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MUTYH-Associated Polyposis (MAP) is caused by biallelic pathogenic germline variants in the MUTYH gene. However, individuals harboring monoallelic MUTYH pathogenic variants in the presence of a positive family history have been reported to have a twofold increased risk of colorectal cancer (CRC) and extra colonic cancers. Our aim was to characterize the spectrum of monoallelic and biallelic germline MUTYH pathogenic variants in Latin American patients and to describe their clinical and genetic characteristics. Patients were identified from eight high-risk genetic cancer centers of five Latin American countries. Statistical analysis was performed using the two-sided P test using the Vassarstats statistical tools. Statistical significance was set at a p value ≤ 0.05. Of the 105 unrelated patients with cancer or colorectal polyposis, 84.8% and 15.2% carried pathogenic monoallelic and biallelic MUTYH variants, respectively. The most common pathogenic variants were p.Gly396Asp and p.Tyr179Cys (55% and 23%, respectively). The mean age at first diagnosis was 48.29 years (range 31-71) and 49.90 years (range 27-87) in biallelic and monoallelic MUTYH patients, respectively. CRC was the only cancer diagnosed in patients with biallelic MUTYH pathogenic variants (75%), while breast cancer (46.1%) was more common than CRC (24.7%) in individuals with monoallelic MUTYH pathogenic variants. We reported a high frequency of European founder variants in our diverse population. Some phenotypic differences from current studies were identified, such as a higher breast cancer burden in monoallelic carriers and a complete absence of extra-colon tumors in biallelic patients.
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Breast cancer (BC) is the most prevalent malignancy in women with Li-Fraumeni syndrome (LFS). The literature on BC in LFS is limited due to its rarity worldwide. A TP53 founder pathogenic variant (c.1010G>A; p.R337H) is responsible for the higher prevalence of this syndrome among women of Brazilian ancestry. Purpose: The aim of the study was to describe the BC phenotype expressed by Brazilian female LFS carriers and compare the data between p.R337H and other TP53 germline pathogenic/likely pathogenic variants (non-p.R337H carriers). Methods: We searched for cases of TP53 germline pathogenic/likely pathogenic variant carriers affected by BC included between 2015 and 2020 in the BLiSS (Brazilian Li-Fraumeni Study) registry at the Sírio-Libanês Hospital. Results: Among 163 adult female carriers from the registry, 91 (56%) had received a BC diagnosis, including 72 p.R337H carriers. BC was the first cancer diagnosed in 90% of cases. Early onset BC (age ≤45 years) was diagnosed in 78.2% of cases (11.5% <31 years; 66.7% 31-45 years; 21.8% >45 years). The median age of BC diagnosis for p.R337H carriers was 39.5 years (range 20-69 years) compared to 34 years (range 21-63 years) for non-p.R337H carriers (p = 0.009). In total, 104 breast tumors were observed in 87 women. Bilateral BC was observed in 29.3% of cases. Histology was available for 96 tumors, comprising 69 invasive breast carcinomas, which were mostly invasive ductal carcinomas (95.6%), 25 ductal in situ carcinomas and 2 soft-tissue sarcomas. Overall, 90.5% of invasive breast carcinomas were hormone receptor (HR)-positive, 39.5% were human epidermal growth factor receptor 2 (HER2)-positive, and 32.8% showed HR and HER2 co-expression. In addition, 55.4% of patients opted for contralateral prophylactic mastectomy after a first BC diagnosis. There were no significant differences in the risk of developing contralateral BC or in the immunohistochemical profile between p.R337H and non-p.R337H groups. Conclusions: The expressed phenotype of p.R337H is similar to that of other TP53 pathogenic/likely pathogenic variants, except for an average older age at the onset of disease; however, this is still younger than the general population.
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BACKGROUND: The microphthalmia-associated transcription factor gene (MITF) belongs to the MYC supergene family and plays an important role in melanocytes' homeostasis. Individuals harboring MITF germline pathogenic variants are at increased risk of developing cancer, most notably melanoma and renal cell carcinoma. CASE PRESENTATION: We describe a cohort of ten individuals who harbor the same MITF c.952G > A (p.Glu 318Lys), or p.E318K, germline pathogenic variant. Six carriers developed at least one malignancy (4 cases of breast cancer; 1 cervical cancer; 1 colon cancer; 1 melanoma; 1 ovarian/fallopian tube cancer). A significant phenotypic heterogeneity was found among these individuals and their relatives. Breast cancer was, overall, the most frequent malignancy observed in this case series, with 13 occurrences of 60 (21.67 %) total cancer cases described among the probands and their relatives. CONCLUSIONS: Our retrospective analysis data raise the hypothesis of a possible association of the MITF p.E318K pathogenic variant with an increased risk of breast cancer.
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Germline pathogenic variants in the DNA mismatch repair genes (MMR): MLH1, MSH2, MSH6, and PMS2, are causative of Lynch syndrome (LS). However, many of the variants mapping outside the invariant splice site positions (IVS ± 1, IVS ± 2) are classified as variants of unknown significance (VUS). Three such variants (MLH1 c.588+5G>C, c.588+5G>T and c.677+5G>A) were identified in 8 unrelated LS families from Argentina, Brazil and Chile. Herein, we collected clinical information on these families and performed segregation analysis and RNA splicing studies to assess the implication of these VUS in LS etiology. Pedigrees showed a clear pattern of variant co-segregation with colorectal cancer and/or other LS-associated malignancies. Tumors presented deficient expression of MLH1-PMS2 proteins in 7/7 of the LS families, and MSI-high status in 3/3 cases. Moreover, RNA analyses revealed that c.588+5G>C and c.588+5G>T induce skipping of exon 7 whereas c.677+5G>A causes skipping of exon 8. In sum, we report that the combined clinical findings in the families and the molecular studies provided the evidences needed to demonstrate that the three MLH1 variants are causative of LS and to classify c.588+5G>C and c.677+5G>A as class 5 (pathogenic), and c.588+5G>T as class 4 (likely-pathogenic). Our findings underline the importance of performing clinical and family analyses, as well as RNA splicing assays in order to determine the clinical significance of intronic variants, and contribute to the genetic counseling and clinical management of patients and their relatives.
Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/genética , Íntrons , Proteína 1 Homóloga a MutL/genética , Sítios de Splice de RNA , Splicing de RNA , Adulto , Argentina , Brasil , Chile , Neoplasias Colorretais/genética , Neoplasias Colorretais Hereditárias sem Polipose/metabolismo , Reparo de Erro de Pareamento de DNA , Éxons , Feminino , Aconselhamento Genético , Humanos , Masculino , Pessoa de Meia-Idade , Endonuclease PMS2 de Reparo de Erro de Pareamento/deficiência , Endonuclease PMS2 de Reparo de Erro de Pareamento/genética , Endonuclease PMS2 de Reparo de Erro de Pareamento/metabolismo , Proteína 1 Homóloga a MutL/deficiência , Proteína 1 Homóloga a MutL/metabolismo , Linhagem , Isoformas de ProteínasRESUMO
We aimed to assess the current genetics practice to manage patients with Lynch syndrome (LS) across Latin America. A Latin American LS survey was sent out to 52 centres/registries, comprising a total of 12 countries from the region. Overall, 33 centres completed the survey, of which the oldest LS registry was established in 1992 in Sao Paulo (Brazil), and the youngest this year in San Jose (Costa Rica). In total, 87% (26/30) of the participating centres/registries belonging to the nine countries are performing genetic testing. Overall, 1352 suspected families were sequenced. Pathogenic variants were identified in 34% of the families, with slightly differing distribution of variants between females and males. Path_MLH1 variants were identified in 39% of females and 50% of males (p = 0.023), while path_MSH2 were identified in 37% of females and males, followed by path_PMS2 in 11% of females and 8% of males, path_MSH6 in 13% of females and 3% of males (p < 0.001) and path_EPCAM in 0.3% of females and 2% of males. In Latin America, 9 of 12 (75%) participating countries had implemented healthcare for LS. LS screening is inconsistently applied within Latin America healthcare systems because of structural differences in the healthcare systems between the countries.
Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/genética , Predisposição Genética para Doença/genética , Testes Genéticos/métodos , Sistema de Registros/estatística & dados numéricos , Inquéritos e Questionários , Adulto , Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Proteínas de Ligação a DNA/genética , Molécula de Adesão da Célula Epitelial/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL/genética , Proteína 2 Homóloga a MutS/genética , América do Sul , Adulto JovemRESUMO
Colorectal cancer (CRC) is one of the most common cancers in Latin America and the Caribbean, with the highest rates reported for Uruguay, Brazil and Argentina. We provide a global snapshot of the CRC patterns, how screening is performed, and compared/contrasted to the genetic profile of Lynch syndrome (LS) in the region. From the literature, we find that only nine (20%) of the Latin America and the Caribbean countries have developed guidelines for early detection of CRC, and also with a low adherence. We describe a genetic profile of LS, including a total of 2,685 suspected families, where confirmed LS ranged from 8% in Uruguay and Argentina to 60% in Peru. Among confirmed LS, path_MLH1 variants were most commonly identified in Peru (82%), Mexico (80%), Chile (60%), and path_MSH2/EPCAM variants were most frequently identified in Colombia (80%) and Argentina (47%). Path_MSH6 and path_PMS2 variants were less common, but they showed important presence in Brazil (15%) and Chile (10%), respectively. Important differences exist at identifying LS families in Latin American countries, where the spectrum of path_MLH1 and path_MSH2 variants are those most frequently identified. Our findings have an impact on the evaluation of the patients and their relatives at risk for LS, derived from the gene affected. Although the awareness of hereditary cancer and genetic testing has improved in the last decade, it is remains deficient, with 39%-80% of the families not being identified for LS among those who actually met both the clinical criteria for LS and showed MMR deficiency.
Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Neoplasias Colorretais Hereditárias sem Polipose/epidemiologia , Proteína 1 Homóloga a MutL/genética , Proteína 2 Homóloga a MutS/genética , Neoplasias Colorretais Hereditárias sem Polipose/genética , Detecção Precoce de Câncer , Feminino , Fidelidade a Diretrizes , Humanos , América Latina/epidemiologia , Masculino , Guias de Prática Clínica como Assunto , Medição de RiscoRESUMO
OBJECTIVE: To analyze the trend of colorectal cancer mortality adjusted for selected indicators, according to sex, by Brazilian federative units and regions, and countrywide from 1996 to 2012. METHODS: This is a temporal time series on colorectal cancer mortality rates, using linear regression analysis, in which the independent variable was the centered year. Models were adjusted for selected indicators. RESULTS: There was an increase in standardized colorectal cancer mortality rates for males in all states and for females in 21 states. In the model adjusted for mortality rate from ill-defined causes, for gross domestic product, and for Gini coefficient, the upward trend remained statistically significant (p < 0.05) countrywide only for men, with 0.17 deaths per 100 thousand inhabitants per year (py). In the States of Piauí (0.09 and 0.20 py), Ceará (0.17 and 0.19 py) and Rio Grande do Sul (0.61 and 0.42 py), there was an increase for both men and women, respectively; only among men in the States of Paraíba (0.16 py), Espírito Santo (0.28 py), São Paulo (0.24 py) and Goiás (0.31 py); and among women in Roraima (0.41 py), Amapá (0.97 P/Y), Maranhão (0.10 py), Sergipe (0.46 P/Y), Mato Grosso do Sul (0.47 py), and the Federal District (0.69 py). CONCLUSION: The increase in colorectal cancer mortality remained significant when assessing Brazil as a whole only among men; in seven States among men, and in nine States among women, regardless of the studied indicators. These differences could be related to the possible increase in incidence and to late access to diagnosis and treatment.
OBJETIVO: Analisar a tendência da mortalidade por câncer colorretal, ajustado por indicadores selecionados, segundo sexo, para unidades federativas, regiões e Brasil, no período de 1996 a 2012. MÉTODOS: Estudo ecológico de série temporal das taxas de mortalidade por câncer colorretal, feita análise de regressão linear, sendo o ano centralizado a variável independente. Os modelos foram ajustados por indicadores selecionados. RESULTADOS: Houve aumento nas taxas de mortalidade padronizadas por câncer colorretal em todos os estados para o sexo masculino e em 21 estados para o sexo feminino. No modelo ajustado por taxa de mortalidade por causas mal definidas, produto interno bruto e coeficiente de Gini, a tendência de aumento foi significativa (p < 0,05) no Brasil, somente para os homens, com 0,17 óbitos por 100 mil habitantes ao ano (aa). Nos estados do Piauí (0,09 e 0,20 aa), Ceará (0,17 e 0,19 aa) e Rio Grande do Sul (0,61 e 0,42 aa) ocorreu aumento em homens e mulheres, respectivamente; somente em homens nos estados da Paraíba (0,16 aa), no Espírito Santo (0,28 aa), em São Paulo (0,24 aa) e Goiás (0,31 aa); e em mulheres nos estados de Roraima (0,41 aa), do Amapá (0,97 aa), Maranhão (0,10 aa), Sergipe (0,46 aa), Mato Grosso do Sul (0,47 aa) e Distrito Federal (0,69 aa). CONCLUSÃO: O aumento da taxa de mortalidade por câncer colorretal manteve-se significativo no Brasil somente entre os homens; em sete estados, entre homens; e em nove estados, entre mulheres, independentemente dos indicadores estudados. Essas diferenças podem estar relacionadas ao possível aumento da incidência e ao acesso tardio ao diagnóstico e tratamento.
Assuntos
Neoplasias Colorretais/mortalidade , Brasil/epidemiologia , Feminino , Humanos , Incidência , Sistemas de Informação , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Mortalidade/tendências , Características de Residência , Fatores Sexuais , Fatores SocioeconômicosRESUMO
Inactivating mutations in the MLH1 gene cause the cancer predisposition Lynch syndrome, but for small coding genetic variants it is mostly unclear if they are inactivating or not. Nine such MLH1 variants have been identified in South American colorectal cancer (CRC) patients (p.Tyr97Asp, p.His112Gln, p.Pro141Ala, p.Arg265Pro, p.Asn338Ser, p.Ile501del, p.Arg575Lys, p.Lys618del, p.Leu676Pro), and evidence of pathogenicity or neutrality was not available for the majority of these variants. We therefore performed biochemical laboratory testing of the variant proteins and compared the results to protein in silico predictions on structure and conservation. Additionally, we collected all available clinical information of the families to come to a conclusion concerning their pathogenic potential and facilitate clinical diagnosis in the affected families. We provide evidence that four of the alterations are causative for Lynch syndrome, four are likely neutral and one shows compromised activity which can currently not be classified with respect to its pathogenic potential. The work demonstrates that biochemical testing, corroborated by congruent evolutionary and structural information, can serve to reliably classify uncertain variants when other data are insufficient.
Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/genética , Predisposição Genética para Doença , Proteína 1 Homóloga a MutL/genética , Mutação , Neoplasias Colorretais Hereditárias sem Polipose/etnologia , Simulação por Computador , Células HEK293 , Humanos , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL/química , Conformação Proteica , América do SulRESUMO
RESUMO: Objetivo: Analisar a tendência da mortalidade por câncer colorretal, ajustado por indicadores selecionados, segundo sexo, para unidades federativas, regiões e Brasil, no período de 1996 a 2012. Métodos: Estudo ecológico de série temporal das taxas de mortalidade por câncer colorretal, feita análise de regressão linear, sendo o ano centralizado a variável independente. Os modelos foram ajustados por indicadores selecionados. Resultados: Houve aumento nas taxas de mortalidade padronizadas por câncer colorretal em todos os estados para o sexo masculino e em 21 estados para o sexo feminino. No modelo ajustado por taxa de mortalidade por causas mal definidas, produto interno bruto e coeficiente de Gini, a tendência de aumento foi significativa (p < 0,05) no Brasil, somente para os homens, com 0,17 óbitos por 100 mil habitantes ao ano (aa). Nos estados do Piauí (0,09 e 0,20 aa), Ceará (0,17 e 0,19 aa) e Rio Grande do Sul (0,61 e 0,42 aa) ocorreu aumento em homens e mulheres, respectivamente; somente em homens nos estados da Paraíba (0,16 aa), no Espírito Santo (0,28 aa), em São Paulo (0,24 aa) e Goiás (0,31 aa); e em mulheres nos estados de Roraima (0,41 aa), do Amapá (0,97 aa), Maranhão (0,10 aa), Sergipe (0,46 aa), Mato Grosso do Sul (0,47 aa) e Distrito Federal (0,69 aa). Conclusão: O aumento da taxa de mortalidade por câncer colorretal manteve-se significativo no Brasil somente entre os homens; em sete estados, entre homens; e em nove estados, entre mulheres, independentemente dos indicadores estudados. Essas diferenças podem estar relacionadas ao possível aumento da incidência e ao acesso tardio ao diagnóstico e tratamento.
ABSTRACT: Objective: To analyze the trend of colorectal cancer mortality adjusted for selected indicators, according to sex, by Brazilian federative units and regions, and countrywide from 1996 to 2012. Methods: This is a temporal time series on colorectal cancer mortality rates, using linear regression analysis, in which the independent variable was the centered year. Models were adjusted for selected indicators. Results: There was an increase in standardized colorectal cancer mortality rates for males in all states and for females in 21 states. In the model adjusted for mortality rate from ill-defined causes, for gross domestic product, and for Gini coefficient, the upward trend remained statistically significant (p < 0.05) countrywide only for men, with 0.17 deaths per 100 thousand inhabitants per year (py). In the States of Piauí (0.09 and 0.20 py), Ceará (0.17 and 0.19 py) and Rio Grande do Sul (0.61 and 0.42 py), there was an increase for both men and women, respectively; only among men in the States of Paraíba (0.16 py), Espírito Santo (0.28 py), São Paulo (0.24 py) and Goiás (0.31 py); and among women in Roraima (0.41 py), Amapá (0.97 P/Y), Maranhão (0.10 py), Sergipe (0.46 P/Y), Mato Grosso do Sul (0.47 py), and the Federal District (0.69 py). Conclusion: The increase in colorectal cancer mortality remained significant when assessing Brazil as a whole only among men; in seven States among men, and in nine States among women, regardless of the studied indicators. These differences could be related to the possible increase in incidence and to late access to diagnosis and treatment.
Assuntos
Humanos , Masculino , Feminino , Neoplasias Colorretais/mortalidade , Fatores Socioeconômicos , Brasil/epidemiologia , Sistemas de Informação , Modelos Lineares , Características de Residência , Fatores Sexuais , Incidência , Mortalidade , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Genetic counselling and testing for Lynch syndrome (LS) have recently been introduced in several Latin America countries. We aimed to characterize the clinical, molecular and mismatch repair (MMR) variants spectrum of patients with suspected LS in Latin America. METHODS: Eleven LS hereditary cancer registries and 34 published LS databases were used to identify unrelated families that fulfilled the Amsterdam II (AMSII) criteria and/or the Bethesda guidelines or suggestive of a dominant colorectal (CRC) inheritance syndrome. RESULTS: We performed a thorough investigation of 15 countries and identified 6 countries where germline genetic testing for LS is available and 3 countries where tumor testing is used in the LS diagnosis. The spectrum of pathogenic MMR variants included MLH1 up to 54%, MSH2 up to 43%, MSH6 up to 10%, PMS2 up to 3% and EPCAM up to 0.8%. The Latin America MMR spectrum is broad with a total of 220 different variants which 80% were private and 20% were recurrent. Frequent regions included exons 11 of MLH1 (15%), exon 3 and 7 of MSH2 (17 and 15%, respectively), exon 4 of MSH6 (65%), exons 11 and 13 of PMS2 (31% and 23%, respectively). Sixteen international founder variants in MLH1, MSH2 and MSH6 were identified and 41 (19%) variants have not previously been reported, thus representing novel genetic variants in the MMR genes. The AMSII criteria was the most used clinical criteria to identify pathogenic MMR carriers although microsatellite instability, immunohistochemistry and family history are still the primary methods in several countries where no genetic testing for LS is available yet. CONCLUSION: The Latin America LS pathogenic MMR variants spectrum included new variants, frequently altered genetic regions and potential founder effects, emphasizing the relevance implementing Lynch syndrome genetic testing and counseling in all of Latin America countries.
Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/epidemiologia , Adulto , Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Neoplasias Colorretais Hereditárias sem Polipose/genética , Biologia Computacional/métodos , Reparo de Erro de Pareamento de DNA , Feminino , Efeito Fundador , Aconselhamento Genético , Predisposição Genética para Doença , Testes Genéticos , Variação Genética , Mutação em Linhagem Germinativa , Humanos , América Latina/epidemiologia , Masculino , Pessoa de Meia-Idade , Vigilância da População , Splicing de RNA , Sistema de Registros , Fatores de RiscoRESUMO
Lynch syndrome (LS) accounts for 3-5% of all colorectal cancers (CRC) and is inherited in an autosomal dominant fashion. This syndrome is characterized by early CRC onset, high incidence of tumors in the ascending colon, excess of synchronous/metachronous tumors and extra-colonic tumors. Nowadays, LS is regarded of patients who carry deleterious germline mutations in one of the five mismatch repair genes (MMR), mostly in MLH1 and MSH2, but also in MSH6, PMS1 and PMS2. To comprehensively characterize 116 Brazilian patients suspected for LS, we assessed the frequency of germline mutations in the three minor genes MSH6, PMS1 and PMS2 in 82 patients negative for point mutations in MLH1 and MSH2. We also assessed large genomic rearrangements by MLPA for detecting copy number variations (CNVs) in MLH1, MSH2 and MSH6 generating a broad characterization of MMR genes. The complete analysis of the five MMR genes revealed 45 carriers of pathogenic mutations, including 25 in MSH2, 15 in MLH1, four in MSH6 and one in PMS2. Eleven novel pathogenic mutations (6 in MSH2, 4 in MSH6 and one in PMS2), and 11 variants of unknown significance (VUS) were found. Mutations in the MLH1 and MSH2 genes represented 89% of all mutations (40/45), whereas the three MMR genes (MSH6, PMS1 and PMS2) accounted for 11% (5/45). We also investigated the MLH1 p.Leu676Pro VUS located in the PMS2 interaction domain and our results revealed that this variant displayed no defective function in terms of cellular location and heterodimer interaction. Additionally, we assessed the tumor phenotype of a subset of patients and also the frequency of CRC and extra-colonic tumors in 2,365 individuals of the 116 families, generating the first comprehensive portrait of the genetic and clinical aspects of patients suspected of LS in a Brazilian cohort.
Assuntos
Adenosina Trifosfatases/genética , Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Enzimas Reparadoras do DNA/genética , Proteínas de Ligação a DNA/genética , Mutação em Linhagem Germinativa , Proteínas de Neoplasias/genética , Adolescente , Adulto , Brasil , Neoplasias Colorretais Hereditárias sem Polipose/genética , Variações do Número de Cópias de DNA , Reparo de Erro de Pareamento de DNA , Feminino , Humanos , Pessoa de Meia-Idade , Endonuclease PMS2 de Reparo de Erro de Pareamento , Proteínas MutL , Adulto JovemRESUMO
BACKGROUND: The development of targeted therapies has undoubtedly broadened therapeutic options for patients with colorectal cancer (CRC). The use of bevacizumab to reduce angiogenesis has been associated with improved clinical outcomes. However, an urgent need for prognostic/predictive biomarkers for anti-angiogenic therapies still exists. METHODS: Clinical data of 105 CRC patients treated with bevacizumab in conjunction with chemotherapy were analyzed. The expression of vascular endothelial growth factor (VEGF) receptors, NOTCH1 receptor and its ligand DLL4 were determined by immunohistochemistry. Tumor samples were arranged on a tissue microarray. The association between protein expression and clinicopathological characteristics and outcomes was determined. RESULTS: Bevacizumab was administered as a first-line of treatment in 70.5 % of our cases. The median progression-free survival (PFS) was 10.2 months. The median overall survival (OS) of the total cohort was 24.4 months. Bevacizumab, as the first-line of treatment, and the presence of liver metastasis were independently associated with objective response rate. Membrane VEGFR1 and VEGFR3 expressions were associated with the presence of lung metastasis; interestingly, VEGFR3 was associated with less liver metastasis. NOTCH1 expression was associated with lymph node metastasis. There was a trend toward association between improved PFS and lower NOTCH1 expression (p = 0.06). Improved OS was significantly associated with lower NOTCH1 expression (p = 0.01). In a multivariate analysis, ECOG (Eastern Cooperative Oncology Group) performance status, liver metastasis, histological grade, and NOTCH1 expression were independently associated with OS. CONCLUSION: Our findings illustrated the expression profile of angiogenesis-related proteins and their association with clinicopathological characteristics and outcomes. NOTCH1 expression is a detrimental prognostic factor in metastatic CRC patients treated with chemotherapy plus bevacizumab.
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Neoplasias Colorretais/tratamento farmacológico , Neoplasias Pulmonares/genética , Receptor Notch1/biossíntese , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/biossíntese , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Inibidores da Angiogênese/administração & dosagem , Bevacizumab/administração & dosagem , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Intervalo Livre de Doença , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/secundário , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/genética , Neovascularização Patológica/patologia , Receptor Notch1/genética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/genéticaRESUMO
TP53 represents a suitable candidate for a colorectal cancer susceptibility locus. The polymorphism in the p53 72nd codon involves a proline to arginine substitution, leading to changes in gene transcription activity, interaction with other proteins and modulation of apoptosis. Studies evaluating the association between this polymorphism and colorectal cancer (CRC) have shown inconsistent results, and none have evaluated the mRNA status of TP53. The aim of the present study was to evaluate the association between this SNP expression at the mRNA level in CRC samples and patient clinicopathological variables and prognosis, p53 protein expression and TP53 mutation. This is the first report to describe the mRNA expression of p53 codon 72 alleles in CRC. We evaluated 101 non-related patients with CRC treated at the A.C. Camargo Cancer Center in Brazil. RNA was isolated from frozen tumor tissues using a trizol-based protocol. The polymorphism was detected using RT-PCR followed by Sanger sequencing. Associations were analyzed using Pearson's Chi-square or Fisher's exact tests, logistic regression and Cox. This polymorphism was significantly associated with clinicopathological variables related to increased tumor aggressiveness. The expression of Arg72 (OR, 3.83; CI 1.02-14.35; P=0.046) and the TNM stage (OR, 7.15; CI 1.45-35.29; P=0.016) were found to be independent predictors for recurrence. These data suggest that the mRNA expression of the Pro72 allele is associated with less favorable tumor features. The allele frequency of the p53 Pro72 was 0.26. The analysis of mRNA is important to determine the specific contribution of the allele expressed. These results suggest that this polymorphism may play a role in CRC.
Assuntos
Adenocarcinoma/genética , Neoplasias Colorretais/genética , Recidiva Local de Neoplasia/genética , Polimorfismo de Nucleotídeo Único , Proteína Supressora de Tumor p53/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Códon , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/mortalidade , Análise Mutacional de DNA , Feminino , Expressão Gênica , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico , Modelos de Riscos Proporcionais , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteína Supressora de Tumor p53/metabolismoRESUMO
BACKGROUND: Patients with multiple colorectal adenomas are currently screened for germline mutations in two genes, APC and MUTYH. APC-mutated patients present classic or attenuated familial adenomatous polyposis (FAP/AFAP), while patients carrying biallelic MUTYH mutations exhibit MUTYH-associated polyposis (MAP). The spectrum of mutations as well as the genotype-phenotype correlations in polyposis syndromes present clinical impact and can be population specific, making important to obtain genetic and clinical data from different populations. METHODS: DNA sequencing of the complete coding region of the APC and MUTYH genes was performed in 23 unrelated Brazilian polyposis patients. In addition, mutation-negative patients were screened for large genomic rearrangements by multiplex ligation-dependent probe amplification, array-comparative genomic hybridization, and duplex quantitative PCR. Biallelic MUTYH mutations were confirmed by allele-specific PCR. Clinical data of the index cases and their affected relatives were used to assess genotype-phenotype correlations. RESULTS: Pathogenic mutations were identified in 20 of the 23 probands (87%): 14 in the APC gene and six in the MUTYH gene; six of them (30%) were described for the first time in this series. Genotype-phenotype correlations revealed divergent results compared with those described in other studies, particularly regarding the extent of polyposis and the occurrence of desmoid tumors in families with mutations before codon 1444 (6/8 families with desmoid). CONCLUSIONS: This first comprehensive investigation of the APC and MUTYH mutation spectrum in Brazilian polyposis patients showed a high detection rate and identified novel pathogenic mutations. Notably, a significant number of APC-positive families were not consistent with the predicted genotype-phenotype correlations from other populations.
Assuntos
Adenoma/genética , Neoplasias Colorretais/genética , DNA Glicosilases/genética , Genes APC , Genótipo , Mutação , Fenótipo , Alelos , Brasil , Hibridização Genômica Comparativa , Feminino , Humanos , Masculino , Linhagem , Reação em Cadeia da PolimeraseRESUMO
BACKGROUND: Some single-nucleotide polymorphisms are associated with higher risk of colorectal cancer development and are suggested to explain part of the genetic contribution to Lynch syndrome. AIM: To evaluate the mutL homolog 1 (MLH1) I219V polymorphism in 124 unrelated South American individuals suspected of having Lynch syndrome, based on frequency, association with pathogenic MLH1 and mutS homolog 2 (MSH2) mutation and clinical features. MATERIALS AND METHODS: DNA was obtained from peripheral blood and polymerase chain reaction (PCR) was performed, followed by direct sequencing. RESULTS: The Val allelic of the I219V polymorphism was found in 51.61% (64/124) of the individuals, with an allelic frequency of 0.3. MLH1 or MHS2 pathogenic mutations were found in 32.81% (21/64) and in 23.33% (14/60) of Val-carriers and non-carriers, respectively. CONCLUSION: The Val-carrying genotype was frequent in the studied population; however, it does not appear to exert any modifier effect on MLH1 or MSH2 pathogenic mutations and the development of colorectal cancer.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Neoplasias Colorretais Hereditárias sem Polipose/genética , Proteínas Nucleares/genética , Polimorfismo Genético , Adulto , Idoso , Sequência de Bases , Neoplasias Colorretais/genética , Feminino , Frequência do Gene , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Proteína 1 Homóloga a MutL , Proteína 2 Homóloga a MutS/genética , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , América do SulRESUMO
BACKGROUND: Familial adenomatous polyposis (FAP) is a hereditary colorectal cancer syndrome caused by a loss of function of the APC gene. Large deletions in APC are a common cause of FAP; despite the existence of a variety of gene dosage detection methodologies, most are labor intensive and time and resource consuming. METHODS: We describe a new duplex qPCR method for gene dosage analysis based on the coamplification of a target and a reference gene in a SYBR Green reaction, followed by a comparison of the ratio between the target and the reference peaks of the melting curve for the test (patient) and control samples. The reliability of the described duplex qPCR was validated for several genes (APC, HPRT1, ATM, PTEN and BRCA1). RESULTS: Using this novel gene dosage method, we have identified an APC gene deletion in a FAP patient undergoing genetic testing. Comparative genomic hybridization based on microarrays (aCGH) was used to confirm and map the extent of the deletion, revealing a 5.2 MB rearrangement (5q21.3-q22.3) encompassing the entire APC and 19 additional genes. CONCLUSION: The novel assay accurately detected losses and gains of one copy of the target sequences, representing a reliable and flexible alternative to other gene dosage techniques. In addition, we described a FAP patient harboring a gross deletion at 5q21.3-q22.3 with an unusual phenotype of the absence of mental impairment and dysmorphic features.
Assuntos
Proteína da Polipose Adenomatosa do Colo/genética , Polipose Adenomatosa do Colo/genética , Dosagem de Genes , Compostos Orgânicos/química , Reação em Cadeia da Polimerase/métodos , Deleção de Sequência , Adulto , Benzotiazóis , Mapeamento Cromossômico , Diaminas , Éxons , Feminino , Rearranjo Gênico , Humanos , Íntrons , Masculino , QuinolinasRESUMO
BACKGROUND: Lynch syndrome (LS) is the most common form of inherited predisposition to colorectal cancer (CRC), accounting for 2-5% of all CRC. LS is an autosomal dominant disease characterized by mutations in the mismatch repair genes mutL homolog 1 (MLH1), mutS homolog 2 (MSH2), postmeiotic segregation increased 1 (PMS1), post-meiotic segregation increased 2 (PMS2) and mutS homolog 6 (MSH6). Mutation risk prediction models can be incorporated into clinical practice, facilitating the decision-making process and identifying individuals for molecular investigation. This is extremely important in countries with limited economic resources. This study aims to evaluate sensitivity and specificity of five predictive models for germline mutations in repair genes in a sample of individuals with suspected Lynch syndrome. METHODS: Blood samples from 88 patients were analyzed through sequencing MLH1, MSH2 and MSH6 genes. The probability of detecting a mutation was calculated using the PREMM, Barnetson, MMRpro, Wijnen and Myriad models. To evaluate the sensitivity and specificity of the models, receiver operating characteristic curves were constructed. RESULTS: Of the 88 patients included in this analysis, 31 mutations were identified: 16 were found in the MSH2 gene, 15 in the MLH1 gene and no pathogenic mutations were identified in the MSH6 gene. It was observed that the AUC for the PREMM (0.846), Barnetson (0.850), MMRpro (0.821) and Wijnen (0.807) models did not present significant statistical difference. The Myriad model presented lower AUC (0.704) than the four other models evaluated. Considering thresholds of ≥ 5%, the models sensitivity varied between 1 (Myriad) and 0.87 (Wijnen) and specificity ranged from 0 (Myriad) to 0.38 (Barnetson). CONCLUSIONS: The Barnetson, PREMM, MMRpro and Wijnen models present similar AUC. The AUC of the Myriad model is statistically inferior to the four other models.
Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/genética , Reparo de Erro de Pareamento de DNA/genética , Mutação em Linhagem Germinativa , Adulto , Idoso , Brasil , Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Países em Desenvolvimento , Feminino , Aconselhamento Genético , Humanos , Funções Verossimilhança , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Mutação , Valor Preditivo dos Testes , Sensibilidade e EspecificidadeRESUMO
Lynch syndrome (LS) is an autosomal dominant syndrome that predisposes individuals to development of cancers early in life. These cancers are mainly the following: colorectal, endometrial, ovarian, small intestine, stomach and urinary tract cancers. LS is caused by germline mutations in DNA mismatch repair genes (MMR), mostly MLH1 and MSH2, which are responsible for more than 85% of known germline mutations. To search for germline mutations in MLH1 and MSH2 genes in 123 unrelated South American suspected LS patients (Bethesda or Amsterdam Criteria) DNA was obtained from peripheral blood, and PCR was performed followed by direct sequencing in both directions of all exons and intron-exon junctions regions of the MLH1 and MSH2 genes. MLH1 or MSH2 pathogenic mutations were found in 28.45% (34/123) of the individuals, where 25/57 (43.85%) fulfilled Amsterdam I, II and 9/66 (13.63%) the Bethesda criteria. The mutations found in both genes were as follows: nonsense (35.3%), frameshift (26.47%), splicing (23.52%), and missense (9%). Thirteen alterations (35.14%) were described for the first time. The data reported in this study add new information about MLH1 and MSH2 gene mutations and contribute to better characterize LS in Brazil, Uruguay and Argentina. The high rate of novel mutations demonstrates the importance of defining MLH1 and MSH2 mutations in distinct LS populations.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Neoplasias Colorretais Hereditárias sem Polipose/genética , Reparo de Erro de Pareamento de DNA , Mutação em Linhagem Germinativa , Proteína 2 Homóloga a MutS/genética , Proteínas Nucleares/genética , Argentina , Brasil , Códon sem Sentido , Neoplasias Colorretais Hereditárias sem Polipose/etnologia , Análise Mutacional de DNA , Mutação da Fase de Leitura , Humanos , Proteína 1 Homóloga a MutL , Mutação de Sentido Incorreto , Reação em Cadeia da Polimerase , UruguaiRESUMO
Ezrin protein acts in the regulation of cytoskeletal and directly influences survival and tumor progression; there is an increase in its expression in metastatic cells and tissues in several types of cancer including colorectal cancer. 250 Patients with colorectal cancer submitted to surgery from 1995 to 2002. Protein expression was carried through by Tissue Micro Array immunohistochemical tests of paraffined neoplasic tissues and associated with clinical variables. Differentiation degree, lymph node invasion, metastasis at diagnosis, and palliative surgery were associated to a higher expression of the protein and survival. Higher expression of the Ezrin correlates with tumor aggressiveness and worse prognosis for colorectal cancer.