[Lynch syndrome]. / Lynch-Syndrom.

Patients with Lynch syndrome, one of the most common hereditary tumor predisposition syndromes, harbor an increased risk for a broad spectrum of especially gastrointestinal and gynecological tumors. Causative for the syndrome are variants in DNA mismatch repair genes, which are passed on to the offspring at a 50% chance (autosomal dominant inheritance). The tumor tissue of these patients usually shows microsatellite instability, which is of increasing relevance regarding prognosis and therapeutic decisions. The detection of a causative genetic variant in a patient enables predictive testing of family members to provide relief to noncarriers and provide carriers with intensified risk-adapted surveillance. In addition, chemoprevention with aspirin (acetylsalicylic acid) has been proven useful for chemoprevention in studies. Therefore, the diagnosis of Lynch syndrome is important for patients and their relatives.

Outcomes and the effect of PGT-M in women with hormone-related hereditary tumor syndrome.

Purpose: To review the outcome of PGT-M in hormone-related hereditary tumor syndrome and evaluate the effect of ovarian induction on tumor growth in those patients. Methods: Medical records of PGT-M were retrospectively analyzed in patients with hormone-related heritage tumors in our reproductive center. A total of eleven women with hereditary breast and ovarian cancer (HBOC) (including BRCA1/2 mutation carriers), and Lynch syndrome (including MMR gene mutation carriers) were included. Thirteen IVF/PGT-M cycles were performed. Eleven for PGT-M and two for fertility preservation. The ovulation protocol, numbers of oocytes retrieved and two pronuclei (2PN) zygotes, PGT-M results, and clinical outcomes were analyzed. Tumor progression was also estimated by comparing transvaginal ultrasound (TVS), MR, CT, or colonoscopy according to the follow-up requirements of different tumors. Results: Eleven IVF/PGT-M cycles were performed with an antagonist protocol; Two cycles were performed with a mild stimulation protocol. The total dose of gonadotropin (Gn) was 1827 IU per patient (range from 1200 to 2625 IU). The median number of oocytes retrieved was 13 (range from 4 to 30), and the median number of 2PN zygotes was 8 (range from 2 to 16). A total of 32 embryos underwent PGT-M, and 9 (28.1%) embryos were suitable for transfer. Six transfer cycles were performed, and 5 cycles got clinical pregnancy (83%) with five newborns (83%). The follow-up examinations conducted 10-18 months after PGT-M/delivery revealed no new lesions or tumor progression. Conclusion: PGT-M results can provide important information for improving the consultation of hormone-related heritage tumor patients regarding their fertility preservation and reproductive options. Ovarian induction for women with hormone-related hereditary tumor syndrome is not associated with tumor progression.

Asymptomatic endometrial cancer with Lynch syndrome; in a woman with primary infertility-A case report and literature review.

Lynch syndrome, also called hereditary non-polyposis colorectal cancer, is an autosomal dominant disorder characterized by germline pathogenic mutations in DNA mismatch repair genes-resulting in increased susceptibility to colorectal, endometrial, and other tumors. This case report presents an incidental finding of endometrial cancer with Lynch syndrome during investigation for primary infertility. A 34-year-old woman presented to the fertility clinic with unexplained primary infertility. Investigations showed possible endometrial polyp, 13 × 11 mm in size. Hysteroscopic polypectomy and endometrial biopsy revealed complex endometrial hyperplasia amounting to endometroid adenocarcinoma. The case was discussed at the West of Scotland Gynecology-Oncology MDT meeting-management options including fertility-sparing treatment or radical surgery were presented to the patient and she opted for the latter. A total laparoscopic hysterectomy with bilateral salpingo-oophorectomy was performed with pathology results consistent with well-differentiated endometroid adenocarcinoma Stage 1A. Peritoneal washings showed no malignant cells. Genetic testing confirmed a diagnosis of Lynch syndrome. On further questioning, it was revealed that the patient had a strong family history of colon cancer but had not previously met the criteria for genetic testing. She was referred to colorectal surgeons and underwent colonoscopy. This showed no abnormality; she was therefore scheduled for 2-yearly colonoscopic surveillance.

Colorectal cancer genetic referral: Are we doing enough?

Purpose: Guidelines are published for referral to genetic counseling and multigene panel genetic testing for colorectal cancer. We hypothesize that these guidelines are not recognized in practice, resulting in the underreferral of patients to genetic counseling. We aimed to investigate the clinical impact of these guidelines. Methods: This was a retrospective cohort study conducted using a single academic-institution colorectal cancer patient registry. The registry included all patients ≥18 years old with a pathologic diagnosis of colon cancer, rectal cancer, or polyposis from January 2018 to January 2020 with complete chart data to determine inclusion into the genetic referral cohort. Results: Out of 225 colon cancer patients, 92 met criteria for referral to genetic testing, but only 56 patients obtained referral and 39 completed testing. For rectal cancer, 29 out of 127 patients met criteria for referral, but only 11 obtained referral and 8 completed testing. Actionable variants, defined as pathogenic or likely pathogenic, were identified in 18 colon cancer and 5 rectal cancer patients. Age made a significant difference in the referral rate for colon cancer (P = 0.02) but not rectal cancer (P > 0.05). Conclusion: Our study demonstrates poor adherence to guideline-based genetic testing. These data emphasize the need for more consistent referral to genetic testing for diagnosis of underlying inherited cancer syndromes.

Recurrent colon cancer in a patient with Muir-Torre syndrome: a case report.

Muir-Torre syndrome (MTS) is a rare subtype of hereditary nonpolyposis colorectal cancer syndrome caused by a defect in DNA mismatch repair leading to microsatellite instability. It is characterized by the presence of at least one sebaceous gland tumor and one internal malignancy, most commonly colorectal and endometrial tumors. These patients have a high propensity for tumorigenesis, and while strict screening protocols are in place, there are only two cases that describe the management approach to recurrent colon cancer. Here, we present a case of recurrent colorectal cancer in a patient with MTS, and describe how it was managed at our facility by a multidisciplinary team.

Screening and surveillance for hereditary colorectal cancer.

Hereditary colorectal cancer is a type of cancer that is caused by a genetic mutation. Individuals with a family history of colorectal cancer, or who have a known hereditary syndrome, are at an increased risk of developing the disease. Screening and surveillance are important tools for managing the risk of hereditary colorectal cancer. Screening involves a combination of tests that can detect precancerous or cancerous changes in the colon and rectum. Surveillance involves regular follow-up examinations to monitor disease progression and to identify new developments. The frequency and type of screening and surveillance tests may vary depending on an individual's risk factors, genetic profile, and medical history. However, early detection and treatment of hereditary colorectal cancer can significantly improve patient outcomes and reduce mortality rates. By implementing comprehensive screening and surveillance strategies, healthcare providers can help individuals at risk of hereditary colorectal cancer to receive timely interventions and make informed decisions about their health. Specific examples of screening and surveillance tests for hereditary colorectal cancer include colonoscopy, genetic testing, and imaging tests. In this review article, we will discuss detailed screening and surveillance of hereditary colorectal cancer.

Testing for deficient mismatch repair and microsatellite instability : A focused update.

Testing to detect mismatch repair deficiency (dMMR) and high-grade microsatellite instability (MSI-H) has become an integral part of the routine diagnostic workup for colorectal cancer (CRC). While MSI was initially considered to be a possible indicator of a hereditary disposition to cancer (Lynch syndrome, LS), today the prediction of the therapy response to immune checkpoint inhibitors (ICI) is in the foreground. Corresponding recommendations and testing algorithms are available for use in primary diagnosis (reviewed in: Rüschoff et al. 2021).Given the increasing importance for routine use and the expanding indication spectrum of ICI therapies for non-CRCs, such as endometrial, small intestinal, gastric, and biliary tract cancers, an updated review of dMMR/MSI testing is presented. The focus is on the challenges in the assessment of immunohistochemical stains and the value of PCR-based procedures, considering the expanded ICI indication spectrum. A practice-oriented flowchart for everyday diagnostic decision-making is provided that considers new data on the frequency and type of discordances between MMR-IHC and MSI-PCR findings, and the possible role of Next Generation Sequencing in clarifying them. Reference is made to the significance of systematic quality assurance measures (e.g., QuIP MSI portal and multicenter proficiency testing), including regular continued training and education.

A Novel Mutation of MSH2 Gene in a Patient with Lynch Syndrome Presenting with Thirteen Metachronous Malignancies.

Lynch syndrome (LS), also known as hereditary nonpolyposis colorectal cancer (HNPCC), accounts for 2-3% of all colorectal cancers. This autosomal dominant disorder is associated with a predisposition to endometrial, stomach, small bowel, pancreatic, biliary tract, ovary, urinary tract, brain, and skin tumors. Lynch syndrome is caused by the mutation of the MLH1, MSH2 (EPCAM), MSH6, and PMS2 genes. In this article, a case study of a 70-year-old female patient with Lynch syndrome is presented. Over a span of 30 years, the patient underwent multiple surgical procedures for a total of thirteen different malignancies. She was found to have a deleterious pathogenic gene MSH2 (NM_000251.2) variant (mutation) c.1774_1775insT in the 12th exon. This variant, c.1774_1775insT, represents a novel finding, as it has not been previously reported in existing databases or literature. No other case of 13 metachronous tumors in a patient with Lynch syndrome was found in the literature.

[Testing deficient mismatch repair and microsatellite instability : A focused update. German version]. / Testung auf Mismatch-Reparatur-Defizienz und Mikrosatelliteninstabilität : Eine fokussierte Aktualisierung.

Testing to detect mismatch repair deficiency (dMMR) and high-grade microsatellite instability (MSI-H) has become an integral part of the routine diagnostic workup for colorectal cancer (CRC). While MSI was initially considered to be a possible indicator of a hereditary disposition to cancer (Lynch syndrome, LS), today the prediction of the therapy response to immune checkpoint inhibitors (ICI) is in the foreground. Corresponding recommendations and testing algorithms are available for use in primary diagnosis (reviewed in: Rüschoff et al. 2021).Given the increasing importance for routine use and the expanding indication spectrum of ICI therapies for non-CRCs, such as endometrial, small intestinal, gastric, and biliary tract cancers, an updated review of dMMR/MSI testing is presented. The focus is on the challenges in the assessment of immunohistochemical stains and the value of PCR-based procedures, considering the expanded ICI indication spectrum. A practice-oriented flowchart for everyday diagnostic decision-making is provided that considers new data on the frequency and type of discordances between MMR-IHC and MSI-PCR findings, and the possible role of Next Generation Sequencing in clarifying them. Reference is made to the significance of systematic quality assurance measures (e.g., QuIP MSI portal and multicenter proficiency testing), including regular continued training and education.

Lynch Syndrome Biopathology and Treatment: The Potential Role of microRNAs in Clinical Practice.

Lynch syndrome (LS), also known as Hereditary Non-Polyposis Colorectal Cancer (HNPCC), is an autosomal dominant cancer syndrome which causes about 2-3% of cases of colorectal carcinoma. The development of LS is due to the genetic and epigenetic inactivation of genes involved in the DNA mismatch repair (MMR) system, causing an epiphenomenon known as microsatellite instability (MSI). Despite the fact that the genetics of the vast majority of MSI-positive (MSI+) cancers can be explained, the etiology of this specific subset is still poorly understood. As a possible new mechanism, it has been recently demonstrated that the overexpression of certain microRNAs (miRNAs, miRs), such as miR-155, miR-21, miR-137, can induce MSI or modulate the expression of the genes involved in LS pathogenesis. MiRNAs are small RNA molecules that regulate gene expression at the post-transcriptional level by playing a critical role in the modulation of key oncogenic pathways. Increasing evidence of the link between MSI and miRNAs in LS prompted a deeper investigation into the miRNome involved in these diseases. In this regard, in this study, we discuss the emerging role of miRNAs as crucial players in the onset and progression of LS as well as their potential use as disease biomarkers and therapeutic targets in the current view of precision medicine.

Distress, anxiety, and depression in persons with hereditary cancer syndromes: Results from a nationwide cross-sectional study in Germany.

BACKGROUND: Persons with hereditary cancer syndromes (carriers) have a higher risk of developing cancer early. They are confronted with decisions regarding prophylactic surgeries, communication within their families, and childbearing. The present study aims to assess distress, anxiety, and depression in adult carriers and identify risk groups and predictors; clinicians can use to screen for particularly distressed persons. METHODS: N = 223 participants (n = 200 women, n = 23 men) with different hereditary cancer syndromes affected and unaffected by cancer answered questionnaires measuring their distress, anxiety, and depression levels. The sample was compared to the general population using one-sample t-tests. The n = 200 women with (n = 111) and without cancer (n = 89) were then compared and predictors for increased levels of anxiety and depression were identified using stepwise linear regression analyses. RESULTS: 66% reported clinical relevant distress, 47% reported clinical relevant anxiety, and 37% reported clinical relevant depression. Compared to the general population, carriers experienced increased distress, anxiety, and depression. Additionally, women with cancer suffered from more depressive symptoms than those without cancer. Past psychotherapy for a mental disorder and high distress were identified as predictors for increased anxiety and depression in female carriers. CONCLUSIONS: The results suggest that the psychosocial consequences of hereditary cancer syndromes are serious. Clinicians could regularly screen carriers regarding anxiety and depression. The NCCN Distress Thermometer can be combined with questions about past psychotherapy to identify especially vulnerable persons. Further studies are needed to develop psychosocial interventions.

Predictive factors based on the health belief model on cancer screening behaviour in first degree relatives of patients with Lynch syndrome-associated colorectal cancer.

Objectives: This study aimed to investigate colorectal cancer-related knowledge, health beliefs, and screening behaviour in first-degree relatives (FDRs) of patients with Lynch syndrome-associated colorectal cancer (CRC) and explore the predictive factors of screening behaviour based on a health belief model. Methods: This cross-sectional study was conducted in the colorectal department of a Class A tertiary hospital in Guangzhou from December 2017 to December 2019. A total of 265 FDRs of 96 patients with Lynch syndrome-related CRC were selected. The study was conducted in the colorectal department of a tertiary cancer centre in Guangzhou. The demographic questionnaire, the simplified CRC knowledge questionnaire, and the Champion's Health Belief Model Scale were used for evaluation. Data were analyzed using statistical description, between-group comparisons, and binary logistic regression. Results: A total of 160 (60.4%), 61 (23.0%), and 44 (16.6%) of the participants had high, medium, and low levels of knowledge about CRC, respectively; the average overall score of health belief was 121.36 ± 13.02. Sixty-one participants (23.0%) underwent Lynch syndrome-associated cancer screening. The predictive factors of screening behaviour included sex (male), age (older), married status (married), multiple primary cancers of the index patients, and high levels of knowledge and health beliefs (P < 0.05). Conclusions: The knowledge and health beliefs of cancer and cancer screening in FDRs of patients with Lynch syndrome-associated CRC should be improved. Both knowledge and beliefs are critical in promoting their cancer screening behaviour. Interventions should focus on health education and enhance health beliefs of the FDRs for better screening behaviour.

Naproxen chemoprevention induces proliferation of cytotoxic lymphocytes in Lynch Syndrome colorectal mucosa.

Background: Recent clinical trial data from Lynch Syndrome (LS) carriers demonstrated that naproxen administered for 6-months is a safe primary chemoprevention that promotes activation of different resident immune cell types without increasing lymphoid cellularity. While intriguing, the precise immune cell types enriched by naproxen remained unanswered. Here, we have utilized cutting-edge technology to elucidate the immune cell types activated by naproxen in mucosal tissue of LS patients. Methods: Normal colorectal mucosa samples (pre- and post-treatment) from a subset of patients enrolled in the randomized and placebo-controlled 'Naproxen Study' were obtained and subjected to a tissue microarray for image mass cytometry (IMC) analysis. IMC data was processed using tissue segmentation and functional markers to ascertain cell type abundance. Computational outputs were then used to quantitatively compare immune cell abundance in pre- and post-naproxen specimens. Results: Using data-driven exploration, unsupervised clustering identified four populations of immune cell types with statistically significant changes between treatment and control groups. These four populations collectively describe a unique cell population of proliferating lymphocytes within mucosal samples from LS patients exposed to naproxen. Conclusions: Our findings show that daily exposure of naproxen promotes T-cell proliferation in the colonic mucosa, which paves way for developing combination of immunoprevention strategies including naproxen for LS patients.

Comparison of clinicopathologic features, survival, and demographics in sebaceous carcinoma patients with and without Muir-Torre syndrome.

BACKGROUND: Visceral malignancies in patients with Lynch syndrome behave less aggressively than in those without Lynch syndrome. The behavior of sebaceous carcinoma (SC) in Muir-Torre syndrome (MTS), a variant of Lynch syndrome, is incompletely investigated. OBJECTIVE: To investigate features and survival of SC patients with and without MTS. METHODS: Retrospective cohort study in the Surveillance, Epidemiology, and End Results 17 database from 2000 to 2019 of patients with SC. Patients were classified as MTS or non-MTS cases based on a threshold score of 2 on the Mayo MTS risk score. RESULTS: We identified 105 (2.8%) MTS cases and 3677 (97.2%) non-MTS cases. On univariate analysis, MTS patients were younger, had a higher proportion of tumors outside the head/neck, and had fewer high-grade tumors. On Kaplan-Meier analysis, MTS patients trended toward having better SC-specific survival. On multivariate Cox proportional hazards analysis adjusting for other covariates, MTS status was an independent predictor of worse overall survival. However, there was no association between MTS status and SC-specific survival. LIMITATIONS: Given relatively high disease-specific survival in SC, our study may have been underpowered to detect a difference on Kaplan-Meier analysis. CONCLUSIONS: Our study suggests SC does not behave more aggressively in patients with MTS.

[Surgical strategies for hereditary colorectal cancer]. / Operative Strategien bei hereditären kolorektalen Karzinomen.

Hereditary colorectal cancer (hCRC) represents a major diagnostic and therapeutic challenge. In addition to the usual diagnostic methods, the family history, histological confirmation and mutation analysis play an important role in identifying the type of hereditary CRC. The diagnosis and classification of hCRC are carried out based on the anamnesis, clinical presentation and histology and the further treatment is determined depending on the underlying type of hCRC. For familial adenomatous polyposis (FAP) coloproctomucosectomy after the end of puberty is always recommended, whereas the treatment recommendations for other forms, such as attenuated FAP (aFAP), MUTYH-associated polyposis (MAP) and hereditary nonpolyposis colon cancer (HNPCC, Lynch syndrome), range from close surveillance and endoscopic control, through segmental resection up to colectomy. Irrespective of the type of hCRC, the treatment regimens necessitate an individualized approach and require close interdisciplinary cooperation. When colorectal resection is performed, minimally invasive procedures should principally be prioritized and some studies could demonstrate a potential benefit of robotic surgery compared to laparoscopy.

PMS2-associated Lynch syndrome: Past, present and future.

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

Primary retroperitoneal nodal endometrioid carcinoma associated with Lynch syndrome: A case report.

We report a rare case of primary nodal, poorly differentiated endometrioid carcinoma associated with Lynch syndrome. A 29-year-old female patient was referred by her general gynecologist for further imaging with suspected right-sided ovarian endometrioid cyst. Ultrasound examination by an expert gynecological sonographer at tertiary center revealed unremarkable findings in the abdomen and pelvis apart from three iliac lymph nodes showing signs of malignant infiltration in the right obturator fossa and two lesions in the 4b segment of the liver. During the same appointment ultrasound guided tru-cut biopsy was performed to differentiate hematological malignancy from carcinomatous lymph node infiltration. Based on the histological findings of endometrioid carcinoma from lymph node biopsy, primary debulking surgery including hysterectomy and salpingo-oophorectomy was performed. Endometrioid carcinoma was confirmed only in the three lymph nodes suspected on the expert scan and primary nodal origin of endometroid carcinoma developed from ectopic Müllerian tissue was considered. As a part of the pathological examination immunohistochemistry analysis for mismatch repair protein (MMR) expression was done. The findings of deficient mismatch repair proteins (dMMR) led to additional genetic testing, which revealed deletion of the entire EPCAM gene up to exon 1-8 of the MSH2 gene. This was unexpected considering her insignificant family history of cancer. We discuss the diagnostic work-up for patients presenting with metastatic lymph node infiltration by cancer of unknown primary and possible reasons for malignant lymph node transformation associated with Lynch syndrome.

Clinical characteristics of pancreatic and biliary tract cancers in Lynch syndrome: A retrospective analysis from the Finnish National Lynch Syndrome Research Registry.

Introduction: Patients with Lynch syndrome (LS) have an increased lifetime risk of pancreatic cancer (PC) and biliary tract cancer (BTC). These cancers have a notoriously pessimistic prognosis due to late diagnosis and limited therapeutic options. There are limited data based on small cohorts reviewing PC and BTC in LS patients. Methods: In this retrospective study of the Lynch Syndrome Registry of Finland (LSRFi), records of genetically verified LS patients diagnosed with PC or BTC between 1982 and 2020 were analyzed. Results: Thirty-nine patients were included: tumor(s) were in the pancreas in 26 patients, in the biliary tract in 10, and in the ampulla of Vater in three. A pathogenic germline variant was found in MLH1 in 33 of 39 patients. Twenty-six patients with 28 tumors located in the pancreas were identified: 23 pancreatic ductal adenocarcinomas (PDACs) and five neuroendocrine tumors (NETs). The median age at diagnosis of PC was 64 years (range of 38-81). In PC, the 5-year overall survival (OS) rate was 20%, and in PDAC, it was 13.6%. Ten patients with BTC were diagnosed: two intrahepatic, five perihilar, two distal extrahepatic cholangiocarcinomas, and one gallbladder carcinoma. Eight patients were male, and the median age at diagnosis was 54 years (range of 34-82). The 5-year OS rate for BTC was 30%. Metachronous tumors were diagnosed in 28 patients (70%). Colorectal cancer was the most common metachronous tumor, diagnosed in 20 patients (51%), and diagnosed prior to PC or BTC in all cases. Curative surgery was attempted on 17 of 39 patients. For 30 patients (91%), the cause of death was PC or BTC; two patients died from another LS-associated cancer, and one died from a stroke. Conclusion: Although the survival of LS patients with PC or BTC is better than in sporadic cancers, it is still poor and may be reflected by the relatively higher surgical resectability accounted for by the earlier age of onset. More studies on analyses of the molecular and immune profile, screening, and management of LS-associated pancreaticobiliary cancers are warranted.

Relative Risk of Bladder and Kidney Cancer in Lynch Syndrome: Systematic Review and Meta-Analysis.

Background: The association between Lynch syndrome (LS) and a higher risk of upper tract urothelial carcinoma is well established, but its effect on the risk of bladder and kidney cancers remains controversial. This review aimed to compare the relative risk (RR) of bladder and kidney cancer in confirmed LS germline mutation carriers compared to the general population. Methods: Medline, Embase, Cochrane Central, and Google Scholar were searched on 14 July 2022 for studies published in English that reported on the rates of urological cancer in adults with confirmed LS germline mutation. The quality of included studies was assessed using Cochrane's tool to evaluate risk of bias in cohort studies. Random effects meta-analysis estimated the pooled relative risk of bladder and kidney cancer in LS carriers compared to the general population. The quality of the overall evidence was evaluated using GRADE. Results: Of the 1839 records identified, 5 studies involving 7120 participants from 3 continents were included. Overall, LS carriers had a statistically significantly higher RR of developing bladder cancer (RR: 7.48, 95% CI: 3.70, 15.13) and kidney cancer (RR: 3.97, 95% CI: 1.23, 12.81) compared to unaffected participants (p < 0.01). The quality of the evidence was assessed as "low" due to the inclusion of cohort studies, the substantial heterogeneity, and moderate-to-high risk of bias. Conclusion: Lynch syndrome is associated with a significant increase in the relative risk of kidney and bladder cancer. Clinicians should adopt a lower threshold for germline mutation genetic testing in individuals who present with bladder cancer. Further studies evaluating the role and cost-effectiveness of novel urine-based laboratory tests are needed. High-quality studies in histologically proven renal cell carcinoma and their underlying germline mutations are necessary to strengthen the association with LS.

Universal Screening for Lynch Syndrome Compared with Pedigree-Based Screening: 10-Year Experience in a Tertiary Hospital.

PURPOSE: Universal screening for Lynch syndrome (LS) refers to routine tumor testing for microsatellite instability (MSI) among all patients with colorectal cancer (CRC). Despite its widespread adoption, real-world data on the yield is lacking in Korean population. We studied the yield of adopting universal screening for LS in comparison with pedigree-based screening in a tertiary center. MATERIALS AND METHODS: CRC patients from 2007-2018 were reviewed. Family histories were obtained and were evaluated for hereditary nonpolyposis colorectal cancer (HNPCC) using Amsterdam II criteria. Tumor testing for MSI began in 2007 and genetic testing was offered using all available clinicopathologic data. Yield of genetic testing for LS was compared for each approach and step. RESULTS: Of the 5,520 patients, tumor testing was performed in 4,701 patients (85.2%) and family histories were obtained from 4,241 patients (76.8%). Hereditary CRC (LS or HNPCC) was present in 69 patients (1.3%). MSI-high was present in 6.9%, and 25 patients had confirmed LS. Genetic testing was performed in 41.2% (47/114) of MSI-high patients, out of which 40.4% (19/47) were diagnosed with LS. There were six additional LS patients found outside of tumor testing. For pedigree-based screening, Amsterdam II criteria diagnosed 55 patients with HNPCC. Fifteen of these patients underwent genetic testing, and 11 (73.3%) were diagnosed with LS. Two patients without prior family history were diagnosed with LS and relied solely on tumor testing results. CONCLUSION: Despite widespread adoption of routine tumor testing for MSI, this is not a fail-safe approach to screen all LS patients. Obtaining a thorough family history in combination with universal screening provides a more comprehensive 'universal' screening method for LS.