Together, colorectal (CRC) and bladder cancer (BlCa) are responsible for a large percentage of cancer related morbidity and mortality in Western society. A dramatic reduction in patient survival occurs as these cancers progress towards invasive and metastatic disease, from a five year survival rate of about 90% for localised disease to approximately 5-10% for advanced disease involving distant metastasis. A greater understanding of disease progression will lead to enhanced screening, diagnostic and treatment strategies, in turn providing an improved prognosis for the patient. The purpose of this study was to expand the current molecular knowledge of CRC and BlCa by elucidating the role of Mxi1 mutations and MTSS1 expression in CRC and BlCa respectively, and to examine the diagnostic potential of these genes. The Mxi1 coding region for 41 tumours, collected by the South Western Sydney Colorectal Cancer Tumour Bank from 2000-2001, was screened for mutations using Dideoxy Fingerprinting (ddF) and sequencing. Sequence alterations were detected in 34% of tumours. Three different polymorphisms and three mutations were detected. One mutation could possibly affect the tumour suppressor function of Mxi1. The presence of a gene mutation did not correlate to any clinical characteristics and is therefore not a suitable diagnostic marker. Microsatellite instability (MSI) status however, significantly correlated with tumour grade. Expression levels of MTSS1 and an associated gene, MTSS2, were examined in 16 BlCa cell lines, 9 clonally-derived BlCa sublines, and 30 transitional cell carcinomas (TCCs) collected by the Heinrich-Heine University from 1993-2000. Variable gene expression was observed in BlCa cell lines and tumour samples. No significant correlation of MTSS expression and invasive ability was observed for the cell lines or tumour samples. Further studies eliminated promoter methylation and p53 functional status as mechanisms involved in MTSS1 and MTSS2 down-regulation. Functional studies performed on stable MTSS1-expressing BlCa lines found that although migration was increased, cells displayed reduced anchorage-independent growth. The invasive ability of these cells was unchanged confirming that expression does not correlate with invasive ability. These data support the role of MTSS1 as a tumour suppressor and not as a metastasis suppressor gene. Although MTSS1 may not be useful in predicting more invasive disease, its role as a tumour suppressor in cancer may be useful.

Together, colorectal (CRC) and bladder cancer (BlCa) are responsible for a large percentage of cancer related morbidity and mortality in Western society. A dramatic reduction in patient survival occurs as these cancers progress towards invasive and metastatic disease, from a five year survival rate of about 90% for localised disease to approximately 5-10% for advanced disease involving distant metastasis. A greater understanding of disease progression will lead to enhanced screening, diagnostic and treatment strategies, in turn providing an improved prognosis for the patient. The purpose of this study was to expand the current molecular knowledge of CRC and BlCa by elucidating the role of Mxi1 mutations and MTSS1 expression in CRC and BlCa respectively, and to examine the diagnostic potential of these genes. The Mxi1 coding region for 41 tumours, collected by the South Western Sydney Colorectal Cancer Tumour Bank from 2000-2001, was screened for mutations using Dideoxy Fingerprinting (ddF) and sequencing. Sequence alterations were detected in 34% of tumours. Three different polymorphisms and three mutations were detected. One mutation could possibly affect the tumour suppressor function of Mxi1. The presence of a gene mutation did not correlate to any clinical characteristics and is therefore not a suitable diagnostic marker. Microsatellite instability (MSI) status however, significantly correlated with tumour grade. Expression levels of MTSS1 and an associated gene, MTSS2, were examined in 16 BlCa cell lines, 9 clonally-derived BlCa sublines, and 30 transitional cell carcinomas (TCCs) collected by the Heinrich-Heine University from 1993-2000. Variable gene expression was observed in BlCa cell lines and tumour samples. No significant correlation of MTSS expression and invasive ability was observed for the cell lines or tumour samples. Further studies eliminated promoter methylation and p53 functional status as mechanisms involved in MTSS1 and MTSS2 down-regulation. Functional studies performed on stable MTSS1-expressing BlCa lines found that although migration was increased, cells displayed reduced anchorage-independent growth. The invasive ability of these cells was unchanged confirming that expression does not correlate with invasive ability. These data support the role of MTSS1 as a tumour suppressor and not as a metastasis suppressor gene. Although MTSS1 may not be useful in predicting more invasive disease, its role as a tumour suppressor in cancer may be useful.

There are two chief molecular pathways to sporadic colorectal cancer (CRC), the chromosomal instability (CIN) and the CpG island methylator phenotype (CIMP) pathways. A third pathway, the pure microsatellite instability pathway, is important in inherited CRC specifically hereditary non-polyposis colorectal cancer. The CIN pathway is characterized by an adenomatous pathological precursor, aneuploidy and microsatellite stability. CIMP pathway cancers, however, are frequently proximal, develop from serrated rather than adenomatous polyps and are strongly associated with BRAF mutation. The CIMP pathway is driven primarily by epigenetic rather than genetic instability. These pathway-specific molecular traits are evident within the pathological precursors to these cancers and thus pathway divergence must occur at the beginning of carcinogenesis or even before. Although DNA methylation is recognized as a key mechanism in colorectal carcinogenesis, relatively little is known about its pattern, regulation and relevance in normal colorectal mucosa. This PhD thesis characterized the profile of DNA methylation in the normal human colorectum and explored its associations with luminal, environmental, dietary and pathological factors. The genes methylated in CRC are characterized as “type A” (Age-related) genes and “type C” (Cancer-specific) genes. Generally, “type A” genes are methylated in both normal and neoplastic tissue with the degree of methylation proportional to the age of the tissue. The methylation of “type C” genes, however, is more specific for neoplastic tissue. The primary study recruited 166 patients undergoing colonoscopy. At colonoscopy, mucosal biopsies were taken from the caecum, transverse colon, sigmoid colon and rectum. DNA methylation was analysed by MethyLight at “type A” (ESR1, GATA5, HIC1, HPP1, SFRP1) and “type C” methylation markers (MGMT, MLH1, CDKN2A, MINT2, MINT31, IGF2, CACNA1G, NEUROG1, SOCS1, RUNX3). LINE-1 methylation was quantified by pyrosequencing. The last 5 “type C” markers comprise a CIMP panel used to identify CIMP cancers. Mean “type A” and CIMP panel methylation Z-scores were calculated. The PMR for each of these CpG island loci was compared to patient age, gender, previous colorectal polyps, smoking history and the presence of concomitant pathology. Most “type A” genes demonstrated strong and direct correlations between methylation and patient age (e.g. ESR1, ρ=0.66, p<0.0001) and had greater methylation within the distal compared to the proximal colorectum (e.g. ESR1, p<0.0001). On multivariate analysis, the mucosal “type A” methylation Z-score had a strong, independent, inverse association with the diagnosis of colorectal adenomas (OR=0.23, p<0.001), the precursor to CIN cancers. The mean CIMP methylation Z-score in normal mucosa, however, was significantly and independently associated with advanced proximal serrated polyps (OR=5.1, p=0.009), the precursor to CIMP cancers. The luminal and epithelial associations with colorectal methylation were explored by a randomized, double-blind, placebo-controlled trial. This experiment was undertaken to determine whether dietary supplementation could modulate epithelial DNA methylation. In addition, the study was designed to evaluate intra-individual reproducibility of the MethyLight technique. The study consisted of a 4 week cross-over trial of resistant starch and Bifidobacterium lactis either alone or as a combined synbiotic preparation, in 20 human volunteers. Rectal biopsies, faeces and serum were collected. Rectal mucosal endpoints included DNA methylation at the CpG island loci and LINE-1, epithelial proliferation (Ki67 immunohistochemistry) and crypt cellularity. Faecal short-chain fatty acid concentrations, pH, ammonia and microbiological profiles (by DGGE and sequencing) were examined. The synbiotic intervention fostered a significantly different faecal stream bacterial community than either the prebiotic or the probiotic interventions alone, but did not show any significant associations with the epithelial or luminal parameters. To explore possible associations between luminal and epithelial parameters and mucosal DNA methylation, the baseline indices were further analysed. There was a strong positive correlation between baseline epithelial proliferation and “type A” marker methylation (ρ = 0.7, p = 0.0001). Thus, “type A” methylation may reflect the cellular age or mitotic burden of a tissue, which is a function of both time and cell turnover. There were consistent inverse trends evident between faecal short-chain fatty acid levels and rectal mucosal DNA methylation. This PhD project found that DNA methylation within the normal colorectal mucosa varied with patient age and region and was strongly associated with the development of pathway-specific pathology, suggesting that the background colorectal field may predict both the at-risk patients and at-risk pathways. Diet and the luminal environment more broadly may influence levels of DNA methylation in the colorectal mucosa and could help to explain regional patterns of colorectal DNA methylation.

No description available.

Colorectal cancer (CRC) patients are stratified by the Tumour, Node and Metastasis (TNM) staging system for clinical decision making. Additional genomic markers have a limited utility in some cases where precise targeted therapy may be available. Thus, classical clinical pathological staging remains the mainstay of the assessment of this disease. Surgical resection is generally considered curative for Stage II patients, however 20-30% of these patients experience disease recurrence and disease specific death. It is imperative to identify these high risk patients in order to assess if further treatment or detailed follow up could be beneficial to their overall survival. The aim of the thesis was to categorise Stage II CRC patients into high and low risk of disease specific death through novel image based analysis algorithms. Firstly, an image analysis algorithm was developed to quantify and assess the prognostic value of three histopathological features through immuno-fluorescence: lymphatic vessel density (LVD), lymphatic vessel invasion (LVI) and tumour budding (TB). Image analysis provides the ability to standardise their quantification and negates observer variability. All three histopathological features were found to be predictors of CRC specific death within the training set (n=50); TB (HR =5.7; 95% CI, 2.38-13.8), LVD (HR =5.1; 95% CI, 2.04-12.99) and LVI (HR =9.9; 95% CI, 3.57- 27.98). Only TB (HR=2.49; 95% CI, 1.03-5.99) and LVI (HR =2.46; 95%CI, 1 - 6.05), however, were significant predictors of disease specific death in the validation set (n=134). Image analysis was further employed to characterise TB and quantify intra-tumoural heterogeneity. Tumour subpopulations within CRC tissue sections were segmented for the quantification of differential biomarker expression associated with epithelial mesenchymal transition and aggressive disease. Secondly, a novel histopathological feature ‘Sum Area Large Tumour Bud’ (ALTB) was identified through immunofluorescence coupled to a novel tissue phenomics approach. The tissue phenomics approach created a complex phenotypic fingerprint consisting of multiple parameters extracted from the unbiased segmentation of all objects within a digitised image. Data mining was employed to identify the significant parameters within the phenotypic fingerprint. ALTB was found to be a more significant predictor of disease specific death than LVI or TB in both the training set (HR = 20.2; 95% CI, 4.6 – 87.9) and the validation set (HR = 4; 95% CI, 1.5 – 11.1). Finally, ALTB was combined with two parameters, ‘differentiation’ and ‘pT stage’, which were exported from the original patient pathology report to form an integrative pathology score. The integrative pathology score was highly significant at predicting disease specific death within the validation set (HR = 7.5; 95% CI, 3 – 18.5). In conclusion, image analysis allows the standardised quantification of set histopathological features and the heterogeneous expression of biomarkers. A novel image based histopathological feature combined with classical pathology allows the highly significant stratification of Stage II CRC patients into high and low risk of disease specific death.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O câncer colorretal representa uma das maiores causas de morbidade e mortalidade relacionadas ao câncer. No Brasil, é o terceiro tipo de câncer mais frequente em homens e mulheres. Muitos estudos estão sendo desenvolvidos no sentido de esclarecer os diversos aspectos moleculares que regulam as alterações fenotípicas exibidas pelas células que constituem o câncer colorretal, no entanto, comparativamente, ainda são poucos os que são dedicados a investigar o papel de modificações co- e pós-traducionais neste processo. Entre os vários tipos destas modificações que ocorrem em proteínas, a glicosilação é a mais comum. Cogita-se que aproximadamente cinquenta por cento de todas as proteínas são glicosiladas. Durante a transformação maligna, mudanças no perfil de expressão de glicanos (carboidratos covalentemente ligados a proteínas ou lipídios) estão envolvidas em uma variedade de mecanismos celulares, tais como: perda da adesão célula-célula e célula matriz, migração, invasão e evasão da apoptose. Neste estudo, foi investigada a atividade antitumoral de inibidores da biossíntese de N-glicanos, swainsonina e tunicamicina, em células derivadas de câncer colorretal (Caco-2, HCT-116 e HT-29). Os resultados obtidos mostram que o tratamento das células HCT-116 com tunicamicina inibe mecanismos celulares relacionados ao fenótipo maligno, como formação de colônia dependente e independente de ancoragem, migração e invasão. Estes resultados sugerem que modulação da biossíntese de N-glicanos parece ser uma potencial ferramenta terapêutica para o tratamento do câncer colorretal. Em outra etapa do trabalho, foram avaliados também o impacto da estimulação com insulina e IGF-1 na expressão N-glicanos bissectados em células tumorais MDA-MB-435. Os resultados obtidos confirmaram também a existência de uma relação entre a estimulação dos receptores de insulina e IGF-1 e a regulação da expressão de N-glicanos bissectados em células tumorais MDA-MB-435, fornecendo assim informações relevantes sobre o papel desempenhado pela sinalização de insulina e IGF-1 durante a progressão de carcinomas. / Colorectal cancer is a major cause of cancer-related morbidity and mortality. In Brazil, it is the third most common cancer. Many studies have been developed to clarify several molecular features which regulate phenotypic changes exhibited by cells that constitute colorectal cancer, however, comparatively, there are few studies dedicated to investigate co- and post-translational modifications of proteins in this process. Glycosylation is the most common post-translational modification of proteins. Approximately fifty percent of all proteins are glycosylated. During malignant transformation, changes in the expression profile of glycans (carbohydrates covalently bound to proteins or lipids) may be involved in a variety of events, including the loss of cellcell and cellmatrix adhesion, migration, invasion, and evasion of apoptosis. In this study, we investigated the in vitro anticancer activity of the N-glycan biosynthesis inhibitors, swainsonine and tunicamycin, in cells derived from colorectal cancer (Caco-2, HCT-116 e HT-29). Our results show that treatment with tunicamycin inhibits cellular mechanisms related to the malignant phenotype, such as anchorage-dependent and anchorage-independent colony formation, migration and invasion, in HCT-116 colon cancer cells. Given these results, we suggest that the modulation of N-glycan biosynthesis appears to be a potential therapeutic tool for CRC treatment. Moreover, we confirmthe existence of an interplay between stimulation with insulin and IGF-1 and bisecting GlcNAc N-glycans expression in MDA-MB435 cancer cells, providing new insights into the role that Insulin/IGF-I signaling play during carcinoma progression.

INTRODUÇAO: O câncer de cólon é a terceira neoplasia mais prevalente no país, com aumento progressivo da incidência associada ao envelhecimento populacional. Os avanços nos tratamentos local e sistêmico do câncer de cólon metastático tem aumentado significativamente o tempo de sobrevida global. Entretanto, ainda não existem biomarcadores consolidados na literatura, capazes de predizer resposta a estes tratamentos ou o prognóstico. No processo da carcinogênese, uma das importantes vias que se encontra alterada é a via de reparo do DNA. A Chk2 é uma proteína quinase com atividade no reparo celular atuando de forma supressora no processo da carcinogênese, sendo que alterações em sua expressão e/ou função têm sido associadas à progressão tumoral em outras neoplasias como no câncer de mama, pulmão, vulva, bexiga, cólon, ovário, osteossarcoma e linfomas. OBJETIVO: Avaliar a expressão imunohistoquímica do Chk2 no câncer de cólon metastático e correlacionar sua expressão com características clínico-patológicas e sobrevida. PACIENTES E MÉTODOS: Foram incluídos 58 pacientes com diagnóstico confirmado de câncer de cólon metastático, tratados em primeira linha com quimioterapia baseada em fluorouracila e oxaliplatina. O tempo mínimo de seguimento foram de 2 anos pós-diagnóstico. Para análise da expressão do Chk2 foram utilizadas as técnicas de tissue microarray e imunohistoquímica. Estes resultados foram correlacionados com características clínicas, patológicas e de sobrevida. Para análise estatística, foi utilizado o programa SPSS17 e o valor de p<0,05 foi considerado estatisticamente significativo. RESULTADOS: A expressão de Chk2 foi positiva em 69% dos pacientes. Houve associação entre a expressão de Chk2 e o status linfonodal (p = 0,012) e entre a sobrevivência (p=0,034). A expressão negativa de Chk2 aumentaram as chances de envolvimento linfonodal (OR:10,2, p=0,03). O tempo de sobrevida global de pacientes Chk2 negativo foi maior (72 versus 59 meses, p=0,155), o mesmo foi observado com o tempo sobrevida livre de progressão (19 versus 13 meses, p=0,293). As curvas de sobrevida foram diferentes de acordo com a expressão do Chk2 em pacientes com ou sem envolvimento linfonodal, sendo menor nos pacientes com Chk2 positivo, p=0,028. Houveram mais óbitos em pacientes com Chk2 positivo. Análise multivariada identificou o performance status segundo a escala de ECOG (p=0,001 ); metástase sincrônica (p=0,037); diferenciação das células tumorais (p=0,029) e expressão de Chk2 (p=0,020) como fatores independentes para sobrevida global. CONCLUSÃO: A expressão positiva do Chk2 no adenocarcinoma de cólon metastático foi indicativa de maior agressividade e disseminação tumoral, impactando de forma negativa na sobrevida e desfecho dos pacientes. / INTRODUCTION: The DNA damage checkpoint pathway has been of interest to the field of cancer biology, since checkpoint defects result in the accumulation of altered genetic information, a central feature of carcinogenesis. Little is known about the role of Chk2 in colorectal cancer tumorigenesis. OBJECTIVE: The purpose of this study was to evaluate Chk2 expression in metastatic colon cancer and correlate this with clinicopathological features and patient survival. PATIENTS AND METHODS: Tissues were obtained from 58 patients with confirmed metastatic colon cancer diagnosis, treated with capecitabine and oxaliplatin chemotherapy as standard doses. Patients included had, at least, 2 years post diagnosis of clinical following. The tissue microarray immunohistochemistry was the technic to evaluate Chk2 expression. Statistics analysis used SPSS 17. A p-value <0,050 was considered to be statistically significant. Immunohistochemical expression of Chk2 and its relationship with clinical and pathological characteristics and survival data was reported. RESULTS: The expression of Chk2 was positive in 69%. There was association between expression of Chk2 and Iymph node status (p=0.012) and between survival (p=0.034). The negative expression of Chk2 enhanced the chances of linfonodal involvement (OR:10,2, p=0.03). The global survival time of Chk2 negative patients was higher (72 versus 59 months, p= 0.155); the same was observed with progression-free survival time (19 versus 13 months, p=0.293). The survival curves were different according to Chk2 expression in patients with or without Iymph node involvement, being lower in patients with Chk2 positive, p=0.028. There were more deaths in patients with Chk2 positive. Multivariate regression analysis identified performance status ECOG (p=0.001), synchronous metastasis (p=0.037), tumor cell differentiation (p=0.029) and expression of Chk2 (p=0.020) as independent factors to overall survival. CONCLUSION: This study demonstrated that the Chk2 positive expression in colon cancer indicates increased tumor spread and tumoral aggressiveness, impacting negatively on survival and outcome of patients.

O presente estudo teve como objetivo investigar se existe uma correlação entre ansiedade, depressão e níveis séricos de citocinas de pacientes com câncer colorretal em diferentes estágios da terapia antitumoral. Para tanto, utilizamos um total de 100 indivíduos, divididos em cinco grupos amostrais. Grupo 1. Voluntários saudáveis livres de qualquer doença psiquiátrica ou associada com alterações do sistema imune (n=20); Grupo 2. Pacientes com diagnóstico de adenocarcinoma colorretal confirmado e que não foram submetidos à ressecção cirúrgica (n=20); Grupo 3. Pacientes submetidos à ressecção cirúrgica e que não iniciaram a terapia adjuvante (n=20); Grupo 4. Pacientes em tratamento quimioterápico há cerca de 3 meses, independentemente do esquema de quimioterapia aplicado (n=20); Grupo 5. Pacientes que concluíram o esquema de quimioterapia adjuvante há cerca de 6 meses (n=20). Depressão e ansiedade foram analisados utilizando Hospital Anxiety and Depression Scale (HADS) e níveis séricos de IL-1, IL-6, IL-8, IL-10, IL-12, TNF-?, TGF-? e Fractalcina foram mensurados por CBA. Níveis clinicamente relevantes de ansiedade e/ou depressão foram verificados em todos os pacientes com CCR em diferentes estágios da terapia antitumoral. Um padrão de produção semelhante foi observado para as citocinas pró-inflamatórias avaliadas. IL-1, IL-6, IL-8, TNF-? e Fractalcina foram encontradas em níveis elevados nos pacientes com CCR em estágio pré (G2) e pós-operatório (G3). Estes níveis foram, contudo, reduzidos durante (G4) e após (G5) o tratamento quimioterápico. Além disso, verificamos níveis diminuidos de IL-10 no soro dos pacientes dos grupos 2 e 3 (pré e pós-operatório). Ao analisarmos a correlação entre a pontuação HADS e os níveis séricos de citocinas, observamos uma associação positiva de ansiedade e/ou depressão com as concentrações de IL-1, IL-6, IL-8, TNF-? e Fractalcina e negativa com IL-10 em pacientes nos diferentes estágios da terapia antitumoral. Estes resultados indicam haver uma importante correlação entre os níveis séricos de citocinas pró-inflamatórias, ansiedade e depressão em pacientes com câncer colorretal, sugerindo que tais citocinas estão envolvidas na patofisiologia dessas comorbidades / This study aimed to investigate whether there is a correlation between anxiety, depression and serum cytokine levels in colorectal cancer in different stages of the antitumor therapy. A sample of 100 subjects was divided in 5 groups. Group 1: Healthy volunteers free of any psychiatric or immune system disease (n=20); Group 2: Patients with colorectal cancer who did not undergo surgical resection (n=20); Group 3: Patients who underwent surgical resection and who did not start adjuvant therapy (n=20); Group 4: Patients undergoing chemotherapy for about 3 months, regardless of chemotherapy protocols applied (n=20); Group 5: Patients who have completed adjuvant chemotherapy regimen for about 6 months (n=20). Depression and anxiety were analyzed using the Hospital Anxiety and Depression Scale (HADS), and serum levels of IL-1, IL-6, IL-8, IL-10, IL-12, TNF-?, TGF-?, and Fractalkine were measured by CBA. Clinically relevant levels of anxiety and/or depression were found in all CRC patients in different stages of the antitumor therapy. A similar pattern of production was observed for proinflammatory cytokines. Elevated levels of IL-1, IL-6, IL- 8, TNF-?, and Fractalkine were found in CRC patients in pre (G2) and postoperative (G3) stages. However, these levels were reduced during (G4) and after (G5) chemotherapy. Furthermore, we found decreased levels of IL-10 in serum of patients in CRC patients in pre and postoperative stages. By analyzing the correlation between HADS scores and serum cytokine levels, we observed a positive association of anxiety and/or depression with the concentrations of IL-1, IL-6, IL-8, TNF-?, and Fractalkine, and negative with IL-10 in patients in different stages of the antitumor therapy. These results indicate an important link between serum levels of proinflammatory cytokines, anxiety and depression in CRC patients, suggesting that such cytokines are involved in the pathophysiology of these comorbidities

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O ultrassom anorretal tridimensional (US 3D) proporciona informaÃÃes acuradas do tamanho do tumor e sua relaÃÃo com os mÃsculos do esfÃncter anal. O objetivo deste estudo foi avaliar a acurÃcia do US 3D em predizer a resposta do cÃncer retal à quimioterapia e radioterapia, confrontando as imagens do US 3D com os achados histopatolÃgicos. Trinta e dois pacientes (idade mÃdia de 59 anos), estadiados em T2 (n=3), T3 (n=23) e T4 (n=6), com metÃstase em linfonodos perirretais em 22 casos, foram submetidos à quimioterapia e radioterapia neoadjuvantes, seguidas de uma segunda avaliaÃÃo com US 3D sete semanas depois. Os pacientes foram agrupados conforme a distÃncia (cm) entre a borda distal do tumor e a borda proximal do esfÃncter anal interno (EAI) (Grupo I, apresentando invasÃo do canal anal; Grupo II &#8804; 2,0cm; Grupo III > 2,0 cm). Todos os pacientes foram operados e os achados histopatolÃgicos foram confrontados com os resultados do US 3D pÃs-neoadjuvÃncia. Cinco pacientes (16%) apresentaram regressÃo completa do tumor. Dezenove pacientes (59%) apresentaram regressÃo parcial do tumor. A distÃncia ao EAI foi > 2,0cm em 11 pacientes (34%). Os 7 (22%) pacientes restantes nÃo apresentaram regressÃo. O US 3D e os achados histopatolÃgicos foram concordantes em 31 (97%) pacientes, com apenas um caso (3%) inconclusivo do US 3D pÃs-neoadjuvÃncia. Comparando as imagens do US 3D com os achados histopatolÃgicos de acordo com a distÃncia entre a borda distal do tumor e a borda proximal do EAI, houve concordÃncia em 100% dos pacientes. A regressÃo tumoral tornou possÃvel a cirurgia com preservaÃÃo do esfÃncter em 16 pacientes (50%) (onze do Grupo III e cinco com regressÃo completa do tumor). O exame histopatolÃgico revelou margens livres em todos os casos. O Ãndice de concordÃncia entre as metÃstases em linfonodos ao US 3D pÃs-neoadjuvÃncia e as peÃas cirÃrgicas foi substancial (87,5%). Concluiu-se que o US 3D pode auxiliar significativamente na seleÃÃo da abordagem cirÃrgica apÃs quimioterapia e radioterapia. Entretanto, uma maior amostra de pacientes à necessÃria para estabelecer parÃmetros ultrassonogrÃficos suficientemente acurados apÃs quimioterapia e radioterapia / O ultrassom anorretal tridimensional (US 3D) proporciona informaÃÃes acuradas do tamanho do tumor e sua relaÃÃo com os mÃsculos do esfÃncter anal. O objetivo deste estudo foi avaliar a acurÃcia do US 3D em predizer a resposta do cÃncer retal à quimioterapia e radioterapia, confrontando as imagens do US 3D com os achados histopatolÃgicos. Trinta e dois pacientes (idade mÃdia de 59 anos), estadiados em T2 (n=3), T3 (n=23) e T4 (n=6), com metÃstase em linfonodos perirretais em 22 casos, foram submetidos à quimioterapia e radioterapia neoadjuvantes, seguidas de uma segunda avaliaÃÃo com US 3D sete semanas depois. Os pacientes foram agrupados conforme a distÃncia (cm) entre a borda distal do tumor e a borda proximal do esfÃncter anal interno (EAI) (Grupo I, apresentando invasÃo do canal anal; Grupo II &#8804; 2,0cm; Grupo III > 2,0 cm). Todos os pacientes foram operados e os achados histopatolÃgicos foram confrontados com os resultados do US 3D pÃs-neoadjuvÃncia. Cinco pacientes (16%) apresentaram regressÃo completa do tumor. Dezenove pacientes (59%) apresentaram regressÃo parcial do tumor. A Three-dimensional anorectal ultrasound (3-DAUS) scanning provides accurate informationes on tumor size and its relation to the anal muscles. The purpose of this study was to evaluate the ability of 3-DAUS to assess response to radiochemotherapy (RCT) for rectal cancer by comparing 3-DAUS images to pathological findings. Thirty two patients (mean age 59 years), staged as T2 (n = 3), T3 (n = 23) or T4 (n = 6), with lymph node metastases in 22 cases, were submitted to neoadjuvant RCT, followed by a second 3-DAUS scan 7 weeks later. The patients were grouped according to the distance (cm) between the distal tumor edge and the proximal border of the internal anal sphincter (IAS) (Group I, presenting anal canal invasion; Group II &#8804; 2.0 cm; Group III > 2.0 cm). All patients were operated on and the pathological findings were compared to post-RCT 3-DAUS scanning results. Five (16%) patients experienced complete tumor regression. Nineteen (59%) tumors regressed partially. Distance to the IAS was >2.0 cm in eleven (34%) patients. The remaining seven (22%) patients experienced no regression. 3-DAUS and pathological findings were concordant in 31 (97%) patients, with only one (3%) nonconclusive post-RCT 3-DAUS result. Comparing 3-DAUS images to pathological findings according to the distance between the distal tumor edge and the proximal border of IAS, there was agreement in 100% of the pacients. Tumor regression made sphincter-saving surgery possible in 16 patients (50%) (eleven in group III and five complete tumor regression). Pathological examination revealed free distal margins in all cases. The index of agreement between lymph node metastases on post-RCT 3-DAUS and surgical specimens was substantial (87,5%). It may be concluded that 3-DAUS can aid significantly in the choice of surgical approach following RCT. However, a greater sample of patients is required to establish sufficiently accurate post-RCT 3-DAUS parameters. Keywords: Ultrasonography. Colorectal cancer. Radiology

Introdução: O câncer colorretal é um dos mais frequentes no mundo ocidental. Novas medidas de prevenção, diagnóstico precoce e tratamento vêm melhorando o prognóstico para os pacientes, com novos achados biológicos inferindo relação com a evolução da doença. A PPARG é um receptor nuclear abundantemente expresso em células epiteliais do cólon, e variações na sua expressão podem ser relacionadas à evolução clínica do câncer colorretal. Objetivo: Avaliar a expressão gênica do PPARG em tumores colorretais e relacionar este dado com variáveis clínicas dos pacientes, como: idade, tipo histológico, CEA, estadiamento e a evolução clínica. Casuística e métodos: Analisamos a expressão gênica do PPARG em 50 amostras de tumores colorretais através da RT-PCR, e 20 amostras de tecido normal adjacente como controle. Os resultados destas quantificações foram correlacionados com as informações clínicas dos prontuários dos respectivos pacientes. Resultados: Houve menor expressão do PPARG no tecido tumoral em comparação ao tecido controle. Dentre os tumores, os pacientes com idade acima de 60 anos, tipo histológico com diferenciação mucinosa, estadiamento mais avançado ao diagnóstico e os pacientes que evoluíram com recidiva da doença ou óbito apresentavam maior expressão do PPARG. Discussão: Analisando os tecidos tumorais, pode-se inferir uma tendência a pior prognóstico nos pacientes com expressão mais elevada de PPARG. Esses achados, correlacionados aos demais estudos já publicados na literatura, apontam uma tendência desfavorável na evolução da doença. Estudos futuros com um maior número de pacientes e várias instituições podem inferir uma importância prognóstica e até terapêutica para a PPARG. / Introduction: Colorectal cancer is one of the most frequent neoplasm in the Western world. New strategies of prevention, early diagnosis and treatment have improved the prognosis for the patients, and new biological findings relate to the prognosis of the disease. PPARG is a nuclear receptor highly expressed in colon epithelial cells, and variations on its expression may be related to the clinical evolution of colorectal cancer. Objective: To evaluate the gene expression of PPARG in colorectal tumors and to correlate this data with clinical variables of the patients, such as: age, histological type, CEA, staging and clinical evolution. Casuistry and methods: We analyzed the gene expression of PPARG in 50 samples of colorectal tumors using RTPCR, and 20 adjacent normal tissue samples as control. The results of these quantifications were correlated with the respective patients\' medical records\' clinical information. Results: There was a lower PPARG expression in the tumor tissue compared to the control tissue. Among the tumors samples, patients older than 60 years, histological type with mucinous differentiation, more advanced staging at the time of diagnosis, and patients who evolved with recurrence of the disease or death presented higher PPARG expression. Discussion: Analyzing the tumor tissues, we can infer a tendency to worse prognosis in patients with higher PPARG expression. These findings, correlated with the other studies already published in the literature, point to na unfavorable trend in the disease\'s evolution. Future studies with a larger number of patients and several institutions may infer a prognostic and even therapeutic importance for PPARG.