molecular and histology evidence from Lynch syndrome adenomas and carcinomas. We determined the frequency of MMR deficiency in adenomas from Lynch syndrome mutation carriers by immunohistochemistry and by systematic literature analysis. To trace back the pathways of pathogenesis, histological growth patterns and mutational signatures were analyzed in Lynch syndrome colorectal cancers. Literature and immunohistochemistry analysis demonstrated MMR deficiency in 491 (76.7%) out of 640 adenomas (95% CI: 73.3% to 79.8%) from Lynch syndrome mutation carriers. Histologically normal MMR‐deficient crypts were found directly adjacent to dysplastic adenoma tissue, proving their role as tumor precursors in Lynch syndrome. Accordingly, mutation signature analysis in Lynch colorectal cancers revealed that KRAS and APC mutations commonly occur after the onset of MMR deficiency. Tumors lacking evidence of polypous growth frequently presented with CTNNB1 and TP53 mutations. Our findings demonstrate that Lynch syndrome colorectal cancers can develop through three pathways, with MMR deficiency commonly representing an early and possibly initiating event. This underlines that targeting MMR‐deficient cells by chemoprevention or vaccines against MMR deficiency‐induced frameshift peptide neoantigens holds promise for tumor prevention in Lynch syndrome.     

Association between tubal ligation and endometrial cancer risk: A Swedish population‐based cohort study

Tubal ligation results in less advanced stages and lower risk of metastatic spread at diagnosis of endometrial cancer (EC) but the primary preventive effect of the procedure is unclear. In a Swedish nationwide population‐based cohort study, we crosslinked registry data for tubal ligation, EC, and death for Swedish women between 1973 and 2010. All women were followed until EC, emigration, hysterectomy for non‐cancerous reasons, death, or end of follow‐up. Primary outcome was incidence of EC and secondary outcome overall survival. We calculated adjusted incidence rates (IR) per 100,000 person‐years and hazard ratios (HR) using Cox regression models. A total of 35,711 cases of EC were identified among 5,385,186 women. The IR of EC among exposed was 17.7 (95% CI 15.7–19.9) versus 29.0 (95% CI 28.7–29.3) among unexposed (per 100,000 women years). Exposed individuals had significantly reduced risk of EC (HR 0.73, 95% CI 0.65–0.83). The mortality rate among women with EC was 72% lower in exposed compared to unexposed (IR 1,441; 95% CI 1,089–1,907 and IR 5,136; 95% CI 5,065–5,209, respectively) which following adjustment corresponded to a HR of 0.71 (95% CI 0.49–1.03). Tubal ligation was associated with lower risk of EC as well as mortality rates in women with EC. Elective tubal ligation may be adopted in future cancer preventive strategies but must be balanced against the irreversibility of the procedure, which preclude further unassisted reproduction.     

Small-bowel cancer in Lynch syndrome: is it time for surveillance?

Small-bowel cancer is part of the tumour spectrum of Lynch syndrome. Lynch syndrome, or hereditary non-polyposis colorectal cancer, is caused by germline mutations in one of the mismatch repair genes. Mutation carriers have an estimated lifetime risk for the development of small-bowel cancer of around 4%, corresponding to a relative risk of more than 100 compared with the general population. Patients with Lynch syndrome generally present with small-bowel cancer 10-20 years earlier than the general population, and small-bowel cancer might be the first clinical manifestation of Lynch syndrome. Tumours in patients with Lynch syndrome are evenly distributed within the small bowel. No specific risk factors, such as type of gene mutation, have been identified thus far. Screening for small-bowel cancer in Lynch syndrome has, until now, not been included in guidelines for surveillance, which might partly be due to the fact that, until recently, the possibilities for visualisation of the small bowel were limited. In view of the improved accessibility of the small bowel with the introduction of capsule endoscopy and double balloon enteroscopy, the question of whether patients should be screened for small-bowel neoplasia has regained attention. In this paper, we discuss the rationale for surveillance of small-bowel cancer in Lynch syndrome and highlight issues that need to be addressed in future studies before recommendations can be made.     

Performance of Lynch syndrome predictive models in quantifying the likelihood of germline mutations in patients with abnormal MLH1 immunoexpression

Lynch syndrome (LS) accounts for up to 4 % of all colorectal cancers (CRC). Detection of a pathogenic germline mutation in one of the mismatch repair genes is the definitive criterion for LS diagnosis, but it is time-consuming and expensive. Immunohistochemistry is the most sensitive prescreening test and its predictive value is very high for loss of expression of MSH2, MSH6, and (isolated) PMS2, but not for MLH1. We evaluated if LS predictive models have a role to improve the molecular testing algorithm in this specific setting by studying 38 individuals referred for molecular testing and who were subsequently shown to have loss of MLH1 immunoexpression in their tumors. For each proband we calculated a risk score, which represents the probability that the patient with CRC carries a pathogenic MLH1 germline mutation, using the PREMM_1,2,6 and MMRpro predictive models. Of the 38 individuals, 18.4 % had a pathogenic MLH1 germline mutation. MMRpro performed better for the purpose of this study, presenting a AUC of 0.83 (95 % CI 0.67–0.9; P < 0.001) compared with a AUC of 0.68 (95 % CI 0.51–0.82, P = 0.09) for PREMM_1,2,6. Considering a threshold of 5 %, MMRpro would eliminate unnecessary germline mutation analysis in a significant proportion of cases while keeping very high sensitivity. We conclude that MMRpro is useful to correctly predict who should be screened for a germline MLH1 gene mutation and propose an algorithm to improve the cost-effectiveness of LS diagnosis.     

Mutation and association analyses of the candidate genes ESR1, ESR2, MAX, PCNA, and KAT2A in patients with unexplained MSH2-deficient tumors

Lynch syndrome (Hereditary non-polyposis colorectal cancer/HNPCC) is a cancer susceptibility syndrome which is caused by germline mutations in DNA mismatch repair (MMR) genes, in particular MLH1 and MSH2. A pathogenic germline mutation in the respective MMR gene is suggested by the finding of a loss of a mismatch repair protein in tumor tissue on immunohistochemical staining combined with an early age of onset and/or the familial occurrence of colorectal cancer. Pathogenic germline mutations are identifiable in around 60% of patients suspected of Lynch syndrome, depending on the familial occurrence. The aim of the present study was to identify novel susceptibility genes for Lynch syndrome. 64 Healthy controls and 64 Lynch syndrome patients with no pathogenic MSH2 mutation but a loss of MSH2 expression in their tumor tissue were screened for rare and disease causing germline mutations in the functional candidate genes ESR1, ESR2, MAX, PCNA, and KAT2A. Thirty variants were identified, and these were then genotyped in an independent sample of 36 mutation negative Lynch syndrome patients and 234 controls. Since a trend towards association was observed for KAT2A, an additional set of 21 tagging SNPs was analyzed at this locus in a final case-control sample of 142 mutation negative Lynch syndrome patients and 298 controls. The mutation analysis failed to reveal any rare disease-causing mutations. No association was found at the single-marker or haplotypic level for any common disease-modifying variant. The present results suggest that neither rare nor common genetic variants in ESR1, ESR2, MAX, PCNA, or KAT2A contribute to the development of Lynch syndrome.     

Causes of death of mutation carriers in Finnish Lynch syndrome families

Lynch syndrome (LS) is an autosomal dominant cancer syndrome including increased life-long risk for colorectal (CRC) and endometrial (EC) cancer, but also for cancers of other types. The risk for CRC is up to 70–80?% and for EC up to 50–60?%. Due to screening and early diagnosing the mortality related to CRC and EC seems to be low. In spite of many studies on surveillance of mutation carriers, there is no comprehensive evaluation on causes of death in LS families. The disease history and cause of death of all the deceased, tested mutation carriers and their mutation negative relatives in the Finnish LS families (N?=?179) was examined utilizing hospital records and relevant national registries. Out of 1069 mutation carriers 151 had succumbed; 97 (64?%) from cancer. Out of 1146 mutation-negative family 44 members had died; 11 (25?%) of them from cancer. In 12 (7.7?%) of the deceased mutation carriers no cancer had been diagnosed. The mean age of death from cancer was 63.2?years vs. 68.8?years from non-cancer causes. Only 7.9?% of the patients with CRC had died from CRC and 5?% of those with EC, respectively. 61?% of the cancer deaths were related to extra-colonic, extra-endometrial cancers. The cumulative overall and cancer specific death rates were significantly increased in Mut+ compared to Mut? family members. Even surveillance yields decrease in the life-long risk and mortality of the most common cancers CRC and EC in LS, almost all mutation carriers will contract with cancer, and two thirds of the deceased have died from cancer. This should be taken in account in genetic counseling. Mutation carriers should be encouraged to seek help for abnormal symptoms.     

Is breast cancer a part of Lynch syndrome?

ABSTRACT: A long-standing question is whether breast cancer is an integral part of Lynch syndrome, also known as hereditary non-polyposis colorectal cancer. A recent study by Lotsari and colleagues analyzes molecular features of breast cancers from families with Lynch syndrome, including germline mutation carriers and their non-mutation carrier siblings, and controls with sporadic breast cancer. The study finds microsatellite instability and loss of mismatch DNA repair protein expression in one third and two thirds of Lynch syndrome samples, respectively, but in none of the non-mutation carriers or controls. Overall, the age of diagnosis of breast cancer in Lynch syndrome mutation carriers is no different than that in non-carriers, but diagnosis age was lower in those carriers whose breast tumors exhibited defects in mismatch repair. These results have important implications for genetic counseling and genetic testing of families with breast cancer and other tumors associated with Lynch syndrome, such as colorectal and endometrial cancers.