Comprehensive assessment of mismatch repair and microsatellite instability status in molecular classification of endometrial carcinoma / 中华妇产科杂志

Objective: To explore the concordance and causes of different mismatch repair (MMR) and microsatellite instability (MSI) detection results in endometrial carcinoma (EC) molecular typing. Methods: A total of 214 EC patients diagnosed from January 2021 to April 2023 were selected at the Department of Pathology, Peking University Third Hospital. The immunohistochemistry (IHC) results of MMR protein were reviewed. Tumor specific somatic mutations, MMR germline mutations, microsatellite scores and tumor mutation burden (TMB) were detected by next-generation sequencing (NGS) with multi-gene panel. Methylation-specific PCR was used to detect the methylation status of MLH1 gene promoter in cases with deficient MLH1 protein expression. In cases with discrepant results between MMR-IHC and MSI-NGS, the MSI status was detected again by PCR (MSI-PCR), and the molecular typing was determined by combining the results of TMB and MLH1 gene promoter methylation. Results: (1) In this study, there were 22 cases of POLE gene mutation subtype, 55 cases of mismatch repair deficient (MMR-d) subtype, 29 cases of p53 abnormal subtype, and 108 cases of no specific molecular profile (NSMP). The median age at diagnosis of MMR-d subtype (54 years old) and the proportion of aggressive histological types (40.0%, 22/55) were higher than those of NSMP subtype [50 years old and 12.0% (13/108) respectively; all P<0.05]. (2) Among 214 patients, MMR-IHC test showed that 153 patients were mismatch repair proficient (MMR-p), 49 patients were MMR-d, and 12 patients were difficult to evaluate directly. MSI-NGS showed that 164 patients were microsatellite stable (MSS; equal to MMR-p), 48 patients were high microsatellite instability (MSI-H; equal to MMR-d), and 2 patients had no MSI-NGS results because the effective sequencing depth did not meet the quality control. The overall concordance between MMR-IHC and MSI-NGS was 94.3% (200/212). All the 12 discrepant cases were MMR-d or subclonal loss of MMR protein by IHC, but MSS by NGS. Among them, 10 cases were loss or subclonal loss of MLH1 and (or) PMS2 protein. Three discrepant cases were classified as POLE gene mutation subtype. In the remaining 9 cases, 5 cases and 3 cases were confirmed as MSI-H and low microsatellite instability (MSI-L) respectively by MSI-PCR, 6 cases were detected as MLH1 gene promoter methylation and 7 cases demonstrated high TMB (>10 mutations/Mb). These 9 cases were classified as MMR-d EC. (3) Lynch syndrome was diagnosed in 27.3% (15/55) of all 55 MMR-d EC cases, and the TMB of EC with MSH2 and (or) MSH6 protein loss or associated with Lynch syndrome [(71.0±26.2) and (71.5±20.1) mutations/Mb respectively] were significantly higher than those of EC with MLH1 and (or) PMS2 loss or sporadic MMR-d EC [(38.2±19.1) and (41.9±24.3) mutations/Mb respectively, all P<0.01]. The top 10 most frequently mutated genes in MMR-d EC were PTEN (85.5%, 47/55), ARID1A (80.0%, 44/55), PIK3CA (69.1%, 38/55), KMT2B (60.0%, 33/55), CTCF (45.5%, 25/55), RNF43 (40.0%, 22/55), KRAS (36.4%, 20/55), CREBBP (34.5%, 19/55), LRP1B (32.7%, 18/55) and BRCA2 (32.7%, 18/55). Concurrent PTEN, ARID1A and PIK3CA gene mutations were found in 50.9% (28/55) of MMR-d EC patients. Conclusions: The concordance of MMR-IHC and MSI-NGS in EC is relatively high.The discordance in a few MMR-d EC are mostly found in cases with MLH1 and (or) PMS2 protein loss or MMR protein subclonal staining caused by MLH1 gene promoter hypermethylation. In order to provide accurate molecular typing for EC patients, MLH1 gene methylation, MSI-PCR, MMR gene germline mutation and TMB should be combined to comprehensively evaluate MMR and MSI status.

Current management status of hereditary colorectal cancer / 中华胃肠外科杂志

Hereditary colorectal cancer accounts for approximately 5% of all colorectal cancer cases, mainly including familial adenomatous polyposis and Lynch syndrome. Total proctocolectomy plus ileal pouch-anal anastomosis and total colectomy plus ileorectal anastomosis are two major procedures for familial adenomatous polyposis, however, the exact impact of these two procedures on surgical efficacy, oncologic efficacy as well as functional results still remains uncertain. Segmental colectomy and total colectomy are two major procedures for Lynch syndrome, each of them both has advantages and disadvantages, and there still lacks a consensus about the optimal strategy because of the nature of retrospective study with a relatively insufficient evidence support. As a result, we would make a review about the current surgical treatment status and future perspectives of hereditary colorectal cancer.

Caracterização clínica, molecular e genética de pacientes com câncer colorretal abaixo de 50 anos / Clinical, molecular and genetic characterization of colorectal cancer patients under 50 years of age

Introdução: Pacientes com câncer colorretal (CCR) em idade jovem (< 50 anos) apresentam maior risco de apresentar variantes germinativas em genes de predisposição ao câncer, entre eles os genes da Síndrome de Lynch (SL) (genes MMR - MLH1, MSH2, MSH6 e PMS2). Detectar a perda de expressão de proteínas de reparo de incompatibilidade de DNA (MMR) é altamente relevante para identificar pacientes com síndrome de Lynch. No entanto, a inativação de MLH1 devido à hipermetilação do promotor ocorre em 15% dos cânceres colorretais (CCRs) esporádicos e está correlacionada com mutações somáticas BRAF. Ainda, apesar das principais síndromes hereditárias de CCR representarem 15-19% dos casos de CCR de início precoce, a etiologia da maior parte dos CCRs nestes pacientes é desconhecida, mesmo com até 25% destes casos apresentando história familiar importante para essa neoplasia. Objetivo: Caracterizar o fenótipo clínico e molecular (somático e germinativo) de pacientes com CCR desenvolvido antes dos 50 anos tratados no A.C.Camargo Cancer Center. Materiais e Métodos: Pacientes com câncer colorretal <50 anos foram selecionados a partir do banco de dados do Departamento de Cirurgia Pélvica ou pelo encaminhamento do Departamento de Oncogenética. A análise de metilação do promotor de MLH1 foi realizada por sequenciamento de nova geração (NGS) a partir de DNA convertido por bissulfito de sódio, em uma metodologia desenvolvida e validada nesse estudo. A análise de mutação de BRAF foi realizada por NGS de amplicon. Para um subgrupo de pacientes com critérios clínicos e moleculares específicos (tumores MMR deficientes, história familiar positiva para CCR, mutação KRAS: G12C e/ou idade <40 anos) foi realizado o sequenciamento germinativo de genes de predisposição ao CCR. Na avaliação das variantes germinativas foi utilizado um painel multigênico com 62 genes de associação conhecida, emergente ou desconhecida para predisposição ao CCR. As variantes identificadas foram classificadas segundo os critérios sugeridos pelo American College of Medical Genetics (ACMG). Resultados: Para análise de metilação de MLH1 utilizamos DNA de tumores FFPE e saliva foi tratado com bissulfito, amplificado por PCR e avaliado por NGS. Em tumores deficientes em MLH1/PMS2, o estado de metilação de MLH1 foi concordante com o estado de mutação BRAF em 90% (18/20) dos casos. Nosso teste NGS baseado em amplicon mostrou uma grande sensibilidade e especificidade para detectar a metilação de MLH1 em amostras de CCR, com alta concordância com a avaliação da mutação BRAF. A avaliação das variantes germinativas foi realizada em 89 pacientes, e identificamos 24 (27%) pacientes com variantes patogênicas ou provavelmente patogênicas (P/PP). A maioria dos pacientes 53% (47/89) apresentaram variantes de significado incerto (VUS) e 18 (20%) pacientes apresentaram apenas variantes sem significado clínico para os 62 genes avaliados. Dos 24 pacientes com variantes patogênicas, 16 (66,6%) apresentaram variantes P/PP em genes da síndrome de Lynch. Cinco pacientes (20%) apresentaram variantes P/PP em MUTYH (3 bialélicos e 2 monoalélicos). Dois (8,3%) pacientes tinham variantes PP em FAN1. Um paciente apresentou uma variante PP em NTHL1 (monoalélica), e para os genes XRCC4 e RAD51C tivemos um paciente cada com alteração. Dois pacientes apresentaram variantes P/PP em mais de 1 gene (1 MLH1 com FAN1, 1 MUTYH com XRCC4). Conclusão: Em nosso trabalho fomos capazes de desenvolver com sucesso uma metodologia baseada em NGS para avaliação de metilação no promotor do gene MLH1, para caracterizar molecularmente as amostras tumorais do grupo de pacientes com deficiência nos genes de reparo relacionados a causas esporádicas (metilação de MLH1 e mutação de BRAF). Além disso, identificamos variantes germinativas com evidência definitiva de predisposição ao CCR em 1 a cada 4 pacientes da nossa coorte, além de termos identificado variantes patogênicas em genes com evidência limitada ou ausente de predisposição hereditária ao câncer CCR, como é o caso dos genes RAD51C, XRCC4 e FAN1.

Introduction: Patients with colorectal cancer (CRC) at a young age (< 50 years) are at greater risk of having germline variants in cancer predisposition genes, including Lynch Syndrome (LS) genes (MMR genes - MLH1, MSH2, MSH6 and PMS2). Detecting the loss of expression of DNA mismatch repair (MMR) proteins is highly relevant to identify patients with Lynch syndrome. However, inactivation of MLH1 due to promoter hypermethylation occurs in 15% of sporadic colorectal cancers (CRCs) and is correlated with somatic BRAF mutations. Also, although the main hereditary syndromes of CRC represent 15-19% of cases of early-onset CRC, the etiology of most CRCs in these patients is unknown, even with up to 25% of these cases presenting an important family history of this neoplasm. Objective: To characterize the clinical and molecular phenotype (somatic and germline) of patients with CRC developed before the age of 50 years treated at the A.C.Camargo Cancer Center. Materials and Methods: Colorectal cancer patients <50 years were selected from the database of the Department of Pelvic Surgery or by referral from the Department of Oncogenetics. MLH1 promoter methylation analysis was performed by next-generation sequencing (NGS) from DNA converted by sodium bisulfite, in a methodology developed and validated in this study. BRAF mutation analysis was performed by amplicon NGS. For a subgroup of patients with specific clinical and molecular criteria (MMR deficient tumors, positive family history for CCR, KRAS:G12C mutation, and/or age <40 years) germline sequencing of CRC predisposing genes was performed. In the evaluation of germline variants, a multigene panel with 62 genes of known, emerging or unknown association for CRC predisposition was used. The identified variants were classified according to the criteria suggested by the American College of Medical Genetics (ACMG). Results: For MLH1 methylation analysis we used DNA from FFPE tumors and saliva was treated with bisulfite, amplified by PCR and evaluated by NGS. In MLH1/PMS2 deficient tumors, MLH1 methylation status was concordant with BRAF mutation status in 90% (18/20) of cases. Our amplicon-based NGS test showed great sensitivity and specificity for detecting MLH1 methylation in CRC samples, with high agreement with the BRAF mutation assessment. The evaluation of germline variants was performed in 89 patients, and we identified 24 (27%) patients with pathogenic or probably pathogenic (P/PP) variants. Most patients 53% (47/89) had variants of uncertain significance (VUS) and 18 (20%) patients had only variants without clinical significance for the 62 genes evaluated. Of the 24 patients with pathogenic variants, 16 (66.6%) had P/PP variants in Lynch syndrome genes. Five patients (20%) had P/PP variants in MUTYH (3 biallelic and 2 monoallelic). Two (8.3%) patients had PP variants in FAN1. One patient had a PP variant in NTHL1 (monoallelic), and for the XRCC4 and RAD51C genes we had one patient each with alteration. Two patients had P/PP variants in more than 1 gene (1 MLH1 with FAN1, 1 MUTYH with XRCC4). Conclusion: In our work, we were able to successfully develop a methodology based on NGS for the evaluation of methylation in the promoter of the MLH1 gene, to molecularly characterize the tumor samples from the group of patients with deficiency in the repair genes related to sporadic causes (MLH1 methylation and BRAF mutation). In addition, we identified germline variants with definitive evidence of predisposition to CRC in 1 out of 4 patients in our cohort, in addition to having identified pathogenic variants in genes with limited or no evidence of hereditary predisposition to CRC cancer, such as the RAD51C genes, XRCC4 and FAN1.

Postcolonoscopy colorectal cancer: an overview and future directions

Over the past decade, there has been a great interest in postcolonoscopy colorectal cancer (PCCRC). Its etiology is complex and multifactorial. Monitoring for PCCRC is even more complex. The strategies to decrease the incidence of PCCRC start by defining the problem, identifying the factors contributing to its development, followed by an attempt to define methods to decrease its incidence.We believe that the quality of the colonoscopy and the endoscopist's expertise are the key factors in decreasing the incidence of PCCRC. (AU)

Identificación del fenotipo de inestabilidad microsatelital en carcinoma colorrectal mediante el análisis de la expresión de proteínas reparadoras del ADN: Revisión narrativa / Identification of microsatellite instability phenotype in colorectal carcinoma through expression analysis of DNA mismatch repair proteins: Narrative review

El carcinoma colorrectal (CCR) es de las primeras causas de mortalidad del mundo, presentando Guatemala una incidencia anual de 7.4/millón de habitantes. El síndrome de Lynch se caracteriza clínicamente por un inicio temprano del CCR con lesiones causadas por alteraciones en genes que codifican proteínas reparadoras.Los microsatélites son regiones del ADN con una unidad repetitiva de uno o más nucleótidos y son susceptibles a errores durante la replicación de ADN de los enterocitos. Existe un sistema de reparación que corrige estos errores. Cuando las proteínas reparadoras de este sistema están mutadas o ausentes, dichos errores del ADN persisten. Estas proteínas reparadoras se expresan en el núcleo de las células colónicas normales y son detecta-bles utilizando estudios de inmunohistoquímica (IHQ). Los genes MLH1 y MSH2 pueden encontrarse mutados en el 90% de los casos de cáncer colorrectal y el resto corresponde a MSH6 y PMS2. Esta vía oncogénica se caracteriza por alteración del sistema de reparación de errores durante la replicación del ADN, controlado por los genes MMR (mismatch repair), principalmente MLH1, MSH2, MSH6 y PMS2. Se realizó una revisión extensa de la literatura en PubMed, Springer y JAMA, usando las palabras clave: fenotipo de CCR, Síndrome de Lynch e inestabilidad microsatelital, detectándose 55 artículos. El objetivo de esta revisión es describir la importancia de la identificación del fenotipo del CCR por medios de IHQ y de pruebas moleculares para el eficaz tratamiento con inmunoterapia anti-PD1/PD-L1.

Colorectal cancer (CRC) is one of the leading causes of mortality in the world. In Guatemala it's an important cause of morbidity (7.4 per million inhabitants). Lynch syndrome is clinically characterized by an early onset of nonpolyposis colorectal carcinoma, with multiple lesions and neoplasms. The syndrome is caused by mutations in genes encoding DNA mismatch repair proteins. The microsatellites are regions of the DNA that repeat between one or more nucleotides and are susceptible to errors during replication, these are corrected by a repair system, when genes are mutated, the errors persist. The genes encoding repair proteins are expressed in the nuclei of normal colonic cells which can be observed using immunohistochemical studies. The MLH1, MSH2 genes are found to be mutated in 90% of the cases and the rest corresponds to the MSH6 and PMS2 genes. This oncogenic pathway characteristically consists of an alteration in the DNA repair system that is controlled by mismatch repair genes (MMR). An extensive research was conducted on PubMed, Springer and JAMA, using the keyword: CRC phenotype, Lynch syndrome and microsatellite instability. 55 articles were found. This review«s objective is to understand the mechanisms of nonpolyposis colorectal cancer and the importance of identifying patients with a mutant phenotype as a predictive factor for the efficacy of the anti-PD1/PDL1 immunotherapy and for prognosis.

Spinal Cord Stimulation as a Treatment Option for Refractory Chemotherapy-Induced Peripheral Neuropathy: Case Report

Colorectal cancer is one of the most common oncological diseases. Chemotherapy is usually recommended as an adjuvant treatment for stage-II, -III, and -IV tumors. Approximately 10% of the patients develop neuropathic pain after chemotherapy, and they may remain refractory despite the administration of drugs that are commonly used to treat neuropathic pain. Spinal cord stimulation is a good treatment option for neuropathic pain of the lower limbs, and it should be trialed in patients with chemotherapy-induced peripheral neuropathy. We report the case of a patient with oxaliplatin-induced neuropathy and neuropathic pain refractory to oral medication who was successfully treated by spinal cord stimulation.

Narrative review comparing the epidemiology, characteristics, and survival in sporadic colorectal carcinoma/Lynch syndrome / Revisão narrativa na comparação da epidemiologia, características e sobrevivência no Carcinoma Colorretal esporádico/Síndrome de Lynch

Abstract Introduction: Colorectal carcinoma is the third most prevalent neoplasm in the world, and the second cause of death by cancer. The most part of these neoplasms are sporadic by somatic mutations, but around 15% are hereditary, such as Lynch syndrome or hereditary nonpolyposis colorectal cancer (HNPCC). Despite being the same tumor, it has differences between these two contexts as well as different prognosis. In Lynch syndrome cases, the survival of these individuals was greater than that observed in sporadic cases. Methods: This review focuses on the different characteristics and development of colorectal carcinoma in sporadic and Lynch syndrome cases, in order to conclude what may motivate the greater survival in the tumors associated with this syndrome. Results: Although the histopathological features drive into a worse prognosis, the colorectal carcinoma in the Lynch Syndrome presents a greater survival comparing to sporadic colorectal carcinoma. Discussion: The greater survival in the colorectal carcinoma in the HNPCC compared to the sporadic carcinomas has been linked to factors such as high microsatellite instability, diploid predominance, earlier screening for colo-rectal carcinoma, deficient DNA repair mechanism, low p53 mutation rate, and presence of lymphoid aggregates involving the neoplasm. Conclusion: Further studies should be conducted to provide new insights about survival of colorectal carcinoma in Lynch syndrome, as well as the therapeutic alternatives for this neoplasia.

Resumo Introdução: O carcinoma colorretal é a terceira neoplasia mais prevalente no mundo, bem como a segunda causa de morte por câncer. A maioria destas neoplasias são esporádicas, devidas a mutações somáticas, mas cerca de 15% são hereditárias como a síndrome de Lynch ou Hereditary Nonpolyposis Colorectal Cancer (HNPCC). Apesar de ser a mesma neoplasia, esta apresenta características clinico-patológicas e moleculares distintas, bem como diferentes prognósticos. Nos casos de síndrome de Lynch, a sobrevida parece ser maior quando comparada com os carcinomas esporádicos. Métodos: Realizamos uma revisão bibliográfica sobre as diferentes características e desenvolvimentos do carcinoma colorretal esporádico e no contexto da síndrome de Lynch, para concluir o que causa a maior sobrevida no caso das neoplasias associadas a esta síndrome. Resultados: Apesar das características histopatológicas apontarem para um pior prognóstico, o HNPCC apresenta uma maior sobrevida em relação ao carcinoma colorretal esporádico. Discussão: A maior sobrevivência nos carcinomas colorretais associados ao HNPCC em comparação com os carcinomas colorretais esporádicos tem sido atribuída a fatores como a elevada instabilidade microssatélite, a predominância diploide, a realização de rastreio para o carcinoma colorretal mais precoce, deficiente mecanismo de reparação de DNA, menor taxa de mutação da p53 e existência de agregados linfoides a envolver a neoplasia. Conclusão: Consideramos que deve ser encorajado o estudo mais aprofundado dos fatores que levam à maior sobrevida do carcinoma colorretal na síndrome de Lynch, bem como de alternativas terapêuticas para esta neoplasia.

Extensive colectomy in colorectal cancer and hereditary nonpolyposis colorectal cancer - long-term results / Colectomia extensa em cancro colorretal e cancro colorretal hereditário sem polipose - resultados a longo prazo

ABSTRACT Background: Colorectal cancer survival is better in hereditary nonpolyposis colorectal cancer patients than in sporadic colorectal cancer patients and even for hereditary nonpolyposis colorectal cancer with colorectal cancer is not consensual that extensive colectomy is preferable to partial colectomy. This study analyzes and compares the long-term results of these two groups of patients submitted to curative subtotal colectomy or total colectomy. Methods: Between 2002 and 2018, 68 patients with colorectal cancer without familial adenomatous polyposis were submitted to a total or subtotal colectomy in a single tertiary center. The patients were divided in two groups: hereditary nonpolyposis colorectal cancer patients (with Amsterdam criteria) and sporadic colorectal cancer patients (the others). The presence of Amsterdam criteria for hereditary nonpolyposis colorectal cancer and germline mutation for mismatch repair genes was confirmed by clinical records. Results and survival were analyzed following surgery. Results: We obtained a sporadic colorectal cancer group with 31 patients and a hereditary nonpolyposis colorectal cancer group with 37 patients. The two groups differ in age but not in gender, tumor stage or surgical morbidity. The overall survival and disease-free survival were good in both groups but even better for hereditary nonpolyposis colorectal cancer group with statistical significance when comparing the two groups. Conclusion: Total or subtotal colectomy for colorectal cancer provides a good survival. These surgical procedures should be considered the first option for colorectal cancer in young hereditary non polyposis colorectal cancer patients. In those cases, they provide good long-term results, avoiding the risk of metachronous colorectal cancer and the surveillance is restricted only to the remaining need for rectum.

RESUMO Introdução: A sobrevivência do cancro colorretal é melhor em pacientes com cancro colorretal hereditário não associado a polipose do que em pacientes com cancro colorretal esporádico. Mesmo em casos de cancro colorretal hereditário sem polipose, a preferência pela colectomia total em relação à parcial não é consensual na literatura. Este estudo analisa e compara os resultados a longo prazo destes dois grupos de pacientes submetidos à colectomia curativa subtotal ou total. Métodos: Entre 2002 e 2018, 68 pacientes com cancro colorretal sem polipose adenomatosa familiar foram submetidos a colectomia total ou subtotal em um único centro terciário. Os pacientes foram divididos em dois grupos: aqueles com cancro colorretal hereditário sem polipose (de acordo com os critérios de Amsterdão) e os com cancro colorretal esporádico (os demais). Os critérios de Amsterdão para cancro colorretal hereditário sem polipose e a presença de mutação germinativa para os genes de reparação de ADN foram confirmados por consulta dos registros clínicos. Os resultados e a sobrevivência foram analisados após a cirurgia. Resultados: No presente estudo, 31 pacientes foram incluídos no grupo de cancro colorretal esporádico e 37 no grupo de cancro colorretal hereditário sem polipose. Diferenças significativas foram observadas em relação à idade, mas não ao gênero, estadio do tumor ou morbilidade cirúrgica. A sobrevivência global e a sobrevivência livre de doença foram boas em ambos os grupos, mas os resultados foram ainda melhores no grupo de cancro colorretal hereditário sem polipose, com significado estatístico. Conclusão: A colectomia total ou a colectomia subtotal para o cancro colorretal proporcionam uma boa sobrevivência e devem ser consideradas a primeira opção de tratamento em pacientes jovens com cancro colorretal hereditário sem polipose. Nestes pacientes, uma cirurgia cólica mais extensa permite a obtenção de bons resultados a longo prazo; reduz o risco de cancro colorretal metácrono e restringe a vigilância endoscópica ao reto remanescente.

A frameshift mutation in exon 19 of MLH1 in a Chinese Lynch syndrome family: a pedigree study / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Lynch syndrome (LS), an autosomal dominantly inherited disease previously known as hereditary non-polyposis colorectal cancer (HNPCC), leads to a high risk of colorectal cancer (CRC) as well as malignancy at certain sites including endometrium, ovary, stomach, and small bowel (Hampel et al., 2008; Lynch et al., 2009). Clinically, LS is considered the most common hereditary CRC-predisposing syndrome, accounting for about 3% of all CRC cases (Popat et al., 2005). LS is associated with mutations of DNA mismatch repair (MMR) genes such as MLH1, MSH2, MSH6, PMS2, and EPCAM (Ligtenberg et al., 2009; Lynch et al., 2009), which can trigger a high frequency of replication errors in both microsatellite regions and repetitive sequences in the coding regions of various cancer-related genes. Immunohistochemistry (IHC) tests followed by genetic analysis of these mutations play a significant role in diagnosis, treatment determination, and therapeutic response prediction of LS (Lynch et al., 2009; Alex et al., 2017; Ryan et al., 2017). Here, we report substitution of one base-pair in exon 1 of MLH3 (c.1397C>A) and a frameshift mutation in exon 19 of MLH1 (c.2250_2251ins AA) in a 43-year-old Chinese male with an LS pedigree.

A single center study of colorectal cancer screening for Lynch syndrome / 中华医学遗传学杂志

OBJECTIVE@#To determine the ratio of deficient mismatch repair (dMMR) proteins and Lynch syndrome among patients undergoing colorectal cancer resection.@*METHODS@#From June 2014 to May 2016, immunohistochemistry for mismatch repair proteins including mutL homolog 1 (MLH1), mutS homolog 2 (MSH2), mutS homolog 6 (MSH6) and PMS1 homolog 2 (PMS2) were carried out on 207 surgically resected specimens. Samples with lost expression of MMR proteins underwent genetic testing.@*RESULTS@#Loss of expression of MMR proteins were found among 21 patients and accounted for 10.14% of the colorectal cancers. dMMR was more common in patients ≤50 years old, or with proximal tumor at splenic flexure and mucinous adenocarcinoma. Ten patients underwent genetic testing, with three pathogenic mutations (MSH6 c.3013C>T, MLH1 c.199G>A and a novel MSH6 c.584delT) and four ambiguous mutations identified. At least 1.4% of the colorectal cancers were diagnosed as Lynch syndrome.@*CONCLUSION@#Routine screening for Lynch syndrome among patients with colorectal cancer with MMR protein immunohistochemistry as preliminary screening method and MMR gene sequencing as diagnostic method is effective and feasible. It can reduce missed diagnosis of Lynch syndrome and bring lifelong benefit to patients and their families.

Síndrome de Lynch: aspectos genéticos, clínicos y diagnósticos / Lynch syndrome: genetic, clinical and diagnostic aspects

Esta revisión tiene como objetivo dar a conocer los aspectos genéticos, clínicos y diagnósticos del síndrome de Lynch, además de brindar la información más relevante acerca de la asesoría genética en estos pacientes y las recomendaciones actuales para su seguimiento.

This review aims to present the genetic, clinical and diagnostic aspects of Lynch syndrome, as well as providing the most relevant information about genetic counseling in these patients and the current recommendations for their surveillance.

Síndrome de Lynch: Caracterización genético clínica y epidemiología. Caso clínico / Lynch syndrome: clinical genetic characterization and epidemiology. Clinical case

El cáncer colorrectal hereditario no polipósico (CCHNP), también llamado síndrome de Lynch, es la forma más común de cáncer colorrectal (CCR) hereditario (1). Se trata de un síndrome con gran carga genética y penetrancia, que se presenta en etapas tempranas de la vida, en diversos miembros de la familia (2). Es una enfermedad autosómica dominante debido a la presencia de mutaciones en los genes reparadores de bases desapareadas de ADN, principalmente MSH2 y MLH1, que representan un 90% del total, y con menor frecuencia, MSH6 y PMS2(3). El 80% de los cánceres colorrectales son de aparición esporádica, el 10% son familiares y el restante 5-10%, tienen carácter hereditario. Se presenta el caso de un hombre de 35 años, con múltiples recurrencias y al menos dos generaciones afectados. Se discuten los aspectos más importantes sobre el diagnostico, manejo y consejo genético en estos casos

The obesity is characterized by the higher content of Hereditary non-polyposis colorectal cancer (HNPCC), also called Lynch syndrome, is the most common form of hereditary colorectal cancer (CRC) (1). It is a syndrome with a high genetic load and penetrance, which occurs in the early stages of life, in several family members (2). It is an autosomal dominant disease due to the presence of mutations in DNA repair genes, mainly MSH2 and MLH1, which represent 90% of the total, and with less frequency MSH6 and PMS2 (3). The 80% of colorectal cancers are sporadic, 10% are familiar and the 5-10% is hereditary. We present the case of a man of 35 years, with multiple recurrences and at least two generations affected. The most important aspects about the diagnosis, management and genetic counseling in these cases are discussed.

Observaciones críticas en torno al ganglio centinela en el cáncer colorrectal / Critical observations about the sentinel lymph node in colorectal cancer

Introducción: La identificación del ganglio centinela durante el tratamiento quirúrgico del cáncer colorrectal puede ayudar a la correcta estadificación posoperatoria y trascender a la quimioterapia adyuvante en el seguimiento a fin de mejorar la supervivencia de estos enfermos. Objetivo: Identificar las técnicas utilizadas para detectar el ganglio centinela mediante acceso convencional o laparoscópico: tinción o radiotrazador, ex vivo o in vivo así como su influencia en la estadificación posoperatoria y en el tratamiento adyuvante correlacionado con la evolución del cáncer de colon. Material y Métodos: Revisión documental en formato electrónico e impreso de publicaciones actualizadas sobre el tema. Desarrollo: El estudio de los linfáticos supone el factor pronóstico más importante en el cáncer colorrectal sin metástasis. La detección del ganglio centinela es la técnica que mejor predice el estado ganglionar de un paciente y permite realizar estudios intensivos que mejoran la estadificación. Conclusiones: El estudio del ganglio centinela es una práctica reproducible sin aumento significativo del tiempo y costos. En el seguimiento de los enfermos clasificados N0 con ganglio centinela positivo parece haber tendencia a un porcentaje mayor de recidivas, lo que podría trascender a cambios en las pautas de tratamiento adyuvante en aras de mejorar la supervivencia(AU)

Introduction: The identification of the sentinel lymph node during surgical treatment of colorectal cancer can help the correct postoperative staging and go beyond adjuvant chemotherapy in the follow-up of patients with the aim to improve survival of these sick people. Objective: To identify the techniques used to detect the sentinel lymph node through either conventional or laparoscopic approach: staining or radiotracer ex vivo or in vivo, as well as its influence in postoperative staging and the adjuvant treatment correlated with the evolution of colon cancer. Material and Methods: Document review of up-to-date publications about the topic in both electronic and printed formats. Development:The study of lymphatics is considered the most important prognostic factor in the colorectal cancer without metastases. The detection of the sentinel node is the technique that best predicts the lymph node status in a patient, and allows to conduct intensive studies to improve staging. Conclusions:The study of the sentinel lymph node is a reproducible practice without a significant increase in time and costs. The follow-up of patients classified as NO with a positive sentinel lymph node seems to have a tendency to a higher percentage of relapses, which could go beyond changes in the adjuvant treatment guidelines aimed at improving survival(AU)

Lynch syndrome – Muir-Torre variant: implication in gynecologic oncology / 부인종양

No abstract available.

Screening for Lynch syndrome using risk assessment criteria in patients with ovarian cancer / 부인종양

OBJECTIVE: Lynch syndrome is a cancer predisposition syndrome caused by germline mutation of DNA mismatch repair (MMR) genes. Lynch syndrome only causes about 0.4% of cases of ovarian cancer, which suggests that universal screening may not be cost-efficient. However, the frequency of Lynch syndrome in ovarian cancer is unclear in the Asian population. The goal of the study was to investigate a screening strategy using family history. METHODS: The subjects were 129 patients with ovarian cancer. Clinical and family history were collected using a self-administered questionnaire, and Society of Gynecologic Oncology (SGO) criteria 2007 and PREMM5 were used for risk assessment. Microsatellite instability, immunohistochemistry, and methylation of MMR genes were analyzed. RESULTS: Of the 129 cases, 25 (19.4%) met the SGO criteria, and 4 of these 25 had MSI-high and MMR deficiency. Two cases had loss of MSH2 and MSH6, indicating MSH2 mutation, and the other two had loss of MLH1 and PMS2, including one without MLH1 methylation indicating MLH1 mutation. These results show that screening using family history can detect Lynch syndrome in 12.0% (3/25) of ovarian cancer cases. The 3 cases were positive for PREMM5, but negative for Amsterdam II criteria and revised Bethesda guidelines. Genetic testing in one case with MSH2 and MSH6 deficiency confirmed the diagnosis of Lynch syndrome with MSH2 mutation. CONCLUSION: This is the first study of screening for Lynch syndrome in ovarian cancer using clinical and family history in an Asian population. This approach may be effective for diagnosis in these patients.

Major clinical research advances in gynecologic cancer in 2017 / 부인종양

In 2017, 10 topics were selected as major clinical research advances in gynecologic oncology. For cervical cancer, efficacy and safety analysis results of a 9-valent human papillomavirus (HPV) vaccine and long-term impact of reduced dose of quadrivalent vaccine were updated. Brief introduction of KEYNOTE trials of pembrolizumab, a monoclonal antibody that blocks the interaction between programmed death (PD)-1 and its ligands, PD-L1 and PD-L2, followed. Tailored surveillance programs for gynecologic cancer related with Lynch syndrome and update on sentinel lymph node mapping were reviewed for uterine corpus cancer. For ovarian cancer, 5 topics were selected including poly(ADP-ribose) polymerases inhibitors and immunotherapy. The other potential practice changers covered in this review were lymphadenectomy in advanced disease, secondary cytoreductive surgery in recurrent disease, weekly dose-dense regimen for first-line chemotherapy, incorporation of bevacizumab maintenance in platinum-sensitive recurrent disease, and effect of platinum-free interval prolongation. Conflicting opinions of academic societies on periodic pelvic examination were introduced in conjunction with relevant literature review. For the field of radiation oncology, results of 2 big trials, The Postoperative Radiation Therapy in Endometrial Carcinoma-3 and Gynecologic Oncology Group-258, for endometrial cancer and recent advance in high-dose-rate brachytherapy for cervical cancer were reported. Topics for breast cancer covered adjuvant capecitabine after preoperative chemotherapy, adjuvant pertuzumab and trastuzumab in early human epidermal growth factor receptor 2-positive disease, olaparib for metastatic cancer in patients with a germline BRCA mutation, 20-year risks of recurrence after stopping endocrine therapy at 5 years, and contemporary hormonal contraception and the risk of breast cancer.

Germline Variants in MLH1, MSH2, and MSH6 in Korean Patients with Lynch Syndrome

BACKGROUND: The phenotypic and genetic spectrum of Lynch syndrome (LS) seems to differ according to ethnicity. The aim of this study was to investigate the clinical, pathological, and genetic features of LS in a large sample of Korean patients. METHODS: We enrolled a total of 232 patients who fulfilled the revised Bethesda criteria (81%, 232/286) from 286 individuals who underwent genetic screening for LS (MLH1, MSH2, and MSH6 sequencing) in the Samsung Medical Center in Korea from 2004 to 2015. Histopathologic findings, microsatellite instability data, and clinical information were collected. RESULTS: We identified 61 different pathogenic or likely pathogenic variants (39 in MLH1, 20 in MSH2, and 2 in MSH6), including 4 novel variants, in 101 unrelated Korean patients (101/232, 44%). When multiple tumor manifestations in a single patient were individually considered, there were 285 cancers recorded from 232 cases. A diverse spectrum of tumors, including colorectal cancer, endometrial cancer, stomach cancer, and ovary cancer, was observed. Patients with genetic alterations were more closely associated with a family history of cancers, double primary cancers, and the development of secondary neoplasms than patients without genetic alterations (P < 0.0001, P=0.0052, and P=0.0010, respectively). CONCLUSIONS: We report the distribution of pathogenic variants in MLH1, MSH2, and MSH6, as well as the tumor spectrum, in a large sample of Korean patients with LS. Genetic testing could be an effective stratification strategy for surveillance of LS. This study sheds light on the genetic features of Asian patients with LS.

Consensus on clinical diagnosis, treatment and pedigree management of hereditary colorectal cancer in China / 中华肿瘤杂志

Hereditary colorectal cancer can be divded into two categories based on the presence or absence of polyps. The first category is characterized by the development of polyposis, which includes familial adenomatous polyposis (FAP); The second category is nonpolyposis colorectal cancer, which is represented by Lynch syndrome. "Consensus on clinical diagnosis, treatment and pedigree management of hereditary colorectal cancer in China" developed by the Genetics Group of the Committee of Colorectal Cancer, Chinese Anti-cancer Association, is composed of three sections, including hereditary nonpolyposis syndrome, polyposis syndrome as well as genetic evaluation of hereditary colorectal cancer. The consensus aims to provide recommendations on management of the respective hereditary syndromes in terms of definition, clinical and pathological features, diagnostic standards, treatment, and follow-ups. In addition to describing diagnostic and treatment strategies, prophylactic treatment as well as genetic screening and pedigree monitoring is highly recommended. Through the establishment of this expert consensus, we hope to promote better understanding of hereditary colorectal cancer for clinicians and encourage standardized treatment through multidisciplinery approaches, eventually improving clinical treatment and pedigree management of hereditary colorectal cancer in China.