Genetic Testing For Lynch Syndrome Research Articles

Microsatellite Instability Is Insufficiently Used as a Biomarker for Lynch Syndrome Testing in Clinical Practice.

The pan-cancer presence of microsatellite instability (MSI)-positive tumors demonstrates its clinical utility as an agnostic biomarker for identifying immunotherapy-eligible patients. Additionally, MSI is a hallmark of Lynch syndrome (LS), the most prevalent cancer susceptibility syndrome among patients with colorectal and endometrial cancer. Therefore, MSI-high results should inform germline genetic testing for cancer-predisposing genes. However, in clinical practice, such analysis is frequently disregarded. A next-generation sequencing (NGS)-based technique was used for MSI analysis in 4,553 patients with various tumor types. Upon request, somatic BRAF gene analysis was conducted. In addition, hereditary testing of cancer-associated genes was performed in MSI-high cases using a capture-based NGS protocol. MLH1 promoter methylation analysis was conducted retrospectively in patients with colorectal and endometrial cancer to further investigate the origin of MSI at the tumor level. The MSI positivity rate for the entire cohort was 5.27%. Endometrial, gastric, colorectal, urinary tract, and prostate cancers showed the highest proportion of MSI-high cases (15.69%, 8.54%, 7.40%, 4.55%, and 3.19%, respectively). A minority of 45 patients (22.73%) among the MSI-high cases underwent germline testing to determine whether the mismatch repair pathway deficiency was inherited. 24.44% of those who performed the genetic test carried a pathogenic variant in an LS-associated gene. Three MSI-high individuals had non-LS gene alterations, including BRCA1, BRCA2, and CDKN2A pathogenic variants, indicating the presence of non-LS-associated gene alterations among MSI-high patients. Although MSI analysis is routinely performed in clinical practice, as many as 77% of MSI-high patients do not undergo LS genetic testing, despite international guidelines strongly recommending it. BRAF and MLH1 methylation analysis could shed light on the somatic origin of MSI in 42.50% of the MSI-high patients; however, MLH1 analysis is barely ever requested in clinical practice.

Experiences of patients and family members with follow-up care, information needs and provider support after identification of Lynch Syndrome

BackgroundLynch Syndrome is among the most common hereditary cancer syndromes and requires ongoing cancer surveillance, repeated screenings and potential risk-reducing surgeries. Despite the importance of continued surveillance, there is limited understanding of patient experiences after initial testing and counseling, the barriers or facilitators they experience adhering to recommendations, and how they want to receive information over time.MethodsA cross-sectional, observational study was conducted among 127 probands and family members who had received genetic testing for Lynch Syndrome. We conducted semi-structured interviews to determine proband and family member experiences after receiving genetic testing results including their surveillance and screening practices, information needs, and interactions with health care providers. Both closed-ended and open-ended data were collected and analyzed.ResultsBoth probands (96.9%) and family members (76.8%) received recommendations for follow-up screening and all probands (100%) and most family members (98.2%) who tested positive had completed at least one screening. Facilitators to screening included receiving screening procedure reminders and the ease of making screening and surveillance appointments. Insurance coverage to pay for screenings was a frequent concern especially for those under 50 years of age. Participants commented that their primary care providers were often not knowledgeable about Lynch Syndrome and surveillance recommendations; this presented a hardship in navigating ongoing surveillance and updated information. Participants preferred information from a knowledgeable health care provider or a trusted internet source over social media or support groups.ConclusionsProbands and family members receiving genetic testing for Lynch Syndrome generally adhered to initial screening and surveillance recommendations. However, factors such as insurance coverage and difficulty finding a knowledgeable healthcare provider presented barriers to receiving recommended follow-up care. There is an opportunity to improve care through better transitions in care, procedures to keep primary care providers informed of surveillance guidelines, and practices so that patients receive reminders and facilitated appointment setting for ongoing screening and surveillance at the time they are due.

The neglected role of preimplantation genetic testing for Lynch syndrome

Preimplantation genetic testing for monogenic/single-gene disorders (PGT-M) is a procedure employed in the field of assisted reproductive technology to avoid the transmission of genetic diseases to the offspring. Hereditary cancer syndromes represent a diffuse and accepted indication for PGT-M, but take-up differs among the different disorders. Its use is markedly lower for the genes causing Lynch syndrome compared with the breast cancer type 1 or 2 susceptibility genes (BRCA1/2), despite the similar prevalence and severity of the two conditions. Reasons to explain this difference have not been explored. First, Lynch syndrome may be more frequently undiagnosed compared with hereditary breast and ovarian cancer syndrome. In addition, the different take-up may be due to different patient perceptions of the conditions and of the management options. Finally, this distinct attitude may depend on the awareness and sensibility of the professionals caring for affected patients. The authors’ considerations are, however, speculative, and specific studies aimed at disentangling the causes of the different receptions of PGT-M are warranted to understand how to tackle this gap. In the meantime, we believe that empowerment regarding PGT-M of all individuals with hereditary cancer syndromes, including Lynch syndrome, is ethically due, and plead for a more active involvement of caregivers.

Medicaid Expansions: Probing Medicaid's Filling of the Cancer Genetic Testing and Screening Space.

Cancer is the third largest source of spending for Medicaid in the United States. A working group of the American Public Health Association Genomics Forum Policy Committee reviewed 133/149 pieces of literature addressing the impact of Medicaid expansion on cancer screening and genetic testing in underserved groups and the general population. Breast and colorectal cancer screening rates improved during very early Medicaid expansion but displayed mixed improvement thereafter. Breast cancer screening rates have remained steady for Latina Medicaid enrollees; colorectal cancer screening rates have improved for African Americans. Urban areas have benefited more than rural. State programs increasingly cover BRCA1/2 and Lynch syndrome genetic testing, though testing remains underutilized in racial and ethnic groups. While increased federal matching could incentivize more states to engage in Medicaid expansion, steps need to be taken to ensure that they have an adequate distribution of resources to increase screening and testing utilization.

MP47-20 UNIVERSAL GERMLINE GENETIC TESTING OF PATIENTS WITH NEWLY DIAGNOSED UPPER TRACT UROTHELIAL CARCINOMA: AN INTERIM ANALYSIS

You have accessJournal of UrologyCME1 May 2022MP47-20 UNIVERSAL GERMLINE GENETIC TESTING OF PATIENTS WITH NEWLY DIAGNOSED UPPER TRACT UROTHELIAL CARCINOMA: AN INTERIM ANALYSIS Craig Labbate, Donika Saporito, Maureen Mork, Eduardo Vilar Sanchez, Eric Jonasch, Mehrad Adibi, and Surena Matin Craig LabbateCraig Labbate More articles by this author , Donika SaporitoDonika Saporito More articles by this author , Maureen MorkMaureen Mork More articles by this author , Eduardo Vilar SanchezEduardo Vilar Sanchez More articles by this author , Eric JonaschEric Jonasch More articles by this author , Mehrad AdibiMehrad Adibi More articles by this author , and Surena MatinSurena Matin More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002618.20AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Upper tract urothelial carcinoma (UTUC) is a known Lynch Syndrome associated malignancy. Screening for LS after diagnosis by immunohistochemistry can be limited by low volume of biopsied tissue. At one tertiary cancer center, we have referred all new diagnoses of UTUC for germline genetic testing. METHODS: All new patients with a diagnosis of upper tract urothelial carcinoma seen between 9/2020 to 10/2021 were referred for genetic counseling and detailed family history assessment. If willing, patients underwent germline genetic testing of MLH1, MSH2, MHS6, PMS2, EPCAM, BRCA1 and BRCA2 by a CLIA certified lab (Invitae, San Francisco, CA). Both direct sequencing and copy number variations were assessed. RESULTS: One hundred fifty-one patients were offered genetic testing of which 76 underwent genetic counseling and 49 proceeded to genetic testing. Of those who underwent testing, there were 5 (10%) detected pathogenic variants (4 in MMR genes [3 MSH6, 1 MSH2], 1 BRCA1). Additionally, 4 (8%) patients had variants of unknown significance (2 MSH2, 1 MSH6, 1 BRCA2). Forty patients had negative genetic testing. No patient, including all 7 with MMR alterations, met strict Amsterdam II criteria for Lynch Syndrome genetic testing by family history. CONCLUSIONS: Universal germline genetic testing of patients with newly diagnosed upper tract urothelial carcinoma revealed that 14% of patients harbored pathogenic or VUS alterations in MMR and 4% within BRCA genes. Universal germline testing may identify a higher incidence of Lynch Syndrome than previously reported in prescreened cohorts. Source of Funding: Pam and Jim Harris UTUC Lynch Syndrome Screening Fund © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e818 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Craig Labbate More articles by this author Donika Saporito More articles by this author Maureen Mork More articles by this author Eduardo Vilar Sanchez More articles by this author Eric Jonasch More articles by this author Mehrad Adibi More articles by this author Surena Matin More articles by this author Expand All Advertisement PDF DownloadLoading ...

A Case of Aplastic Anemia and Colon Cancer With Underlying Spliceosome Mutation: Is It an Incidental Finding or a Novel Association?

Alternative splicing is an epigenetic mechanism that plays a role in the development and function of antigen-specific lymphocytes. One such is the zinc-finger-RNA-binding-motif-and-serine/arginine-rich-2 (ZRSR2), which is clinically implicated in myelodysplastic syndrome and leukemia. Here, we present a case of a young male with myriad autoimmune conditions and adenocarcinoma of the colon in the setting of ZRSR2 mutation.A 28-year-old male with common variable immunodeficiency disease, atopic dermatitis, autoimmune gastroenteropathy, inflammatory polyarthropathy, primary bone marrow failure, colon cancer, and family history of Lynch syndrome was admitted to our hospital for an acute flare of autoimmune enteropathy secondary to subtherapeutic tacrolimus levels.He initially developed pancytopenia at the age of 26 years. Workup for HIV, hepatitis, cytomegalovirus, human-herpesvirus 6, parvovirus was negative. Partial thromboplastin time (PTT), international normalized ratio (INR), d-dimer, ferritin, iron profile, antinuclear antibodies (ANA) screen was unremarkable. Direct, indirect, and super-combs antibodies were undetectable. Chromosomal study for Fanconi-related chromosomal breakage and telomerase gene panel was negative. Flow cytometry did not reveal an abnormal clone. Bone marrow biopsy showed markedly hypocellular marrow with reduced trilineage hematopoiesis and 1% blasts with normal cytogenetics, immunohistochemistry, fluorescence in situ hybridization (FISH), and negative for myelodysplastic syndrome and paroxysmal nocturnal hemoglobinuria (PNH). Cincinnati inherited children’s bone marrow transplant (BMT) panel was negative. He was diagnosed with aplastic anemia and was treated with antithymocyte globulin, cyclosporine, prednisone, and currently tacrolimus. At the age of 26 years, he was diagnosed with colon cancer. Immunohistochemistry was positive for MLH1, but the confirmatory genetic testing for Lynch syndrome was negative. He underwent total proctocolectomy and ileostomy and is currently in remission. Next-generation sequencing of bone marrow revealed a germline homozygous ZRSR2 mutation. ZRSR2 spliceosome mutations are more common in males as it’s an X-linked gene. They are seen in myelodysplastic syndrome, leukemia, increased autoimmune phenomenon, and 35 cases of colon cancer associated with this mutation are reported. In the setting of aplastic anemia and lynch negative colon cancer, we suspect our patient could have aplastic anemia due to an autoimmune phenomenon, underlying common variable immunodeficiency disease (CVID), or the new ZRSR2 mutation could be playing a role. Further studies and research is warranted to determine its true association with the disease entities. The underlying contributing factor is ZRSR2 mutation.

Reporting Subclonal Immunohistochemical Staining of Mismatch Repair Proteins in Endometrial Carcinoma in the Times of Ever-Changing Guidelines.

The current College of American Pathologists reporting guideline for mismatch repair protein (MMRP) immunohistochemistry for Lynch syndrome (LS) screening considers the presence of any positive nuclear staining as intact MMRP expression. This would include tumors with combined areas of subclonal retention and loss of MMRP staining. To evaluate the clinical significance of reporting subclonal staining patterns of MMRP immunohistochemistry in endometrial carcinoma. We retrospectively reviewed 455 consecutive MMRP immunohistochemistry results of endometrial carcinoma in hysterectomy specimens from 2012 through 2017 and identified cases with subclonal MMRP staining. These results were correlated with the patient's personal and family history of LS-associated carcinoma, MLH1 promoter methylation status, and LS genetic testing. Subclonal staining of MMRP was seen in 48 of 455 cases (10.5%) on review. Thirty cases demonstrated isolated subclonal staining and were reported by pathologists as follows: subclonal (n = 5), complete MMRP loss (n = 4), and intact MMRP (n = 21). Eighteen cases had subclonal staining in combination with complete loss of other MMRP. Cases reported as subclonal or complete MMRP loss had appropriate clinical follow-up. Two of 2 cases with isolated subclonal MSH6 loss tested positive for LS. One of 3 cases with isolated subclonal MLH1/PMS2 loss was negative for MLH1 promoter methylation; LS genetic testing was not performed because of cost. Our study reveals that LS germline mutation can be detected in endometrial carcinoma patients whose tumors display sole subclonal MMRP staining. Our results stress the importance of reporting subclonal staining patterns to ensure appropriate clinical follow-up.

Cascade Genetic Testing for Lynch Syndrome: Current Understanding, Challenges, and Emerging Opportunities

Cascade genetic testing, a highly effective method of identifying high penetrance cancer risk mutations in the family, is a promising method of prevention. Cascade testing is defined as directed genetic testing of at-risk relatives of individuals known to have actionable mutations However, it is tremendously underutilized in clinical practice, and the reasons are complex and diverse. We discuss these reasons and consider areas of research for key findings, strengths and weaknesses. We offer testable solutions for increasing interest and use of cascade testing opportunities in families and in clinical practice using colorectal cancer as an example. This area of clinical research has great potential to save lives by improving cancer prevention and early detection in families at high genetic risk, and should be actively pursued with resources and ideas.

Abstract PO-052: A multisystem approach doubles the number of patients referred for genetic testing and diagnosed with Lynch syndrome with equally success among ethnic/racial groups

Abstract Background: Lynch syndrome (LS) affects 1/279 individuals and accounts for 3-5% of all colorectal cancers (CRC). LS is due to germline mutations in mismatch repair (MMR) genes MLH1, MSH2, MSH6, or PMS2. Tumors exhibit MMR deficiency, expressed as loss of MMR protein expression on immunohistochemistry (IHC). A subset of sporadic tumors also has MMR deficiency due to inactivation of MLH1 via promoter methylation and about 2/3 have BRAFV600E mutations. Increased surveillance and chemoprevention reduce cancer incidence and mortality in LS. LS is largely underdiagnosed, particularly among minorities. Universal screening of CRC tumors through IHC is recommended in order to help identify patients for LS genetic testing. Nevertheless, even in programs that have implemented this, minority patients with MMR deficient tumors were found to be consistently under-referred mostly due to referral bias. We set up a strategy to increase LS and tackle disparities in cancer genetics (CG). Methods: This study reports on the analysis of universal CRC IHC testing for MMR expression, initially followed by BRAF V600E and later by MLH1 testing for loss of MLH1/PMS2 expression, from implementation (1/1012) until 1/1021. In 6/2015, a system was established where a designated Pathologist reviewed all results and a list of identified candidates for germline LS testing (abnormal MMR expression/wild type BRAF or methylation of MLH1) was sent to the CG program. After a two-week period, if no referral had been placed, a genetic counselor (GC) messaged the provider requesting a referral. The pathology side was fully automated in 9/2018 through the monitoring engine Repetitive Tasks Scheduling Engine (RTSE) that pulls data stored in the underlying relational database-Adaptive Server Enterprise, which is accessible to RTSE via a Java Database Connectivity API. This process automatically generates weekly emails that report all cases with suspicion criteria for LS to CG. Results: Since 1-2012, 1,433 patients with CRC underwent tumor testing and were included in this study: 78.5% non-Hispanic white (NHW); 12.2% African American (AA); 6.77% Hispanic (H). Prior to the interventions 25% of eligible patients were referred to CG and none among AA. Once the interventions were established, appropriate referrals prior to messaging the provider were 39.5% for NHW, 35.7% for AA, and 42.8% for H. As a result of the messages, referral rates increased to 80.5% (p=0.00) in NHW, 85.7% in AA (p=0.05), and 71.5% in H (ns). The total number of patients diagnosed with LS since universal testing started was 19: 2 prior to the interventions (0.8% of all CRC); 17 during the interventions (1.5% of all CRC). Conclusion: A systematic, automated, multi-system approach, that includes a targeted message to providers can double the number of appropriate referrals for genetic testing to rule out Lynch syndrome and resulted in almost twice the percentage of LS diagnosis with equal success among AA, H, and NHW. Citation Format: Vinit Singh, Amanda Ganzak, Peter Gershkovich, Joanna Gibson, Rosa M. Xicola, Xavier Llor. A multisystem approach doubles the number of patients referred for genetic testing and diagnosed with Lynch syndrome with equally success among ethnic/racial groups [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-052.

What would I do? Perspectives on the factors underlying Lynch syndrome genetic testing and results sharing decisions for high-risk colorectal cancer patients.

ObjectiveUniversal tumour testing for Lynch syndrome (LS) in all incident colorectal cancers (CRCs) and sequential diagnostic genetic testing is cost‐effective in Australia. Because of this, our study aimed to understand factors underlying possible decisions faced by tumour test‐positive CRC patients and their at‐risk relatives throughout the LS diagnosis pathway.MethodsSemi‐structured telephone interviews were conducted with 23 participants, using four hypothetical scenarios. Vignette‐guided closed‐ and open‐ended questions asked about LS genetic testing uptake, discussing diagnosis with at‐risk relatives, and risk‐reducing interventions. Personal perspectives on genetic testing were collected pre‐post vignette discussion. Inductive thematic analysis was performed on open‐ended questions. Decisional pathway diagrams were developed to convey factors influencing complex decision‐making processes.ResultsParticipant responses incorporated unfolding scenario information, resulting in three decision themes: (1) wanting to know one's LS status; (2) informing family about LS; (3) navigating risk‐reducing interventions. Across all themes, ‘knowledge’ emerged as a facilitator, and ‘negative emotional experience’ as a barrier. Personal supportive views toward genetic testing increased post‐interview.ConclusionsWhen communicating with tumour test‐positive CRC patients or their relatives about LS genetic testing, providing guidance/resources to inform decisions around risk‐reducing interventions and informing family members is critical. Scenario‐driven interviews provide insight into what individuals might do when facing complex healthcare decisions and could aid informed decision‐making. This approach may be applicable in other conditions, particularly with mainstreaming being increasingly introduced into the genetic context.

Cost-effectiveness of DNA testing for Lynch syndrome for colorectal cancer patients in Switzerland

Abstract Purpose To estimate the cost-effectiveness of genetic testing for Lynch syndrome among newly diagnosed patients with colorectal cancer and targeted testing for their relatives in Switzerland. Methods We integrated decision tree and Markov model to calculate incremental costs per quality adjusted life-year saved for universal genetic testing for Lynch syndrome relative to using preliminary tumor tests (immunohistochemistry or microsatellite instability) followed by DNA sequencing test for patients with colorectal cancer. Results The incremental cost-effectiveness ratio (ICER) of the proposed strategy using universal genetic testing for Lynch syndrome with systematic CASCADE testing of their relatives is CHF 65,058 per QALY saved, which is cost-effective in Swiss settings where cost-effectiveness threshold is CHF 100,000 per QALY saved. The gained utility is 361,358 QALYs saved. Sensitivity analysis demonstrated cost-effectiveness of the proposed strategies in most of the scenarios. Conclusions The overall effectiveness of the universal genetic testing is greatly dependent on willingness of patients and relatives to be tested and compliance with the increased surveillance. Therefore, close cooperation across different stakeholders such as family doctors, oncologists, genetic clinicians, and laboratories is crucial to encourage and educate patients about the importance of the LS screening. Key messages Universal genetic testing for Lynch syndrome for all patients with colorectal caner is cost-effective in Swiss settings. Close cooperation across all stakeholders such as family doctors, oncologists, genetic clinicians, and laboratories is crucial to encourage and educate patients about the importance of the LS testing.

Retroactive assessment for DNA mismatch repair deficiency in women with a history of endometrial cancer

Objectives. Beginning in 2014, the Society of Gynecologic Oncology and the American College of Obstetricians and Gynecologists have recommended universal tumor testing for mismatch repair deficiency in endometrial cancer. Mismatch repair testing can triage patients who may benefit from genetic testing for Lynch syndrome. Many women previously diagnosed with endometrial cancer have not undergone mismatch repair tumor testing. We sought to determine the feasibility of retroactive assessment for mismatch repair deficiency among women with diagnosed with endometrial cancer prior to 2014. Methods. Between 2016 and 2018, we identified 36 patients presenting for gynecologic oncology follow-up visits who were previously diagnosed with endometrial cancer. The endometrial pathology underwent tumor assessment for loss of expression of mismatch repair proteins by immunohistochemistry. Patients with abnormal mismatch repair testing were referred to genetic counseling and, if indicated, for germline genetic testing. Results. Thirty-six patients underwent retroactive tumor immunohistochemistry, yielding 10 (28%) abnormal results, including nine (25%) with loss of one or more mismatch repair proteins and one with inconclusive staining (2.8%). All ten patients with abnormal immunohistochemistry were referred to genetic counseling; 9 (90%) accepted the referral and proceeded with genetic testing. One pathogenic mutation was identified in CHEK2 (11%). Five patients (56%) were found to have a variant of unknown significance. Conclusions. Implementation of universal retroactive tumor testing for mismatch repair deficiency in patients previously diagnosed with endometrial cancer is feasible. With the growing use of new molecular classification protocols for endometrial tumors, identification of mismatch repair deficiency may have significant clinicopathologic implications.

Cancer Previvors in an Active Duty Service Women Population: An Opportunity for Prevention and Increased Force Readiness.

BackgroundThe majority of active duty service women (ADS) are young, have access to healthcare, and meet fitness standards set by the U.S. military, suggesting that ADS represent a healthy population at low risk of cancer. Breast cancer is, however, the most common cancer in ADS and may have a significant effect on troop readiness with lengthy absence during treatment and inability to return to duty after the treatment. The identification of unaffected ADS who carry germline mutations in cancer predisposition genes (“previvors”) would provide the opportunity to prevent or detect cancer at an early stage, thus minimizing effects on troop readiness. In this study, we determined (1) how many high-risk ADS without cancer pursued genetic testing, (2) how many previvors employed risk-reducing strategies, and (3) the number of undiagnosed previvors within an ADS population.MethodsThe Clinical Breast Care Project (protocol WRNMMC IRB #20704) database of the Murtha Cancer Center/Walter Reed National Military Medical Center was queried to identify all ADS with no current or previous history of cancer. Classification as high genetic risk was calculated using National Comprehensive Cancer Network 2019 guidelines for genetic testing for breast, ovary, colon, and gastric cancer. The history of clinical genetic testing and risk-reducing strategies was extracted from the database. Genomic DNA from ADS with blood specimens available for research purposes were subjected to next-generation sequencing technologies using a cancer predisposition gene panel.ResultsOf the 336 cancer-free ADS enrolled in the Clinical Breast Care Project, 77 had a family history that met National Comprehensive Cancer Network criteria for genetic testing for BRCA1/2 and 2 had a family history of colon cancer meeting the criteria for genetic testing for Lynch syndrome. Of the 28 (35%) high-risk women who underwent clinical genetic testing, 11 had pathogenic mutations in the breast cancer genes BRCA1 (n = 5), BRCA2 (n = 5), or CHEK2 (n = 1). Five of the six ADS who had a relative with a known pathogenic mutation were carriers of the tested mutation. All of the women who had pathogenic mutations detected through clinical genetic testing underwent prophylactic double mastectomy, and three also had risk-reducing salpingo-oophorectomy. Two (6%) of the 33 high-risk ADS tested only in the research setting had a family history of breast/ovarian cancer and carried pathogenic mutations: one carried a BRCA2 mutation, whereas the other carried a mutation in the colon cancer predisposition gene PMS2. No mutations were detected in the 177 low-risk women tested in the research setting.DiscussionWithin this unaffected cohort of ADS, 23% were classified as high risk. Although all of the previvors engaged in risk-reduction strategies, only one-third of the high-risk women sought genetic testing. These data suggest that detailed family histories of cancer should be collected in ADS and genetic testing should be encouraged in those at high risk. The identification of previvors and concomitant use of risk-reduction strategies may improve health in the ADS and optimize military readiness by decreasing cancer incidence.

Prevalence and Molecular Characterization of Defective DNA Mismatch Repair in Small-bowel Carcinoma in a Japanese Hospital-based Population.

Objectives: To investigate the prevalence and molecular characteristics of defective DNA mismatch repair (dMMR) in small-bowel carcinoma (SBC) in a Japanese-hospital population. Methods: Immunohistochemistry was performed to evaluate the expression of MMR proteins (MLH1, MSH2, MSH6, and PMS2) in formalin-fixed paraffin-embedded sections prepared from surgically resected primary SBCs from 30 patients during March 2002 to March 2017. Genetic testing for Lynch syndrome was performed in patients who demonstrated MMR protein loss. Results: Two of 30 patients (6.7%) demonstrated concomitant loss of MSH2/MSH6 protein expression. Further genetic testing identified a pathogenic MSH2 variant in one of these patients. Conclusions: The prevalence of dMMR SBCs in a Japanese hospital-based population seems lower than that reported in previous studies. To determine whether dMMR SBCs might be strongly linked to Lynch syndrome, there is a need for further investigation with a larger sample size.

Double somatic mismatch repair gene pathogenic variants as common as Lynch syndrome among endometrial cancer patients

ObjectiveLynch syndrome is the most common cause of inherited endometrial cancer, attributable to germline pathogenic variants (PV) in mismatch repair (MMR) genes. Tumor microsatellite instability (MSI-high) and MMR IHC abnormalities are characteristics of Lynch syndrome. Double somatic MMR gene PV also cause MSI-high endometrial cancers. The aim of this study was to determine the relative frequency of Lynch syndrome and double somatic MMR PV. Methods341 endometrial cancer patients enrolled in the Ohio Colorectal Cancer Prevention Initiative at The Ohio State University Comprehensive Cancer Center from 1/1/13–12/31/16. All tumors underwent immunohistochemical (IHC) staining for the four MMR proteins, MSI testing, and MLH1 methylation testing if the tumor was MMR-deficient (dMMR). Germline genetic testing for Lynch syndrome was undertaken for all cases with dMMR tumors lacking MLH1 methylation. Tumor sequencing followed if a germline MMR gene PV was not identified. ResultsTwenty-seven percent (91/341) of tumors were either MSI-high or had abnormal IHC indicating dMMR. As expected, most dMMR tumors had MLH1 methylation; (69, 75.8% of the dMMR cases; 20.2% of total). Among the 22 (6.5%) cases with dMMR not explained by methylation, 10 (2.9% of total) were found to have Lynch syndrome (6 MSH6, 3 MSH2, 1 PMS2). Double somatic MMR PV accounted for the remaining 12 dMMR cases (3.5% of total). ConclusionsSince double somatic MMR gene PV are as common as Lynch syndrome among endometrial cancer patients, paired tumor and germline testing for patients with non-methylated dMMR tumor may be the most efficient approach for LS screening.

Diagnostics of Mutations in MMR/EPCAM Genes and Their Role in the Treatment and Care of Patients with Lynch Syndrome.

Lynch syndrome (LS), also known as hereditary nonpolyposis colorectal cancer (HNPCC), is a disorder caused by an autosomal dominant heterozygous germline mutation in one of the DNA mismatch repair (MMR) genes. Individuals with LS are at an increased risk of developing colorectal and extracolonic cancers, such as endometrial, small bowel, or ovarian. In this review, the mutations involved with LS and their diagnostic methods are described and compared, as are their current uses in clinical decision making. Nowadays, LS diagnosis is based on a review of family medical history, and when necessary, microsatellite instability (MSI) or/and immunohistochemistry (IHC) analyses should be performed. In the case of a lack of MMR protein expression (dMMR) or MSI-H (MSI-High) detection in tumor tissue, molecular genetic testing can be undertaken. More and more genetic testing for LS is based mainly on next-generation sequencing (NGS) and multiplex ligation-dependent probe amplification (MLPA), which provide better and quicker information about the molecular profile of patients as well as individuals at risk. Testing based on these two methods should be the standard and commonly used. The identification of individuals with mutations provides opportunities for the detection of cancer at an early stage as well as the introduction of proper, more effective treatment, which will result in increased patient survival and reduced costs of medical care.

Uptake and predictors of colonoscopy use in family members not participating in cascade genetic testing for Lynch syndrome

Cascade genetic testing provides a method to appropriately focus colonoscopy use in families with Lynch syndrome (LS). However, research suggests that up to two-thirds at risk to inherit LS don’t participate. Within the United States, no studies have assessed colonoscopy use within this elusive and high-risk subset. We set forth to (1) document colonoscopy use within those not undergoing genetic testing (NGT) and (2) identify factors associated with completing colonoscopy. Data came from a cross sectional survey of families with molecularly confirmed LS. One hundred seventy-six (176) adults participated; 47 of unknown variant status and 129 with variant status known (59 carriers/70 non-carriers). Despite a high level of awareness of LS (85%) and identical recommendations for colonoscopy, NGT reported significantly lower use of colonoscopy than carriers (47% vs. 73%; p = 0.003). Our results show that perceived risk to develop colon cancer (AOR = 1.99, p < 0.05) and physician recommendations (AOR = 7.64, p < 0.01) are significant predictors of colonoscopy use across all family members controlling for carrier status. Given these findings, health care providers, should assess patients’ perceived risk to develop cancer, assist them in adjusting risk perceptions and discuss recommendations for colonoscopy with all members in families with LS.Trial Registration Clinical Trials.gov Identifier: NCT00004210.

Patients with unexplained mismatch repair deficiency are interested in updated genetic testing

BackgroundIndividuals who have colorectal or endometrial cancers displaying loss of immunohistochemical staining of one or more mismatch repair proteins without an identifiable causative germline pathogenic variant have unexplained mismatch repair deficiency (UMMRD). Comprehensive germline genetic testing for Lynch syndrome (LS) includes sequencing and deletion/duplication analysis of MLH1, MSH2, MSH6, and PMS2, deletion analysis of EPCAM, and MSH2 inversion analysis. Updated genetic testing to include elements of comprehensive LS testing not previously completed could further clarify LS status in individuals with UMMRD, allowing for tailored screening guidelines for affected individuals and their family members. However, patient understanding of the potential impact of updated genetic testing for LS is unclear. This study aimed to evaluate the interest in and perceived impact of updated genetic testing among individuals with UMMRD at a tertiary academic center.MethodsA survey evaluating interest in and perceived impact of updated genetic testing was mailed to 98 potential participants. Electronic health record review was completed for all individuals meeting eligibility criteria. Thirty-one individuals responded to the survey.ResultsResults indicate this population is highly interested in updated genetic testing with the perceived impact being primarily for family members to have appropriate genetic testing and screening. Electronic health record review indicates that clinicians have an evolving understanding of causes of UMMRD, representing a potential change in assessment of cancer risk.ConclusionsUpdated risk assessment and genetic counseling with a discussion of the benefits and limitations of germline and somatic genetic testing, is essential as the understanding of UMMRD and genetic testing recommendations for this population evolve.

Prevalence and molecular characteristics of DNA mismatch repair deficient endometrial cancer in a Japanese hospital-based population.

The prevalence and molecular characteristics of defective DNA mismatch repair endometrial cancers in the Japanese population have been underexplored. Data supporting clinical management of patients with Lynch-like syndrome and germline variant of uncertain significance of mismatch repair genes are still lacking. Immunohistochemistry of mismatch repair proteins (MLH1, MSH2, MSH6 and PMS2) was performed on formalin-fixed paraffin-embedded sections prepared from resected primary endometrial cancers in 395 women with a median age of 59years. Genetic and/or epigenetic alterations of the mismatch repair genes were also investigated. Loss of expression of one or more mismatch repair proteins was observed in 68 patients (17.2%). A total of 17 out of 68 patients (25%, 4.3% of all cases) were identified as candidates for genetic testing for Lynch syndrome after excluding 51 patients with MLH1 hypermethylated cancer. Fourteen of these 17 patients subjected to genetic testing were found to have Lynch syndrome (n=5), germline variant of uncertain significance (n=2) or Lynch-like syndrome (n=7). Compared with patients with Lynch syndrome, those with germline variant of uncertain significance and Lynch-like syndrome tended to demonstrate an older age at the time of endometrial cancer diagnosis (P=0.07), less fulfillment of the revised Bethesda guidelines (P=0.09) and lower prevalence of Lynch syndrome-associated tumors in their first-degree relatives (P=0.01). This study provides useful information for management in patients with DNA mismatch repair endometrial cancer. Specifically, cancer surveillance as recommended in patients with Lynch syndrome might not be necessary in patients with germline variant of uncertain significance and Lynch-like syndrome and their relatives.

Mismatch Repair-Deficient Rectal Cancer and Resistance to Neoadjuvant Chemotherapy.

Evaluate response of mismatch repair-deficient (dMMR) rectal cancer to neoadjuvant chemotherapy. dMMR rectal tumors at Memorial Sloan Kettering Cancer Center (New York, NY) were retrospectively reviewed for characteristics, treatment, and outcomes. Fifty patients with dMMR rectal cancer were identified by IHC and/or microsatellite instability analysis, with initial treatment response compared with a matched MMR-proficient (pMMR) rectal cancer cohort. Germline and somatic mutation analyses were evaluated. Patient-derived dMMR rectal tumoroids were assessed for chemotherapy sensitivity. Of 21 patients receiving neoadjuvant chemotherapy (fluorouracil/oxaliplatin), six (29%) had progression of disease. In comparison, no progression was noted in 63 pMMR rectal tumors (P = 0.0001). Rectal cancer dMMR tumoroids reflected this resistance to chemotherapy. No genomic predictors of chemotherapy response were identified. Of 16 patients receiving chemoradiation, 13 (93%) experienced tumor downstaging; one patient had stable disease, comparable with 48 pMMR rectal cancers. Of 13 patients undergoing surgery, 12 (92%) had early-stage disease. Forty-two (84%) of the 50 patients tested positive for Lynch syndrome with enrichment of germline MSH2 and MSH6 mutations when compared with 193 patients with Lynch syndrome-associated colon cancer (MSH2, 57% vs 36%; MSH6, 17% vs 9%; P < 0.003). Over one-fourth of dMMR rectal tumors treated with neoadjuvant chemotherapy exhibited disease progression. Conversely, dMMR rectal tumors were sensitive to chemoradiation. MMR status should be performed upfront in all locally advanced rectal tumors with careful monitoring for response on neoadjuvant chemotherapy and genetic testing for Lynch syndrome in patients with dMMR rectal cancer.