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Objective To report the frequency of Lynch syndrome (LS) in a cohort of patients from Southeast Brazil bearing endometrial cancer (EC), using a tumor screening universal approach. Methods A total of 242 endometrial carcinomas were screened by immunohistochemistry (IHC) and microsatellite instability (MSI) for detection of DNA mismatch repair deficiency (dMMR). MLH1 methylation was assessed to identify sporadic cases. Patients with dMMR tumors were recruited for germline variant analysis by next-generation sequencing of the MLH1, MSH2, MSH6, PMS2, and EPCAM genes. Results Ninety-three out of 242 tumors (38.5%) were classified as dMMR based on MSI and IHC results. Of these, 54 cases were selected for germline analysis, and 37/54 (68.5%) were available for sequencing. Ten patients (10/37, 27%) harbored germline pathogenic or likely pathogenic variants, most of them in the MSH6 gene (4/10, 40%). Seven variants of uncertain significance were found. Eight novel germline variants were identified. The LS prevalence in our cohort was of at least 4.1%. LS patients presented lower mean age at cancer diagnosis compared with patients diagnosed with sporadic EC. Individuals with dMMR tumors, without germline pathogenic variants detected in LS-genes (“Lynch-like” syndrome), had an intermediate mean age at cancer diagnosis between LS and sporadic cases. Conclusion This is the first report of the LS prevalence in EC screened by a universal approach in Brazil. Our findings contribute to a better understanding of the mutational landscape of this syndrome in Brazil, which is relevant for improved identification, genetic counseling, prevention and control of cancer in LS.

Homologous recombination deficiencies are associated with increased platinum sensitivity and potential response to poly (ADP-ribose) polymerase inhibitors in epithelial ovarian cancer. As an alternative to germline testing or somatic tumor sequencing, BRCA1 deficiency can be detected by immunohistochemistry and might predict homologous recombination deficiencies. This study aimed to assess the association between BRCA1 expression by immunohistochemistry and the prognosis of patients with epithelial ovarian cancer. We conducted a systematic review and meta-analysis following the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement. We searched PubMed, EMBASE, Web of Science, and Scopus databases through July 2019. Reference lists of selected articles were screened for further studies. We conducted qualitative synthesis and meta-analyses of hazard ratios for overall survival and progression-free survival. Of 41 studies of BRCA1 expression using immunohistochemistry, 18 evaluated the association of BRCA1 expression with patient survival (2738 cases). The loss of BRCA1 expression was associated with improved overall survival (hazard ratio = 0.67, 95% confidence interval 0.57–0.77) and progression-free survival (hazard ratio = 0.70, 95% confidence interval 0.58–0.84). Negative BRCA1 expression assessed by immunohistochemistry was associated with a better prognosis in epithelial ovarian cancer.

BackgroundLoss of function in either breast cancer type 1 susceptibility protein (BRCA1) or breast cancer type 2 susceptibility protein (BRCA2) is a major risk factor for epithelial ovarian cancer (EOC) development. BRCA1 or BRCA2 deficiencies are associated with short-term prognosis and might have importance for the treatment of women with the disease. However, the screening of all possible mechanisms of dysfunction is expensive, time-consuming and difficult to apply in clinical practice. On the other hand, immunohistochemistry (IHC) is a simple and reliable method to access the expression of several proteins in tumour tissues.Materials and methodsThis systematic review aims to evaluate the current usage of IHC to detect BRCA1 and BRCA2 deficiencies in EOC. We searched and evaluated all primary literature on the use of IHC for evaluating BRCA1 and BRCA2 proteins expression in EOC. The main concepts for the search were: ovarian neoplasms, IHC, BRCA1 and BRCA2.ResultsForty-four studies from 925 unique titles were included. A total of 4206 tumour samples were evaluated for BRCA1 and 1041 for BRCA2 expression. Twelve BRCA1 primary antibodies were used in 41 studies, and the most common was the MS110 clone (75.6%). Seven BRCA2 primary antibodies were used in ten studies. Using the cut-off of 10%, 47.0% of EOCs are associated with loss of BRCA1 and 34.5% with the loss of BRCA2 expression.ConclusionIHC was effective to detect loss of BRCA1 protein expression in EOC; however, data on BRCA2 expression were heterogeneous and difficult to interpret.

Background: The goal of this study was to screen point mutations and deletions in APC and MUTYH genes in patients suspected of familial adenomatous polyposis (FAP) in a Brazilian cohort. Methods: We used high-resolution melting, Sanger direct sequencing and multiplex ligation-dependent probe association (MLPA) assays to identify point mutations, and large genomic variations within the coding regions of APC and MUTYH genes. Results: We identified 19 causative mutations in 40 Brazilian patients from 20 different families. Four novel mutations were identified in the APC gene and two in the MUTYH gene. We also found a high intra- and inter-familial diversity regarding extracolonic manifestations, and gastric polyps were the most common manifestation found in our cohort. Conclusion: We believe that the FAP mutational spectrum can be population-specific and screening FAP patients in different populations can improve pre-clinical diagnosis and improve clinical conduct.

O câncer de ovário é a neoplasia maligna ginecológica de maior letalidade no mundo. As proteínas BRCA1 e BRCA2, frequentemente alteradas nos carcinomas epiteliais de ovário, apresentam-se como potenciais biomarcadores diagnósticos, preditivos de risco, de prognóstico e de resposta terapêutica, tais como quimioterapia à base de platina e terapia alvo como os inibidores da poli (ADP-ribose) polimerase (PARP). Apesar de numerosos estudos independentes utilizando a técnica imuno-histoquímica (IHQ) para avaliar o nível de expressão dessas proteínas e a relação com a sobrevida das pacientes com câncer de ovário, os resultados permanecem controversos. O objetivo deste estudo foi sintetizar a evidência científica sobre a utilização da IHQ para a detecção das proteínas BRCA1 e BRCA2 no carcinoma epitelial de ovário e a relação com o prognóstico das pacientes. Este estudo seguiu as diretrizes Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA). Estudos analisando a expressão IHQ de BRCA1 e BRCA2 em pacientes com carcinoma epitelial de ovário invasivo foram identificados para a revisão sistemática por meio de buscas sistemáticas nos bancos de dados PubMed, Embase, Web of Science, Scopus até junho de 2019 e as listas de referências para estudos adicionais. Meta-análises de modelos de efeito fixo e aleatório foram realizadas para gerar dados combinados dos hazard ratio (HR) com os respectivos intervalos de confiança de 95% (IC95%) para sobrevida global (SG) e sobrevida livre de progressão (SLP) de acordo com o nível de expressão proteica. Avaliou-se a qualidade de cada estudo pelas escalas Newcastle-Ottawa Scale (NOS) e European Lung Cancer Working Party (ELCWP). Dos 44 estudos elegíveis para a revisão sistemática (4.735 pacientes), 50,0% dos tumores apresentaram imunoexpressão negativa de BRCA1 (41 estudos) e 61,0% de BRCA2 (dez estudos). Quatorze estudos relacionaram a expressão de BRCA1 com a sobrevida e foram incluídos para a meta-análise. No entanto, não houve a possibilidade de combinar os resultados da expressão de BRCA2. A perda de expressão de BRCA1 em 48,5% dos casos foi associada com a melhora da SG (HR=0,77; IC95%=0,60- 0,99; p=0,0415) e SLP (HR=0,75, IC95% 0,59-0,94). A alta heterogeneidade entre os estudos de SG (I 2 =72%, p

A Síndrome Hereditária do Câncer de Mama e/ou Ovário (HBOC) é caracterizada por famílias com história de câncer de mama e/ou ovário e associada a um padrão de herança autossômica dominante. Esta síndrome abrange cerca de 10% e 15% de todos os casos de câncer de mama e de ovário, respectivamente. Os genes BRCA1 e BRCA2 são genes de alta penetrância associados ao aumento de até 20x no risco para o desenvolvimento do câncer de mama e/ou ovário. Entretanto, apenas 20-30% dos casos de HBOC apresentam variantes patogênicas nestes genes e estudos têm evidenciado a contribuição de outros genes ligados às vias de reparo do DNA para o aumento de risco para HBOC. Na população brasileira, variantes em genes como ATM, ATR, CHEK2, MLH1, MSH2, MSH6, POLQ, PTEN e TP53, têm sido relatadas em até 7,35% dos casos estudados. Assim, o objetivo destes estudo foi realizar a pesquisa e caracterização de variantes em 21 genes relacionados à HBOC (ATM, ATR, BARD1, BRCA1, BRCA2, BRIP1, CDH1, CHEK2, FAM175A, MLH1, MRE11A, MSH2, MSH6, NBN, PALB2, PMS2, PTEN, RAD50, RAD51, TP53 e UIMC1) em 95 indivíduos diagnosticados com suspeita clínica de HBOC no Sudeste brasileiro. Foram identificadas 78 variantes patogênicas ou de significado incerto com conflito de informações sobre patogenicidade na literatura, em 19 dos 21 genes analisados. Cerca de 23,4% dos pacientes apresentaram variantes patogênicas nos genes BRCA1, BRCA2 e TP53, frequência maior que a identificada por outros estudos na população brasileira. No entanto, 83,3% das variantes identificadas são de significado incerto. A análise de associação identificou 13 destas VUS, em 8 genes, como significativamente associadas ao risco para HBOC. Os pacientes portadores destas variantes não apresentaram alterações no número de cópias para os genes BRCA1/BRCA2. Cinco variantes no BRCA1 foram identificadas como sendo segregadas em haplótipo, mas este não foi associado ao risco para HBOC. Duas variantes nos genes FAM175A e UIMC1 apresentaram alta frequência nos casos estudados e pacientes duplo heterozigotos apresentaram deficiência no reparo de danos causado após irradiação. Duas variantes no gene PALB2 associadas ao risco não afetaram a interação com BRCA1 e apresentaram atividade de reparo similar à proteína selvagem. No entanto, uma variante no CHEK2 levou à instabilidade da proteína e diminuição nos níveis de ativação de CHK2. Embora não associadas ao risco, duas variantes identificadas nos genes PMS2 e BRIP1 foram classificadas como possivelmente patogênicas. Esta variante no gene BRIP1 apresentou sensibilidade ao tratamento à mitomicina C, evidenciando uma deficiência na função desta proteína. Estudos como este evidenciam como outros genes envolvidos em vias de reparo do DNA podem estar contribuindo para a patogênese do HBOC. A caracterização destas variantes é imprescindível para estimar os riscos associados e assim possibilitar o acompanhamento clínico e aconselhamento genético adequados para pacientes diagnosticados clinicamente com HBOC, que, em sua maioria, permanecem sem um diagnóstico molecular elucidado. The Hereditary Breast and Ovarian Cancer Syndrome (HBOC) is characterized by families with a history of breast/ovarian cancer with an autosomal dominant inheritance patern. This syndrome covers about 10% to 15% of all cases of breast and ovarian cancer, respectively. The BRCA1 and BRCA2 genes are high penetrance genes associated with an increased risk of up to 20x for breast and ovarian cancer. However, only 20-30% of HBOC cases present pathogenic mutations in those genes, and other DNA repair genes have emerged as increasing the risk for HBOC. In the Brazilian population, mutations in genes such as ATM, ATR, CHEK2, MLH1, MSH2, MSH6, POLQ, PTEN and TP53 have been reported in up to 7.35% of the studied cases. The aim of this study was to investigate and characterize mutations in 21 HBOC-related genes (ATM, ATR, BARD1, BRCA1, BRCA1, BRIP1, CDH1, CHEK2, FAM175A, MLH1, MRE11A, MSH2, MSH6, NBN, PALB2, PMS2, PTEN, RAD50, RAD51, TP53 and UIMC1) in 95 individuals clinically diagnosed with HBOC in the Southeastern Brazil. We identified 78 pathogenic mutations and variants of uncertain significance with conflicting data on pathogenicity for 19 of the 21 genes analysed. About 23.4% of the patients presented pathogenic mutations in BRCA1, BRCA2 and TP53, a frequency higher than that identified by other studies in the Brazilian population. However, 83.3% of the identified variants are of uncertain significance. Five BRCA1 variants were identified as being segregated in haplotype, but this was not associated with risk for HBOC. Two variants in FAM175A and UIMC1 genes presented high frequency in the studied cases and when in double heterozygosity, presented deficiency in the repair of DNA damage after irradiation. The association analysis showed 13 VUS in 8 genes, as significantly associated with increased risk for HBOC, and the patients that carry those VUS did not present copy number variations for BRCA1/BRCA2 genes. Two PALB2 variants associated with risk did not affect the interaction with BRCA1 and presented repair activity similar to the wild type protein. However, one variant in CHEK2 led to protein instability and decreased levels of CHK2 activation. Although not associated with an increased risk, two variants identified in PMS2 and BRIP1 were classified as possibly pathogenic. The BRIP1 variant showed sensitivity to mitomycin C treatment, evidencing a deficiency in the protein function. Data such as this show how much other DNA repair genes may be contributing to the HBOC pathogenesis, emphasizing how essential the characterization of variants of unknow significance is for estimating the risks and thus enabling adequate clinical follow-up and genetic counseling for patients clinically diagnosed with HBOC, which, for the most part, remain without an elucidated molecular diagnosis.