L’immunothérapie représente une avancée majeure dans la prise en charge des patients atteints de cancer. L’utilisation thérapeutique récente des anticorps anti-"checkpoints", qui renforcent la réponse immunitaire cellulaire naturelle anti-tumorale, a relancé l’intérêt d’approches d’immunothérapie cellulaire spécifique dans les cancers. Malgré tout, l’identification d'antigènes capables de stimuler efficacement des lymphocytes T (LT) anti-tumoraux représente un obstacle majeur au développement de telles approches. Pour identifier de tels antigènes, des cellules présentatrices d’antigène (CPA) artificielles (CPAA), capables d’exprimer, après transduction gamma-rétrovirale, des peptides directement codés ou des antigènes entiers, dégradés par ces cellules, comme le feraient des CPA humaines, en peptides présentés au sein de la molécule du CMH de classe I la plus fréquente chez l'homme, HLA-A2.1, ont été développées au laboratoire. Ces CPAA sont capables de stimuler efficacement des LT cytotoxiques (LTC) spécifiques contre des antigènes tumoraux. Deux grandes approches d’identification des antigènes tumoraux d’intérêt thérapeutique, ont été utilisées. La première est une approche directe d’identification des peptides basée sur l’élution des peptides HLA-A2.1-restreints présentés par nos CPAA et leur analyse par spectrométrie de masse. La seconde est une approche d’immunologie inverse basée sur des prédictions in silico d’épitopes HLA-A2.1-restreints reposant sur des données biochimiques des poches du CMH. Dans les deux approches, des tests fonctionnels d’activation de LTC spécifiques ont été effectués avec nos CPAA. Dans la première étude, nous avons utilisé la spectrométrie de masse en tandem couplée à la chromatographie en phase liquide, qui a été jusqu'à présent la technologie permettant l'identification rapide de centaines de ligands du CMH dans différentes approches expérimentales. En partant de CPAA codant les peptides immunogènes connus M1m, M1 ou FSP02, des LTC spécifiques de ces peptides ont été obtenus, et nous avons réussi à les caractériser par spectrométrie de masse. En partant de CPAA codant les protéines entières desquelles ces peptides sont dérivés, des LTC spécifiques des peptides ont également été obtenus mais nous n’avons pas réussi à les caractériser par spectrométrie de masse. Des peptides très immunogènes, capables de stimuler de fortes réponses immunitaires cellulaires anti-tumorales, peuvent donc échapper à une détection par spectrométrie de masse, rendant ainsi discutable l'utilisation de cette technique pour sélectionner des peptides d’intérêt clinique. Dans la deuxième étude, nous sommes partis de peptides prédits. Nous avons pu monter des réponses immunitaires spécifiques contre les néoépitopes FSP25 et FSP26 prédits in silico, dérivés de la protéine mutée CASP5 (-1) retrouvée chez 60% de patients atteints de cancer colorectal (CCR) à instabilité microsatellitaire (IMS). La CASP5 est impliquée dans l’apoptose et nous avons montré que les patients atteints d’un CCR à IMS présentant cette mutation avaient un moins bon pronostic. Nous avons également montré que chez des patients HLA-A2+ atteints d’un CCR à IMS présentant la mutation, des LTC pouvaient être obtenus contre les épitopes FSP25 et FSP26, capables de lyser spécifiquement la lignée cellulaire HLA-A2.1+ HCT116 dérivée d’un CCR à IMS présentant également la mutation, faisant de la protéine mutée CASP5 (-1) une cible thérapeutique de choix chez ces patients. Dans ces deux études, nos CPAA constituaient un outil de choix pour le développement d’approches d’immunothérapie spécifique personnalisée, soit cellulaire adoptive, pour déterminer quels antigènes devraient être ciblés ou pour directement activer et amplifier in vitro des LT injectés in vivo, soit vaccinale, pour déterminer les antigènes les plus immunogènes à inclure dans un vaccin efficace. / Immunotherapy represents a major advance in cancer patient management. Recent use of anti-checkpoint antibodies, that reinforce the natural cellular anti-tumor immune response, has revived interest for specific cellular immunotherapy approaches in cancers. Nevertheless, the difficulty of identifying highly immunogenic tumor antigens capable of specifically stimulating efficient anti-tumor T lymphocytes (TLs) is a considerable barrier to the development of such approaches. In order to identify such antigens, artificial antigen presenting cells (AAPCs) expressing the most common HLA class I molecule, HLA-A2.1, were developed in the laboratory. After gammaretroviral transduction, these AAPCs also express a directly-encoded peptide of interest or a full-length antigen, degraded by these cells into peptides as human antigen presenting cells (APCs) do. These AAPCs are capable of efficiently stimulating specific cytotoxic T lymphocytes (CTLs) against tumor antigens. Two major approaches for the identification of tumor antigens of therapeutic interest have been used. The first one is a direct approach of identification of HLA-A2.1-restricted peptides based on the elution of HLA-A2.1-peptide complexes expressed by our AAPCs and their analysis by mass spectrometry. The second one is a reverse immunology approach based on in silico predictions of HLA-A2.1-restricted epitopes using available MHC pocket biochemical data. In both approaches, functional tests were performed in vitro with our AAPCs to test the immunogenicity of the studied peptides. In the first study, we used tandem mass spectrometry coupled with liquid chromatography, which has been until today the technology of choice for the rapid identification of hundreds of MHC ligands in different experimental approaches. Starting from AAPCs encoding known immunogenic M1m, M1 and FSP02 peptides, specific CTLs could be obtained against these peptides, and we were able to characterize them by mass spectrometry. Starting from AAPCs encoding full length antigens from which these peptides are derived, peptide-specific CTLs were also obtained, but we were unable to characterize them by mass spectrometry. Therefore, highly immunogenic peptides, capable of stimulating strong anti-tumor cellular immune responses, may not be detected by mass spectrometry, rendering questionable the use of this technique for selecting clinically relevant peptides. In the second study, we started from predicted peptides. We were able to mount specific immune responses against FSP25 and FSP26 in silico predicted neoepitopes, derived from the CASP5 (-1) mutated protein found in 60% of microsatellite instability (MSI) colorectal cancer (CCR) patients. CASP5 is involved in programmed cell death and we have shown that MSI CRC patients whose tumors harbored this CASP5 (-1) mutation had less good prognosis. We have also shown that in HLA-A2+ MSI CASP5 (-1)-mutated CRC patients, specific CTLs could be obtained against FSP25 and FSP26 epitopes, capable of specifically lysing HLA-A2+ MSI CRC cell line HCT116 also harboring this mutation. Therefore, the mutated caspase-5 protein might be a therapeutic target of major interest for personalized specific immunotherapy strategies in the context of MSI CASP5 (-1)-mutated CRCs. In both studies, our AAPCs were a tool of choice for the development of personalized specific immunotherapy strategies, either for cellular adoptive approaches, to determine which antigens should be targeted or to directly activate and amplify in vitro antigen of interest-specific TLs which would be transferred in vivo, or for vaccine approaches, to identify the most immunogenic antigens which should be included in an efficacious vaccine

There is evidence that kinetics of tumour markers (TMs) CEA, CA15-3 and CA19-9 provide valuable information about disease state over time in patients with advanced breast and colorectal cancer but the literature contains differences in methodology so comparing findings is difficult. By modifying criteria developed by Rustin and colleagues [1-5] in ovarian carcinoma we have retrospectively identified a subset of patients (those with progressive (P) TMs) where survival is significantly reduced compared with those with responsive (R) TMs. This is true for CEA, CA15-3 and CA19-9 at the first chemotherapy given in advanced disease (chem1) (Hazard ratios (HR) = 9.99, 8.89, 5.75, P ¿ 0.001 in all cases) and CEA and CA19-9 at the second chemotherapy (chem2) (HR = 7.95, 9.00, P = 0.001 and 0.002 respectively) in patients with breast cancer. It is also true for CEA at chem1 in patients with colorectal cancer (HR = 2.51, P <0.001). Further studies are necessary to see if treatment directed by these criteria can influence survival. CEA and CA19-9 Rustin category in colorectal patients and CA15-3 Rustin category in breast patients correlated significantly with radiological category at chem1 and chem2 (CEA rs = 0.45 and 0.43, CA19-9 rs = 0.26 and 0.35, CA15-3 rs = 0.28 and 0.44). CA19-9 also correlates with radiological category at chem2 (rs = 0.38) in breast patients. This provides valuable information because RECIST criteria can delay radiological identification of disease progression compared with WHO criteria [6, 7] and new therapies may act to stabilise tumour growth rather than reduce it [8]. / Oncology Research Trust Fund at Airedale NHS Trust

by Chiu Yuk Lan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 127-133). / Abstract also in Chinese. / TABLE OF CONTENTS / ABSTRACT (ENGLISH) --- p.a / ABSTRACT (CHINESE) --- p.b / ACKNOWLEDGEMENTS --- p.iv / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- Cancer in Food-service Workers --- p.1 / Chapter 1.2 --- Carcinogenicity of Cooking Fumes --- p.1 / Chapter 1.3 --- High Risk of Lung Cancer in Chinese Women --- p.2 / Chapter 1.4 --- Why do We Conduct This Study? --- p.3 / Chapter 1.5 --- Implication of This Study --- p.4 / Chapter 1.6 --- What Types of Cancer were Included in This Study? --- p.4 / Chapter 1.7 --- Aims and Hypothesis of This Study --- p.5 / Chapter 1.8. --- Outline of the Thesis --- p.5 / Chapter CHAPTER 2 --- LITERATURE REVIEW --- p.8 / Chapter 2.1. --- Occupational Epidemiological Studies --- p.8 / Chapter 2.1.1 --- Studies of occupation and cancer occurrence based on routine records --- p.8 / Chapter 2.1.2 --- Retrospective cohort studies among food service workers --- p.21 / Chapter 2.1.3 --- Case-control studies --- p.27 / Chapter 2.1.4 --- Case reports --- p.29 / Chapter 2.1.5 --- Summary --- p.29 / Chapter 2.2. --- Mutagens and Carcinogens in Cooking Fumes --- p.39 / Chapter 2.2.1 --- Mutagens and carcinogens in cooking fumes --- p.40 / Chapter 2.2.2 --- Summary --- p.42 / Chapter CHAPTER 3 --- METHODS --- p.44 / Chapter 3.1 --- Study Design --- p.44 / Chapter 3.2 --- Study Population and Subjects --- p.46 / Chapter 3.3 --- Reference Population --- p.48 / Chapter 3.4 --- Sample Size Estimation --- p.48 / Chapter 3.5 --- Data Sources and Data Collection --- p.49 / Chapter 3.6 --- Data Processing --- p.53 / Chapter 3.7 --- Data Analyses --- p.54 / Chapter 3.7.1 --- Standardised proportional mortality ratio (SPMR) --- p.54 / Chapter 3.7.2 --- Adjusted' SPMRs --- p.56 / Chapter 3.7.3 --- Mortality odds ratio (MOR) --- p.58 / Chapter 3.8. --- Exploring if Smoking could be a Confounding Factor --- p.62 / Chapter CHAPTER 4 --- RESULTS --- p.64 / Chapter 4.1 --- Characteristics of the Food-service Workers --- p.64 / Chapter 4.2 --- Cancer Mortality Patterns of Food-service Workers --- p.69 / Chapter 4.3 --- Adjusted SPMRs --- p.72 / Chapter 4.4 --- Mortality Odds Ratios (MORs) --- p.76 / Chapter 4.5 --- Mortality Odds Ratios Using Multiply Reference Diseases --- p.77 / Chapter 4.6. --- Comparing SPMRs with MORs --- p.82 / Chapter 4.7. --- Internal Comparison --- p.83 / Chapter 4.8 --- Summary of Results --- p.90 / Chapter 4.9. --- Survey on Smoking and Drinking Prevalence among Current Food-service Workers --- p.92 / Chapter 4.9.1 --- Smoking habit --- p.92 / Chapter 4.9.2 --- Drinking habit --- p.94 / Chapter CHAPTER 5 --- DISCUSSION OF FINDINGS --- p.95 / Chapter 5.1 --- Outcomes for This Study --- p.95 / Chapter 5.1.2 --- Cancer risks for the kitchen workers --- p.96 / Chapter 5.1.3 --- Cancer risks for the outside kitchen workers --- p.102 / Chapter 5.2 --- Limitations of the Methods Adopted in the Present study --- p.107 / Chapter 5.2.1 --- Standardised proportional mortality ratio (SPMR) --- p.107 / Chapter 5.2.2 --- Morality odds ratio (MOR) --- p.109 / Chapter 5.3 --- Bias and Control --- p.111 / Chapter 5.3.1 --- Selection bias --- p.111 / Chapter 5.3.2 --- Information bias --- p.113 / Chapter 5.3.3 --- Confounding --- p.116 / Chapter 5.4 --- Implications from the Results of the Present Study --- p.117 / Chapter 5.5 --- Conclusion --- p.119 / APPENDIX --- p.121 / Appendix 1 --- p.121 / Appendix 2 --- p.123 / Appendix 3 --- p.124 / Appendix 4 --- p.125 / REFERENCES --- p.127

Infusões prolongadas de 5-fluorouracil são mais seguras e potencialmente mais efetivas no tratamento do câncer de cólon metastático do que infusões rápidas da mesma medicação. No entanto, infusões prolongadas requerem a disponibilidade de um acesso venoso central, bem como de bombas de infusão dispendiosas. O desenvolvimento de fluoropirimidinas orais permitiu que pacientes fossem expostos ao 5-fluorouracil por longo tempo, com maior conveniência. UFT e leucovorin administrados três vezes ao dia demonstraram previamente uma eficácia equivalente, com menor toxicidade, quando comparados a um regime convencional de infusão rápida de 5- fluorouracil e leucovorin. Este estudo com 98 pacientes foi desenhado e conduzido com objetivo de demonstrar equivalência no tempo de progressão com o uso de UFT e leucovorin administrados duas vezes ao dia, com o uso da mesma combinação administrada três vezes ao dia. Objetivos secundários incluíram análise de toxicidade, resposta objetiva e sobrevida global. O tempo mediano de progressão foi de 3,8 meses, comparado com 3,5 meses observados com o uso da medicação três vezes ao dia e a taxa de resposta foi de 11%, com uma sobrevida mediana de 12,8 meses, sendo comparável aos resultados de 12% e 12,4 meses obtidas com o uso da combinação três vezes ao dia. A incidência de diarréia com graus 3 e 4 foi de 30% no regime de administração duas vezes ao dia, e 21% no de três vezes ao dia. Esses resultados sugerem que o uso de UFT e leucovorin duas vezes ao dia tem eficácia e toxicidade similares àquelas obtidas com o uso da mesma medicação três vezes ao dia. / Prolonged infusions have been shown to be safer and potentially more effective than bolus regimens of 5- fluorouracil as treatment for advanced colorectal cancer. However, infusional 5- fluorouracil requires central venous access and costly infusion pumps. Development of oral fluoropyrimidines has allowed longer exposures to 5-fluorouracil with increased convenience. UFT and leucovorin given thrice daily showed improved safety and no significant difference in survival or response rate compared with bolus 5- fluorouracil and leucovorin. This study with 98 patients was conducted to evaluate whether UFT and leucovorin given twice daily provided comparable time to progression (TTP) to the same combination administered three times a day. Secondary objectives included evaluation of toxicity, overall tumor response rate, and survival. Median time to progression was 3.8 months, compared with 3.5 months observed with the thrice-daily regimen. The twice-daily regimen had a response rate of 11% and median survival of 12.8 months, comparable to the 12% and 12.4 months seen with the thrice-daily regimen. The incidence of grade 3-4 drug-related diarrhea was 30% on the twice-daily and 21% on the thrice-daily schedule. Results suggest that the twice-daily schedule has similar safety and efficacy to the thrice-daily schedule.

O objetivo do estudo foi estudar a expressão de timidilato sintase (TS) como fator preditivo para eficácia de quimioterapia adjuvante com 5-fluorouracil (5-FU) e como fator prognóstico para sobrevida em pacientes portadores de câncer colorretal. Trata-se de estudo retrospectivo em uma série de 114 pacientes com carcinoma colorretal estádios II ou III, distribuídos em dois grupos: 1)cirurgia exclusiva (n=61); 2)cirurgia seguida de quimioterapia com 5-FU (n=53). A expressão de TS foi determinada por imunoistoquímica. Observou-se que a expressão intratumoral de TS foi capaz de selecionar pacientes que se beneficiaram com emprego de quimioterapia adjuvante, mas não se mostrou como variável independente para risco de recidiva ou óbito / The purpose of this study was trying to assess the value of TS expression as a predictive factor in the efficacy of adjuvant chemotherapy in colorectal cancer, as well as its independent prognostic value for survival. It deals with a retrospective study that assesses a series of 114 individuals with high risk colorectal cancer, distributed into two different groups: 1)surgery alone (n=61); 2)surgery and 5-FU-based chemotherapy (n=53). TS expression was determined by immunohistochemistry. We observed that TS expression may select patients that benefit from adjuvant chemotherapy, but it was not shown as an independent variable for the risk of recurrence or death

O butirato é um importante ácido graxo de cadeia curta proveniente da fermentação bacteriana de vários tipos de fibras no cólon. Diversos estudos têm demonstrado que o butirato desempenha um papel importante na prevenção do câncer e na manutenção da homeostase colônica, por meio da regulação da proliferação celular, diferenciação e apoptose. A acetilação das histonas tem sido proposta como um dos possíveis mecanismos de ação responsável pelo efeito quimiopreventivo do butirato. O objetivo desse trabalho foi avaliar o papel da tributirina (TB), um pró-fármaco do ácido butírico, na fase de pós-iniciação da carcinogênese de cólon induzida por dimetilhidrazina (DMH), enfatizando a expressão das histonas acetiladas (H3K9 e H4K16) e das proteínas pró e anti-apoptóticas da família Bcl-2 (Bak, Bcl-xL). Durante 5 semanas consecutivas, ratos Wistar receberam diariamente TB (200 mg/100 g peso corpóreo; grupo TB) ou maltodextrina (MD; 300 mg/100 g peso corpóreo; grupo MD; controle isocalórico). Focos de Criptas Aberrantes (FCAs) são lesões pré-neoplásicas e biomarcadores da carcinogênese de cólon. Esses foram analisados nos cólons corados com azul de metileno a 0,02%, porém, nenhuma diferença estatística foi encontrada entre os grupos, TB e MD (p>0,05). A mucosa colônica foi utilizada para analisar a expressão de H3K9 e H4K16 por western blot, contudo, não houve diferença significativa entre os grupos TB e MD. A expressão da proteína pró-apoptotica Bak também foi semelhante nos grupos TB e MD; todavia, a expressão da proteína anti-apoptótica Bcl-XL foi menor no cólon distai dos ratos tratados com TB sugerindo participação dessa na indução de apoptose. Portanto, apesar de trabalhos apontarem para os resultados benéficos do butirato, são necessários mais estudos in vivo para o melhor entendimento dos efeitos mediados pelo butirato na carcinogênese de cólon. / Butyrate is an important short-chain fatty acid, product of intestinal bacterial fermentation of mainly dietary fiber. Several studies have shown that butyrate has an important role in the maintenance of colonic homeostasis as regulator of colonocyte proliferation, differentiation and apoptosis. Thus may play a role in cancer prevention. Histone deacetylation has been proposed to be one of the possible mechanisms of action of butyrate mediated effects on colon carcinogenesis. The aim of this study was to evaluate the role of tributyrin (TB), a butyric acid pro-drug, on post-initiation phase of colon carcinogenesis induced by dimethylhydrazine (DMH), emphasizing the expression of acetylated histones (H3K9, H4K16) and BeI-2 family proteins (Bak, Bcl-XL) mediated apoptosis. During 5 consecutive weeks, Wistar rats received daily TB (200 mg/100 9 body weight; TB group) or maltodextrin (MD; 300 mg/100 9 body weight; MD group; isocaloric control). Aberrant Crypt Focus (ACFs) are considered pre-neoplastic cells and biomarker of colon carcinogenesis. ACFs were counted on colons stained with 0,02% methylene blue, under a light microscope. No statistic differences were found for ACF when compared both groups receiving TB or MD (p>0,05). Colonic mucosa scraping was used for analysis of H3K9 and H4K16 by Western Blot. No significant differences were demonstrated between TB and MD groups. Bak expression were similar between TB and MD groups, but Bcl-XL expression seems to be reduced only on distal colon of the TB group, suggesting that TB may induce apoptosis Although most studies point towards beneficial results of butyrate, more in vivo studies are needed to contribute to our current understanding of butyrate-mediated effects on colon carcinogenesis.

Introdução: Pacientes com doença inflamatória intestinal (DII) tem risco aumentado de desenvolvimento de displasias e neoplasias colônicas, a partir de 8 anos de diagnóstico da doença. O desenvolvimento de técnicas que melhorem a acurácia diagnostica destas displasias tem impacto científico, econômico e na prática clínica. Materiais and Métodos: O NBI (narrow band image) tem sido descrito como um método comparável à cromoscopia para a detecção de diversos tipos de cânceres do trato gastrointestinal superior e do sistema respiratório. Neste estudo, as duas técnicas foram comparadas em pacientes com DII de longa data. Resultados: 34 pacientes foram randomizados (18 para a cromoscopia e 16 para o NBI). 66,7% e 68,8% dos pacientes eram do gênero feminino, com média de idade de 48,5 e 49,6 anos, nos grupos cromoscopia e NBI, respectivamente. 61,1% dos pacientes do grupo cromoscopia e 56,2% do grupo NBI tinham doença de Crohn (DC). Nenhuma destas variáveis alcançou diferença estatísticamente significante na comparação entre os grupos: comportamento da DC, localização da retocolite ulcerativa, presença de atividade inflamatória endoscópica e sintomas no momento do exame. O tempo médio gasto para a realização do exame foi de 45,8 minutos no grupo cromoscopia e de 34,1 minutos no grupo NBI. Sobre a presença de displasias, 22,2% dos pacientes no grupo cromoscopia apresentaram lesões displásicas no exame histológico (todas as biopsias foram direcionadas pela presença de lesões), enquanto que, no grupo NBI, nenhuma lesão displásica foi encontrada (qui-quadrado= 4,477; &#8721;crítico> 3,841, considerando um erro a de 5%). Foram encontrados três lesões adenomatosas e uma lesão displásica tipo DALM (dysplasia-associated lesion or mass), típica da DII. Quando realizada a correção de Yattes, ara amostras pequenas, foi observado &#8721; = 2,180 (&#8721;crítico> 3,841, considerando um erro a de 5%). Conclusões: Esses dados mostram diferença estatística entre as técnicas endoscópicas (NBI e cromoscopia). Eles revelam uma forte tendência estatística de superioridade da cromoscopia, comparada ao NBI. / Introduction: Patients with inflammatory bowel disease (IBD) are under increased risk of colonic dysplasia and neoplasia, approximately, 8 years after diagnosis. The development of techniques that improve the diagnostic ability to detect those dysplasias has scientific, economic and practical impact. Materials and Methods: The NBI (narrow band image) has been described as a valuable method comparable to chromoendoscopy for the detection of many cancers of the upper digestive and respiratory systems. The two techniques were compared in this study in patients with IBD after at least 8 years from diagnosis. Results: 34 patients were randomized (18 for chromoendoscopy and 16 for NBI). 66.7% and 68.8% were female, mean age of 48.5 and 49.6 years, in chromoendoscopy and NBI groups, respectively. The mean disease duration was 14.7 (DP 6.5 years 2) and 15.6 years (DP 9.0 years 2) for chromoendoscopy and NBI, respectively. 61.1% of patients in the chromoendoscopy group and 56.2% in the NBI had Crohn\'s disease (CD). None of those epidemiological data, extension and behavior of CD and Ulcerative Colitis, use of medications, endoscopic grade of disease activity and symptoms at the time of the exam disclosed statistical significance. The average time of examination was 45.8 minutes for the chromoendoscopy group, versus 34.1 minutes for the NBI group. Regarding the presence of dysplasia, 22,2% of patients in the chromoendoscopy group showed some dysplastic lesions on histological examination (all biopsies directed to mucosal lesions), while no patients in the NBI group had such lesions (chi-square = 4.477; &#8721;critical> 3.841, considering an error of 5%). We found three adenomas and one dysplastic lesions of the type DALM (dysplasia-associated lesion or mass), typical of IBD. When we look at correcting by means of the Yates correction test for small samples, we observed &#8721; = 2,180 (&#8721;critical > 3.841, considering an error of 5%). Conclusion: Those data have shown statistical difference between the endoscopic techniques (NBI and chromoendoscopy). They revealed a strong statistical tendency of superiority of chromoendoscopy compared to NBI.

Avaliou-se a atividade quimiopreventiva da tributirina (TB), e da vitamina A (VA) administradas em associação ou não, antes, durante e após a iniciação em ratos submetidos a modelo de carcinogênese de cólon. Ratos Wistar receberam VA [1 mg/100 g de p.c (grupo VA)], tributirina [200 mg/100 g de p.c (grupo TB)] ou associação de VA com TB (grupo VA+TB). Ratos tratados com óleo de milho e maltodextrina serviram como controle (GC). Avaliou-se a presença de focos de criptas aberrantes (FCA) e sua localização nos cólons, além de danos e do padrão de metilação global do DNA na mucosa colônica. No cólon total, distal e proximal, o grupo TB apresentou menor (p<0,05) número de FCA com 4 ou mais criptas/cm2, considerados mais agressivos, em relação ao GC. Quanto aos danos no DNA, os grupos VA, TB e VA+TB apresentaram cometas de comprimentos menores (p<0,05) em comparação ao GC. Não houve diferenças estatisticamente significantes quanto ao padrão de metilação global do DNA. Assim, TB consiste em agente quimiopreventivo promissor da carcinogênese de cólon quando administrada isoladamente, mas não em associação com a VA. 15 / Chemopreventive activities of tributyrin (TB) and vitamin A (VA) were administered in combination or not, before, during and after the initiation in rats subjected to carcinogenesis model of colon. Wistar rats received VA [1 mg/100 g of b.w (group VA)], tributyrin [200 mg/100 g of b.w (TB group)] or association of VA with BD (group VA + TB). Rats treated with corn oil and maltodextrin were used as control (GC). The presence of aberrant foci crypts (ACF) was evaluated and their location in colon tissue was determined. In addition, DNA damages and the global pattern of DNA methylation in colonic cells was measured. In total colon as in distal and proximal portions, the TB group presented lower (p <0.05) number of ACF with 4 or more crypts/cm2 in comparison to the GC group. The number of ACF with 4 or more crypts /cm2 was used as criteria of aggressiveness. In relation to the damage of DNA, the VA, VA + TB and TB groups exhibits smaller nucleoids lengths (p <0.05) compared to the GC group. There were no statistically significant differences on the global pattern of DNA methylation. So TB is promising chemopreventive agent in carcinogenesis of the colon when administered alone, but not in combination with the VA.

Suspeita-se da Síndrome de Lynch (SL) a partir da história pessoal e familial do indivíduo. Posteriormente, os dados histopatológicos, imuno-histoquímicos e moleculares podem ser utilizados para aprimorar o diagnóstico da doença. Entretanto, um grande desafio no diagnóstico da Síndrome de Lynch é a baixa acurácia dos critérios clínicos utilizados. OBJETIVOS: Avaliar a frequência de SL em pacientes submetidos a tratamento cirúrgico por câncer colorretal e com história familial de câncer. Avaliar quais dos critérios clínicos e/ou moleculares seriam mais informativos no diagnóstico desta Síndrome na população brasileira. PACIENTES E MÉTODOS: Estudaram-se 458 casos de câncer colorretal (CCR), do Serviço de Coloproctologia do Departamento de Gastroenterologia do Hospital das Clínicas - FMUSP, de janeiro de 2005 a dezembro de 2008. História familial (HF) positiva para CCR ocorreu em 118 pacientes. Promoveu-se a revisão das lâminas para critérios histopatológicos de MSI (diretrizes de Bethesda), avaliação imuno-histoquímica (IHC) para as proteínas MLH1, MSH2, MSH6, PMS2, através do complexo avidina-biotina-peroxidase e instabilidade de microssatélites (MSI) (BAT-25, BAT-26, NR-21, NR-24 e MONO-27). Realizada a análise da mutação somática para o BRAF em todos os casos com MSI positiva. RESULTADOS: Dos 118 pacientes com HF, 61 (51,69%) preencheram pelo menos um dos critérios de Bethesda revisados. 36 eram do sexo feminino (59%), média de idade de 53,2 anos. Nove (14,7%) pacientes apresentaram todos os critérios de Amsterdam I. Cinquenta e dois tumores localizaram-se no cólon esquerdo. Os componentes histopatológicos de MSI incluíram: linfócitos intratumoral (47,5%), característica expansiva do tumor (29,5%) e o componente mucinoso (27,8%) (componentes histopatológicos de MSI instável) em 44 (72%). A IHC estava alterada em oito (13%) e a MSI em 12 pacientes (20%). Houve associação entre os critérios de Amsterdam I e MSI e na IHC com MLH1 e PMS2. Houve associação entre os critérios de Bethesda revisados com o sexo, na histopatologia com o componente mucinoso e a reação Crohn like; com a MSI e na IHC com o MLH1 e PMS2. O BRAF foi realizado nos 12 casos com MSI positiva e em todos os casos foram negativos. Os indivíduos que apresentaram o critério 4 de Bethesda revisado (CCR ou câncer associado a SL, diagnosticado em um ou mais parentes de primeiro grau, desde que uma das neoplasias tenha ocorrido antes dos 50 anos de idade), tiveram uma chance 10,6 vezes maior de apresentar MSI positiva. Propôs-se um escore para caracterizar pacientes com SL baseado nas variáveis estudadas nesta pesquisa. CONCLUSÕES: A frequência de Síndrome de Lynch nos pacientes submetidos a ressecção por câncer e com história familial foi de 20%. O critério 4 de Bethesda revisado associou-se mais fortemente à presença de instabilidade de microssatélites na população estudada. O escore desenvolvido neste estudo contribui como uma ferramenta prática na ampliação diagnóstica da Síndrome de Lynch / Lynch Syndrome is suspected due to the personal and familial history of the individual. Subsequently, histopathological, immunohistochemical and molecular data can be used to improve diagnosis of the disease. However, a major challenge in the diagnosis of Lynch Syndrome is the low accuracy of clinical criteria. OBJECTIVES: To assess the frequency of Lynch Syndrome in patients with familial cancer history submitted to colorectal cancer resection. To assess what clinical and / or molecular criteria would be the most informative in the diagnosis of this syndrome in Brazilian population. PATIENTS AND METHODS: 458 colorectal cancer (CRC) cases were studied, from the Coloproctology Unit of the Department of Gastroenterology, Hospital das Clinicas - USP, from January 2005 to December 2008. Positive family history (FH) for CRC occurred in 118 patients. The pathologic slides were reviewed for histological criteria for MSI (Bethesda guidelines), immunohistochemical analysis (IHC) for MLH1, MSH2, MSH6, PMS2 proteins, through the avidin-biotin-peroxidase complex, and microsatellite instability (MSI) (BAT-25, BAT-26, NR-21, NR-24 and MONO-27). BRAF somatic mutation was analyzed in all cases with positive MSI. RESULTS: Of the 118 patients with HF, 61 (51.69%) met at least one of the revised Bethesda criteria. Thirty-six were female (59%), and the mean age was 53.2 years. Nine (14.7%) patients presented all Amsterdam criteria I. Fifty-two tumors were located in the left colon. MSI histopathological components included: intratumoral lymphocytes (47.5%), expansive characteristics of the tumor (29.5%) and mucinous component (27.8%) (Histological unstable components of MSI) in 44 (72%). IHC was abnormal in eight (13%) and MSI in 12 patients (20%). There was an association between the Amsterdam criteria I and MSI; and between IHC with MLH1 and PMS2. There was an association with the revised Bethesda criteria with: sex, mucinous histology and Crohn\'s like reaction; with MSI and IHC with PMS2 and MLH1. BRAF was performed in 12 patients with MSI positive, and all were negative. Patients who presented the revised Bethesda criteria 4 (CRC or cancer associated with SL, diagnosed in one or more first-degree relatives, with one of the neoplasms occurred before 50 years of age), had a 10.6 increased chance to display positive MSI. Based on the studied variables, we proposed a score to characterize the Lynch Syndrome. CONCLUSIONS: The frequence of Lynch Syndrome in patients who were submitted to cancer resection, and had a cancer familial history was 20%. The criterion 4 Revised Bethesda was associated more strongly with the presence of microsatellite instability in the studied population. The developed score contributes as a practical tool in the diagnosis of Lynch Syndrome

Contexte  Le cancer colorectal, deuxième par ordre de fréquence chez les femmes françaises, se développe principalement à partir de lésions précancéreuses, des adénomes. Les facteurs associés à l’obésité sont multiples, incluant des événements de début de vie, le niveau socio-économique et le comportement alimentaire ; l’obésité a aussi été associée de façon assez constante au risque de cancer colorectal. Cependant les associations entre des facteurs anthropométriques spécifiques ou au cours de la vie et le risque de tumeurs colorectales selon la filiation adénome-cancer ou selon le site sont moins claires. La ménopause est un événement de vie majeur et est associée à des modifications anthropométriques, tandis que le traitement hormonal de la ménopause (THM) est susceptible d’interagir avec les aspects anthropométriques mais aussi directement avec le risque de tumeur. De plus, la prescription du THM dépend de plusieurs paramètres, dont l’importance du suivi médical. Enfin, si le dépistage des tumeurs colorectales est conseillé à partir de 50 ans (soit aux environs de la ménopause) les attitudes vis-à-vis du dépistage varient selon de nombreux paramètres incluant les antécédents familiaux de cancer, le niveau socio-économique et les comportements de santé. Objectif  Le risque de tumeurs colorectales dépend ainsi de nombreux facteurs étroitement liés, parmi lesquels nous avons choisi d’étudier les relations complexes entre facteurs anthropométriques au cours de la vie, utilisation de THM et antécédents personnels de coloscopie, et le risque d’adénomes et de cancers colorectaux. Population  Les analyses ont été effectuées sur les données de la cohorte de femmes françaises E3N, comportant environ 1400 cas d’adénomes diagnostiqués parmi 17000 femmes ayant passé une coloscopie au cours du suivi (1993-2002) et 690 cas de cancers diagnostiqués parmi 92000 femmes au cours du suivi (1990-2008). Résultats  Notre étude a mis en évidence plusieurs aspects originaux. Tout d’abord, nous avons mis en évidence que les trois facteurs d’exposition principaux étudiés étaient associés au risque de tumeurs colorectales de façon significativement hétérogène en fonction du site, renforçant l’hypothèse selon laquelle il existe trois entités bien distinctes le long du cadre colorectal. Les caractéristiques anthropométriques typiquement occidentales (IMC et tour de taille élevés) étaient associées à un risque accru de tumeurs du côlon gauche, tandis que les associations originales que nous avons décrites entre taille assise et risque d’adénomes du côlon droit, et entre corpulence dans l’enfance et plus faible risque d’adénomes du rectum suggèrent de nouvelles pistes de recherche pour ces sites à l’étiologie mal connue. La mise en évidence d’une association positive entre prise de THM de type estrogènes seul (habituellement prescrit aux femmes hystérectomisées) et risque d’adénomes, en particulier du côlon gauche, et d’une association inverse entre le même type de THM et le risque de cancer, en particulier du côlon gauche, n’étant pas cohérentes avec les associations décrites dans la littérature, nous a conduit a explorer un éventuel biais de dépistage. La pratique de coloscopie était effectivement plus fréquente chez les femmes utilisant des estrogènes seuls (et donc aux antécédents d’hystérectomie), tandis que les antécédents de fibrome utérin étaient associés à un risque accru d’adénomes. De leur côté, les antécédents personnels de coloscopie étaient associés à une diminution de risque de cancer, surtout du côlon gauche, tandis que la réduction de risque des cancers du rectum devenait semblable à celle observée pour le côlon gauche dans la période la plus récente. Conclusion  En conclusion, nos résultats suggèrent qu’il existe des moyens efficaces de prévention des tumeurs distales, mais que la prévention des tumeurs du côlon droit demande des études spécifiques et peut-être de nouveaux paradigmes. / Background  Colorectal cancer, the second most common cancer in French women, mostly develops from precancerous lesions, the adenomas. Factors associated with adult obesity are multiple, including early life events, the socio-economic level, and eating habits; obesity has also been, in turn, quite consistently associated with colorectal cancer risk. However, associations between specific anthropometric components or lifetime anthropometry and colorectal tumours according to the adenoma-carcinoma sequence or to tumour site are less clear. Menopause is a major event in women, and is associated with changes in anthropometric features, while menopausal hormone therapy (MHT) may interact with post-menopausal anthropometry but also with tumour risk per se. In addition, prescription of this MHT depends on various parameters including quality of medical follow-up. Finally, while screening for colorectal tumours is advocated after the age of 50 (thus around menopausal age), attitudes towards colorectal screening differ according to many factors including family history of cancer, the socio-economic level, and attitudes towards a healthy behaviour. Objective  Thus colorectal tumour risk depends on many interrelated factors, among which we chose to investigate the complex relationship between lifetime anthropometric features, MHT use and personal history of colonoscopy, and colorectal adenoma and cancer risk. Population  This study was based on data from the French E3N cohort, including approximately 1400 adenoma cases diagnosed among 17000 women who underwent a colonoscopy during follow-up (1993-2002), and 690 cancer cases diagnosed among 92000 women (1990-2008).Results  Our study brought out several original findings. First our findings regarding all three major studied exposures displayed significant heterogeneity between sites, thus enforcing the hypothesis of separate entities according to site along the large bowel. Typical Western anthropometric features (high BMI and high waist circumference) were associated with left colon tumours, while the original findings of sitting height associated with risk of right colon tumours and of a large silhouette in childhood inversely associated with rectal tumours may bring out new hypotheses regarding these less understood sites. The findings of a positive association between estrogens only MHT use (usually prescribed in hysterectomised women) and adenoma risk, especially left colon adenomas, and an inverse association between the same MHT and cancer risk, especially left colon cancer, which are not consistent with associations generally described in the literature, led us to explore potential screening biases. Indeed, colonoscopy screening was more common in women who used estrogens alone (so with a history of hysterectomy), while colorectal adenomas were more common in women with uterine leiomyoma. Colonoscopy screening in turn was associated with a reduced risk of colorectal cancer, especially left colon cancer, while the risk reduction for rectal cancers became similar to that of left colon cancer in the most recent years. Conclusion  Altogether, our findings suggest efficient ways to prevent distal tumours, while prevention of right colon tumours requires further specific investigations and new paradigms.