High Risk For Lynch Syndrome Research Articles

Microsatellite instability in endometrial cancer: the role of diagnostic methods and their clinical application. Expert consensus

Deficient DNA mismatch repair (dMMR) is a rare molecular disorder found in 20-30 % of endometrial tumors. Laboratory identification of dMMR/microsatellite instability (MSI) has a high diagnostic value, since these impairments are considered as biomarkers of endometrial adenocarcinoma. They help to identify patients at high risk of Lynch syndrome, evaluate the disease prognosis, and estimate the efficacy of immune checkpoint inhibitors and their combinations. This review details current concepts of MSI diagnostics and discusses its predictive value in patients with endometrial cancer. It also describes a new diagnostic algorithm for the detection of dMMR and MSI.

A152 ASSESSING THE USE OF A VALIDATED LYNCH SCREENING QUESTIONNAIRE IN THE OUTPATIENT SETTING AND SUBSEQUENT CHANGES IN PATIENT MANAGEMENT

Abstract Background Colorectal cancer (CRC) is the second most common cause of cancer related deaths in Canada. Approximately 1 in 13 males and 1 in 18 females will develop colorectal cancer in their lifetimes. As many as 10% of CRC may be associated with an inherited syndrome. Lynch Syndrome (LS) is the most common cause of inherited CRC, estimated to account for 3-4% of all CRC cases. . A study by Kastrinos et al. found that a simple, 3 item survey, identified 77% of individuals with known LS. Implementation of this questionnaire at a gastroenterology office may help identify patients at risk for LS. Purpose To assess whether implementation of a validated questionnaire to screen for LS is feasible in an outpatient gastroenterology clinic, and if these results would change patient management by gastroenterologists. Method Included in this study were all patients 18 years or older, who had been referred to one of the gastroenterologists at Pacific Gastroenterology Associates in Vancouver, British Columbia. Exclusion criteria included those patients less than 18 years of age, and patients previously seen by the HCP. Each subject was asked the following three questions: (1) Do you have a first-degree relative with CRC or LS-related cancer diagnosed before age 50? (2) Have you had CRC or polyps diagnosed before age 50? (3) Do you have ≥3 relatives with CRC?. Answering yes to any question was considered a positive screen. Gastroenterologists were initially blinded to the content of the questionnaire and results. After completion of the questionnaire and formal gastroenterology consultation, the patients who screened positive for an increased risk of LS had their results unblinded to their primary gastroenterologist. Gastroenterologists were then asked if the survey results changed their management. Result(s) A total of 655 patients were screened, with 33 (5.0%) screening positive for question 1, 71 (10.8%) screening positive for question 2, and 17 (2.6%) screening positive for question 3. In total, 106 (15.9%) of individuals surveyed screened positive indicating higher risk for hereditary colorectal cancer. Subsequent reassessment by gastroenterologists of patients screening positive with the LS questionnaire (n=51) yielded no change to 47 patients (92%), screening with colonoscopy not originally planned for 1 patient (2%), re-consultation for further risk assessment for 2 patients (4%) and 1 referral to the Hereditary Cancer Program (2%). Conclusion(s) Utilization of a simple 3-question survey as part of regular patient intake in a gastroenterology office resulted in an increased number of individuals being identified as being high risk for Lynch syndrome, with a subsequent increase in endoscopic screening not otherwise planned, further assessment for colon cancer risk, and an increased referral to the Hereditary Cancer Program. Please acknowledge all funding agencies by checking the applicable boxes below None Disclosure of Interest None Declared

Lynch syndrome testing of colorectal cancer patients in a high-income country with universal healthcare: a retrospective study of current practice and gaps in seven australian hospitals

BackgroundTo inform effective genomic medicine strategies, it is important to examine current approaches and gaps in well-established applications. Lynch syndrome (LS) causes 3–5% of colorectal cancers (CRCs). While guidelines commonly recommend LS tumour testing of all CRC patients, implementation in health systems is known to be highly variable. To provide insights on the heterogeneity in practice and current bottlenecks in a high-income country with universal healthcare, we characterise the approaches and gaps in LS testing and referral in seven Australian hospitals across three states.MethodsWe obtained surgery, pathology, and genetics services data for 1,624 patients who underwent CRC resections from 01/01/2017 to 31/12/2018 in the included hospitals.ResultsTumour testing approaches differed between hospitals, with 0–19% of patients missing mismatch repair deficiency test results (total 211/1,624 patients). Tumour tests to exclude somatic MLH1 loss were incomplete at five hospitals (42/187 patients). Of 74 patients with tumour tests completed appropriately and indicating high risk of LS, 36 (49%) were missing a record of referral to genetics services for diagnostic testing, with higher missingness for older patients (0% of patients aged ≤ 40 years, 76% of patients aged > 70 years). Of 38 patients with high-risk tumour test results and genetics services referral, diagnostic testing was carried out for 25 (89%) and identified a LS pathogenic/likely pathogenic variant for 11 patients (44% of 25; 0.7% of 1,624 patients).ConclusionsGiven the LS testing and referral gaps, further work is needed to identify strategies for successful integration of LS testing into clinical care, and provide a model for hereditary cancers and broader genomic medicine. Standardised reporting may help clinicians interpret tumour test results and initiate further actions.

Colorectal Cancer in North-Eastern Iran: a retrospective, comparative study of early-onset and late-onset cases based on data from the Iranian hereditary colorectal cancer registry

BackgroundThe incidence rate of colorectal cancer (CRC) is increasing among patients below 50 years of age. The reason for this is unclear, but could have to do with the fact that indicative variables, such as tumour location, gender preference and genetic preponderance have not been followed up in a consistent mann er. The current study was primarily conducted to improve the hereditary CRC screening programme by assessing the demographic and clinicopathological characteristics of early-onset CRC compared to late-onset CRC in northeast Iran.MethodsThis retrospective study, carried out over a three-year follow-up period (2014–2017), included 562 consecutive CRCs diagnosed in three Mashhad city hospital laboratories in north-eastern Iran. We applied comparative analysis of pathological and hereditary features together with information on the presence of mismatch repair (MMR) gene deficiency with respect to recovery versus mortality. Patients with mutations resulting in absence of the MMR gene MLH1 protein product and normal BRAF status were considered to be at high risk of Lynch syndrome (LS). Analyses using R studio software were performed on early-onset CRC (n = 222) and late-onset CRC (n = 340), corresponding to patients ≤50 years of age and patients > 50 years.ResultsFrom an age-of-onset point of view, the distribution between the genders differed with females showing a higher proportion of early-onset CRC than men (56% vs. 44%), while the late-onset CRC disparity was less pronounced (48% vs. 52%). The mean age of all participants was 55.6 ± 14.8 years, with 40.3 ± 7.3 years for early-onset CRC and 65.1 ± 9.3 years for late-onset CRC. With respect to anatomical tumour location (distal, rectal and proximal), the frequencies were 61, 28 and 11%, respectively, but the variation did not reach statistical significance. However, there was a dramatic difference with regard to the history of CRC in second-degree relatives between two age categories, with much higher numbers of family-related CRCs in the early-onset group. Expression of the MLH1 and PMS2 genes were significantly different between recovered and deceased, while this finding was not observed with regard to the MSH6 and the MSH2 genes. Mortality was significantly higher in those at high risk of LS.ConclusionThe variation of demographic, pathological and genetic characteristics between early-onset and late-onset CRC emphasizes the need for a well-defined algorithm to identify high-risk patients.

Performance characteristics of brief family history questionnaire to screen for Lynch syndrome in women with newly diagnosed ovarian cancers

<h3>Objectives:</h3> Ovarian cancer (OC) is the third most common Lynch syndrome (LS)-associated cancer in women but there is no established screening strategy to identify LS in this population. In centers without access to universal tumor immunohistochemistry (IHC) testing for mismatch repair (MMR) deficiency, family history may identify patients with OC suspected of LS, prompting a referral to genetic counseling. We have previously developed and shown that patient-administered 4-item brief Family History Questionnaire (bFHQ) can effectively identify women with confirmed LS in those with newly diagnosed endometrial cancers. The objective of this study was to assess whether bFHQ can be used as a screening tool to identify women with OC at high risk of LS. <h3>Methods:</h3> Prospective cohort study recruited women with newly diagnosed non-serous/non-mucinous OC from three cancer centers in Ontario, Canada. Participants completed bHFQ, extended Family History Questionnaire (eFHQ; encompassing Amsterdam II criteria, Society of Gynecologic Oncology 20-25% criteria and Ontario Ministry of Health criteria), IHC for MMR proteins and universal germline testing (reference standard) for LS. The sensitivity, specificity, positive and negative predictive values (PPV, NPV) were compared between the family history screening strategies and MMR IHC to identify LS. <h3>Results:</h3> Of 215 women, 169 (79%) were evaluable with both bFHQ and germline mutation status; 12 of these 169 were confirmed to have LS (7%). Median age was 53 years (range 21-71), and for all 12 patients with LS, OC was their sentinel malignancy (100%). Nine of 12 patients (75%) with LS were correctly identified by bFHQ, compared to 6 of 11 (55%) by eFHQ and 11 of 13 (85%) by IHC. The sensitivity, specificity, PPV and NPV values of bFHQ were 75%, 66%, 15% and 98%, compared to 55%, 92%, 35% and 96% for eFHQ and 85%, 90%, 39% and 99% for IHC respectively (Table 1). IHC was the most sensitive and specific approach. The 4-item bFHQ was more sensitive than eFHQ and took less than 10 minutes for each patient to complete. <h3>Conclusions:</h3> Patient-administered bFHQ may serve as an adequate screening tool to triage women with OC for further genetic assessment for LS, especially in centers without access to universal tumor testing for IHC for MMR or microsatellite instability.

Familial pancreatic cancer: who should be considered for genetic testing?

Determining how many female patients who underwent breast imaging meet the eligibility criteria for genetic testing for familial pancreatic cancer (FPC). A total of 42,904 patients seen at the Newton-Wellesley Hospital between 2007 and 2009 were retrospectively reviewed. The first four categories were based on pancreatic cancer-associated syndromes: (1) hereditary breast and ovarian cancer (HBOC), (2) Lynch syndrome (LS), (3) familial atypical multiple mole melanoma (FAMMM), and (4) family history of FPC (FH-FPC). PancPRO (5) and MelaPRO (6) categories were based on risk scores from Mendelian risk prediction tool. Exactly 4445 of 42,904 patients were found to be in at least one of the six risk categories. About 5.7% of patients were classified as being at high risk for HBOC, 2.3% as being at high risk for LS, 0.1% as being at high risk for FAMMM, 0.1% as being at high risk for FH-FPC, 2.7% as being at high risk based on PancPRO, and 0.2% as being at high risk based on MelaPRO. About 10.4% of the female patients were classified as being at high risk for FPC. This finding emphasizes the importance of applying criteria to the general population, in order to ensure that individuals with high risk are identified early.

Somatic mismatch repair testing in evaluation of Lynch syndrome: The gap between preferred and current practices.

Lynch syndrome (LS) is a hereditary cancer predisposition syndrome primarily defined by increased risk for colorectal and uterine cancers. Individuals with germline pathogenic variants in the mismatch repair (MMR) genes (MLH1, MSH2/EPCAM, MSH6, and PMS2) are diagnosed with LS and recommended high-risk screening protocols to increase prevention and early detection of LS-related cancers. Tumor testing can help identify those at high risk for LS, but sometimes creates uncertainty with discordant screening and germline results, or unexplained mismatch repair deficiency (UMMRD). Somatic testing for MMR genes may help resolve UMMRD, potentially clarifying LS status and modifying cancer surveillance. However, guidelines for such testing are currently limited. This survey of cancer genetic counselors (GCs) aimed to examine current versus preferred ordering practices and interpretation of somatic MMR testing results in LS evaluation. Two hundred eligible GCs practicing in the United States and Canada were recruited from the National Society of Genetic Counselors. Participants answered questions regarding ordering practices, barriers to somatic MMR testing, theoretical scenarios, and desire for further guidelines. Statistical analysis was performed using chi-square, Fisher's exact, and Wilcoxon rank-sum tests, while themes were identified from free-text responses. Most respondents did not include somatic MMR testing in the LS work-up, despite three-quarters reporting they were 'somewhat comfortable' or 'extremely comfortable' with interpreting these results. Approximately half of participants indicated interest in ordering concurrent somatic MMR and germline testing for each of the four theoretical scenarios. Over three-quarters of individuals reported barriers to ordering somatic MMR testing, with cost and coordinating tissue samples most commonly cited. The frequently reported laboratory- and insurance-related barriers may contribute to the gap between preferred and current ordering practices for somatic MMR testing. Nearly all respondents endorsed additional guidelines for this testing, which could reduce barriers and inform screening recommendations for patients with UMMRD and their family members.

Mismatch Repair Protein Expression in Endometrioid Intraepithelial Neoplasia/Atypical Hyperplasia: Should We Screen for Lynch Syndrome in Precancerous Lesions?

Screening for Lynch syndrome (LS) is routinely performed in patients with endometrial carcinoma. Currently, no screening recommendations exist for LS in precancerous lesions. The study goal was to determine the incidence of abnormal protein expression in endometrioid intraepithelial neoplasia/atypical hyperplasia (EIN/AH). We analyzed mismatch repair (MMR) protein expression by immunohistochemistry in EIN/AH concurrent with MMR-deficient endometrial carcinomas, and in endometrial biopsy/curettage specimens with EIN/AH from an unselected group of patients. Of 63 patients with MMR-deficient endometrial carcinoma, 34 demonstrated loss of MLH1/PMS2 expression; 1 showed loss of PMS2 alone; 12 showed loss of MSH2/MSH6, and 15 had loss of MSH6 alone. Genetic testing identified deleterious mutations in 14 cases (LS). 15 tumors demonstrated MLH1 promoter hypermethylation. Abnormal MMR expression in EIN/AH and adjacent carcinoma was concordant in 100% of LS cases and 71% of MLH1 promoter hypermethylation cases. Of 118 patients from the unselected group with EIN/AH, 4 (3%) cases demonstrated absent expression of one or more MMR proteins. Of these, 2 patients were later confirmed to have deleterious mutations in subsequent specimens with endometrial carcinoma. The prevalence of abnormal MMR expression in EIN/AH adjacent to carcinoma and in the unselected group of patients with EIN/AH is similar to the reported prevalence of LS in endometrial carcinoma. Identifying patients at high risk for LS through abnormal MMR expression in EIN/AH provides the benefit of early surveillance, treatment and timely diagnosis for the patient and affected family members.

Using behaviour change and implementation science to address low referral rates in oncology

BackgroundPatients undergoing surgery for bowel cancer now have a routine screening test to assess their genetic predisposition to this and other cancers (Lynch syndrome). A result indicating a high risk should trigger referral to a genetic clinic for diagnostic testing, information, and management. Appropriate management of Lynch syndrome lowers morbidity and mortality from cancer for patients and their family, but referral rates are low. The aim of this project was to increase referral rates for patients at high risk of Lynch syndrome at two Australian hospitals, using the Theoretical Domains Framework (TDF) Implementation approach.MethodsMultidisciplinary teams at each hospital mapped the referral process and discussed barriers to referral. A 12-month retrospective audit measured baseline referral rates. The validated Influences on Patient Safety Behaviours Questionnaire was administered to evaluate barriers using the TDF. Results were discussed in focus groups and interviews, and interventions co-designed, guided by theory. Continuous monitoring audits assessed change in referral rates.ResultsTeams (n = 8, 11) at each hospital mapped referral processes. Baseline referral rates were 80% (4/5) from 71 screened patients and 8% (1/14) from 113 patients respectively. The questionnaire response rate was 51% (36/71). Most significant barrier domains were: ‘environmental context;’ ‘memory and decision making;’ ‘skills;’ and ‘beliefs about capabilities.’ Focus groups and interviews with 19 healthcare professionals confirmed these domains as significant. Fifteen interventions were proposed considering both emerging and theory-based results. Interventions included: clarification of pathology reports, education, introduction of e-referrals, and inclusion of genetic status in documentation.Audits continued to December 2016 showing a change in pathology processes which increased the accuracy of screening. The referral rate remained low: 46% at Hospital A and 9% Hospital B. Results suggest patients who have their referral deferred for some reason are not referred later.ConclusionLynch syndrome is typical of low incidence problems likely to overwhelm the system as genomic testing becomes mainstream. It is crucial for health researchers to test methods and define generalizable solutions to address this problem. Whilst our approach did not improve referrals, we have deepened our understanding of barriers to referral and approaches to low frequency conditions.

Universal tumor screening for Lynch syndrome: perspectives of Canadian pathologists and genetic counselors.

Universal screening of all newly diagnosed colorectal cancer tumors can identify individuals at high risk for Lynch syndrome (LS), a hereditary cancer syndrome predisposing carriers to increased risk of colorectal, endometrial, and other cancers. To inform planning of a universal tumor screening program for LS in our jurisdiction, we undertook online surveys of Canadian pathologists and genetic counselors to describe existing tumor screening programs. Online surveys were hosted on SurveyMonkey between October 2016 and March 2017. Fifty-three pathologists and 66 genetic counselors completed surveys (total n = 119). While attitudes towards tumor screening were positive, considerable variability was observed in the existence of tumor screening, test ordering criteria, and practices. Most respondents indicated consent was not obtained for tumor screening nor were educational materials provided to patients; however, opting out of additional mutation testing in the event of a positive tumor screen was endorsed. Results add to the growing literature on providers' perspectives on population-based tumor screening programs and inform ways to offer these. Findings highlight the need to develop methods of patient education that allow meaningful opt-out decisions. The variability we observed also suggests the need for national standards and guidance on tumor screening for LS.

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.

Lessons learnt from implementation of a Lynch syndrome screening program for patients with gynaecological malignancy

Despite a trend towards universal testing, best practice to screen patients presenting with gynaecological malignancy for Lynch syndrome (LS) is uncertain. We report our institutional experience of a co-ordinated gynaecological LS screening program. All patients with endometrial carcinoma or carcinosarcoma, or gynaecological endometrioid or clear cell carcinomas undergo reflex four panel immunohistochemistry (IHC) for MLH1, PMS2, MSH2 and MSH6 followed by cascade somatic hypermethylation analysis of the MLH1 promoter locus for dual MLH1/PMS2 negative tumours. On the basis of these results, genetic counselling and targeted germline mutation testing is then offered to patients considered at high risk of LS. From 1 August 2013 to 31 December 2015, 124 patients were screened (mean age 64.6 years). Thirty-six (29.0%) demonstrated abnormal MMR IHC: 26 (72.2%) showed dual loss of MLH1/PMS2, five (13.9%) dual loss of MSH2/MSH6, three (8.3%) isolated loss of MSH6, and two (5.6%) isolated loss of PMS2. Twenty-five of 26 (96.1%) patients with dual MLH1/PMS2 loss demonstrated MLH1 promoter methylation. Therefore, 11 (8.9%) patients screened were classified as high risk for LS, of whom nine (81.8%) accepted germline mutation testing. Three (2.4% of total screened) were confirmed to have LS, two with germline PMS2 and one with germline MSH2 mutation. Massive parallel sequencing of tumour tissue demonstrated somatic mutations which were concordant with the IHC results in the remainder. Interestingly, the one MLH1/PMS2 IHC negative but not hypermethylated tumour harboured only somatic MLH1 mutations, indicating that universal cascade methylation testing in MLH1/PMS2 IHC negative tumours is very low yield and could be reconsidered in a resource-poor setting. In conclusion, universal screening for LS in patients presenting with gynaecological malignancy using the algorithm described above identified LS in three of 124 (2.4%) of our population. Only three of nine (33.3%) patients considered at high risk for LS by combined IHC and hypermethylation analysis were proven to have LS. Only one of the LS patients was less than 50 years of age and none of these patients would have been identified had more restrictive Amsterdam or Bethesda criteria been applied.

Mo1067 High Yield Pro-Active Outreach Program for Identifying Patients At High Risk for Lynch Syndrome After Surgery for Colorectal Cancer -Results of a Pilot Study

Mo1067 High Yield Pro-Active Outreach Program for Identifying Patients At High Risk for Lynch Syndrome After Surgery for Colorectal Cancer -Results of a Pilot Study

A clinical scoring system to identify patients with sebaceous neoplasms at risk for the Muir–Torre variant of Lynch syndrome

The Muir-Torre syndrome variant of Lynch syndrome is characterized by the presence of sebaceous neoplasms (adenoma, epithelioma/sebaceoma, carcinoma) and Lynch syndrome-associated cancers (colon, endometrial, and others). Several clinical scoring systems have been developed to identify patients with colon cancer at high risk of Lynch syndrome. However, no such system has been described for patients presenting with sebaceous neoplasms. Based on logistic regression analysis, a scoring system was developed for patients with sebaceous neoplasm to identify those with the highest likelihood of having Muir-Torre syndrome. The final version of the scoring system included variables such as age at presentation of initial sebaceous neoplasm, total number of sebaceous neoplasms, personal history of a Lynch-related cancer, and family history of Lynch-related cancers. Patients with a score of 3 or more were more likely to have Muir-Torre syndrome (28 of 29 patients), those with a score of 2 had intermediate likelihood (12 of 20 patients), and no patient with a score of 0 or 1 was diagnosed with Muir-Torre syndrome. The Mayo Muir-Torre syndrome risk scoring system appears to identify whether patients who present with sebaceous neoplasms are in need of further Lynch syndrome evaluation using easily ascertained clinical information. Abnormal mismatch repair gene immunohistochemistry of a sebaceous neoplasm is a poor predictor in regard to diagnosing Lynch syndrome.

Microsatellite Instability Testing in Colorectal Carcinoma: A Practical Guide

In this month’s “Road Ahead” article, we continue last month’s theme that focused on the role of pathology in the care of our GI patients. Many gastroenterologists have successfully incorporated pathology into their core practices either within a business infrastructure or as part of a larger health care system. Dr Gibson and her colleagues at Yale University School of Medicine have helped inform us about a particularly difficult management problem: how to handle the genetically high-risk patients we see frequently in our hospitals and endoscopy units. New comprehensive practice guidelines concerning management of hereditary colon cancer syndromes are in development, but this short article provides a clear and concise guide for the practicing gastroenterologist.

Easy‐to‐use online referral test detects most patients with a high familial risk of colorectal cancer

Currently only 12-30% of individuals with a high risk of Lynch syndrome, the most common hereditary colorectal cancer (CRC) syndrome, are referred for genetic counselling. We assessed the sensitivity, usability and user experiences of a new online referral test aimed at improving referral of high-risk individuals for genetic counselling. Sensitivity was assessed by entering pedigree data from high-risk individuals (i.e. Lynch syndrome mutation carriers) into the referral test to determine whether genetic counselling was recommended. For usability, we assessed nonmedical staff members' ability to determine referral, according to guidelines, in seven fictive clinical cases using the referral test after minimal training. Real-life users answered questions about their experience with the referral test. Sensitivity of the referral test was 91% for mutation carriers with CRC (n=164) and 73% for all affected and nonaffected mutation carriers (n=420). Nonmedical staff members (n=20) determined referral according to guidelines in 84% of cases using the referral test. Ten per cent (256/2470) of real-life users provided feedback about experiences; of those, 71% reported that the referral test increased reassurance, certainty about their familial risk and/or certainty about referral. The referral test has a high sensitivity in detecting individuals with a high risk of Lynch syndrome and is suitable for use in clinical practice. Widespread use of the referral test should improve cancer prevention in high-risk patients and their relatives.

Increasing Lynch Syndrome Identification Through Establishment of a Hereditary Colorectal Cancer Registry

Lynch syndrome contributes to 5% of all colorectal cancers. Patients seen in most surgical clinics have limited or no family histories documented and are rarely assessed for hereditary syndromes. In 2007 a clinic-based hereditary colorectal cancer registry was established to screen for Lynch syndrome and facilitate genetic counseling/testing. To evaluate the effectiveness of the hereditary colorectal cancer registry to identify high-risk colorectal cancer patients and have them referred for genetic counseling/testing for Lynch syndrome. A retrospective review and cohort comparison of both prospectively collected and retrospective data. The colorectal surgical clinic at Vanderbilt University Medical Center. All newly diagnosed colorectal cancer patients seen between January 2006 and October 2010. To assess the identification of colorectal cancer patients at high risk for Lynch syndrome and for the occurrence of genetic counseling/testing before and after the establishment of a hereditary registry by comparing the results from the colorectal cancer patients seen the year prior to the establishment of the registry (January - December 2006, "control period") with those patients seen after initiation of the registry (January 2007 - October 2010, "registry period"). During the "registry period," 495 colorectal cancer patients were seen in the clinic and 257 (51.9%) were high risk for Lynch syndrome. Forty-nine patients (9.8%) underwent genetic testing, with 27 (5.4%) positive for a gene mutation, of which half were >50 years old. By comparison, in 2006, 115 colorectal cancer patients were seen in the clinic but only 4 patients (3.5%) went on for further assessment, and only 1 had genetic testing. Retrospective assessment showed that at least 22 patients (19.1%) had warranted further investigation in 2006. This was a single-institution, retrospective review. Establishment of a hereditary colorectal cancer registry with a clinic-based protocol improves identification of Lynch syndrome.

Psychological distress in newly diagnosed colorectal cancer patients following microsatellite instability testing for Lynch syndrome on the pathologist’s initiative

According to the Dutch Guideline on Hereditary Colorectal Cancer published in 2008, patients with recently diagnosed colorectal cancer (CRC) should undergo microsatellite instability (MSI) testing by a pathologist immediately after tumour resection if they are younger than 50 years, or if a second CRC has been diagnosed before the age of 70 years, owing to the high risk of Lynch syndrome (MIPA). The aim of the present MIPAPS study was to investigate general distress and cancer-specific distress following MSI testing. From March 2007 to September 2009, 400 patients who had been tested for MSI after newly diagnosed CRC were recruited from 30 Dutch hospitals. Levels of general distress (SCL-90) and cancer-specific distress (IES) were assessed immediately after MSI result disclosure (T1) and 6 months later (T2). Response rates were 23/77 (30%) in the MSI-positive patients and 58/323 (18%) in the MSI-negative patients. Levels of general distress and cancer-specific distress were moderate. In the MSI-positive group, 27% of the patients had high general distress at T1 versus 18% at T2 (p = 0.5), whereas in the MSI-negative group, these percentage were 14 and 18% (p = 0.6), respectively. At T1 and T2, cancer-specific distress rates in the MSI-positive group and MSI-negative group were 39 versus 27% (p = 0.3) and 38 versus 36% (p = 1.0), respectively. High levels of general distress were correlated with female gender, low social support and high perceived cancer risk. Moderate levels of distress were observed after MSI testing, similar to those found in other patients diagnosed with CRC. Immediately after result disclosure, high cancer-specific distress was observed in 40% of the MSI-positive patients.

Synchronous Breast Cancers With Different Morphologic and Molecular Phenotypes Occurring in Lynch Syndrome

The increasingly widespread use of immunohistochemistry in the detection of DNA mismatch repair proteins has led to the observation of various unusual tumor types that occur in Lynch syndrome and exhibit mismatch repair protein deficiency. Understanding the clinical significance of such unusual tumors has become increasingly desirable. Here, we report a case of 2 synchronous breast cancers occurring in a 74-year-old woman who carried a deleterious germline mutation in MSH2 and who survived an endometrial and a colonic carcinoma. Both breast cancers were of lobular type with similar expression patterns for estrogen receptor, progesterone receptor, and Her2/neu. However, the 2 cancers differed in other characteristics. One tumor showed a solid alveolar histologic pattern with prominent tumor-infiltrating lymphocytes and loss of MSH2 and MSH6 protein on immunohistochemical staining. In contrast, the other tumor was of classic type with no apparent lymphocytic infiltration and no loss of mismatch repair protein. Such a case carries practical implications as it suggests that certain breast cancers may serve as tissue samples for the detection of mismatch repair deficiency in families at high risk for Lynch syndrome, thus expanding the test sample repertoire for genetic workup in these families. Furthermore, the case exemplifies the complexity of tumorigenesis in Lynch syndrome patients. The observation that, of the 2 breast cancers, increased tumor-infiltrating lymphocytes were present only in the tumor that showed mismatch repair protein abnormality is in keeping with what has been observed in the colon and other sites. Such persistent genotype-phenotype correlation across different organs affords the promise that molecular classification may allow identification of biologically distinct tumor subsets beyond the confines of the tumor's primary anatomic location.

Detection of DNA mismatch repair proteins in fresh human blood lymphocytes - towards a novel method for hereditary non-polyposis colorectal cancer (Lynch syndrome) screening

BackgroundA broad population-based assay to detect individuals with Lynch Syndrome (LS) before they develop cancer would save lives and healthcare dollars via cancer prevention. LS is caused by a germline mutation in a DNA mismatch repair (MMR) gene, especially protein truncation-causing mutations involving MSH2 or MLH1. We showed that immortalized lymphocytes from LS patients have reduced levels of full-length MLH1 or MSH2 proteins. Thus, it may be feasible to identify LS patients in a broad population-based assay by detecting reduced levels of MMR proteins in lymphocytes.MethodsAccordingly, we determined whether MSH2 and MLH1 proteins can also be detected in fresh lymphocytes. A quantitative western blot assay was developed using two commercially available monoclonal antibodies that we showed are specific for detecting full-length MLH1 or MSH2. To directly determine the ratio of the levels of these MMR proteins, we used both antibodies in a multiplex-type western blot.ResultsMLH1 and MSH2 levels were often not detectable in fresh lymphocytes, but were readily detectable if fresh lymphocytes were first stimulated with PHA. In fresh lymphocytes from normal controls, the MMR ratio was ~1.0. In fresh lymphocytes from patients (N > 50) at elevated risk for LS, there was a bimodal distribution of MMR ratios (range: 0.3-1.0).ConclusionsFinding that MMR protein levels can be measured in fresh lymphocytes, and given that cells with heterozygote MMR mutations have reduced levels of full-length MMR proteins, suggests that our immunoassay could be advanced to a quantitative test for screening populations at high risk for LS.