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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Fatores preditivos para recidiva local e para ressecção incompleta de adenocarcinoma gástrico precoce tratado através da exérese endoscópica / Predictive factors for local recurrence and incomplete resection of early gastric cancer treated by endoscopic resection

Hondo, Fábio Yuji 09 May 2007 (has links)
O câncer gástrico precoce é definido como adenocarcinoma que não ultrapassa a camada submucosa, independentemente o acometimento linfonodal. O diagnóstico é feito através do exame de endoscopia digestiva alta e da avaliação histopatológica. Pode ser tratado através de mucosectomia endoscópica, sendo reconhecidos vários fatores que influenciam a chance de cura após a ressecção. Quando o adenocarcinoma gástrico precoce bem diferenciado está à restrito a mucosa, com margens de ressecção livres de neoplasia, sem ulceração histológica, invasão linfática ou venosa é alta a chance de cura após a ressecção endoscópica. A freqüência de recidiva local nestes casos varia de 2,8% a 5,7%. Por outro lado, a expressão de antígenos por células tumorais detectadas através da imunohistoquímica pode indicar o comportamento biológico dos tumores. O carcinoma gástrico precoce tipo diferenciado pode apresentar propriedades fenotípicas diferentes que se correlacionam com a expressão de mucinas. Através da expressão de mucinas é possível estratificar o adenocarcinoma diferenciado em tipo intestinal, gástrico, misto ou indeterminado. O objetivo deste estudo foi avaliar os fatores preditivos para a ressecção incompleta e recidiva local do câncer gástrico precoce tratado através de mucosectomia endoscópica e com acompanhamento superior a um ano. De junho de 1994 a dezembro de 2005, avaliaram-se 46 pacientes com câncer gástrico precoce submetidos a 47 mucosectomias endoscópicas. Através da análise de dados de prontuário, identificaram-se possíveis fatores preditivos para a ressecção endoscópica incompleta e para a recidiva local. Vinte e dois pacientes com critérios para alta probabilidade de cura foram avaliados prospectivamente em relação aos fatores para recidiva e submetidos a perfil imunohistoquímico das lesões ressecadas. Houve recuperação de peças ressecadas em 18 (81,8%) casos. Neste grupo, houve recidiva local em cinco (27,7%) casos. Assim, os pacientes foram avaliados pelos dados demográficos, endoscópicos e histopatológicos. As mucosectomias endoscópicas foram consideradas como ressecção completa ou incompleta. No grupo ressecção completa, os pacientes foram divididos nos subgrupos com ou sem recidiva. Os pacientes com critérios de alta probabilidade para cura foram divididos nos grupos com ou sem recidiva e comparados pelos dados demográficos, endoscópicos, e histopatológicos e imunohistoquímico. As peças ressecadas foram avaliadas quanto à expressão dos marcadores Muc-2, Muc-5a, CD-10, p-53 e Ki-67. O tempo médio de seguimento foi de 69,4 meses ± 36,5 meses. Sobrevida em cinco anos foi de 84,78%. Observaram-se sete (15,21%) óbitos. Houve ressecção completa em 36 casos (76,6%). Foram fatores preditivos de ressecção incompleta, as localizações em parede posterior de terço superior e inferior do estômago (p= 0,035), o tipo histológico indiferenciado (p=0,021), o tamanho da lesão maior que dois centímetros (p= 0,022) e o número de fragmentos maiores ou iguais a dois fragmentos (p= 0,013). Em análise estatística multivariada, o tipo histológico indiferenciado (OR= 0,8; IC (95%)= 0,036-0.897) e números de fragmentos (OR=7,34; IC (95%) = 1.266- 42.629) foram fatores preditivos independentes para ressecção incompleta. No grupo ressecção completa, observou-se que quanto maior o tamanho da lesão, maior o número de fragmentos ressecados (p=0,018). Houve recidiva local em 9 casos (25%). Como fator preditivo para recidiva local, destaca-se a técnica tipo cap com 5/7 casos (71,4%) (p=0,006). Na análise dos pacientes com critérios de alta probabilidade de cura, os dados demográficos (sexo, idade e raça), endoscópicos (tipo macroscópico, localização, número de fragmentos ressecados, técnica de ressecção empregada) e histopatológico (tamanho da lesão e nível de invasão) não mostraram diferença estatística significativa entre os grupos sem ou com recidiva. A análise imunohistoquímica revelou que o marcador Muc-5a esteve presente em 4/5 (80%) dos casos do grupo com recidiva (p=0,026) e quando se estratificaram os casos pela expressão de mucinas, observou-se que o tipo misto se apresentou em 4/5 (80%) casos no grupo com recidiva e o tipo intestinal em 10/13(76,9%) casos no grupo sem recidiva (p=0,004). O adenocarcinoma indiferenciado e números de fragmentos são fatores preditores para ressecção incompleta. O tamanho e a localização da lesão também foram fatores preditores de ressecção incompleta, porém, não de forma independente. A recidiva local teve como fator preditivo o tipo de técnica. O estudo imunohistoquímico se mostrou importante na presunção de recidiva local, nos casos em que os critérios para alta probabilidade de cura foram respeitados. O adenocarcinoma gástrico com expressão das mucinas para o fenótipo do tipo misto se mostrou como fator preditivo para recidiva local do câncer gástrico precoce. / Endoscopic mucosal resection (EMR) has recently become an accepted treatment for early gastric cancer. The histopathologic criteria that are used to define curative endoscopic resection include: intramucosal well-differentiated adenocarcinoma, lateral and deep margins free of tumor, no histologic ulceration, and lastly, no venous or lymphatic emboli. These criteria were defined by a large series of EMR from Japanese centers. Local neoplastic recurrence has been described in up to 6% of cases even when all of the above mentioned criteria are met. On the other hand, the antigen expression of neoplastic cells is related to the biologic behavior of several tumors. The aim of this study was evaluate the factors that predict incomplete resection and local recurrence of early gastric cancer treated by EMR followed up for at least one year in a Western tertiary referral center. It was also evaluated the role of different type of mucins, p53 and ki-67 expression as predictive factors of recurrence even when the standard histopathologic criteria for cure were met. The patients were evaluated retrospectively from June 1994 to December 2005. Forty six patients (23 female and 23 male; mean age 69 ± 14.1y) with early gastric cancer were submitted to EMR. Twenty-two patients with a diagnosis of early gastric cancer were considered cured by EMR were evaluated prospectively for local reccurrence. Local recurrences occurred in five (22.7%) of them. It was possible to perform immunohistochemistry panel in 18 (81.8%) resected specimens. Demographic data (gender, age and race), endoscopic (macroscopic classification, localization, number of resected fragments and technique employed) were retrospectively collected. Histopathologic data (size of tumor, depth of invasion and adenocarcinoma classification) were prospectively assessed by one senior pathologist blinded to the previous diagnosis. Resection was considered incomplete when the lateral or deep margins of the specimen proved positive for tumor. In the complete resection group, patients were followed up, and at the end of this study were divided into two groups: patients recurrence with and without local recurrence. The patients with histopathologic criteria for cure were divided into two groups: with local recurrence and without local recurrence. These were then compared by demographic, endoscopic, histologic and immunohistochemistry profiles. Expression of Muc-2, Muc-5a, CD-10, p-53 and ki-67 were analyzed. Mucin expression allowed a reclassification of the well- differentiated gastric cancer in intestinal, gastric, mixed or null phenotypes. The mean follow up was 69.4 months ± 36.5 months. Five-year survival was 84.78%. Seven (15.21%) patients died from other diseases not related to the gastric lesion. Complete resection was possible in 36 cases (76,6%). Predictive factors for incomplete resection were localization (p= 0,035), histologic type (p=0,021), size of the lesion (p= 0,022) and number of fragments resected (p= 0,013). In the multivariate statistical analysis, the undifferentiated histologic type (OR= 0,8; IC (95%)= 0,036-0.897) and piece-meal resection (OR=7,34; IC (95%) = 1.266-42.629) were independent risk factors for incomplete resection. On the other hand, in the complete resection group, it was noted that lesions >2cm were more frequently resected in piece-meal fashion (p=0,018). Local recurrence occured in 9 cases (group I) (25%). The cap technique was the only predictive factor for local recurrence (5/7 cases - 71,4%, p=0,006). In the group of patients with histopathologic criteria for cure, the demographic (gender, age and race), endoscopic (macroscopic classification, localization, total number of resected fragments, EMR technique) and histopathologic findings (size of the tumor and depth of invasionm1, m2,m3), p-53 and ki-67 expressions did not correlate with neoplastic recurrence. Muc-5a marker was expressed in 80%(4/5) of the cases in group I and in 15.4% (12/13) of the cases in group II (p=0,026). The mixed phenotype (Muc-2 and Muc- 5a positive) was found in 80%(4/5) of the cases of group I and the intestinal type (Muc-2 positive and Muc-5a negative) in 76.9% (10/13) of group II (p=0,004). In conclusion, the undifferentiated adenocarcinoma and piece-meal resection were independent risk factors for incomplete resection. The cap technique for EMR was related to local recurrence after complete resection. Larger lesions are usually resected in more than one fragment. The expression of Muc-5a and the mixed phenotype of well-differentiated adenocarcinoma were related to a higher probability of local recurrence after EMR of early gastric lesions considered cured by the endoscopic intervention.
62

O papel da exclusão duodenal na regulação dos níveis glicêmicos em pacientes diabéticos tipo 2 submetidos a gastrectomia com reconstrução em Y de Roux por câncer gástrico / The role of duodenal exclusion in the regulation of glycemic levels in type 2 diabetic patients submitted to gastrectomy with Roux-en-Y reconstruction by gastric cancer

Franciss, Maurice Youssef 20 March 2019 (has links)
INTRODUÇÃO: a cirurgia bariátrica tem se mostrado efetiva no tratamento de comorbidades relacionadas à obesidade como o Diabetes Mellitus tipo 2 (DM2), sugerindo que mecanismos além da perda de peso estão envolvidos. Diversos estudos têm atribuído a melhora da regulação glicêmica à secreção de incretinas pelo intestino distal, devido ao estímulo da rápida passagem de alimento por esta região; outra hipótese confere o resultado à exclusão do intestino proximal, porém detalhes dos mecanismos de ação e do seu papel em indivíduos não obesos ainda precisam ser esclarecidos. Indivíduos com DM2 operados por motivos diferentes da obesidade representam adequado modelo para analisar resultados clínicos da exclusão duodenal. OBJETIVO: analisar a mudança da glicemia em pacientes diabéticos submetidos a gastrectomia total ou subtotal com derivação em Y de Roux por câncer gástrico. PACIENTES E MÉTODOS: estudo observacional, analítico, tipo coorte com abordagem retrospectiva, desenvolvido em duas instituições públicas de saúde no município de São Paulo, aprovado por comitê de ética em pesquisa. Foram verificados os prontuários físicos e eletrônicos, com respeito às variáveis demográficas (sexo, idade) e clínicas (comorbidades, Índice de Massa Corpórea-IMC, glicemia de jejum, hemoglobina glicada e uso de medicamentos) antes da operação (T0) e um ano após (T1). A amostra foi composta por 129 pacientes acima de 18 anos, com diagnóstico de DM2 e Adenocarcinoma gástrico, submetidos a gastrectomia com reconstrução em Y de Roux. Foram excluídos 26 pacientes por falta de acompanhamento ou óbito antes de um ano de pós-operatório; a amostra de análise (n=103) foi representada por 50,5% (n=52) de mulheres e 49,5% homens (n=51), com idade média de 65,5 ± 9,57 anos (41-89 anos). A distribuição do IMC foi de 25 a 30 kg/m2 em 44,7% (n=46), abaixo de 25 kg/m2 em 38,8% (n=40) e maior que 30 kg/m2 em 16,5% (n=17). A gastrectomia subtotal foi realizada em 79,6% (n=82) dos pacientes. Para a análise estatística, usaram-se medidas de tendência central, teste t de Student e regressão logística com o modelo CART. RESULTADOS: após um ano de pós-operatório, a média de glicemia diminuiu de 147,6 mg/dL (T0) para 134 mg/dL (T1) (p=0,046), porém 70% dos pacientes com glicemia > 100 no T0 permaneceram com o mesmo valor no T1. A hemoglobina glicada não teve mudança significativa (7,5% no T0 vs 7,0% no T1, p=0,988). A média do IMC diminuiu de 26,5 kg/m2 (T0) para 24,3 kg/m2 (T1) (p < 0,001). Após um ano, 6,7% (n=6) tiveram suspensão da medicação com resolução do DM2 e 11,2% (n=10) diminuíram a medicação hipoglicemiante, enquanto que, em 60,7% (n=54), permaneceu inalterada e, em 21,4% (n=19), piorou. Os pacientes com IMC entre 30-35 kg/m2 foram os que tiveram melhor resposta em relação à normalização dos níveis glicêmicos. O modelo de regressão logística mostrou como preditores da mudança na medicação a idade ( < 62,5 anos) e o IMC ( > 30,2 kg/m2) com valor preditivo 71,4%. CONCLUSÕES: o estudo demonstrou que não houve melhora da glicemia nos pacientes com DM2 submetidos a gastrectomia total ou subtotal com reconstrução em Y Roux, com IMC abaixo de 30 kg/m2, nem foram observadas evidências que corroborem a Teoria do Intestino Proximal. Há indícios de que a cirurgia possa influenciar o controle glicêmico quando o IMC é > 30 kg/m2 e a idade, inferior a 62,5 anos / INTRODUCTION: Bariatric surgery has been shown to be effective in the treatment of obesity-related comorbidities such as Type 2 Diabetes Mellitus (DM2), suggesting that mechanisms in addition to weight loss are involved. Several studies have attributed the improvement of glycemic regulation to the secretion of incretins in the distal intestine, due to the stimulation of the fast passage of food by this region. Another hypothesis confers the result to the exclusion of the proximal intestine; however, details of the mechanisms of action and their role in non-obese individuals have yet to be clarified. Individuals with DM2 operated for other reasons than obesity, represent an adequate model to analyze clinical outcomes of duodenal exclusion. AIM: to analyze the glycemia changes in diabetic patients submitted to total or subtotal gastrectomy with Roux-en-Y derivation for gastric cancer. PATIENTS AND METHODS: An observational, analytical, cohort study with a retrospective approach, developed in two public health institutions in the city of São Paulo, approved by a research ethics committee. The physical and electronic charts concerning to demographics (sex, age) and clinical variables (comorbidities, Body Mass Index (BMI), fasting glycemia, glycated hemoglobin and medication use) were checked before surgery (T0) and one year after (T1). The sample consisted of 129 patients over 18 years of age, diagnosed with DM2 and Gastric Adenocarcinoma, who underwent gastrectomy with Roux-en-Y reconstruction. Twenty-six patients were excluded due to lack of follow-up or death before one year of postoperative; the analysis sample (n=103) was represented by women 50.5% (n=52) and 49.5% men (n=51), with a mean age of 65.5 years (SD=9.57; 41-89 years). The distribution of BMI was 25 to 30 kg/m2 in 44.7% (n=46), below 25 kg/m2 in 38.8% (n=40) and greater than 30 kg/m2 in 16.5 % (n=17). Subtotal gastrectomy was performed in 79.6% (n=82) of the patients. Statistical analysis used central tendency measures, Student\'s t-test and logistic regression with the CART model. RESULTS: After one year of postoperative, mean glucose levels decreased from 147.6 mg/dL (T0) to 134 mg/dL (T1) (p=0.046), but 70% of patients with glycemia > 100 at T0, remained with the same value in T1. Glycated hemoglobin had no significant change (7.5% in T0 vs. 7.0% in T1, p=0.988). The mean BMI decreased from 26.5 kg/m2 (T0) to 24.3 kg/m2 (T1) (p < 0.001). After one year, 6.7% (n=6) had discontinuation of the medication with the resolution of DM2, and 11.2% (n=10) decreased the hypoglycemic medication, while in 60.7% (n=54) there no was change, and in 21.4% (n=19) it worsened. Patients with BMI between 30-35 kg/m2 were the ones that had the best response regarding the normalization of glycemic levels. The logistic regression model showed predictors of change in medication, age ( < 62.5 years) and BMI ( > 30.2 kg/m2) with a predictive value of 71.4%. CONCLUSIONS: The study demonstrated that there was no improvement of glycemia in patients with DM2 who underwent total or subtotal gastrectomy with Roux-in-Y reconstruction, with a BMI below 30 kg/m2. No evidence was found corroborating the theory of the proximal intestine. There are indications that surgery may influence glycemic control when BMI > 30 kg/m2 and age less than 62.5 years
63

A invasão da gordura perigástrica determina pior prognóstico nos doentes com adenocarcinomas gástricos que comprometem a serosa / A infiltração da gordura perigástrica determina pior prognóstico nos doentes com adenocarcinoma gástricos que comprometem a serosa

Paiva, Rubens Kesley Siqueira de 12 August 2009 (has links)
No Ocidente, o adenocarcinoma gástrico operado com intenção curativa geralmente compromete a serosa. A AJCC considera que o prognóstico em 5 anos dos doentes neste grupo pode variar de mais 70% a menos de 7% devido características anatomopatológicas da doença. Métodos: Foi realizado estudo retrospectivo observacional de 354 pacientes com cânceres gástricos que comprometem a serosa, operados com intenção curativa, no período de janeiro de 1997 a dezembro de 2005, seguidos até dezembro de 2008 no Instituto Nacional de Câncer, Brasil. Foram analisados os dados clínicos, cirúrgicos, anatomopatológicos e padrão de recidiva destes doentes, divididos em 2 grupos: Grupo pT3(A), invasão exclusiva da serosa; e Grupo pT3(B), invasão da serosa mais tecido mesogástrico. Resultados: Nos 354 doentes a média de idade foi de 60 ±12, com predomínio do sexo masculino (58,8%). O grupo pT3(A) 89 (25,1%) casos e o pT3(B) 265 (74,9%). A estimativa global de sobrevida foi de 54%, com média de 69 ±2 meses (95% IC 33,9 a 74,7 meses). Os fatores influenciaram na sobrevida em 5 anos foram: a localização distal do tumor (48%, p<0,04); pT3(A) versus pT3(B) (70% versus 48%, respectivamente, p<0,000); pN3 (12%, p<0,000); invasão angiolinfática (45%, p=0,002); invasão neural (44%, p<0,000). A análise multivariada mostrou o pT3(A/B) (p=0,02) e pN (p<0,000) como fatores prognósticos independentes. A taxa de recidiva global foi de 43,3%, com predomínio peritoneal (19,2%) seguida da hematogênica (11,2%). Nos pT3A ocorreram 25 (28,1%) casos de recidivas versus 125 (47,2%) nos pT3B (p=0,002). Dos 68 casos de recidivas peritoneais, 57 (83%) ocorreram em pT3B (p=0,05). Dos 40 casos de recidivas linfonodais, 30 (75%) ocorreram em pT3B (p=0,8). Dos 39 casos de recidivas hematogênicas, 33 (84%) ocorreram em pT3B (p=0,1). Dos 27 casos de recidivas locorregionais, 25 (92%) ocorreram em pT3B (p=0,01). Conclusão: A invasão direta dos tecidos vizinhos que se dirigem ao estômago é a forma mais frequente de tumores pT3 e determina pior prognóstico. O comprometimento do tecido mesogástrico representa um risco aumentado de linfonodos metastáticos, infiltração angiolinfática ou neural, recidiva peritoneal e locorregional; e necessita de tratamento adjuvante. Sua detecção pode reclassificar o estágio pT3 em 2 subestágios perfeitamente distintos, pT3A e pT3B. / Background: In the West, adenocarcinoma of the stomach resected with curative intent is usually found to involve the serosa. The AJCC says the 5 year survival prognosis for such patients ranges from more than 70% to less than 7% depending on histopathologic characteristics of the tumor. Methods: Prospective observational study of 354 patients with gastric cancers involving the serosa, resected with curative intent, from January 1997 to December 2005, and followed until December 2008 at the National Cancer Institute of Brazil. The cohort was divided into two groups: pT3(A), comprised of patients whose tumor invaded only the serosa; and pT3(B), where the tumor invaded the serosa and the perigastric tissue. Clinical outcomes including recurrence and mortality were measured for the two groups and related to demographic, clinical, surgical, anatomic and histopathologic variables. Results: Mean age was 60 ±12 years; males were 58.8% of the cohort. The pT3(A) group had 89 cases (25.1%), and the pT3(B) group 265 cases (74.9%). The global estimated five year survival was 54%, with a mean survival of 69 ±2 months (95% CI: 33.9 to 74.7 months). Factors that influenced 5 year survival included: distal location of the tumor in the stomach (48%, p<0.04); pT3(A) versus pT3(B) (70% versus 48%, respectively, p<0.000); pN3 (12%, p<0.000); angiolymphatic invasion (45%, p=0.002); neural invasion (44%, p<0.000). Multivariate analysis demonstrated pT3(A/B) (p=0.02) and pN (p<0.000) as independent prognostic factors. The global recurrence rate was 43.3%. Recurrence occurred in 28.1% of the 25 pT3(A) cases versus 47.2% of the 125 pT3B cases (p=0.002). Recurrence was predominantly peritoneal (19.2%) followed by hematogeneous (11.2%).Of the 68 cases of peritoneal recurrence, 57 (83%) occurred in the pT3(B) group (p=0.05). Of the 40 cases of lymph node recurrence, 30 (75%) occurred in the pT3(B) group (p=0.8). Of the 39 cases of hematogenous recurrence, 33 (84%) occurred in the pT3(B) group (p=0.1). Of the 27 cases of loco-regional recurrence, 25 (92%) occurred in the pT3(B) group (p=0.01). Conclusion: The direct invasion of tissues neighboring the stomach is the most frequent presentation of pT3 tumors and determines with worse prognosis.Involvement of the mesogastric tissue is associated with an increased risk of lymph nodes metastases, angiolymphatic or neural infiltration, peritoneal and loco-regional recurrence, and the need for adjuvant treatment.The presence of mesogastric involvement should be used to reclassify stage pT3 in two completely distinct substages, pT3(A) and pT3(B).
64

Fatores associados ao risco de desenvolvimento de adenocarcinoma gástrico: estudo caso-controle / Risk factors associated with the development of gastric adenocarcinoma: case-control study

Ramos, Marcus Fernando Kodama Pertille 15 May 2017 (has links)
INTRODUÇÃO: O câncer vem apresentando um impacto cada vez maior nas populações em todo o mundo. Apesar de recente queda global na sua incidência, o câncer gástrico ainda é o quinto tipo mais comum. Sua patogênese é multifatorial, envolvendo a interação de fatores genéticos, ambientais e infecciosos. OBJETIVO: Avaliar a associação de tabagismo, consumo de álcool e nível de escolaridade com o desenvolvimento de câncer gástrico. MÉTODOS: Trata-se de um estudo caso-controle de base hospitalar em que foram incluídos pacientes com diagnóstico de adenocarcinoma de estômago confirmado por exame histopatológico sem tratamento prévio para a neoplasia. Posteriormente, os casos foram divididos em subtipos de acordo com a histologia (intestinal e difuso) e localização da lesão (proximal, distal e outras). Os indivíduos do grupo controle foram selecionados entre pacientes admitidos no mesmo hospital, sem história ou suspeita de câncer de estômago, emparelhados por frequência aos casos segundo sexo e idade. Tabagismo foi classificado em maços-ano e consumo de álcool em gramas-ano. RESULTADOS: Foram analisados 240 casos e 499 controles recrutados no período de junho de 2001 a dezembro de 2007. Não frequentaram a escola ou apresentavam ensino fundamental incompleto 94 indivíduos (39,2%) no grupo dos casos e 187 (37,5%) no grupo de controles. Ensino universitário foi atingido por 12 indivíduos (5%) no grupo de casos e por 45 indivíduos (9%) do grupo de controles. Não houve associação de nível de escolaridade com risco de desenvolvimento de câncer de estômago. Tabagismo esteve associado ao risco de câncer gástrico com odds ratio (OR) de 2,25 (IC95%: 1,53-3,31) para ex-tabagistas e de 2,67 (IC95%: 1,72-4,13) para tabagistas atuais. Com relação à localização e tipo histológico, tabagismo foi associado com todos os subtipos de tumores gástricos analisados, com destaque para os tumores proximais que apresentaram OR de 5,38 (IC95%: 2,15-13,45) para consumo superior a 38 maços-ano. Consumo de álcool também esteve associado a risco de desenvolvimento de câncer gástrico em todos os subtipos analisados. Entretanto, esta associação apresentou características distintas do tabagismo. Ex-consumidores de álcool apresentaram risco mais elevado (OR=3,81; IC95%: 2,45-5,91) que consumidores atuais (OR=2,06; IC95%: 1,31-3,26). A análise da interação mostrou que o efeito conjunto de tabagismo e consumo de álcool encontrado foi maior que o esperado, evidenciando interação positiva [?=1,51 (IC 95%: 1,05 - 1,96)]. CONCLUSÕES: Tabagismo e consumo de álcool apresentaram associação com o risco de desenvolvimento de câncer gástrico, com destaque para tabagistas atuais e maior consumo de maços-ano. O consumo associado do tabaco e do álcool aumenta esse risco / BACKGROUND: Cancer has an increasing impact on populations around the world. Despite a recent overall decline in incidence, gastric cancer stills the fifth most common type. Its pathogenesis is multifactorial involving the interaction of genetic, environmental and infectious factors. OBJECTIVES: To evaluate the association of smoking, alcohol consumption and education level with the development of gastric cancer. METHODS: This is a hospital-based case-control study that included patients with gastric adenocarcinoma confirmed by histopathological examination without prior treatment. Subsequently, patients were divided into subtypes according to histology (intestinal and diffuse) and location of the lesion (proximal, distal and others). Control subjects were selected among patients admitted to the same hospital with no history of gastric câncer, and were frequency-matched to cases for age and sex. Smoking was classified in pack-years and alcohol consumption in grams per year. RESULTS: We analyzed 240 cases and 499 controls recruited from June 2001 to December 2007. Not attended school or had incomplete elementary school 94 subjects (39.2%) in the group of cases and 187 (37.5%) in the control group. University education was achieved by 12 subjects (5%) in the case group and 45 subjects (9%) in the control group. There was no association of education level with increased risk of stomach cancer. Smoking was associated with increased risk of gastric cancer with an odds ratio (OR) of 2.25 (95%CI: 1.53-3.31) for former smokers and 2.67 (95%CI: 1.72-4.13) for current smokers. With respect to location and histological type, smoking was associated with all subtypes of gastric tumors analyzed with emphasis on the proximal tumors that had OR of 5.38 (95%CI: 2.15-13.45) for consumption over 38 packs-years. Alcohol consumption was also associated with increases risk of gastric cancer development in all analyzed subtypes. However, this association showed distinct characteristics of smoking. Former drinkers had higher risk (OR=3.81; 95%CI: 2.45-5.91) than current users (OR=2.06; 95%CI: 1.31-3.26). The analysis of the interaction showed that the combined effect of smoking and alcohol consumption was higher than expected, thus showing up a positive interaction [?= 1.51 (95%CI: 1.05-1.96)]. CONCLUSIONS: Smoking and alcohol consumption were associated with the risk of gastric cancer development, especially for current smokers and higher consumption of pack-years. Association of tobacco and alcohol consumption increases this risk
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Anticancer effect of histone deacetylase inhibitors in gastric cancer cell line.

January 2006 (has links)
Tang Angie. / Thesis submitted in: November 2005. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 151-172). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.iii / Abstract in Chinese --- p.vi / Table of Contents --- p.vii / List of Publications --- p.xi / Awards --- p.xii / List of Abbreviations --- p.xiii / List of Tables --- p.xv / List of Figures --- p.xvi / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Literature Review --- p.3 / Chapter 2.1 --- Gastric cancer-overview --- p.3 / Chapter 2.1.1 --- Epidemology --- p.3 / Chapter 2.1.2 --- Pathology --- p.3 / Chapter 2.1.3 --- Etiologies and Risk Factors --- p.4 / Chapter I. --- Environmental factors --- p.4 / Chapter a. --- Helicobacter pylori infections --- p.4 / Chapter b. --- Epstein-Barr virus (EBV) --- p.6 / Chapter c. --- Dietary factors --- p.6 / Chapter d. --- Smoking --- p.6 / Chapter II. --- Genetic Factors --- p.7 / Chapter a. --- Hereditary Gastric Cancer --- p.7 / Chapter b. --- Genetic polymorphism --- p.8 / Chapter III. --- Cyclooxygenases (COX) enzymes --- p.10 / Chapter IV. --- Molecular carcinogenesis --- p.11 / Chapter a. --- Activation of proto-oncogenes --- p.11 / Chapter b. --- Candidate tumor suppressor genes --- p.12 / Chapter 1. --- Gene mutation and deletion --- p.12 / Chapter 2. --- Epigenetic Silencing --- p.13 / Chapter 2.2 --- Epigenetics --- p.14 / Chapter 2.2.1 --- DNA methylation --- p.15 / Chapter 2.2.2 --- Histone modification --- p.28 / Chapter I. --- Histone acetylation and deacetylation --- p.32 / Chapter II. --- Histone methylation --- p.32 / Chapter III. --- Histone phosphorylation --- p.34 / Chapter IV. --- Histone ubiquitylation --- p.34 / Chapter 2.3 --- "HAT, HDAC and HDAC inhibitors" --- p.36 / Chapter 2.3.1 --- HAT --- p.38 / Chapter 2.3.2 --- HDAC --- p.39 / Chapter (a) --- Class I --- p.40 / Chapter (b) --- Class II --- p.41 / Chapter (c) --- Class III --- p.42 / Chapter (d) --- Mammalian HDAC and their mechanism of deacetylation --- p.44 / Chapter 2.3.3 --- HDAC inhibitors --- p.45 / Chapter I. --- Class I/II natural inhibitors --- p.47 / Chapter II. --- Class I/II synthetic inhibitors --- p.48 / Chapter III. --- Sirtuins inhibitors --- p.49 / Chapter IV. --- Activity of HDAC inhibitors in vitro --- p.50 / Chapter a. --- Effect in the gene expression --- p.50 / Chapter b. --- Non-transcriptional effects --- p.55 / Chapter c. --- Activity of HDAC inhibitors with other agents --- p.57 / Chapter d. --- Effects in xenograft tumor models --- p.57 / Chapter V. --- Clinical trials of HDAC inhibitors --- p.59 / Chapter Chapter 3 --- Aims of the study --- p.63 / Chapter Chapter 4 --- Materials and Methods --- p.64 / Chapter 4.1 --- Cell culture --- p.64 / Chapter 4.2 --- Drug treatment --- p.64 / Chapter 4.2.1 --- Suberoylanilide Hydroxamic Acid treatment --- p.64 / Chapter 4.2.2 --- Trichostatin A treatment --- p.65 / Chapter 4.3 --- Cell proliferation assay --- p.66 / Chapter 4.4 --- Apoptotic assay --- p.67 / Chapter 4.5 --- Flow cytometry --- p.67 / Chapter 4.5.1 --- Cell preparation --- p.67 / Chapter 4.5.2 --- Propidium Iodide staining --- p.68 / Chapter 4.5.3 --- Annexin V-FITC staining --- p.68 / Chapter 4.5.4 --- Flow cytometer analysis --- p.69 / Chapter 4.6 --- Total RNA extraction --- p.70 / Chapter 4.7 --- DNA extraction --- p.71 / Chapter 4.8 --- Protein extraction --- p.72 / Chapter 4.9 --- Western blottng --- p.72 / Chapter 4.10 --- Microarray analysis --- p.74 / Chapter 4.10.1 --- Sample preparation for microarray --- p.74 / Chapter 4.10.2 --- Hybridization --- p.75 / Chapter 4.10.3 --- Scanning and data processing --- p.75 / Chapter 4.10.4 --- Data analysis --- p.76 / Chapter 4.11 --- Primer design --- p.77 / Chapter 4.12 --- RT-PCR --- p.77 / Chapter 4.12.1 --- Reverse transcription --- p.77 / Chapter 4.12.2 --- Quantitative RT-PCR --- p.78 / Chapter 4.13 --- Methlyation study --- p.79 / Chapter 4.13.1 --- Demethylation by 5-aza-2'deoxycytidine --- p.79 / Chapter 4.13.2 --- Bisulfite modification --- p.79 / Chapter 4.13.3 --- Methylation-specific PCR (MSP) --- p.79 / Chapter Chapter 5 --- Results --- p.81 / Chapter 5.1 --- Morphological changes in AGS cells --- p.81 / Chapter 5.2 --- Anti-cancer effects of HDAC inhibitors --- p.81 / Chapter 5.2.1 --- Effect of HDAC inhibitors on cell growth --- p.81 / Chapter a. --- SAHA inhibits cell proliferation --- p.82 / Chapter b. --- TSA inhibits cell proliferation --- p.82 / Chapter 5.2.2 --- Cell cycle analysis --- p.87 / Chapter a. --- Effect of SAHA on cell cycle --- p.87 / Chapter b. --- Effect of TSA on cell cycle --- p.88 / Chapter 5.2.3 --- Induction of apoptosis on AGS cells --- p.92 / Chapter a. --- SAHA induces apoptotic cell death --- p.92 / Chapter b. --- TSA induces apoptotic cell death --- p.94 / Chapter 5.3 --- Induction of histone expression on AGS cells --- p.102 / Chapter 5.3.1 --- HDAC inhibitors induced acetylation of histone H3 --- p.102 / Chapter 5.3.2 --- HDAC inhibitors induced acetylation of histone H4 --- p.103 / Chapter 5.4 --- SAHA- and TSA-induced gene expression profiles --- p.106 / Chapter 5.5 --- Verification of gene expression by quantitative RT-PCR --- p.108 / Chapter 5.6 --- Methylation study --- p.113 / Chapter Chapter 6 --- Discussion --- p.116 / Chapter 6.1 --- Improved treatment strategy is needed for gastric cancer. --- p.116 / Chapter 6.2 --- HDAC inhibitors as potential anti-cancer agents --- p.117 / Chapter 6.3 --- Potential anti-cancer effect of TSA and SAHA on AGS cells --- p.120 / Chapter I. --- Morphological changes of AGS gastric cancer cells --- p.120 / Chapter II. --- Inhibition of cell proliferation --- p.120 / Chapter III. --- Induction of cell cycle arrest --- p.121 / Chapter IV. --- Induction of apoptosis --- p.122 / Chapter 6.4 --- Expression of acetylated histones upon treatment with TSA and SAHA --- p.124 / Chapter 6.5 --- Identify potential target genes upon treatment with TSA and SAHA --- p.125 / Chapter 6.5.1 --- Candidate genes involved in cell cycle --- p.126 / Chapter a. --- P21WAF1 --- p.126 / Chapter b. --- p27kip1. --- p.128 / Chapter c. --- Cyclin E & Cyclin A --- p.128 / Chapter d. --- Signal-induced proliferation-associated gene 1 (SIPA1) .… --- p.129 / Chapter 6.5.2 --- Candidate genes involved in apoptosis and anti-proliferation --- p.130 / Chapter a. --- BCL2-interacting killer (apoptosis-inducing) (BIK) (Pro-apoptotic gene) --- p.131 / Chapter b. --- Thioredoxin interacting protein (TXNIP) (Proapoptotic gene) / Chapter c. --- Cell death-inducing DFFA-like effector b (CIDEB) (apoptosis induction) --- p.132 / Chapter d. --- B-cell translocation gene 1 (BTG1) - (anti-proliferation) --- p.133 / Chapter e. --- Quiescin 6 (QSCN6) (anti-proliferation) --- p.133 / Chapter f. --- "Cysteine-rich, angiogenic inducer, 61 (CYR61) (anti-proliferative)" --- p.134 / Chapter g. --- Metallothionein 2A (MT2A) (apoptosis induction and anti-proliferative) --- p.134 / Chapter 6.5.3 --- Other genes reported to be up-regulated with HDAC inhibitors treatment --- p.135 / Chapter a. --- Glia maturation factor-gamma (GMFG) --- p.135 / Chapter b. --- v-fos FBJ murine osteosarcoma viral oncogene homolog (FOS) / Chapter c. --- Interleukin 8 (IL-8) --- p.136 / Chapter d. --- Insulin-like growth factor binding protein- 2 (IGFBP2) --- p.137 / Chapter e. --- Integrin alpha chain 7 (ITGA7) --- p.138 / Chapter 6.5.4 --- Selected highly up-regulated genes with HDAC inhibitors treatment --- p.139 / Chapter a. --- Aldo-keto reductase family 1,member C3 (AKR1C3) --- p.139 / Chapter b. --- GPI-anchored metastasis-associated protein homolog (C4.4A) --- p.139 / Chapter c. --- "Serine (or cysteine) proteinase inhibitor,clade I (neuroserpin), member 1 (SERPINI1)" --- p.140 / Chapter d. --- "Serine (or cysteine) proteinase inhibitor,clade E (nexin, plasminogen activator inhibitor type 1), member 1 (SERPINE1)" --- p.140 / Chapter e. --- Adrenomedullin (ADM) --- p.141 / Chapter f. --- Dehydrogenase/reductase (SDR family) member 2 (HEP27) --- p.142 / Chapter g. --- Cholecystokinin (CCK) --- p.142 / Chapter h. --- Silver homolog (mouse) (SILV) --- p.143 / Chapter 6.6 --- Genes regulated by gene promoter hypermethylation in AGS cells --- p.143 / Chapter Chapter 7 --- Conclusion --- p.147 / Chapter Chapter 8 --- Further Studies --- p.150 / References --- p.151 / Appendix I --- p.151 / Appendix II --- p.III / Appendix III --- p.IV / Appendix IV --- p.VI
66

Vírus Epstein-Barr, instabilidade de microssatélite e expressão de PD-L1 nos adenocarcinomas gástricos: aspectos clínico-patológicos e prognósticos / Epstein-Barr virus, microsatellite instability and PD-L1 expression in gastric adenocarcinomas: clinicopathological and prognostic aspects

Pereira, Marina Alessandra 13 August 2018 (has links)
Introdução: O câncer gástrico (CG) foi recentemente categorizado em subtipos moleculares, os quais incluem os tumores Epstein-Barr (EBV)-positivo e com instabilidade de microssatélites (MSI). Esta distinção pode nos fornecer informações prognósticas e identificar alvos terapêuticos, tais como o PD-L1. Objetivo: O objetivo desse estudo foi avaliar a presença de EBV, MSI e expressão de PD-L1 no CG e suas associações com características clinicopatológicas e prognósticas. Métodos: Foram avaliados retrospectivamente 287 pacientes com CG submetidos à gastrectomia D2 com intenção curativa entre 2009 e 2016, através da técnica de tissue microarray. As proteínas de reparo do DNA (MLH1, MSH2, MSH6, PMS2) e o PD-L1 foram avaliados por imuno-histoquímica. O EBV foi avaliado por hibridação in situ. Resultados: Identificou-se a presença de EBV e MSI em 10,5% e 27% dos CGs, respectivamente. A maioria dos CGs com MSI apresentou perda simultânea da expressão de MLH1 e PMS2 (60%). O CG EBV-positivo associou-se ao sexo masculino (p=0,032), localização proximal (p < 0,001), tipo indeterminado de Lauren (p < 0,001), histologia pouco diferenciada (p=0,043) e infiltrado inflamatório acentuado (p < 0,001). Os tumores com MSI foram associados à idade mais avançada (p=0,002), gastrectomia subtotal (p=0,004), pN0 (p=0,024) e ao estágio pTNM menos avançado (p=0,020). Observou-se a imunoexpressão de PD-L1 em 8,8% dos casos, com expressão predominante no CG EBV-positivo (p < 0,001). O CG com MSI apresentou melhor sobrevida livre de doença (p=0,006) e sobrevida global (p=0,049) comparado ao EBV-negativo/microssatélite estável (MSS). Na análise multivariada, o status MSI/MSS permaneceu como fator de risco independente associado à recidiva da doença. Conclusão: O CG EBV-positivo apresentou aumento da expressão de PD-L1, enquanto o CG com MSI relacionou-se à melhor sobrevida. Ambos os subgrupos representam entidades distintas de CG e sua identificação é viável por técnicas diagnósticas convencionais. A caracterização destes subtipos de CG possibilita a aplicação de terapias direcionadas e permite ampliar o poder prognóstico dos atuais sistemas de classificação e estadiamento / Introduction: Gastric cancer (GC) has recently been categorized in molecular subtypes, which include Epstein-Barr (EBV)-positive and microsatellite instable (MSI) tumors. This distinction provides prognostic information and identifies therapeutic targets, such as PD-L1. Objective: The aim of this study was to evaluate the presence of EBV, MSI and PD-L1 expression in GC and their associations with clinicopathological characteristics and prognosis. Methods: We retrospectively evaluated 287 patients with GC who underwent D2-gastrectomy with curative intent from 2009 to 2016 through tissue microarray technique. DNA mismatch repair proteins (MLH1, MSH2, MSH6, PMS2) and PD-L1 were assessed by immunohistochemistry. EBV was detected by in situ hybridization. Results: The presence of EBV and MSI was identified in 10.5% and 27% of GCs, respectively. Most MSI GCs showed simultaneous loss of MLH1 and PMS2 expression (60%). EBV positivity was related to male (p=0.032), proximal location (p < 0.001), undetermined Lauren type (p < 0.001), poorly differentiated histology (p=0.043) and intense inflammatory infiltrate (p < 0.001). MSI-tumors were associated with older age (p=0.002), subtotal gastrectomy (p=0.004), pN0 (p=0.024) and more initial pTNM stage (p=0.020). PD-L1 immunoexpression was observed in 8.8% of cases, with predominant expression in EBV-positive GC (p < 0.001). MSI correlated with better disease-free survival (p=0.006) and overall survival (p=0.049) compared to the EBV-negative/microsatellite stable (MSS). In the multivariate analysis, the MSI/MSS status remained as independent risk factor associated with disease recurrence. Conclusion: EBV-positive GCs had increased PD-L1 expression, while MSI GC had better survival outcome. Both subgroups are distinct GC entities and their recognition is feasible by conventional diagnostic techniques. The characterization of these GC subtypes enables the application of targeted therapies and allows to extend the prognostic power of current classification and staging systems
67

Epigenetic identification of paired box gene 5 as a functional tumor suppressor associated with poor prognosis in patients with gastric cancer. / CUHK electronic theses & dissertations collection

January 2010 (has links)
Background & aims. DNA methylation induced tumor suppressor gene silencing plays an important role in carcinogenesis. By using methylation-sensitive representational difference analysis, we identified paired box gene 5 (PAX5) being methylated in human cancer. PAX5 locates at human chromosome 9p13.2 and encodes a 391 amino acids transcription factor. However, the role of PAX5 in gastric cancer is still unclear. Hence, we analyzed its epigenetic inactivation, biological functions, and clinical implications in gastric cancer. / Conclusions. Our results demonstrated that PAX5 promoter methylation directly mediates its transcriptional silence and commonly occurs in gastric cancer. PAX5 gene can act as a functional tumor suppressor in gastric carcinogenesis by playing an important role in suppression of cell proliferation, migration, invasion, and induction of cell apoptosis. Detection of methylated PAX5 may be utilized as a biomarker for the prognosis of gastric cancer patients. / Methods. Methylation status of PAX5 promoter in gastric cancer cell lines and clinical samples was evaluated by methylation specific polymerase chain reaction (MSP) and bisulfite genomic sequencing (BGS). The effects of PAX5 re-expression in cancer cell lines were determined in proliferation, cell cycle, apoptosis, migration and invasion assays. Its in vivo tumorigenicity was investigated by injecting cancer cells with PAX5 expression vector subcutaneously into the dorsal flank of nude mice. Chromosome Immunoprecipitation (ChIP) and cDNA expression array were performed to reveal the molecular mechanism of the biological function of PAX5. / Results. PAX5 was silenced or down-regulated in seven out of eight of gastric cancer cell lines examined. A significant down-regulation was also detected in paired gastric tumors compared with their adjacent non-cancer tissues (n = 18, P = 0.0196). In contrast, PAX5 is broadly expressed in all kinds of normal adult and fetal tissues. The gene expression of PAX5 in the gastric cancer cell line is closely linked to the promoter hypermethylation status. In addition, the expression levels could be restored by exposure to demethylating agents 5-aza-21-deoxycytidine. Re-expression of PAX5 in AGS, BGC823 and HCT116 cancer cells reduced colony formation (P &lt; 0.01) and cell viability (P &lt; 0.05), arrested cell cycle in G0/G1 phase (P = 0.0055), induced cell apoptosis (P &lt; 0.05), repressed cell migration and invasion (P = 0.0218) in vitro. It also inhibited tumor growth in nude mice (P &lt; 0.05). The molecular basis of its function were investigated by cDNA expression array and demonstrated that ectopic expression of PAX5 up-regulated tumor suppressor gene P53, anti-proliferation gene P21, pro-apoptosis gene BAX, anti-invasion gene MTSS1 and TIMP1; and down-regulated anti-apoptosis gene BCL2, cell cycle regulator cyclinD1, migration related gene MET and MMP1. ChIP assay indicated that P53 and MET are direct transcriptional target of PAX5. Moreover, PAX5 hypermethylation was detected in 90% (145 of 161) of primary gastric cancers compared with 16% (3 of 19) of non-cancer tissues (P &lt; 0.0001). After a median follow-up period of 15.4 months, multivariate analysis revealed that gastric cancer patients with PAX5 methylation had a significant poor overall survival compared with the unmethylated cases (P = 0.0201). / Li, Xiaoxing. / Advisers: Hsiang Fu Kung; Jun Yu. / Source: Dissertation Abstracts International, Volume: 72-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 134-159). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
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Avaliação da Anexina A1, FPR1, FPR2 e miRNAs em adenocarcinoma gástrico / Evaluation of Annexin A1, FPR1, FPR2 and miRNAs in gastric adenocarcinoma

Stuchi, Nathália Maciel Maniezzo [UNESP] 31 May 2016 (has links)
Submitted by NATHÁLIA MACIEL MANIEZZO STUCHI null (nmmbiomedica@hotmail.com) on 2016-07-28T14:13:21Z No. of bitstreams: 1 Tese capa dura.pdf: 5464428 bytes, checksum: f53c801765e2d85e4f507ebaaebe4625 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-07-28T15:52:03Z (GMT) No. of bitstreams: 1 stuchi_nmm_dr_sjrp.pdf: 5464428 bytes, checksum: f53c801765e2d85e4f507ebaaebe4625 (MD5) / Made available in DSpace on 2016-07-28T15:52:03Z (GMT). No. of bitstreams: 1 stuchi_nmm_dr_sjrp.pdf: 5464428 bytes, checksum: f53c801765e2d85e4f507ebaaebe4625 (MD5) Previous issue date: 2016-05-31 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Apesar do declínio da incidência, o câncer gástrico ocupa ainda a terceira posição em causa de morte por câncer no mundo, tendo como principal fator de risco a bactéria Helicobacter pylori. Esta bactéria pode levar a uma inflamação persistente através da produção de citocinas pró-inflamatórias e de espécies reativas de oxigênio e nitrogênio, estimulando a proliferação celular bem como outros processos envolvidos na carcinogênese. Ainda envolvidos nestes processos tem sido observada a participação de microRNAs, que exercem papel importante na regulação pós-transcricional, influenciando processos fisiológicos normais da célula bem como aqueles ligados às doenças, como por exemplo o câncer gástrico. Alguns miRNAs podem atuar como oncogenes, genes supressores de tumor e biomarcadores para diversas patologias, podendo alvejar genes relacionados com inflamação e câncer como o gene ANXA1 (Anexina-A1). A Anexina-A1 é uma proteína anti-inflamatória e com ação anti-proliferativa, que se liga à receptores do tipo formil peptídeo como por exemplo FPR1 e FPR2, ambos sabidamente relacionados com a progressão de doenças como o câncer. Desta forma o presente trabalho teve como objetivos avaliar a expressão da proteína Anexina A1 e seus receptores FPR1 e FPR2, bem como avaliar a expressão do RNAm da ANXA1 e de miRNAs que possam modular a expressão desse gene (hsa-mir-27a, hsa-mir-196a e hsa-mir-222) em adenocarcinoma gástrico e correlacionar estes resultados com os aspectos clínico-patológicos. Foram avaliadas 31 amostras de adenocarcinoma gástrico, assim como as regiões metaplásica ou normal adjacentes ao tumor. A quantificação relativa (RQ) do RNAm da ANXA1 e miRNAs foi realizada por PCR quantitativo em tempo real utilizando ensaio TaqMan, e a expressão proteica da AnxA1, FPR1 e FPR2 por imuno-histoquímica e análise densitométrica. Em relação à expressão gênica relativa foram observados o aumento da expressão da ANXA1 nos tumores (RQ=1,374; p<0,001), assim como do miR-196a que apresentou aumento de expressão tanto no tecido metaplásico (RQ= 4,784; p=0,0016) e tumoral (RQ=16,99; p< 0,001) em relação ao tecido normal. O miR-27a não se apresentou diferencialmente expresso nos diferentes tecidos e houve diminuição da expressão do miR-222 (RQ=0,687; p=0,01) no tecido tumoral em relação ao tecido normal. Apenas o miR-196a e a ANXA1 apresentaram correlação significantemente inversa (r= -0,55; p=0,003), e este miRNA foi o único que apresentou associação com o sexo feminino, devido aumento de expressão em mulheres. Quando se comparou a expressão relativa aos parâmetros clínico-patológicos e tumorais não foram encontradas diferenças significativas. Quanto à expressão proteica o FPR2 não apresentou marcação no tecido normal, metaplásico e tumoral. Contudo a AnxA1 e FPR1 apresentaram imunomarcação positiva amplamente distribuída no tecido tumoral e positivamente correlacionados tanto no epitélio (r=0,87; p<0,0001) como estroma (r=0,62; p=0,004). Portanto, nossos resultados sugerem que a ANXA1 é modulada pelo miR-196a em câncer gástrico, e evidenciam que tanto a AnxA1 como o FPR1 também estão envolvidos no processo de carcinogênese gástrica. Tais achados podem abrir possibilidades para futuros estudos sobre novos alvos terapêuticos já que AnxA1 e FPR1 são possíveis alvos farmacológicos, e as terapias baseadas em microRNAs tem sido amplamente pesquisadas. / Gastric cancer still ranks third in cause of cancer death worldwide, despite the decline in its incidence, being Helicobacter pylori the main risk factor for this disease. This bacterium can lead to persistent inflammation via the production of proinflammatory cytokines and reactive oxygen and nitrogen species, stimulating cell proliferation and other processes involved in carcinogenesis. Still involved in this process, it has been observed the participation of miRNAs, which play an important role in post- transcriptional regulation, influencing normal physiological processes of the cell as well as those linked to diseases such as gastric cancer. Some miRNAs can act as oncogenes, tumor suppressor genes and biomarkers for various diseases, can targetting genes linked to inflammation and cancer such as ANXA1 gene (Annexin A1). Annexin A1 is an anti-inflammatory protein with anti-proliferative action that binds to formyl peptide receptors such as, FPR1 and FPR2, both known to be related to the progression of diseases such as cancer. Thus, the present study aimed to evaluate the expression of Annexin A1, FPR1 and FPR2 receptors, and the expression of mRNA ANXA1 and miRNAs (hsa-mir-27a, hsa-mir-196a and hsa-miR 222) in gastric adenocarcinoma, also correlate these results to the clinicopathological features. 31 adenocarcinoma samples were evaluated, as well as normal or metaplastic region adjacent to the tumor. Relative quantification (RQ) of miRNA and mRNA ANXA1 was evaluated by TaqMan assay and protein expression AnxA1, FPR1 and FPR2 by immunohistochemistry and densitometry analysis. Regarding the relative expression the following results were observed, increased expression in tumors of ANXA1 (RQ = 1.374; p < 0.001) and miR- 196a that showed increased expression it he metaplastic tissue (RQ = 4.784; p = 0.0016) and tumor (RQ = 16.99; p < 0.001) compared to normal tissue. The miR- 27a did not appear differentially expressed in different tissues and there was a decrease of miR -222 expression (RQ = 0.687; p = 0.01) in tumor tissue compared to normal tissue. Only the miR-196a and ANXA1 presented a significant inverse correlation (r = -0.55; p = 0.003), and this miRNA was the only one that showed association to female gender, due to increased expression in women when comparing the relative expression to clinicopathological parameters and tumor features. The FPR2 was not expressed in normal, metaplasic and tumor tissue. However, the AnxA1 and FPR1 were widely distributed positive immunostaining in tumor tissue and positively correlated both in the epithelium (r = 0.87 ; p < 0.0001) and stromal (r = 0.62 ; p = 0.004). Thus, our results suggest that ANXA1 is modulated by miR-196a in gastric cancer, and evidencing that both AnxA1 and FPR1 are also involved in gastric carcinogenesis process. These data open the possibility for future studies on new therapeutic targets since AnxA1 and FPR1 are adjustable pharmacological targets, and microRNAs ` therapies have been widely researched. / FAPESP: 2012/15036-8 / CNPq: 474776/2013-1
69

Vírus Epstein-Barr, instabilidade de microssatélite e expressão de PD-L1 nos adenocarcinomas gástricos: aspectos clínico-patológicos e prognósticos / Epstein-Barr virus, microsatellite instability and PD-L1 expression in gastric adenocarcinomas: clinicopathological and prognostic aspects

Marina Alessandra Pereira 13 August 2018 (has links)
Introdução: O câncer gástrico (CG) foi recentemente categorizado em subtipos moleculares, os quais incluem os tumores Epstein-Barr (EBV)-positivo e com instabilidade de microssatélites (MSI). Esta distinção pode nos fornecer informações prognósticas e identificar alvos terapêuticos, tais como o PD-L1. Objetivo: O objetivo desse estudo foi avaliar a presença de EBV, MSI e expressão de PD-L1 no CG e suas associações com características clinicopatológicas e prognósticas. Métodos: Foram avaliados retrospectivamente 287 pacientes com CG submetidos à gastrectomia D2 com intenção curativa entre 2009 e 2016, através da técnica de tissue microarray. As proteínas de reparo do DNA (MLH1, MSH2, MSH6, PMS2) e o PD-L1 foram avaliados por imuno-histoquímica. O EBV foi avaliado por hibridação in situ. Resultados: Identificou-se a presença de EBV e MSI em 10,5% e 27% dos CGs, respectivamente. A maioria dos CGs com MSI apresentou perda simultânea da expressão de MLH1 e PMS2 (60%). O CG EBV-positivo associou-se ao sexo masculino (p=0,032), localização proximal (p < 0,001), tipo indeterminado de Lauren (p < 0,001), histologia pouco diferenciada (p=0,043) e infiltrado inflamatório acentuado (p < 0,001). Os tumores com MSI foram associados à idade mais avançada (p=0,002), gastrectomia subtotal (p=0,004), pN0 (p=0,024) e ao estágio pTNM menos avançado (p=0,020). Observou-se a imunoexpressão de PD-L1 em 8,8% dos casos, com expressão predominante no CG EBV-positivo (p < 0,001). O CG com MSI apresentou melhor sobrevida livre de doença (p=0,006) e sobrevida global (p=0,049) comparado ao EBV-negativo/microssatélite estável (MSS). Na análise multivariada, o status MSI/MSS permaneceu como fator de risco independente associado à recidiva da doença. Conclusão: O CG EBV-positivo apresentou aumento da expressão de PD-L1, enquanto o CG com MSI relacionou-se à melhor sobrevida. Ambos os subgrupos representam entidades distintas de CG e sua identificação é viável por técnicas diagnósticas convencionais. A caracterização destes subtipos de CG possibilita a aplicação de terapias direcionadas e permite ampliar o poder prognóstico dos atuais sistemas de classificação e estadiamento / Introduction: Gastric cancer (GC) has recently been categorized in molecular subtypes, which include Epstein-Barr (EBV)-positive and microsatellite instable (MSI) tumors. This distinction provides prognostic information and identifies therapeutic targets, such as PD-L1. Objective: The aim of this study was to evaluate the presence of EBV, MSI and PD-L1 expression in GC and their associations with clinicopathological characteristics and prognosis. Methods: We retrospectively evaluated 287 patients with GC who underwent D2-gastrectomy with curative intent from 2009 to 2016 through tissue microarray technique. DNA mismatch repair proteins (MLH1, MSH2, MSH6, PMS2) and PD-L1 were assessed by immunohistochemistry. EBV was detected by in situ hybridization. Results: The presence of EBV and MSI was identified in 10.5% and 27% of GCs, respectively. Most MSI GCs showed simultaneous loss of MLH1 and PMS2 expression (60%). EBV positivity was related to male (p=0.032), proximal location (p < 0.001), undetermined Lauren type (p < 0.001), poorly differentiated histology (p=0.043) and intense inflammatory infiltrate (p < 0.001). MSI-tumors were associated with older age (p=0.002), subtotal gastrectomy (p=0.004), pN0 (p=0.024) and more initial pTNM stage (p=0.020). PD-L1 immunoexpression was observed in 8.8% of cases, with predominant expression in EBV-positive GC (p < 0.001). MSI correlated with better disease-free survival (p=0.006) and overall survival (p=0.049) compared to the EBV-negative/microsatellite stable (MSS). In the multivariate analysis, the MSI/MSS status remained as independent risk factor associated with disease recurrence. Conclusion: EBV-positive GCs had increased PD-L1 expression, while MSI GC had better survival outcome. Both subgroups are distinct GC entities and their recognition is feasible by conventional diagnostic techniques. The characterization of these GC subtypes enables the application of targeted therapies and allows to extend the prognostic power of current classification and staging systems
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PrevalÃncia de lesÃes precursoras do cÃncer gÃstrico e do Helicobacter pylori em familiares de pacientes com cÃncer gÃstrico / Gastric precancerous lesions and Helicobacter pylori infection in relatives of gastric cancer

Cicero Roberio AraÃjo Motta 10 August 2004 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / A infecÃÃo pelo Helicobacter pylori acomete mais da metade da populaÃÃo mundial, sendo esta bactÃria reconhecida como carcinÃgeno do grupo I pela OrganizaÃÃo Mundial de SaÃde-OMS. Familiares em primeiro grau de pacientes com cÃncer gÃstrico tÃm um maior risco de desenvolver cÃncer gÃstrico. Avaliamos a prevalÃncia de lesÃes precursoras do cÃncer gÃstrico e do Helicobacter pylori nos familiares em primeiro grau de pacientes com cÃncer gÃstrico, quando comparado a controles sem histÃria familiar. Cento e quatro familiares foram recrutados à partir de 40 casos de cÃncer gÃstrico tipo nÃo-cÃrdia e foram comparados com cento e dezoito controles, nÃo havendo diferenÃas estatisticamente significantes entre os dois grupos com relaÃÃo a idade, sexo, tabagismo, etilismo e condiÃÃes socioeconÃmicas garantindo a homogeneidade da amostra. Todos os pacientes foram submetidos a avaliaÃÃo endoscÃpica e biÃpsias seguindo o protocolo de Sydney. A anÃlise histopatolÃgica foi realizada pÃr um Ãnico patologista experiente e mascarado quanto a origem das amostras. Ainda que a prevalÃncia da atrofia e da metaplasia intestinal tenha ocorrida de forma similar nos dois grupos, a associaÃÃo destas lesÃes foi mais encontrada nos familiares que nos controles (p=0,021). A metaplasia intestinal tipo incompleta foi mais significante nos familiares (p=0,001), assim como a displasia (p=0,025). O padrÃo de gastrite encontrado nos familiares foi o de pangastrite associada a presenÃa de folÃculos linfÃides, padrÃo este jà definido como o de fenotÃpico de maior risco para a carcinogÃnese gÃstrica. NÃo houve diferenÃa estatisticamente significante entre os dois grupos com relaÃÃo a prevalÃncia do H. pylori , porÃm a topografia da infecÃÃo envolvendo antro e corpo foi maior nos familiares (p=0,001). De acordo com os resultados obtidos neste estudo, encontramos que familiares de pacientes com cÃncer gÃstrico tÃm uma maior prevalÃncia de alteraÃÃes histopatolÃgicas, estando estas alteraÃÃes confinadas a presenÃa do Helicobacter pylori / Infection by Helicobacter pylori, a bacterial species classified by WHO as being carcinogenic (group I) affects more than half the world population. First-degree relatives to patients with gastric cancer are at increased risk of developing gastric cancer. The present study evaluated the prevalence of precursor lesions of gastric cancer and infection by Helicobacter pylori in first-degree relatives to patients with gastric cancer as compared to controls with no family history of gastric cancer. One hundred four first-degree relatives to 40 patients with noncardiac gastric cancer were enrolled in the study and compared to 108 controls. The groups were statistically homogenous in terms of age. All patients were submitted to endoscopic evaluation and biopsy as described in the Sydney protocol. The histopathological analysis was carried out by a single, experienced pathologist blinded to the origin of the samples. Although the prevalence of atrophy and intestinal metaplasia was similar for the two groups, association with these lesions was more common among relatives than controls (p=0.021). Incomplete intestinal metaplasia was also more significant among relatives (p=0.001), as was displasia (p=0.025). The group of relatives presented a pattern of pangastritis associated with lymphoid follicles characteristic of increased risk for gastric carcinogenesis. There was no statistically significant difference between the groups with regard to the prevalence of H. pylori, though infection involving body and antrum was more prevalent among relatives (p=0.001). Our findings suggest that relatives to patients with gastric cancer present a greater prevalence of histopathological changes associated with the presence of H. pylori

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