Universal Lynch Syndrome Screening Research Articles

MLH1 Promoter Methylation Could Be the Second Hit in Lynch Syndrome Carcinogenesis.

(1) Background: MLH1 hypermethylation is an epigenetic alteration in the tumorigenesis of colorectal cancer (CRC) and endometrial cancer (EC), causing gene silencing, and, as a consequence, microsatellite instability. Commonly, MLH1 hypermethylation is considered a somatic and sporadic event in cancer, and its detection is recognized as a useful tool to distinguish sporadic from inherited conditions (such as, Lynch syndrome (LS)). However, MLH1 hypermethylation has been described in rare cases of CRC and EC in LS patients. (2) Methods: A total of 61 cancers (31 CRCs, 27 ECs, 2 ovarian cancers, and 1 stomach cancer) from 56 patients referred to cancer genetic counselling were selected for loss of MLH1 protein expression and microsatellite instability. All cases were investigated for MLH1 promoter methylation and MLH1/PMS2 germline variants. (3) Results: Somatic MLH1 promoter hypermethylation was identified in 16.7% of CRC and in 40% of EC carriers of MLH1 germline pathogenic variants. In two families, primary and secondary MLH1 epimutations were demonstrated. (4) Conclusions: MLH1 hypermethylation should not be exclusively considered as a sporadic cancer mechanism, as a non-negligible number of LS-related cancers are MLH1 hypermethylated. Current flow charts for universal LS screening, which include MLH1 methylation, should be applied, paying attention to a patient's family and personal history.

EE513 Economic Evaluation of Universal Lynch Syndrome Screening Protocols Among Newly Diagnosed Patients with Endometrial Cancer

Between 2%-6% of endometrial cancer (EC) cases are attributable to Lynch syndrome (LS). Although universal tumor screening for LS among patients with EC is recommended by professional societies, implementation remains suboptimal. Our objective is to compare the relative performance, costs, and efficiency of different LS screening protocols among newly diagnosed EC patients from a U.S. healthcare system perspective.

Universal screening for Lynch syndrome in operated colorectal cancer by immunohistochemistry: a cohort of patients in Liaoning province, China.

Lynch syndrome (LS) is the most common hereditary colorectal cancer syndrome worldwide. Due to the decreasing family size in Liaoning province. The Bethesda and Amsterdam II criteria have lower sensitivity and specificity and are not suitable for the local population. Immunohistochemistry screening for mutations in DNA mismatch repair (MMR) in newly diagnosed colorectal cancer can improve the detection rate of LS. All newly diagnosed colorectal cancer patients who underwent surgery between January 2018 and June 2020 at Cancer Hospital of China Medical University and Shengjing Hospital of China Medical University from Liaoning China were included retrospectively, and the ratio of universal LS screening by immunohistochemistry, MMR protein deficiency (dMMR) ratio, MLH1 loss, MSH2 loss, MSH6 loss, and PMS2 loss was analyzed. The clinicopathological characteristics of patients with pMMR and dMMR were analyzed. A total of 7019 colorectal cancer patients underwent surgery and 4802 (68.41%) patients were screened by immunohistochemistry for MMR, 258 (5.37%) cases were reported to have a loss of MMR expression. In the dMMR group, a higher number of patients were under 50 years old, more tumors were located at the right colon, less patients have lymph node metastasis, more tumors were stage II, and histological types of mucinous carcinoma or signet ring carcinoma were more common, compared with the pMMR group. Only 2.71% dMMR patients meet Amsterdam criteria II, 2.71% of patients meet Revised Bethesda guidelines, and 17.83% meet Chinese LS criteria. Twenty-five dMMR patients were confirmed by next-generation sequencing and five families were confirmed as Lynch family. These data imply that universal screening for LS by immunohistochemistry may be effective in Liaoning province.

P131 - DNA mismatch repair testing in upper tract urothelial carcinoma patients - Is Universal Lynch Syndrome screening necessary?

P131 - DNA mismatch repair testing in upper tract urothelial carcinoma patients - Is Universal Lynch Syndrome screening necessary?

O10 - DNA mismatch repair testing in upper tract urothelial carcinoma patients - Is universal Lynch syndrome screening necessary?

O10 - DNA mismatch repair testing in upper tract urothelial carcinoma patients - Is universal Lynch syndrome screening necessary?

221 Lynch Syndrome - Do We Really Screen for It?

Abstract Aim Firstly, assess the compliance of our Trust with the DG27 NICE Guidelines (2017) recommending universal screening of patients with Colorectal Cancer (CRC) for Lynch Syndrome (LS), using Immunohistochemistry or Microsatellite Instability testing. Secondly, provide a cost estimate for the Trust to implement universal screening for LS. Method Retrospective data collection for all CRC resection specimens reported by the Trust's Pathology Lab in 2019, and check of pathology reports, Clinic letters, and lab results through the Trust's electronic system for screening for LS. Cost estimates were calculated using information from the Histopathology Department and similar Audits by other NHS Trusts. Results From the 361 colorectal resection specimens examined at the Trust's Pathology lab, 340 were not screened for LS (NICE Guidelines compliance = 5.8%). Of the 21 screened, 12 patients did not have LS, and for 9 screening was not completed. By categorising the patients into groups by age, location of cancer, and presence of synchronous or metachronous cancers, we found that there was no consistent rationale behind screening (i.e., patients with phenotypical characteristics traditionally related to LS were not screened). We estimated that universal LS screening would cost the Trust approximately £25,000 annually. Conclusions There is extremely poor compliance with the NICE Guidelines in a Trust with one of the highest numbers of CRC resections annually. Even the Amsterdam Criteria are not used to screen patients for LS. Screening could change the surgical and oncological management of the patients and also suggest different surveillance and prophylaxis for the affected family members.

Hereditary evaluation and genetic counselling in young individuals with colorectal cancer in a population-based cohort

AimEarly-onset colorectal cancer should raise suspicions of a hereditary colorectal cancer (CRC) syndrome, including Lynch syndrome (LS) and Familial Adenomatous Polyposis (FAP). Collection of family history and genetic counselling (GC) is mandatory but previous studies have revealed low awareness of hereditary CRC among clinicians why there has been an incentive to implement universal LS screening. In this population-based cohort study, we aimed to observe the uptake of GC in the Swedish South-Eastern medical care region for young CRC patients and to investigate the frequency of patients diagnosed with LS. MethodsPatients below 50 years of age diagnosed with CRC between 2008 and 2017 were identified from the national Swedish Colorectal Cancer Registry. Medical records were reviewed regarding family history, co-morbidity and referral for GC, with a follow-up time of at least three years. ResultsThe analysis included 278 patients with 287 tumours, 108 (38%) located in rectum and 179 (62%) in colon. One hundred sixteen (42%) individuals were referred to the Regional Clinical Genetics service, whereof 74 (27%) underwent complete investigation. Thirteen (18%) patients were identified with a mutation, eleven (15%) had LS and two (3%) FAP. The remaining 61 (82%), without proven mutation, were considered as familial CRC. Younger age correlated with a higher chance of referral for GC. ConclusionThe study found that only a minority of young CRC patients underwent genetic counselling, contrary to clinical guidelines. Hereditary CRC is therefore probably underdiagnosed even among young individuals.

Results of an immunohistochemistry-based universal screening strategy for Lynch syndrome in patients with colorectal cancer treated in a public hospital from Latin-America

BackgroundThere is limited evidence regarding the implementation of an immunohistochemistry-based universal screening for Lynch Syndrome (LS) in Latin America. The aim of this study was to evaluate the results of a universal screening strategy in colorectal cancer in a public hospital from Latin-America. MethodsSingle center prospective study including patients who underwent colorectal resection for CRC between March 1, 2016 and March 1, 2017. Mismatch Repair status (MMR) based on immunohistochemistry (IHC) was obtained. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for revised Bethesda and modified Amsterdam II criteria. Kaplan-Meier analysis was performed for overall and relapse free survival. Results65 patients were enrolled (35 women). Median age 58 years (22-88). Main tumor location was left colon (48%). Nineteen patients (29%) had positive Bethesda Criteria. Eight patients (12%) with MMR deficiency were detected by IHC: 5 MLH1/PMS2, 2 MSH2/MSH6 and 1 MSH6. The sensibility and specificity for Bethesda Criteria to assess MMR loss were 50% and 73.8%, respectively. Among the patients with MLH1 loss, one patient had a mutated BRAF and two MLH1 promoter hypermethylation. Of the five eligible patients for genetic study, one did not present mutations, three corresponded to a variable of uncertain significance and one had a pathogenic variant of MSH2. The 5-year overall survival was 63.1% without any difference according MMR status. ConclusionsDespite the barriers in public health from Latin America, higher detection rates of patients who should undergo germline sequence study for LS supports the implementation of a universal LS screening strategy.

Two-Antibody Staining Method, A Cost-Saving Strategy for Universal Lynch Syndrome Screening in Endometrial Cancers

Objective: Lynch syndrome is an autosomal dominant disorder that increases the risk of cancers in many sites. In women, endometrial cancer is often a sentinel tumor and thus immunohistochemistry for mismatch repair (MMR) proteins MLH1, MSH2, MSH6 and PMS2 is encouraged as a screening test. To reduce cost, staining for only 2 MMR proteins PMS2 and MSH6 has been proposed. This study aimed to determine whether a 2-antibody staining test is enough to screen for Lynch syndrome in endometrial cancer patients.Materials and Methods: Cases of endometrial carcinoma with immunohistochemistry for 4 MMR proteins were reviewed. Results of immunohistochemistry screening were compared between all four antibodies and only two (PMS2 and MSH6) antibodies.Results: Loss of expression of any MMR proteins was detected in 51 out of 203 cases (25.12%). Twenty-three cases (45%) showed loss of MLH1 and PMS2; 13 cases (25%) showed loss of MSH2 and MSH6; five cases (10%) showed loss of MSH6; seven cases (14%) showed loss of PMS2 and three cases (6%) showed loss of MSH2. The 2-antibody method detected 48 cases (94%) with a MMR deficiency but failed to detect three cases (6%) with an isolate loss of MSH2. The screening results from the 2-antibody method are 98.5% (200/203) in accordance with the original 4-antibody method.Conclusion: The 2-antibody method is a quite effective option to screen for Lynch syndrome in endometrial cancers. However, MSH2 mutations may be missed in a few cases.

Economic Evaluation of Universal Lynch Syndrome Screening Protocols among Newly Diagnosed Patients with Colorectal Cancer.

We conducted an updated economic evaluation, from a healthcare system perspective, to compare the relative effectiveness and efficiency of eight Lynch syndrome (LS) screening protocols among newly diagnosed colorectal cancer (CRC) patients. We developed decision analytic models for a hypothetical cohort of 1000 patients. Model assumptions and parameter values were based on literature and expert opinion. All costs were in 2018 USD. For identifying LS cases, the direct germline sequencing (DGS) protocol provided the best performance (sensitivity 99.90%, 99.57–99.93%; specificity 99.50%, 97.28–99.85%), followed by the tumor sequencing to germline sequencing (TSGS) protocol (sensitivity, 99.42%, 96.55–99.63%; specificity, 96.58%, 96.46–96.60%). The immunohistochemistry (IHC) protocol was most efficient at $20,082 per LS case identified, compared to microsatellite instability (MSI) ($22,988), DGS ($31,365), and TSGS ($104,394) protocols. Adding double-somatic testing to IHC and MSI protocols did not change sensitivity and specificity, increased costs by 6% and 3.5%, respectively, but reduced unexplained cases by 70% and 50%, respectively. DGS would be as efficient as the IHC protocol when the cost of germline sequencing declines under $368 indicating DGS could be an efficient option in the near future. Until then, IHC and MSI protocols with double-somatic testing would be the optimal choices.

PCN39 Economic Evaluation of Universal Lynch Syndrome Screening Protocols Among Newly Diagnosed Patients with Colorectal Cancer

The objective of this study was to conduct an updated economic analysis, from a healthcare system perspective, to evaluate the relative effectiveness and efficiency of multiple Lynch syndrome (LS) screening protocols among newly diagnosed colorectal cancer (CRC) patients that are deemed viable based on current evidence.

Comparison of universal screening in major lynch-associated tumors: a systematic review of literature.

Lynch syndrome (LS) is associated with an increased lifetime risk of several cancers including colorectal (CRC), endometrial (EC), ovarian (OC), urinary (UT) and sebaceous tumors (ST). The benefit for universal screening in CRC and EC is well known. However, this benefit in other major lynch-associated tumors is unclear. We performed a systematic review of all published articles in the MEDLINE database between 2005 to 2017 to identify studies performing universal screening for LS in unselected CRC, EC, OC, UT and ST. All cases with MSI-H (instability in two or more markers) or missing one or more proteins on IHC testing were considered screening positive. Cases with MLH1 promoter hypermethylation or BRAF mutation positive were considered to have somatic mutations. A total of 3788 articles were identified in MEDLINE yielding 129 study arms from 113 studies. The overall pooled yield of universal LS screening and germline mismatch gene mutation was significantly different across the major LS-associated tumors (Mann Whitney test, p < 0.001). The pooled screening yield was highest in ST [52.5% (355/676), 95% CI 48.74-56.26%] followed by EC [22.65% (1142/5041), 95% CI 21.54-23.86%], CRC [11.9% (5649/47,545), 95% CI 11.61-12.19%], OC [11.29% (320/2833), 95% CI 10.13-12.47%] and UT [11.2% (31/276), 95% CI 7.48-14.92%]. ST also had the highest pooled germline positivity for mismatch repair gene mutation [18.8%, 33/176, 95%CI 13.03-24.57], followed by EC [2.6% (97/3765), 95% CI 2.09-3.11], CRC [1.8% (682/37,220), 95% CI 1.66-1.94%], UT [1.8%(3/164), 95% CI - 0.24-3.83%] and OC [0.83%(25/2983), 95% CI 0.48-1.12%]. LS screening in EC yielded significantly higher somatic mutations compared to CRC [pooled percentage 16.94% [(538/3176), 95%CI 15.60-18.20%] vs. 5.23% [(1639/26,152), 95% CI 4.93-5.47%], Mann Whitney test, p < 0.0001. Universal LS testing should be routinely performed in OC, UT and STs in addition to CRC and EC. Our findings also support consideration for IHC and somatic mutation testing before germline testing in EC due to higher prevalence of somatic mutations as well as germline testing in all patients with ST. Our results have implications for future design of LS screening programs and further studies are needed to assess the cost effectiveness and burden on genetic counselling services with expanded universal testing for LS.

False Negative Rate (2%) of Lynch Syndrome Screening Utilizing A Two-Antibody (PMS2/MSH6) Immunohistochemistry Panel: Failure To Detect a Subset of MSH2-Deficient Endometrial Carcinomas

Abstract Introduction/Objective Lynch syndrome (LS) is an inherited condition caused by defective DNA mismatch repair (MMR), leading to a higher incidence of cancers of multiple sites. Screening for LS is now recommended for new diagnoses of endometrial cancer (EC) using either two- (PMS2, MSH6) or four-antibody (2/4Ab) (PMS2, MSH6, MSH2, MLH1) immunohistochemical (IHC) panels. The 2Ab panel assumes consistent loss of expression of the minor dimer component, PMS2 or MSH6, when the major component, MLH1 or MSH2, respectively, is lost due to mutation. Recent studies have indicated that 2Ab testing may lead to underdiagnosis of MSH2-deficient tumors in cases where MSH6 staining is weak or focal, potentially leading to underdiagnosis of LS. Methods We conducted a retrospective study using archived slides for 293 cases of EC (identified via LIS search from 2016-2019) that were screened using the 2Ab panel (expanded to 4Ab when PMS2 or MSH6 were negative). MSH6 expression was reviewed; if weak, focal (less than 10% staining), or both, MSH2 IHC was performed. When a previously undetected loss of MSH2 expression was found, the attending clinician was informed such that referral to medical genetics could be arranged. Results Results Overall, 68 (23.2%) tumors were MMR deficient, with 54 (18.4%) showing MLH1/PMS2 loss, 7 (2.4%) with MSH2/MSH6 loss, 2 (0.7%) with isolated PMS2 loss, 4 (1.4%) with isolated MSH6 loss, and 6 (2.0%) with isolated MSH2 loss (i.e. intact but weak/focal MSH6, seen in biopsy and hysterectomy specimens). Interestingly, 1 tumor (1.5%) demonstrated loss of MSH6, MLH1 and PMS2. Two tumors (0.7%) with isolated MSH2 loss were previously unrecognized as MMR-deficient and hence at high risk for LS. Both cases were evaluated by PCR for microsatellite instability (MSI) and confirmed to have high-degree MSI. Conclusion This study identifies the frequency of mismatch repair deficient endometrial cancers in Atlantic Canada, highlights a potential pitfall of using two-stain IHC screening for Lynch syndrome, and supports emerging recommendations for universal Lynch syndrome screening in EC.

Clinicopathologic characteristics and outcomes of endometrial Cancer patients with mismatch repair deficiency in the era of universal Lynch syndrome screening

Objective: To evaluate clinicopathologic characteristics and survival impact associated with mismatch repair (MMR) deficient subgroups of endometrial cancer (EC) in patients undergoing universal screening for Lynch Syndrome.Methods: A retrospective cohort study using a prospectively maintained gynecologic oncology registry of patients who underwent surgery for EC was conducted. All pathology specimens underwent tumor testing using immunohistochemistry for MMR deficiency with reflex MLH1 promotor methylation testing. Tumors were classified as MMR-I (intact MMR expression), MMR-DM (MMR deficient due to MLH1 methylation), and MMR-DU (MMR deficient without MLH1 methylation). Univariate and multivariate analysis performed to determine factors associated with MMR-DM. Progression-free survival (PFS) and overall survival (OS) analyzed by stage and endometrioid subgroup.Results: From 2012 to 2016, 1018 EC patients were identified and screened. Overall, 71.6% were classified as MMR-I, 23.8% MMR-DM, and 4.6% MMR-DU. In comparison to MMR-DU, MMR-DM tumors were associated with older age, postmenopausal status, lymphovascular space invasion, and pure endometrioid histology. Compared to MMR-I, MMR-DM tumors were associated with older age, endometrioid histology, lymphovascular space invasion, and higher grade on multivariable analysis. There was no difference in PFS and OS between the three groups overall. In patients with endometrioid EC, MMR-DM tumors were associated with lower PFS vs. MMR-I (HR:2.51, CI:1.54, 4.10, P < 0.001). This effect persisted for stage I/II endometrioid EC (HR 2.66, CI:1.34, 5.26 p = 0.005). No difference in PFS or OS was noted among stage III/IV endometrioid tumors.Conclusion: MMR deficiency is associated with adverse prognostic factors and worse PFS among endometrioid tumors, particularly in early stage EC. MMR testing outside of LS screening has prognostic value, warranting consideration for inclusion as a biomarker in prospective clinical trials.

Worldwide variation in lynch syndrome screening: case for universal screening in low colorectal cancer prevalence areas.

To perform a systematic assessment of universal Lynch syndrome (LS) screening yield in colorectal cancer (CRC) patients around the world. Universal screening for LS is recommended in all CRC patients. However, the variation in yield of LS screening in the setting of significant global variation in CRC prevalence is unknown. A systematic review of articles in the MEDLINE database was performed to identify studies performing universal screening for LS. All cases with microsatellite instability (MSI-H) or missing one or more proteins on immunohistochemistry (IHC) were considered screening positive. The overall pooled yield of universal LS screening in 97 study arms from 89 identified studies was 11.9% (5649/47545) and the overall pooled percentage of confirmed LS patients was 1.8% (682/37220). LS screening positivity varied significantly based on geographic region (Kruskal Wallis test, p < 0.001) and reported 5-year CRC prevalence in the country (Fisher's exact, p < 0.001). Significant inverse correlation was found between LS screening positivity and 5-year CRC prevalence (Pearson correlation, r = - 0.56, p < 0.001). The overall yield of LS screening was 15.00% (382/2553) and rate of confirmed LS was 7.7% (113/1475) in LS screening done in patients ≤ 50years (16 studies). There is significant geographic variation in LS screening positivity with higher yield in countries with lower prevalence of CRC. Our results highlight the importance of universal LS screening in younger patients and low CRC prevalence countries.

NTRK gene rearrangements are highly enriched in MLH1/PMS2 deficient, BRAF wild-type colorectal carcinomas-a study of 4569 cases.

NTRK gene rearrangements are important to identify as predictors of response to targeted therapy in many malignancies. Only 0.16-0.3% of colorectal carcinomas (CRCs) harbor these fusions making universal screening difficult. We therefore investigated whether pan-Trk immunohistochemistry (IHC), mismatch repair deficiency (MMRd), and BRAFV600E mutation status could be used to triage molecular testing for NTRK gene rearrangements in CRC. CRCs from 4569 unselected patients underwent IHC in TMA format with two different anti-pan-Trk rabbit monoclonal antibodies. All positive cases were confirmed on whole sections and underwent RNA-sequencing. Pan-Trk IHC was positive in 0.2% of CRCs (9/4569). Both antibodies demonstrated similar staining characteristics with diffuse positive staining in all neoplastic cells. Of note 8/9 (89%) IHC positive cases were both MMRd (all showing MLH1/PMS2 loss) and lacked BRAFV600E mutation. That is, IHC was positive in 5.3% (8/152) MLH1/PMS2/BRAFV600E triple negative CRCs, but only 0.02% (1/4417) not showing this phenotype. All nine IHC positive CRCs demonstrated gene rearrangements (LMNA-NTRK1 in 5 CRCs, TPR-NTRK1, STRM-NTRK1, MUC2-NTRK2, and NTRK1 with an unknown partner in one each), suggesting close to 100% specificity for IHC in this sub-population. NTRK fusions were associated with right sided (p = 0.02), larger tumors (p = 0.029) with infiltrative growth (p = 0.021). As a part of universal Lynch syndrome screening many institutions routinely test all CRCs for MMRd, and then proceed to reflex BRAFV600E mutation testing in MLH1/PMS2 negative CRCs. We conclude that performing pan-Trk IHC on this preselected subgroup of MLH1/PMS2/BRAFV600E triple negative CRCs (only 3.3% of all CRC patients) is a resource effective approach to identify the overwhelming majority of CRC patients with NTRK gene fusions.

Universal Testing to Identify Lynch Syndrome Among Women With Newly Diagnosed Endometrial Carcinoma.

Lynch syndrome (LS) is an autosomal dominant cancer syndrome caused by a germline mutation in the mismatch repair (MMR) genes. Protocols based on immunohistochemical expression of MMR proteins in cancer are used to identify patients with LS. The universal LS screening protocol of the Tom Baker Cancer Centre (Calgary, AB) of all patients diagnosed between April 1, 2013 and April 1, 2015 with endometrioid carcinoma of the endometrium was audited through a retrospective chart review. LS status and frequency of protocol compliance at each of the key steps were calculated (Canadian Task Force Classification II-2). The cohort consisted of 375 patients. MMR immunohistochemical testing was requested for 321 (85.6%). Expression of at least one protein was lost in 86 (26.8%). Twenty-one (6.5%) patients were eligible for genetic counselling because PMS2, MSH2, or MSH6 protein expression was lost in 19, and two patients had a family history of LS. Eleven (91.7%) of 12 (57.1%) who attended had germline testing, and six (54.5%) showed a mutation diagnostic of LS. LS status among the cohort of 375 patients was positive in six (1.6%), negative in 294 (78.4%), and unknown in 75 (20%) because of protocol non-compliance. LS was confirmed in six (2%) of the 321 women who completed the protocol. This is the first audit of a Canadian-based universal LS screening protocol of patients with endometrial cancer. The success of the protocol is endorsed by the 80% compliance and by the 2% prevalence of LS, which is within the published range.

Lynch syndrome screening in gynaecological cancers: results of an international survey with recommendations for uniform reporting terminology for mismatch repair immunohistochemistry results.

Lynch syndrome (LS) is associated with an increased risk of developing endometrial carcinoma (EC) and ovarian carcinoma (OC). There is considerable variability in current practices and opinions related to screening of newly diagnosed patients with EC/OC for LS. An online survey was undertaken to explore the extent of these differences. An online questionnaire was developed by a panel of experts and sent to all members of the British Association of Gynaecological Pathologists (BAGP) and the International Society of Gynecological Pathologists (ISGyP). Anonymised results were received and analysed. Thirty-six BAGP and 44 ISGyP members completed the survey. More than 90% of respondents were aware of the association of LS with both EC and OC, but 34% were not aware of specific guidelines for LS screening. Seventy-one per cent of respondents agreed that universal screening for LS should be carried out in all newly diagnosed EC cases, with immunohistochemistry (IHC) alone as the preferred approach. Only 36% of respondents currently performed IHC or microsatellite instability testing on all newly diagnosed EC cases, with most of the remaining respondents practising selective screening, based on clinical or pathological features or both. A significant minority of respondents (35%) believed that patient consent was required before performance of mismatch repair (MMR) protein IHC. Almost all respondents favoured the use of standardised terminology for reporting MMR protein staining results, and this is proposed herein. There is wide support for universal LS screening in patients with EC, but this survey highlights areas of considerable variation in practice.

Suboptimal Adherence in Clinical Practice to Guidelines Recommendation to Screen for Lynch Syndrome.

Identification of Lynch syndrome (LS) followed by annual/biannual surveillance colonoscopy markedly reduces the risk of developing new colorectal cancer (CRC) among those with LS. (1) To determine the current practice of identifying LS in the USA and Canada, and current surveillance and management practices for those diagnosed with LS; (2) to determine whether variances in current practice are physician/region dependent or influenced by ease of access to specialist clinics. An online survey request was sent to practicing gastroenterologists through the Canadian Association of Gastroenterology and the American College of Gastroenterology. Fisher's exact tests were performed to determine the factors associated with screening for LS and separately for follow-up, surveillance, and management. A total of 249 participants were recruited, of which 237 were gastroenterologists and included in the analysis. Less than one-third of practicing gastroenterologists indicated that their CRC patients were undergoing screening tests to identify LS. While 42% (65/153) of participants from the USA stated that their patients were undergoing universal LS screening (i.e., among all diagnosed with CRC), only 12% (6/49) of participants from Canada reported this practice (p < 0.001). There was no difference in reported practice between the physicians that do and do not have access to hereditary clinics (35% vs. 34% testing; p = 0.54). Appropriate surveillance interval to look for CRC in patients with LS was recommended by most. This survey suggests there is a significant difference in practice between Canada and the USA in regard to identification of LS, with suboptimal practice throughout North America.

Implementing universal Lynch syndrome screening (IMPULSS): protocol for a multi-site study to identify strategies to implement, adapt, and sustain genomic medicine programs in different organizational contexts

BackgroundSystematic screening of all colorectal tumors for Lynch Syndrome (LS) has been recommended since 2009. Currently, implementation of LS screening in healthcare systems remains variable, likely because LS screening involves the complex coordination of multiple departments and individuals across the healthcare system. Our specific aims are to (1) describe variation in LS screening implementation across multiple healthcare systems; (2) identify conditions associated with both practice variation and optimal implementation; (3) determine the relative effectiveness, efficiency, and costs of different LS screening protocols by healthcare system; and (4) develop and test in a real-world setting an organizational toolkit for LS screening program implementation and improvement. This toolkit will promote effective implementation of LS screening in various complex health systems.MethodsThis study includes eight healthcare systems with 22 clinical sites at varied stages of implementing LS screening programs. Guided by the Consolidated Framework for Implementation Research (CFIR), we will conduct in-depth semi-structured interviews with patients and organizational stakeholders and perform economic evaluation of site-specific implementation costs. These processes will result in a comprehensive cross-case analysis of different organizational contexts. We will utilize qualitative data analysis and configurational comparative methodology to identify facilitators and barriers at the organizational level that are minimally sufficient and necessary for optimal LS screening implementation.DiscussionThe overarching goal of this project is to combine our data with theories and tools from implementation science to create an organizational toolkit to facilitate implementation of LS screening in various real-world settings. Our organizational toolkit will account for issues of complex coordination of care involving multiple stakeholders to enhance implementation, sustainability, and ongoing improvement of evidence-based LS screening programs. Successful implementation of such programs will ultimately reduce suffering of patients and their family members from preventable cancers, decrease waste in healthcare system costs, and inform strategies to facilitate the promise of precision medicine.Trial registrationN/A