Recommendations to improve identification of hereditary and familial colorectal cancer in Europe

The genetic landscape of Lynch syndrome in the Israeli population

Deciphering the spectrum and founder disease-causing variants (DCVs) in specific populations can shape and facilitate the diagnostic process of Lynch Syndrome (LS). The aim of this report was to comprehensively update on the genetic landscape of LS in the ethnically diverse Israeli-Jewish population. The cohort included 1080 carriers from 588 families; some from underrepresented, understudied Israeli ethnic groups recruited from 8 genetic institutes and high-risk clinics throughout the country. Variant classification was performed according to the American College of Medical Genetics criteria. A total of 157 DCVs were identified, 12 are reported here for the first time, and 9 reclassified. MSH2 DCVs were identified in 286 families (49%). Most DCVs (125/157, 80%) were noted in one or two families only. Sixteen DCVs, each detected in ≥ 5 families, and accounted for LS in 378/588 (64%) families. Constitutional mismatch repair deficiency (CMMRD) was diagnosed in 7 families. Twenty-five carriers (2.3%) had an additional DCV or risk alleles in another cancer susceptibility gene. In conclusion, MMR gene variant distribution in Israel is diverse. MSH2 is most commonly mutated due to founder DCVs. Though the 16 prevalent LS-associated DCVs were frequently detected in our cohort, none of them is frequently reported in the general population. These data should facilitate variant interpretation, spouse and cascade testing.

Identification of people with Lynch syndrome from those presenting with colorectal cancer in England: baseline analysis of the diagnostic pathway

It is believed that >95% of people with Lynch syndrome (LS) remain undiagnosed. Within the National Health Service (NHS) in England, formal guidelines issued in 2017 state that all colorectal cancers (CRC) should be tested for DNA Mismatch Repair deficiency (dMMR). We used a comprehensive population-level national dataset to analyse implementation of the agreed diagnostic pathway at a baseline point 2 years post-publication of official guidelines. Using real-world data collected and curated by the National Cancer Registration and Analysis Service (NCRAS), we retrospectively followed up all people diagnosed with CRC in England in 2019. Nationwide laboratory diagnostic data incorporated somatic (tumour) testing for dMMR (via immunohistochemistry or microsatellite instability), somatic testing for MLH1 promoter methylation and BRAF status, and constitutional (germline) testing of MMR genes. Only 44% of CRCs were screened for dMMR; these figures varied over four-fold with respect to geography. Of those CRCs identified as dMMR, only 51% underwent subsequent diagnostic testing. Overall, only 1.3% of patients with colorectal cancer had a germline MMR genetic test performed; up to 37% of these tests occurred outside of NICE guidelines. The low rates of molecular diagnostic testing in CRC support the premise that Lynch syndrome is underdiagnosed, with significant attrition at all stages of the testing pathway. Applying our methodology to subsequent years' data will allow ongoing monitoring and analysis of the impact of recent investment. If the diagnostic guidelines were fully implemented, we estimate that up to 700 additional people with LS could be identified each year.

Immunotherapy-related biomarkers: Confirmations and uncertainties

Immunotherapy profoundly changed oncology treatment, becoming one of the main therapeutical strategies. Remarkable improvement has been achieved in survival outcomes, but the percentage of patients who benefit from immunotherapy is still limited. Only one-third of patients receiving immune checkpoint inhibitors (ICIs) achieve long-term response. Several patients are not responsive to treatment or relapse after an initial response. To date, programmed death-ligand 1, microsatellite instability, and tumor mutational burden are the three biomarkers validated to predict the ICIs response, but a single variable seems still insufficient in the patient's selection. Considering the substantial and increasing use of these drugs, the identification of new predictive biomarkers of ICI response is of paramount importance. We summarize the state of the art and the clinical use of immune biomarkers in oncology, highlighting the strength and weaknesses of currently approved biomarkers, describing the emerging tissues and circulating biomarkers, and outlining future perspectives.

Dominantly inherited micro-satellite instable cancer - the four Lynch syndromes - an EHTG, PLSD position statement

The recognition of dominantly inherited micro-satellite instable (MSI) cancers caused by pathogenic variants in one of the four mismatch repair (MMR) genes MSH2, MLH1, MSH6 and PMS2 has modified our understanding of carcinogenesis. Inherited loss of function variants in each of these MMR genes cause four dominantly inherited cancer syndromes with different penetrance and expressivities: the four Lynch syndromes. No person has an "average sex "or a pathogenic variant in an "average Lynch syndrome gene" and results that are not stratified by gene and sex will be valid for no one. Carcinogenesis may be a linear process from increased cellular division to localized cancer to metastasis. In addition, in the Lynch syndromes (LS) we now recognize a dynamic balance between two stochastic processes: MSI producing abnormal cells, and the host's adaptive immune system's ability to remove them. The latter may explain why colonoscopy surveillance does not reduce the incidence of colorectal cancer in LS, while it may improve the prognosis. Most early onset colon, endometrial and ovarian cancers in LS are now cured and most cancer related deaths are after subsequent cancers in other organs. Aspirin reduces the incidence of colorectal and other cancers in LS. Immunotherapy increases the host immune system's capability to destroy MSI cancers. Colonoscopy surveillance, aspirin prevention and immunotherapy represent major steps forward in personalized precision medicine to prevent and cure inherited MSI cancer.

The MSH2 c.793-1G>A variant disrupts normal splicing and is associated with Lynch syndrome

Instruction

Lynch syndrome (LS) is the most common inherited cancer predisposition disorder of colorectal cancer (CRC) which is associated with pathogenic variants in 4 mismatch repair (MMR) genes. Here, we reported a multi-generation Chinese family clinically diagnosed with LS.

Methods

To identify the underlying pathogenic gene variants, 30 whole blood samples and 4 colorectal cancer tissue samples and their clinical data were obtained from this four-generation family. Microsatellite instability-high (MSI) testing, immunohistochemistry (IHC), and Whole-Exome Sequencing (WES) were performed to identify the MMR/MSI and the underlying gene variants. The minigene splicing assay and in vitro splicing assay were used to explore the function of this variant.

Results

MSI-H and dMMR was revealed by the MSI testing and IHC, Whole-Exome Sequencing (WES) in 3 patients successfully identified a splicing variant (c.793-1G>A) in intron 4 of MSH2. Sanger sequencing validated the WES results, and all the "healthy" individuals carrying the variant have been identified in the family by PCR. Bioinformatics analysis and in vitro minigene assay showed that the pathogenic variant affected the splicing process of MSH2 gene to generate 2 kinds defective transcription products, and consequently reduced the expression of MSH2 protein. The mutation carriers were later recommended for colonoscopy and other important cancer diagnostic inspections every 1-2 years because they both have a higher risk of LS.

Discussion

We found a pathogenic splicing variant (rs863225397, c.793-1G>A) of MSH2 gene, and furtherly confirmed that this mutation plays an important role in LS patients of this pedigree based on the vitro study. Our study indicates that one splicing mutation in the MSH2 gene (c.793-1G>A) causes LS and highlights the importance of LS gene testing.

Lynch syndrome cancer vaccines: A roadmap for the development of precision immunoprevention strategies

Hereditary cancer syndromes (HCS) account for 5~10% of all cancer diagnosis. Lynch syndrome (LS) is one of the most common HCS, caused by germline mutations in the DNA mismatch repair (MMR) genes. Even with prospective cancer surveillance, LS is associated with up to 50% lifetime risk of colorectal, endometrial, and other cancers. While significant progress has been made in the timely identification of germline pathogenic variant carriers and monitoring and early detection of precancerous lesions, cancer-risk reduction strategies are still centered around endoscopic or surgical removal of neoplastic lesions and susceptible organs. Safe and effective cancer prevention strategies are critically needed to improve the life quality and longevity of LS and other HCS carriers. The era of precision oncology driven by recent technological advances in tumor molecular profiling and a better understanding of genetic risk factors has transformed cancer prevention approaches for at-risk individuals, including LS carriers. MMR deficiency leads to the accumulation of insertion and deletion mutations in microsatellites (MS), which are particularly prone to DNA polymerase slippage during DNA replication. Mutations in coding MS give rise to frameshift peptides (FSP) that are recognized by the immune system as neoantigens. Due to clonal evolution, LS tumors share a set of recurrent and predictable FSP neoantigens in the same and in different LS patients. Cancer vaccines composed of commonly recurring FSP neoantigens selected through prediction algorithms have been clinically evaluated in LS carriers and proven safe and immunogenic. Preclinically analogous FSP vaccines have been shown to elicit FSP-directed immune responses and exert tumor-preventive efficacy in murine models of LS. While the immunopreventive efficacy of "off-the-shelf" vaccines consisting of commonly recurring FSP antigens is currently investigated in LS clinical trials, the feasibility and utility of personalized FSP vaccines with individual HLA-restricted epitopes are being explored for more precise targeting. Here, we discuss recent advances in precision cancer immunoprevention approaches, emerging enabling technologies, research gaps, and implementation barriers toward clinical translation of risk-tailored prevention strategies for LS carriers. We will also discuss the feasibility and practicality of next-generation cancer vaccines that are based on personalized immunogenic epitopes for precision cancer immunoprevention.

PMS2-associated Lynch syndrome: Past, present and future

Carriers of any pathogenic variant in one of the MMR genes (path_MMR carriers) were traditionally thought to be at comparable risk of developing a range of different malignancies, foremost colorectal cancer (CRC) and endometrial cancer. However, it is now widely accepted that their cancer risk and cancer spectrum range notably depending on which MMR gene is affected. Moreover, there is increasing evidence that the MMR gene affected also influences the molecular pathogenesis of Lynch syndrome CRC. Although substantial progress has been made over the past decade in understanding these differences, many questions remain unanswered, especially pertaining to path_PMS2 carriers. Recent findings show that, while the cancer risk is relatively low, PMS2-deficient CRCs tend to show more aggressive behaviour and have a worse prognosis than other MMR-deficient CRCs. This, together with lower intratumoral immune infiltration, suggests that PMS2-deficient CRCs might have more in common biologically with sporadic MMR-proficient CRCs than with other MMR-deficient CRCs. These findings could have important consequences for surveillance, chemoprevention and therapeutic strategies (e.g. vaccines). In this review we discuss the current knowledge, current (clinical) challenges and knowledge gaps that should be targeted by future studies.

Potential risks associated with the use of ionizing radiation for imaging and treatment of colorectal cancer in Lynch syndrome patients

The aim of this review is to investigate the literature pertaining to the potential risks of low-dose ionizing radiation to Lynch syndrome patients by use of computed tomography (CT), either diagnostic CT colonography (CTC), standard staging CT or CT surveillance. Furthermore, this review explores the potential risks of using radiotherapy for treatment of rectal cancer in these patients. No data or longitudinal observational studies of the impact of radiation exposure on humans with Lynch syndrome were identified. Limited experimental studies utilizing cell lines and primary cells exposed to both low and high radiation doses have been carried out to help determine radio-sensitivity associated with DNA mismatch repair gene deficiency, the defining feature of Lynch syndrome. On balance, these studies suggest that mismatch repair deficient cells may be relatively radio-resistant (particularly for low dose rate exposures) with higher mutation rates, albeit no firm conclusions can be drawn. Mouse model studies, though, showed an increased risk of developing colorectal tumors in mismatch repair deficient mice exposed to radiation doses around 2 Gy. With appropriate ethical approval, further studies investigating radiation risks associated with CT imaging and radiotherapy relevant doses using cells/tissues derived from confirmed Lynch patients or genetically modified animal models are urgently required for future clinical guidance.

Routine informed consent for mismatch repair testing in endometrial cancers: Review and ethical analysis

OBJECTIVE

To review available data regarding consent for tumor testing for mismatch repair (MMR), and to make recommendation for ethical best practices based on synthesis of contemporary data and ethical principles.

METHODS

PubMed and CINAHL databases were searched through September 2021; articles reporting on consent for MMR tumor testing for patients at risk for Lynch Syndrome were abstracted. Additional articles were identified through review of references. Key data and ethical principles were extracted, summarized, and analyzed in the context of contemporary clinical practice.

RESULTS

16 articles met inclusion criteria for this review, none of which specifically related to MMR testing for endometrial cancers. All but two studies were published prior to the approval of pembrolizumab for treatment of MMR-deficient tumors. Scant available data suggest that routine consent prior to tumor testing is uncommon; however, several decision aids improved patient knowledge and satisfaction prior to deciding whether to proceed with tumor testing. Previous ethical analyses invoke clinical utility, potential germline implications, and logistical factors in making recommendations regarding consent practices. These analyses varied in their final recommendations; however, all had significant deficits in their arguments related to contemporary clinical care for patients with endometrial cancer.

CONCLUSION

Current data are needed to assess the impact of potential consent strategies for tumor testing. Based on available data, and consistent with contemporary ethical best practices, we recommend that planned MMR testing of endometrial cancers be discussed routinely with patients verbally or in surgical consent documents.

A comparative examination of colorectal cancer burden in European Union, 1990-2019: Estimates from Global Burden of Disease 2019 Study

AIM

This study examines the burden of colorectal cancer (CRC) in European Union (EU) countries in the last 3 decades.

METHODS

The data pertaining to CRC burden were procured from the Global Burden of Disease 2019 Study for 28 EU countries (including United Kingdom) for the period 1990-2019. The age-standardized rates of CRC were utilized to compare the country-wise burden and joinpoint regression models were applied to examine the trends.

RESULTS

In EU, CRC incident cases increased by 70.2% from 261,306 to 444,872 and deaths increased by 36.8% from 155,823 to 213,174 between 1990 and 2019. The age-standardized incidence rate (ASIR) increased by 11.9% from 37.8/100,000 to 42.3/100,000 between 1990 and 2019; in contrast, the age-standardized mortality rate (ASMR) decreased by 16.9% (1990: 22.4/100,000; 2019: 18.6/100,000) and age-standardized DALYs rate (ASDALR) decreased by 18.6% (1990: 472.9/100,000; 2019: 385.1/100,000) in the study period. In 2019, Hungary was the leading country in terms of ASMR (28.6/100,000) and ASDALR (630.3/100,000), and Lithuania (29.2/100,000) had the lowest ASIR, whereas Finland had the lowest ASMR (12.3/100,000) and ASDALR (253.6/100,000) in 2019.

CONCLUSION

CRC incidence is increasing in EU and mortality rates, although decreasing, are still unacceptably high. CRC control efforts must be focused around early detection using screening and prevention through reduction of modifiable risk factors. Increasing CRC incidence rates in young adults in recent years requires more research to pinpoint risk factors, and there must be more awareness of this recent development among general public and clinicians.

Predicting Colorectal Cancer Using Residual Deep Learning with Nursing Care

Presently, colorectal cancer is the second most dangerous cancer; around 13% of people have been affected; and it requires an effective image analysis and earlier cancer prediction (IAECP) system for reducing the mortality rate. Here, the IAECP system uses MRI radio imaging for predicting colorectal cancer. During this process, high- and low-level features are required to examine cancer in an earlier stage. Due to the limitation of the conventional feature extraction process, both features are difficult to extract from cancer suffered locations. Hence, a deep learning system (DLS) is used to examine the entire bowel MRI image to identify the cancer-affected location, feature extraction, and feature training process. Furthermore, the DLS-based IAECP system helps improve the overall colorectal cancer identification accuracy for further process. The derived bowel features are trained by applying the residual convolution network, which minimizes the error between predicted and actual values. Finally, the test query images are compared with the trained image by applying the sum, which is more absolute to the cross-correlation template feature matching (SACC) algorithm. The experimental process is performed using 100,000 histological data sets, which is considered a publicly available data set. Moreover, the introduced method does not use generic features, whereas the deep learning features help improve the overall IAECP prediction rate (99.8%) ratio as predicted at lab-scale analysis.

Identification and management of Lynch syndrome in the Middle East and North African countries: outcome of a survey in 12 countries

BACKGROUND

Lynch syndrome (LS), the most common inherited form of colorectal cancer (CRC), is responsible for 3% of all cases of CRC. LS is caused by a mismatch repair gene defect and is characterized by a high risk for CRC, endometrial cancer and several other cancers. Identification of LS is of utmost importance because colonoscopic surveillance substantially improves a patient's prognosis. Recently, a network of physicians in Middle Eastern and North African (ME/NA) countries was established to improve the identification and management of LS families. The aim of the present survey was to evaluate current healthcare for families with LS in this region.

METHODS

A questionnaire was developed that addressed the following issues: availability of clinical management guidelines for LS; attention paid to family history of cancer; availability of genetic services for identification and diagnosis of LS; and assessment of knowledge of LS surveillance. Members of the network and authors of recent papers on LS from ME/NA and neighbouring countries were invited to participate in the survey and complete the online questionnaire.

RESULTS

A total of 55 individuals were invited and 19 respondents from twelve countries including Algeria, Azerbaijan, Cyprus, Egypt, Iran, Jordan, Kuwait, Lebanon, Morocco, Palestine, Tunisia, and Turkey completed the questionnaire. The results showed that family history of CRC is considered in less than half of the surveyed countries. Guidelines for the management of LS are available in three out of twelve countries. The identification and selection of families for genetic testing were based on clinical criteria (Amsterdam criteria II or Revised Bethesda criteria) in most countries, and only one country performed universal screening. In most of the surveyed countries genetic services were available in few hospitals or only in a research setting. However, surveillance of LS families was offered in the majority of countries and most frequently consisted of regular colonoscopy.

CONCLUSION

The identification and management of LS in ME/NA countries are suboptimal and as a result most LS families in the region remain undetected. Future efforts should focus on increasing awareness of LS amongst both the general population and doctors, and on the improvement of the infrastructure in these countries.

Recent advances in Lynch syndrome

Lynch syndrome is one of the most common hereditary cancer syndromes and is characterized by the development of many cancers, such as colorectal cancer (CRC), endometrial cancer, ovarian cancer, stomach cancer and many other cancers. Lynch syndrome is caused by pathogenic germline variants in one of four DNA mismatch repair genes (MLH1, MSH2, MSH6, or PMS2) or by an EPCAM deletion. The MLH1 variant is correlated with the highest risk of CRC, while the MSH2 variant is correlated with the highest risk of other cancers. CRC is the most common cancer type that develops in individuals with Lynch syndrome, followed by endometrial cancer. Recent advances have been made to help us further understand the molecular pathogenesis of this disease and help improve diagnostic testing efficiency and surveillance strategies. Moreover, recent advances in immunotherapy provided by clinical trials also provide clinicians with more chances to better treat Lynch syndrome. This study aims to review many advances in the molecular genetics, clinical features, diagnosis, surveillance and treatment of Lynch syndrome.

Application and Prospects of Molecular Imaging in Immunotherapy

Recently, immunotherapies that target the interactions of programmed cell death 1 (PD-1) with its major ligands, programmed death ligand 1 (PD-L1) and programmed death ligand 2 (PD-L2), have achieved significant success. To date, several immune checkpoint inhibitors targeting the PD-1/PD-L1 pathway have been developed to treat melanoma, non-small cell lung cancer, head and neck cancer, renal cell carcinoma, and urothelial carcinoma. Despite promising outcomes with immunotherapy, there are many limitations to several current immune biomarkers for predicting immune benefits and to traditional imaging for evaluating the efficacy and prognosis of immunotherapy and monitoring adverse reactions. In this review, we recommend a novel imaging method, molecular imaging. This paper reviews the application and prospects of molecular imaging in the context of current immunotherapies in regard to the following aspects: 1) detecting the expression of PD-1/PD-L1; 2) evaluating the efficacy of immunotherapy; 3) assessing patient prognosis with immunotherapy; 4) monitoring the toxicity of immunotherapy; and 5) other targets imaging.

Analysis of metachronous colorectal neoplasms and survival following segmental or extended resection in patients with hereditary non-polyposis colorectal cancer

PURPOSE

The high incidence of metachronous colorectal tumours in patients with hereditary non-polyposis colorectal cancer (HNPCC) encourages extended resection (ER); however, the optimal surgical approach remains unclear. We evaluated the incidences of metachronous colorectal neoplasms following curative colorectal cancer segmental resection (SR) vs ER in patients with HNPCC and investigated patients' oncologic outcomes according to surgical modality and mismatch repair status.

METHODS

We retrospectively investigated medical records of patients with HNPCC (per the Amsterdam II criteria) treated for primary colon cancer at our institution between 2001 and 2017. All patients underwent intensive endoscopic surveillance.

RESULTS

We included 87 patients (36 who underwent SR and 51 who underwent ER). The cumulative incidence of metachronous adenoma was higher in the SR group. One patient in the SR group (2.8%) and 3 in the ER group (5.9%) developed metachronous colon cancer; the difference was not significant (P = 0.693). Four patients in the SR group (11.1%) and 1 in the ER group (2.0%) developed distant recurrences; again, the difference was not significant (P = 0.155). Moreover, no significant differences were observed in the 5-year overall survival rates of patients in the SR and ER groups (88.2% vs 95.5%, P = 0.446); the same was true for 5-year disease-free survival rates (79.5% vs 91.0%, P = 0.147).

CONCLUSION

The incidence of metachronous cancer was not significantly different between the ER and SR groups; however, that of cumulative metachronous adenoma was higher in the SR group. Hence, intensive surveillance colonoscopy may be sufficient for patients with HNPCC after non-extensive colon resection.

Risk factors for metachronous colorectal cancer in Lynch syndrome patients: a registry-based observational mono-institutional study cohort

BACKGROUND

Risk factors for metachronous colorectal cancer (mCRC) in Lynch Syndrome (LS) patients are essential for colorectal cancer (CRC) treatment strategy to perform not only a curative but also preventive surgery. The aim of this study was to evaluate the risk factors for mCRC development in LS patients to define the patient subset that may benefit an extended curative and preventive surgical resection.

METHODS

Patient's clinical history, oncological, molecular and follow-up were collected retrospectively from the Hereditary Digestive Tumors Registry at the National Cancer Institute of Milan. The age-related cumulative risk of mCRC was calculated using the Kaplan-Meier method. Factors significantly associated with mCRC were analyzed with a Cox regression model. Overall and specific competitive risks were also calculated.

RESULTS

In a total of 1346 CRC patients, 159 (11.8%) developed a mCRC after a mean follow-up of 138 months from the primary tumor. The independent risk factors reported by a multivariate analysis were: pathogenetic variants in MLH1 and MSH2 (HR 2.96 and 1.91, respectively) and history of colorectal adenomas (HR 1.54); whereas female sex and extended surgery were protective (HR 0.59 and 0.79, respectively).

CONCLUSIONS

Among a high-risk population for CRC, in particular LS, an extended surgery may be considered in CRC patients with specific risk factors (MLH1 or MSH2 germline pathogenic variants, history of colorectal adenomas) to reduce the risk of mCRC development.

Molecular pathology of Lynch syndrome

Lynch syndrome (LS) is characterised by predisposition to colorectal, endometrial, and other cancers and is caused by inherited pathogenic variants affecting the DNA mismatch repair (MMR) genes MLH1, MSH2, MSH6, and PMS2. It is probably the most common predisposition to cancer, having an estimated prevalence of between 1/100 and 1/180. Resources such as the International Society for Gastrointestinal Hereditary Cancer's MMR gene variant database, the Prospective Lynch Syndrome Database (PLSD), and the Colon Cancer Family Register (CCFR), as well as pathological and immunological studies, are enabling advances in the understanding of LS. These include defined criteria by which to interpret gene variants, the function of MMR in the normal control of apoptosis, definition of the risks of the various cancers, and the mechanisms and pathways by which the colorectal and endometrial tumours develop, including the critical role of the immune system. Colorectal cancers in LS can develop along three pathways, including flat intramucosal lesions, which depend on the underlying affected MMR gene. This gives insights into the limitations of colonoscopic surveillance and highlights the need for other forms of anti-cancer prophylaxis in LS. Finally, it shows that the processes of autoimmunisation and immunoediting fundamentally constrain the development of tumours in LS and explain the efficacy of immune checkpoint blockade therapy in MMR-deficient tumours. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Microsatellite Instability: Diagnosis, Heterogeneity, Discordance, and Clinical Impact in Colorectal Cancer

Tumor DNA mismatch repair (MMR) deficiency testing is important to the identification of Lynch syndrome and decision making regarding adjuvant chemotherapy in stage II colorectal cancer (CRC) and has become an indispensable test in metastatic tumors due to the high efficacy of immune checkpoint inhibitor (ICI) in deficient MMR (dMMR) tumors. CRCs greatly benefit from this testing as approximately 15% of them are dMMR but only 3% to 5% are at a metastatic stage. MMR status can be determined by two different methods, microsatellite instability (MSI) testing on tumor DNA, and immunohistochemistry of the MMR proteins on tumor tissue. Recent studies have reported a rate of 3% to 10% of discordance between these two tests. Moreover, some reports suggest possible intra- and inter-tumoral heterogeneity of MMR and MSI status. These issues are important to know and to clarify in order to define therapeutic strategy in CRC. This review aims to detail the standard techniques used for the determination of MMR and MSI status, along with their advantages and limits. We review the discordances that may arise between these two tests, tumor heterogeneity of MMR and MSI status, and possible explanations. We also discuss the strategies designed to distinguish sporadic versus germline dMMR/MSI CRC. Finally, we present new and accurate methods aimed at determining MMR/MSI status.

From colorectal cancer pattern to the characterization of individuals at risk: Picture for genetic research in Latin America

Colorectal cancer (CRC) is one of the most common cancers in Latin America and the Caribbean, with the highest rates reported for Uruguay, Brazil and Argentina. We provide a global snapshot of the CRC patterns, how screening is performed, and compared/contrasted to the genetic profile of Lynch syndrome (LS) in the region. From the literature, we find that only nine (20%) of the Latin America and the Caribbean countries have developed guidelines for early detection of CRC, and also with a low adherence. We describe a genetic profile of LS, including a total of 2,685 suspected families, where confirmed LS ranged from 8% in Uruguay and Argentina to 60% in Peru. Among confirmed LS, path_MLH1 variants were most commonly identified in Peru (82%), Mexico (80%), Chile (60%), and path_MSH2/EPCAM variants were most frequently identified in Colombia (80%) and Argentina (47%). Path_MSH6 and path_PMS2 variants were less common, but they showed important presence in Brazil (15%) and Chile (10%), respectively. Important differences exist at identifying LS families in Latin American countries, where the spectrum of path_MLH1 and path_MSH2 variants are those most frequently identified. Our findings have an impact on the evaluation of the patients and their relatives at risk for LS, derived from the gene affected. Although the awareness of hereditary cancer and genetic testing has improved in the last decade, it is remains deficient, with 39%-80% of the families not being identified for LS among those who actually met both the clinical criteria for LS and showed MMR deficiency.

Universal determination of microsatellite instability using BAT26 as a single marker in an Argentine colorectal cancer cohort

Microsatellite instability (MSI) is a hallmark tool for Lynch syndrome (LS) screening and a prognostic marker for sporadic colorectal cancer (CRC). In regions with limited resources and scarce CRC molecular characterization as South America, the implementation of universal MSI screening is under debate for both its purposes. We sought to estimate the frequency of BAT26 in colorectal adenocarcinomas and to determine associated clinical and histological features. Consecutive patients from a CRC registry were included. BAT26 determination was performed in all cases; if instability was found, immunohistochemistry (IHC) and BRAF mutation analyses were done, as appropriate. Differences were assessed by chi-squared or Fisher's exact test, or by T test or Mann-Whitney. Multiple logistic regression was used to identify factors independently associated with BAT26-unstable tumors. We included 155 patients; mean age was 65.6 (SD 14.4) and 56.1% were male. The frequency of BAT26-unstable tumors was 22% (95% CI 15.7-29.3). Factors independently associated with BAT26-unstable tumors were right colon localization (OR 3.4, 95% CI 1.3-8.7), histological MSI features (OR 5.1, 95% CI 1.9-13.6) and Amsterdam criteria (OR 23.2, 95% CI 1.9-286.7). IHC was altered in 85.3% BAT26-unstable tumors and 70.6% lacked MLH1 expression; 47.8% of these harbored BRAF V600E mutation. We provide evidence to link the frequency of BAT26 to an increased diagnostic yield (up to 1.4-folds) of suspected LS cases in comparison to the revised Bethesda guidelines alone. In regions with limited resources, clinical and histological features associated with BAT26-unstable status could be useful to direct MSI screening in sporadic CRCs and may help guide clinical care and future research.

Testing strategies to reduce morbidity and mortality from Lynch syndrome

OBJECTIVE

Lynch syndrome (LS) has an autosomal dominant inheritance pattern and is associated with increased risk for colorectal cancer (CRC) and other cancers. Various strategies are used to identify patients at risk and offer surveillance and preventive programs, the cost effectiveness of which is much dependent on the prevalence of LS in a population. Universal testing (UT) is proposed as an effective measure, targeting all newly diagnosed CRC patients under a certain age.

MATERIALS AND METHODS

LS cases were identified in a cohort of 572 consecutive CRC patients. Immunohistochemistry was performed in 539 cases, using antibodies against mismatch repair proteins MLH1, PMS2, MSH2, and MSH6. Microsatellite instability and gene mutation screening were performed in 57 cases.

RESULTS

In total 11 pathogenic variants were detected, identifying LS in 1.9% of new CRC cases. Comparing the results with current clinical methods, 2 pathogenic variants were found with Amsterdam criteria and 9 when using either Bethesda guidelines or our institution's prior clinical criteria. Pathogenic variants in MSH6 were the most common in our series. We also found different outcomes using different age cut offs.

CONCLUSION

Our study demonstrates that UT of tumors before age on onset at 75 years would most likely be cost-efficient and essentially equivalent to applying the Bethesda guidelines or our institution's prior clinical criteria on all new CRC.

Information exchange between patients with Lynch syndrome and their genetic and non-genetic health professionals: whose responsibility?

Individuals at high risk for Lynch syndrome (LS) should be offered genetic counselling, since preventive options are available. However, uptake of genetic services and follow-up care are currently suboptimal, possibly caused by inadequate exchange of information. Therefore, this qualitative study aims to gain insight in the process of information exchange between patients diagnosed with LS and their non-genetic (i.e., general practitioner, gastroenterologist, gynaecologist) and genetic (i.e., clinical geneticist or genetic counsellor) health professionals concerning referral for genetic counselling and follow-up care. Participants comprised 13 patients diagnosed with LS (8 index patients and 5 of their affected relatives) and 24 health professionals (6 general practitioners, 8 gastroenterologists, 6 gynaecologists and 4 genetic health professionals). Analysis of the interview transcripts was performed in parallel and again after the interviews, following guidelines for qualitative research and using MAXQDA software. The main finding is that patients may ‘get lost’ between health professionals who lack a clear overview of their own and each other’s role and responsibilities in the referral and follow-up care for patients with possible LS. Education of non-genetic health professionals and optimisation of communication between health professionals might help to enable more timely diagnosis of LS and allow patients to address their doubts and questions to the most appropriate healthcare professional.

General practitioner attitudes towards prescribing aspirin to carriers of Lynch Syndrome: findings from a national survey

A dose non-inferiority study comparing 100 mg, 300 mg and 600 mg of aspirin for cancer prevention among Lynch Syndrome carriers is underway (Colorectal Adenoma/Carcinoma Prevention Programme trial 3, CaPP3). To guide implementation of the findings, we investigated general practitioner (GP) attitudes towards aspirin prescribing for Lynch Syndrome carriers. We surveyed 1007 UK GPs (9.6% response rate). Using a within-subjects design, GPs read a statement on harms and benefits of aspirin and indicated their willingness to prescribe aspirin at three doses (100 mg, 300 mg, 600 mg). Approximately two-thirds (70.8%) of GPs had heard of Lynch Syndrome or its associated names, and among those 46.7% were aware of the cancer preventive effects of aspirin among carriers. Two-thirds (68.1%) of GPs reported feeling comfortable discussing harms and benefits of aspirin with a Lynch Syndrome patient. Willingness to prescribe was 91.3% at 100 mg, and declined to 81.8% at 300 mg and 62.3% at 600 mg (p < 0.001). In multivariable analyses, willingness to prescribe (600 mg) was higher among GPs ≥50 years (OR 1.46, 95% CI 1.03-2.07), more experienced GPs (OR 1.50, 95% CI 1.10-2.04), GPs who were aware of the cancer preventive effects of aspirin (OR 1.58, 95% CI 1.20-2.09), and those who reported seeing a Lynch Syndrome patient in practice (OR 1.44, 95% CI 1.01-2.05, p = 0.045). GPs report limited awareness of Lynch Syndrome and the preventive effects of aspirin among carriers. To ensure the optimal dose identified in the CaPP3 trial is readily available to patients, prescribing guidance and strategies to educate GPs should be developed.

First description of mutational analysis of MLH1, MSH2 and MSH6 in Algerian families with suspected Lynch syndrome

Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal dominant disorder characterized by the early onset of colorectal cancer (CRC) linked to germline defects in Mismatch Repair (MMR) genes. We present here, the first molecular study of the correlation between CRC and mutations occurring in these genes performed in twenty-one unrelated Algerian families. The presence of germline mutations in MMR genes, MLH1, MSH2 and MSH6 genes was tested by sequencing all exons plus adjacent intronic sequences and Multiplex ligand-dependent probe amplification (MLPA) for testing large genomic rearrangements. Pathogenic mutations were identified in 20 % of families with clinical suspicion on HNPCC. Two novel variants described for the first time in Algerian families were identified in MLH1, c.881_884delTCAGinsCATTCCT and a large deletion in MSH6 gene from a young onset of CRC. Moreover, the variants of MSH2 gene: c.942+3A>T, c.1030C>T, the most described ones, were also detected in Algerian families. Furthermore, the families HNPCC caused by MSH6 germline mutation may show an age of onset that is comparable to this of patients with MLH1 and MSH2 mutations. In this study, we confirmed that MSH2, MLH1, and MSH6 contribute to CRC susceptibility. This work represents the implementation of a diagnostic algorithm for the identification of Lynch syndrome patients in Algerian families.

Risk of metachronous colorectal cancer following colectomy in Lynch syndrome: a systematic review and meta-analysis

AIM

Lynch syndrome (LS) accounts for 2-4% of all colorectal cancer (CRC) cases, and is associated with an increased risk of developing metachronous colorectal cancer (mCRC). The role of extended colectomy in LS CRC is controversial. There are limited studies comparing the risk of mCRC following segmental colectomy and extended colectomy. The objective of this systematic review is to evaluate the risk of developing mCRC following segmental and extended colectomy for LS CRC and endoscopic compliance.

METHOD

A systematic review of major databases was performed using predefined terms. All original articles published in English comparing the risk of mCRC in LS patients after segmental and extended colectomy from 1950 to January 2016 were included.

RESULTS

The search retrieved 324 studies. Six studies involving 871 patients met the inclusion criteria. Of these, 705 (80.9%) underwent segmental colectomy and 166 (19.1%) extended colectomy. Average follow-up was 91.2 months. The mCRC rate was 22.8% and 6% in the segmental and extended colectomy groups, respectively. The segmental group were over four times more likely to develop mCRC (OR 4.02, 95% CI: 2.01-8.04, P < 0.0001). mCRC occurred in patients after segmental colectomy despite 1-2-yearly postoperative endoscopic surveillance.

CONCLUSION

This result suggests that extended colectomy reduces the risk of mCRC by over four-fold compared with segmental colectomy. mCRC occurred in the segmental group despite postoperative endoscopic surveillance. This needs to be borne in mind when deciding on the appropriate surgical management of LS patients with CRC. We recommend that extended colectomy should be considered for patients with confirmed LS CRC.

Outcome of 24 years national surveillance in different hereditary colorectal cancer subgroups leading to more individualised surveillance

BACKGROUND

Individuals with hereditary non-polyposis colorectal cancer (HNPCC) have a high risk of colorectal cancer (CRC). The benefits of colonic surveillance in Lynch syndrome and Amsterdam-positive (familial CRC type X familial colorectal cancer type X (FCCTX)) families are clear; only the interval between colonoscopies is debated. The potential benefits for families not fulfilling the Amsterdam criteria are uncertain. The aim of this study was to compare the outcome of colonic surveillance in different hereditary subgroups and to evaluate the surveillance programmes.

METHODS

A prospective, observational study on the outcome of colonic surveillance in different hereditary subgroups based on 24 years of surveillance data from the national Danish HNPCC register.

RESULTS

We analysed 13 444 surveillance sessions, including 8768 incidence sessions and 20 450 years of follow-up. CRC was more incident in the Lynch subgroup (2.0%) than in any other subgroup (0.0-0.4%, p<0.0001), but the incidence of advanced adenoma did not differ between the Lynch (3.6%) and non-Lynch (2.3-3.9%, p=0.28) subgroups. Non-Lynch Amsterdam-positive and Amsterdam-negative families were similar in their CRC (0.1-0.4%, p=0.072), advanced adenoma (2.3-3.3%, p=0.32) and simple adenoma (8.4-9.9%, p=0.43) incidence. In moderate-risk families, no CRC and only one advanced adenoma was found.

CONCLUSIONS

The risk of CRC in Lynch families is considerable, despite biannual surveillance. We suggest less frequent and more individualised surveillance in non-Lynch families. Individuals from families with a strong history of CRC could be offered 5-year surveillance colonoscopies (unless findings at the preceding surveillance session indicate shorter interval) and individuals from moderate-risk families could be handled with the population-based screening programme for CRC after an initial surveillance colonoscopy.

Clinical characteristics of synchronous colorectal cancers in Japan

BACKGROUND

Incidence and clinical characteristics of synchronous colorectal cancer (sCRC) patients significantly vary among studies, likely due to differences in surveillance methodology. If remain undetected, sCRC can progress to more advanced stages seriously aggravating patient prognosis. We studied the incidence and clinicopathological characteristics of Japanese patients with sCRCs who underwent surgery for primary CRC and received exhaustive perioperative surveillance.

METHODS

We recruited 1005 patients with surgically resected CRCs between January 2007 and December 2011. The associations of clinical and pathological factors with sCRC development were assessed by univariate and multivariate logistic regression.

RESULTS

Eighty-four patients (8.4 %) developed sCRCs, 16 of them (19.0 %) harboring three or more cancers. Companion sCRCs were smaller and earlier stage than the index lesion (P < 0.0001). In multivariate analysis, advanced age (odds ratio (OR) 1.03 per year; P = 0.009) and left colon tumor location (OR 1.78; P = 0.013) are associated with higher risk of sCRCs, particularly in females. Overall survival did not differ between solitary CRC and sCRC (P = 0.62).

CONCLUSIONS

Our results highlight the importance of perioperative colonoscopy examination to ensure the absence of sCRCs that, being small and early staged, are more difficult to detect. The incidence of sCRC, and notably of triple or more sCRCs, was higher than previously recognized. Because they are also significantly higher than expected by merely stochastic accumulation of individual cancerous lesions, we suggest that the occurrence of many sCRC reflects a hitherto uncharacterized predisposition condition.

Evaluation of a population-based approach to familial colorectal cancer

As Newfoundland has the highest rate of familial colorectal cancer (CRC) in the world, we started a population‐based clinic to provide colonoscopic and Lynch syndrome (LS) screening recommendations to families of CRC patients based on family risk. Of 1091 incident patients 51% provided a family history. Seventy‐two percent of families were at low or intermediate–low risk of CRC and colonoscopic screening recommendations were provided by letter. Twenty‐eight percent were at high and intermediate–high risk and were referred to the genetic counsellor, but only 30% (N = 48) were interviewed by study end. Colonoscopy was recommended more frequently than every 5 years in 35% of families. Lower family risk was associated with older age of proband but the frequency of screening colonoscopy recommendations varied across all age groups, driven by variability in family history. Twenty‐four percent had a high MMR predict score for a Lynch syndrome mutation, and 23% fulfilled the Provincial Program criteria for LS screening. A population‐based approach in the provision of colonoscopic screening recommendations to families at risk of CRC was limited by the relatively low response rate. A family history first approach to the identification of LS families was inefficient.

Identification of familial colorectal cancer and hereditary colorectal cancer syndromes through the Dutch population-screening program: results ofa pilot study

OBJECTIVES

In 2014, a population-screening program using immuno-faecal occult blood testing (I-FOBT) has started in the Netherlands. The aims of this study were to evaluate the proportion of individuals in the Dutch screening program with a positive I-FOBT that fulfill the criteria for familial colorectal cancer (FCC) and to evaluate the proportion of participants that needs genetic counseling or colonoscopic surveillance.

MATERIAL AND METHODS

This retrospective observational study was performed in two large hospitals. Individuals aged between 55 and 75 years with a positive I-FOBT that underwent colonoscopy were included. A detailed family history was obtained in all individuals.

RESULTS

A total of 657 individuals with a positive I-FOBT test underwent colonoscopy. A total of 120 (18.3%) participants were found to have a positive family history for CRC, 20 (3.0%) fulfilled the FCC criteria, 4 (0.6%) the Bethesda guidelines and 1 (0.2%) participant the Amsterdam criteria. Multiple adenomas (>10) were found in 21 (3.2%) participants. No cases of serrated polyposis were identified. Based on these criteria and guidelines, a total of 35 (5.3%) required referral to the clinical geneticist and the relatives of 20 (3.0%) participants should be referred for surveillance colonoscopy.

CONCLUSION

Obtaining a detailed family history at the time of intake of participants with a positive I-FOBT in the Dutch surveillance program increased the identification of participants with familial CRC.

Primary care management of women with breast cancer-related concerns-a dynamic cohort study using a network database

The aim of this study was to determine the incidence, management and diagnostic outcomes of breast cancer-related concerns presented in primary care. A dynamic cohort study was performed in the anonymised routine electronic medical records (EMRs) extracted from 49 General Practices in the Netherlands (163,471 person-years, women aged 18-75). Main Outcome Measures were: (1) incidence rates for breast cancer-related concerns in Primary Care, (2) proportions of these women with and without symptoms of the breast referred for further investigation, (3) proportions of referrals (not) according to the guideline and (4) proportions of women with breast cancer-related concerns diagnosed with breast cancer during follow-up. Breast cancer-related concerns are presented frequently in Primary Care (incidence rate 25.9 per 1,000 women annually). About half these women are referred for further investigation. There is room to improve General Practitioner management, mainly for women with an increased lifetime risk of developing breast cancer. Information concerning family history of cancer is often missing in the EMR. Since cancer is rarely diagnosed during follow-up, particularly when symptoms are absent, reduction of unnecessary concerns is plausible if identification of those without an increased risk is improved.

Detection of DNA repair protein in colorectal cancer of patients up to 50 years old can increase the identification of Lynch syndrome?

The aim of this study was to compare the results of protein level of the DNA mismatch repair genes with the clinical diagnosis of Lynch syndrome according to the Amsterdam II criteria in patients 50 years and younger who underwent surgery for colorectal cancer. The subjects of analysis were 48 patients 50 years old and younger. Immunohistochemistry assays were performed to detect proteins from the DNA mismatch repair genes. Clinicopathological data and Amsterdam II criteria for the diagnosis of hereditary nonpolyposis colorectal cancer were obtained by analyzing medical records. Two (4 %) patients satisfied the Amsterdam II criteria for Lynch syndrome, and both presented levels of all of the studied mismatch repair proteins. A total of 13 (27 %) patients exhibited the absence of protein levels of the studied mismatch repair genes. None of these patients were considered suspicious for Lynch syndrome according to the Amsterdam II criteria. Screening for the level of proteins of the mismatch repair system in all colorectal cancer patients 50 years and younger can increase the identification of patients with suspicion of Lynch syndrome.

A systematic review and economic evaluation of diagnostic strategies for Lynch syndrome

BACKGROUND

Lynch syndrome (LS) is an inherited autosomal dominant disorder characterised by an increased risk of colorectal cancer (CRC) and other cancers, and caused by mutations in the deoxyribonucleic acid (DNA) mismatch repair genes.

OBJECTIVE

To evaluate the accuracy and cost-effectiveness of strategies to identify LS in newly diagnosed early-onset CRC patients (aged < 50 years). Cascade testing of relatives is employed in all strategies for individuals in whom LS is identified.

DATA SOURCES AND METHODS

Systematic reviews were conducted of the test accuracy of microsatellite instability (MSI) testing or immunohistochemistry (IHC) in individuals with CRC at risk of LS, and of economic evidence relating to diagnostic strategies for LS. Reviews were carried out in April 2012 (test accuracy); and in February 2012, repeated in February 2013 (economic evaluations). Databases searched included MEDLINE (1946 to April week 3, 2012), EMBASE (1980 to week 17, 2012) and Web of Science (inception to 30 April 2012), and risk of bias for test accuracy was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) quality appraisal tool. A de novo economic model of diagnostic strategies for LS was developed.

RESULTS

Inconsistencies in study designs precluded pooling of diagnostic test accuracy results from a previous systematic review and nine subsequent primary studies. These were of mixed quality, with significant methodological concerns identified for most. IHC and MSI can both play a part in diagnosing LS but neither is gold standard. No UK studies evaluated the cost-effectiveness of diagnosing and managing LS, although studies from other countries generally found some strategies to be cost-effective compared with no testing. The de novo model demonstrated that all strategies were cost-effective compared with no testing at a threshold of £20,000 per quality-adjusted life-year (QALY), with the most cost-effective strategy utilising MSI and BRAF testing [incremental cost-effectiveness ratio (ICER) = £5491 per QALY]. The maximum health benefit to the population of interest would be obtained using universal germline testing, but this would not be a cost-effective use of NHS resources compared with the next best strategy. When the age limit was raised from 50 to 60 and 70 years, the ICERs compared with no testing increased but remained below £20,000 per QALY (except for universal germline testing with an age limit of 70 years). The total net health benefit increased with the age limit as more individuals with LS were identified. Uncertainty was evaluated through univariate sensitivity analyses, which suggested that the parameters substantially affecting cost-effectiveness: were the risk of CRC for individuals with LS; the average number of relatives identified per index patient; the effectiveness of colonoscopy in preventing metachronous CRC; the cost of colonoscopy; the duration of the psychological impact of genetic testing on health-related quality of life (HRQoL); and the impact of prophylactic hysterectomy and bilateral salpingo-oophorectomy on HRQoL (this had the potential to make all testing strategies more expensive and less effective than no testing).

LIMITATIONS

The absence of high-quality data for the impact of prophylactic gynaecological surgery and the psychological impact of genetic testing on HRQoL is an acknowledged limitation.

CONCLUSIONS

Results suggest that reflex testing for LS in newly diagnosed CRC patients aged < 50 years is cost-effective. Such testing may also be cost-effective in newly diagnosed CRC patients aged < 60 or < 70 years. Results are subject to uncertainty due to a number of parameters, for some of which good estimates were not identified. We recommend future research to estimate the cost-effectiveness of testing for LS in individuals with newly diagnosed endometrial or ovarian cancer, and the inclusion of aspirin chemoprevention. Further research is required to accurately estimate the impact of interventions on HRQoL.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42012002436.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Evaluation after five years of the cancer genetic counselling programme of Valencian Community (Eastern Spain)

To evaluate the cancer genetic counselling programme in Valencian Community using intermediate indicators. Descriptive analysis of organisational and effectiveness indicators from the start in 2005 until December 2010: correct referral of patients according to the area from where they were referred (primary or hospital-based care) and syndrome; families identified as having each syndrome; suitability of the genetic testing for individuals with a cancer diagnosis (index cases, IC) and relatives of ICs with mutations; family size; and results of genetic testing on genes, ICs and relatives. 9,942 individuals attended, 87.7 % were referred by hospital-based care and 8.4 % by primary care. 7,516 patients (79 %) fulfilled cancer genetic counselling criteria (82 % from hospital-based care and 46 % from primary care). Amongst those who fulfilled the criteria, 59 % of referrals were related to hereditary breast ovarian cancer syndrome and 32 % to hereditary non-polyposis colorectal cancer. ICs were found in 3,082 families (78.7 %) and genetic testing was carried out on 91.3 % of them. Pathogenic mutations were detected in 21.8 % of the ICs and the testing was then offered to their relatives (an average of 3 per IC). Pathogenic mutations were found in 54 % of the assessed relatives. Results in 5 years confirm the appropriateness of these facilities, as part of an integrated health service, to identify families and individuals with genetic risk to offer them personalized counselling. Improvements have to be made with regard to the information given to both health professionals and patients about the risk criteria for various syndromes.

Clinical management of hereditary colorectal cancer syndromes

Hereditary factors are involved in the development of a substantial proportion of all cases of colorectal cancer. Inherited forms of colorectal cancer are usually subdivided into polyposis syndromes characterized by the development of multiple colorectal polyps and nonpolyposis syndromes characterized by the development of few or no polyps. Timely identification of hereditary colorectal cancer syndromes is vital because patient participation in early detection programmes prevents premature death due to cancer. Polyposis syndromes are fairly easy to recognize, but some patients might have characteristics that overlap with other clinically defined syndromes. Comprehensive analysis of the genes known to be associated with polyposis syndromes helps to establish the final diagnosis in these patients. Recognizing Lynch syndrome is more difficult than other polyposis syndromes owing to the absence of pathognomonic features. Most investigators therefore recommend performing systematic molecular analysis of all newly diagnosed colorectal cancer using immunohistochemical methods. The implementation in clinical practice of new high-throughput methods for molecular analysis might further increase the identification of individuals at risk of hereditary colorectal cancer. This Review describes the clinical management of the various hereditary colorectal cancer syndromes and demonstrates the advantage of using a classification based on the underlying gene defects.

Clinically relevant lessons from Family HealthLink: a cancer and coronary heart disease familial risk assessment tool

PURPOSE

A descriptive retrospective study was performed using two separate user cohorts to determine the effectiveness of Family HealthLink as a clinical triage tool.

METHODS

Cohort 1 consisted of 2,502 users who accessed the public website. Cohort 2 consisted of 194 new patients in a Comprehensive Breast Center setting. For patient users, we assessed documentation of family history and genetics referral. For all users seen in a genetics clinic, the Family HealthLink assessment was compared with that performed by genetic counselors and genetic testing outcomes.

RESULTS

For general public users, the percentage meeting high-risk criteria were: for cancer only, 22.2%; for coronary heart disease only, 24.3%; and for both diseases, 10.4%. These risk stratification percentages were similar for the patient users. For the patient users, there often was documentation of family history of certain cancer types by oncology professionals, but age of onset and coronary heart disease family history were less complete. Of 142 with high-risk assignments seen in a genetics clinic, 130 (91.5%) of these assignments were corroborated. Forty-two underwent genetic testing and 17 (40.5%) had new molecular diagnoses established.

CONCLUSION

A significant percentage of individuals are at high familial risk and may require more intensive screening and referral. Interactive family history triage tools can aid this process.Genet Med 17 6, 493-500.

Report of a Novel Mutation in MLH1 Gene in a Hispanic Family from Puerto Rico Fulfilling Classic Amsterdam Criteria for Lynch Syndrome

In Puerto Rico, colorectal cancer (CRC) represents the second leading cause of cancer in men and women. Familial CRC accounts for 10–15% of the total CRC cases, while Lynch syndrome accounts for approximately 2–4% of cases. Limited information is available about the prevalence, clinical manifestations, and genetic mutations of hereditary CRC in US Hispanic individuals. In this paper we report a novel mutation in the hMLH1 gene in a Puerto Rican Hispanic family with Lynch syndrome recruited through the Puerto Rico Familial Colorectal Cancer Registry (PURIFICAR). Our proband was identified by applying Amsterdam and Bethesda criteria for Lynch syndrome, analysis of protein expression by immunohistochemistry, and genetic sequencing of the mismatch repair genes. A novel mutation at c.2044_2045 in hMLH1 consisting of the deletion of two consecutive nucleotides (AT) at exon 18 was identified. This deletion causes a frameshift in the protein coding sequence at p.682 resulting in premature termination and a truncated MLH1 protein. To our knowledge, this mutation has not been previously reported in the literature. The detection of this novel mutation in MLH1 further emphasizes the need for genetic testing in at-risk patients for hereditary CRC from various ethnic and racial backgrounds.

Current status of long non-coding RNAs in human cancer with specific focus on colorectal cancer

The latest investigations of long non-coding RNAs (lncRNAs) have revealed their important role in human cancers. LncRNAs are larger than 200 nucleotides in length and fulfill their cellular purpose without being translated into proteins. Though the molecular functions of some lncRNAs have been elucidated, there is still a high number of lncRNAs with unknown or controversial functions. In this review, we provide an overview of different lncRNAs and their role in human cancers. In particular, we emphasize their importance in tumorigenesis of colorectal cancer, the third most common cancer worldwide.

On the limits of genetic responsibility: Communication and consent for tumour testing for Lynch syndrome

Testing cancers for mismatch repair (MMR) gene defects assists selection of families for genetic testing for cancer predisposing Lynch syndrome. Performing MMR tumour testing without consent is debated, though little empirical work has been undertaken. We address this by examining the significance of testing for those who have consented without prior genetic counselling, particularly their ‘accounts’ of testing via displays of knowledge and responsibility. Semi-structured interviews were conducted with participants recruited from a UK genetics service. Participants had difficulties in formulating the benefits of testing when consent was facilitated by a relative or by mail. Discourse analysis revealed that in the absence of specific or accurate understandings of tumour testing, participants displayed responsibility towards themselves and others by generalising and diminishing the implications of testing. Within the framework of ‘genetic responsibility’, MMR tumour testing seems less important in participants’ accounts compared to more definitive genetic testing. If facilitating genetic knowledge and responsibility are goals of genetic testing then developing appropriate consent procedures for MMR tumour testing is an important consideration. Further research is required to differentiate whether genetic counselling is a precondition for enacting genetic responsibility or whether intrinsic differences between types of testing make the concept less relevant.

Clinical characterization and mutation spectrum in Hispanic families with adenomatous polyposis syndromes

Several genetically defined hereditary colorectal cancer (CRC) syndromes are associated with colonic polyposis including familial adenomatous polyposis (FAP) and MUTYH adenomatous polyposis (MAP). Limited data exists on the clinical characterization and genotypic spectrum of polyposis syndromes among Hispanics. To describe the phenotype and genotype of Puerto Rican Hispanic patients with FAP and MUTYH and compare with other ethnic and racial groups. Probands were identified from the Puerto Rico Familial Colorectal Cancer Registry (PURIFICAR). Recruited individuals completed risk factors, medical, and family history questionnaires and underwent genetic testing for genotype analysis. Frequency analysis, Chi square, Fisher's exact and Wilcoxon rank-sum tests were used for statistical analysis methods. A total of 31 FAP (from 19 families) and 13 MAP (from 13 families) Hispanic patients recruited from the PURIFICAR were evaluated. Among the FAP cases, mean age at diagnosis was 27.6 (range 9-71 years); 67.7 % cases had more than 100 polyps and 41.9 % had upper gastrointestinal polyps. Among the 19 FAP families, there were 77 affected FAP individuals and 26 colorectal cancer cases. Genetic mutations were available for 42.2 % of FAP families; all mutations identified were unique. Surgeries were reported in 31 cases; 14 (45.2 %) prophylactic surgeries and 6 (19.4 %) therapeutic surgeries for management of CRC. Among MAP cases, mean age at diagnosis was 53 (range 34-76 years). Genetic analysis revealed homozygous biallelic mutations (G382D) in 53.8 %, compound heterozygous mutations (G382/Y165C) in 23 %, and non-G382/Y165C monoallelic mutations in 23 %. Familial cancer registries should be promoted as vehicles for detection, education and follow up of families at-risk of acquiring familial cancers. PURIFICAR is the first and only familial cancer registry in Puerto Rico providing these services to families affected with familial cancer syndromes promoting education, testing and surveillance of at-risk family members, and focusing on cancer prevention efforts. The fact that only 40 % of FAP patients had access to genetic testing stresses the need to promote the establishment of policies supporting genetic testing coverage by medical insurance companies in order to provide patients with the highest standard of care to prevent cancer. Furthermore, our results suggest that Hispanics may have uncommon mutations in adenomatous polyposis related genes, which emphasize the need for full gene sequencing to establish genetic diagnosis.

Lynch syndrome: the patients' perspective

People with Lynch syndrome have a high lifetime risk for the development of colorectal, endometrial and several other types of cancer. Lynch syndrome is caused by germline mutations in genes encoding DNA mismatch repair proteins. In this review, issues that concern Lynch patients are highlighted from the patients' perspective. Both authors are affected by Lynch syndrome and are active in Lynch patient organizations. The goal of this review is to assist heath care providers in the improvement of care for individuals who share our disorder. Institutional and/or national guidelines that should lead to the identification of Lynch patients have been developed in many countries. However, adherence to these guidelines is poor and the consequence is severe underdiagnosis of Lynch syndrome. An important task of patient organizations is therefore to increase awareness of Lynch syndrome among the general public and health care providers. Because diagnosis of Lynch syndrome based on family history is difficult, the use of molecular and or histological techniques that permit unequivocal diagnosis should be more aggressively promoted. Since Lynch syndrome encompasses a broad spectrum of cancers, a multidisciplinary treatment and screening protocol for all Lynch patients is necessary. Lynch patients must be seen by a team of specialists that are knowledgeable in the various manifestations of Lynch syndrome. Because tumors with mismatch repair deficiency have specific properties, identification of effective chemotherapy regimens, specifically targeted to patients with deficiencies in DNA repair mechanisms, must be developed. The high lifetime risk of developing cancer in Lynch patients warrants lifestyle advice and research into chemopreventive measures that reduce the risk of cancer in this vulnerable group. Implementation of these recommendations will result in greatly improved quality of life for people affected with Lynch syndrome, it is therefore important that health care providers and patient organizations work together to achieve these goals.

100 years Lynch syndrome: what have we learned about psychosocial issues?

In the care of patients with Lynch Syndrome (LS), a range of psychosocial issues are encountered, which significantly affect patient outcomes. A brief historical background of 'psycho-onco-genetics' (the domain where psychology, oncology and genetics meet) in relation to LS is presented, followed by an overview of important psychosocial issues identified in the past 20 years. The identification of mismatch repair genes in 1993-1994 made possible genetic counseling and testing for patients who had cancer and for potentially high-risk relatives without cancer. At that time, concerns were raised about the potentially negative psychosocial impact of predictive genetic testing. Since 1993, a large number of studies have been conducted to investigate the possible psychosocial benefits and limitations of such testing. This article presents an overview of: the uptake of and motivations for genetic testing, its psychosocial impact (e.g. psychological adaptation, impact on risk perception and self-concept, and concerns about, and experiences of, genetic discrimination), psychological screening instruments, adherence to and decision-making about preventive strategies, family communication, lifestyle changes, reproductive technology utilization, and professional psychosocial support needs of members of families with LS. Finally, challenges for the future are discussed, including population screening and genomic testing.

Mismatch repair protein immunohistochemistry: a useful population screening strategy for Lynch syndrome

Lynch syndrome (LS), the most frequent form of hereditary colorectal cancer, shows a highly penetrant, autosomal dominant pattern of inheritance. Distinction of LS colorectal carcinoma instances from the much more common sporadic colorectal carcinoma cases is of paramount importance. Revised Bethesda Guidelines were developed to diagnose LS by evaluating a combination of clinical and pathologic data. The aim of the present study was to evaluate the usefulness of the pathology items included in the Revised Bethesda Guidelines. We have prospectively studied a series of 1624 consecutive colorectal carcinomas with an algorithm including immunohistochemical analysis of mismatch repair proteins and molecular study of microsatellite instability and BRAF c.1799 T > A (p.V600E) gene mutations. Patients with tumors showing LS features were referred for germline mutation analysis. By applying our algorithmic approach, we were able to identify LS features in 89 colorectal cancer patients, of whom only 27 met Revised Bethesda Guidelines pathology criteria. Of the 89 patients, 47 were then studied at the Genetic Counseling Unit, and LS was confirmed in 18, of whom 7 had not been identified by the Revised Bethesda Guidelines. Our study shows that the Revised Bethesda Guidelines failed to detect 70% of patients at risk of LS. Our algorithmic approach is a realistic and effective tool for LS identification. We strongly recommend the implementation of universal population screening for LS among all patients with newly diagnosed colorectal carcinoma.

Impact of academic affiliation and training on knowledge of hereditary colorectal cancer

BACKGROUND

Knowledge about hereditary colorectal cancer (CRC) can aid cancer screening and prevention in high-risk patients. Genetic testing, once conducted primarily at academic centers, is now routinely performed in a variety of clinics. Nonacademic physicians may not be aware of hereditary CRC standards of care.

METHODS

From August to November 2012, a survey was administered to predominantly primary care physicians evaluating academic center affiliation, past training in genetics and knowledge regarding hereditary CRC.

RESULTS

One hundred forty physicians completed the survey. Knowledge of hereditary CRC was neither associated with academic affiliation nor with training during medical school or residency, but with continuing medical education (CME) training. Those with CME training were more likely to know that screening could be enhanced for patients with a hereditary cancer risk (OR = 4.49, 95% CI = 1.40-14.38) and that an individual with hereditary CRC would have different screening recommendations (OR = 7.49, 95% CI = 1.37-40.81). Residency training and CME training were associated with more frequent hereditary risk assessment.

CONCLUSION

Genetics training may be associated with physicians' knowledge and assessment of hereditary CRC. Training at the CME level in particular may be integral to the delivery of genetic services in clinical practice.

UK colorectal cancer patients are inadequately assessed for Lynch syndrome

OBJECTIVE

To establish whether colorectal cancer patients in two centres in the UK are screened appropriately for Lynch syndrome, in accordance with current international guidance.

DESIGN

Patients newly diagnosed with colorectal cancer over an 18-month period were identified from the UK National Bowel Cancer Audit Programme. Their records and management were reviewed retrospectively.

SETTING

Two university teaching hospitals, Imperial College Healthcare and Oxford Radcliffe Hospitals NHS Trusts.

OUTCOMES MEASURED

Whether patients were screened for Lynch syndrome-and the outcome of that evaluation, if it took place-were assessed from patients' clinical records. The age, tumour location and family history of screened patients were compared to those of unscreened patients.

RESULTS

Five hundred and fifty three patients with newly diagnosed colorectal cancer were identified. Of these, 97 (17.5%) satisfied the revised Bethesda criteria, and should have undergone further assessment. There was no evidence that those guidelines had been contemporaneously applied to any patient. In practice, only 22 of the 97 (22.7%) eligible patients underwent evaluation. The results for 14 of those 22 (63.6%) supported a diagnosis of Lynch syndrome, but only nine of the 14 (64.3%) were referred for formal mismatch repair gene testing. No factors reliably predicted whether or not a patient would undergo Lynch syndrome screening.

CONCLUSIONS

Colorectal teams in the UK do not follow international guidance identifying the patients who should be screened for Lynch syndrome. Patients and their families are consequently excluded from programmes reducing colorectal cancer incidence and mortality. Multidisciplinary teams should work with their local genetics services to develop reliable algorithms for patient screening and referral.

Knowledge of and practice patterns for hereditary colorectal cancer syndromes in korean surgical residents

Purpose

Obtaining a detailed family history through detailed pedigree is essential in recognizing hereditary colorectal cancer (CRC) syndromes. This study was performed to assess the current knowledge and practice patterns of surgery residents regarding familial risk of CRC.

Methods

A questionnaire survey was performed to evaluate the knowledge and the level of recognition for analyses of family histories and hereditary CRC syndromes in 62 residents of the Department of Surgery, Seoul National University Hospital. The questionnaire consisted of 22 questions regarding practice patterns for, knowledge of, and resident education about hereditary CRC syndromes.

Results

Two-thirds of the residents answered that family history should be investigated at the first interview, but only 37% of them actually obtained pedigree detailed family history at the very beginning in actual clinical practice. Three-quarters of the residents answered that the quality of family history they obtained was poor. Most of them could diagnose hereditary nonpolyposis colorectal cancer and recommend an appropriate colonoscopy surveillance schedule; however, only 19% knew that cancer surveillance guidelines differed according to the family history. Most of our residents lacked knowledge of cancer genetics, such as causative genes, and diagnostic methods, including microsatellite instability test, and indicated a desire and need for more education regarding hereditary cancer and genetic testing during residency.

Conclusion

This study demonstrated that surgical residents' knowledge of hereditary cancer was not sufficient and that the quality of the family histories obtained in current practice has to be improved. More information regarding hereditary cancer should be considered in education programs for surgery residents.

Germline deletions in the EPCAM gene as a cause of Lynch syndrome - literature review

Lynch syndrome (clinically referred to as HNPCC – Hereditary Non-Polyposis Colorectal Cancer) is a frequent, autosomal, dominantly-inherited cancer predisposition syndrome caused by various germline alterations that affect DNA mismatch repair genes, mainly MLH1 and MSH2. Patients inheriting this predisposition are susceptible to colorectal, endometrial and other extracolonic tumors. It has recently been shown that germline deletions of the last few exons of the EPCAM gene are involved in the etiology of Lynch syndrome. Such constitutional mutations lead to subsequent epigenetic silencing of a neighbouring gene, here, MSH2, causing Lynch syndrome. Thus, deletions of the last few exons of EPCAM constitute a distinct class of mutations associated with HNPCC. Worldwide, several investigators have reported families with EPCAM 3’end deletions. The risk of colorectal cancer in carriers of EPCAM deletions is comparable to situations when patients are MSH2 mutation carriers, and is associated with high expression levels of EPCAM in colorectal cancer stem cells. A lower risk of endometrial cancer was also reported. Until now the standard diagnostic tests for Lynch syndrome have contained analyses such as immunohistochemistry and tests for microsatellite instability of mismatch repair genes. The identification of EPCAM deletions or larger EPCAM-MSH2 deletions should be included in routine mutation screening, as this has implications for cancer predisposition.

Survival of patients with Stage III colon cancer is improved in hereditary non-polyposis colorectal cancer compared with sporadic cases. A Danish registry based study

AIM

Patients with hereditary non-polyposis colorectal cancer (HNPCC) seem to have a better prognosis than those with sporadic colorectal cancer (CRC). The aim was to compare survival after Stage III CC in patients with HNPCC with those having sporadic CC.

METHOD

A total of 230 patients with hereditary cancer from the Danish HNPCC Register and 3557 patients with sporadic CC from the Danish Colorectal Cancer Database, diagnosed during May 2001-December 2008, were included. HNPCC patients were classified according to mismatch repair mutation status and family pedigree. Sporadic cases had no known family history of cancer. Patient characteristics, geographical differences and survival data were analysed.

RESULTS

The overall survival (OS) was better in HNPCC patients compared with sporadic CC after stratification for sex and age (P = 0.02; CI 1.04-1.7). The 5-year survival was 70% in HNPCC patients compared with 56% in sporadic CC (P < 0.001). No survival difference was found between HNPCC subgroups but a tendency to better OS was seen in patients with Lynch syndrome. No geographical differences in OS were found. The median follow-up was 3.9 (0-9.5) years for HNPCC vs 3.2 (0-9.6) years for sporadic CC.

CONCLUSION

HNPCC patients with Stage III CC have a better OS compared with sporadic CC. No significant difference in OS was found within HNPCC subgroups.

Population-based molecular screening for Lynch syndrome: implications for personalized medicine

PURPOSE

Molecular screening techniques are available to identify hereditary Lynch syndrome in people with newly diagnosed colorectal cancer (CRC). We aimed to determine whether decisions of patients or clinicians reduced detection of Lynch syndrome.

PATIENTS AND METHODS

A prospective cohort of 245 consecutive individuals with mismatch repair-deficient CRC recruited from a population-based molecular screening program of all incident patient cases of CRC in a health care region of 1.2 million inhabitants. All incident CRCs were analyzed for mismatch repair protein loss, supported by BRAF mutation and microsatellite instability testing. Advice regarding referral for germline testing was provided to treating surgeons.

RESULTS

The mean age of patients was 72.5 ± standard deviation of 12 years; 64% were women; 65% had BRAF-mutant cancers. Consent for germline testing was received from 194 patients (79%): 120 with low and 74 with high likelihood of Lynch syndrome based on tumor molecular profile. Of patients who consented, 143 provided samples for germline analysis, with 12 of 143 showing a mutation (8.4%; 95% CI, 4.4% to 14.2%). Among the 102 patients who chose not to provide a sample or did not consent, an estimated 5.3 of 102 had germline mutations (5.2%; 95% CI, 2.0% to 17.5%).

CONCLUSION

A universal screening strategy for Lynch syndrome is potentially effective because the overall estimate of germline mutations was 17.3 of 245 patient cases (7.1%; 95% CI, 2.8% to 18.2%). However, the true value of screening is likely to be greatly limited by the decisions and circumstances of patients in taking up germline testing.

Role of microsatellite instability in the management of colorectal cancers

Microsatellite instability is the consequence of a deficient mismatch repair system. It has a key role in the diagnostic strategy of Lynch syndrome, where tumours are all characterized by the presence of this phenotype. Microsatellite instability is therefore essential in the selection of colorectal cancer patients in whom a germline analysis of Mismatch Repair genes is possibly indicated. Moreover, microsatellite instability tumours are associated with a good prognosis and a resistance to fluorouracil-based adjuvant chemotherapy, which has a clinical application mainly in stage II colon cancer patients in whom adjuvant chemotherapy has a less beneficial effect than in stage III and outcome in presence of microsatellite instability is excellent. Recent data suggest that impact of microsatellite instability on benefit to fluorouracil-based adjuvant chemotherapy is dependent of the molecular mechanism involved in this genetic instability since an improved survival has been reported with adjuvant fluorouracil in microsatellite instability colorectal cancers of germline origin but not in sporadic cases. Predictive value of microsatellite instability on response to fluorouracil/oxaliplatin adjuvant chemotherapy has been less evaluated but recent studies suggest that the favorable outcome of Microsatellite instability tumours is maintained in patients receiving FOLFOX.