Immunohistochemical expression of HER-2/NEU-CERBB-2 in patients with adenocarcinoma of the stomach / Expressão imunoistoquímica do HER-2/NEU-CERBB-2 em pacientes com adenocarcinoma do estômago

Objectives: To determine the prevalence of Her-2/Neu-cerbb-2 in the gastric mucosa of patients with gastric adenocarcinoma in a brazilian patient group. Methods: The immunohistochemical expression of Her-2/Neu was studied in 37 formalin-fixed paraffin–embedded tissue sections. Results: The immunohistochemical reaction produced by the anti-HER- 2/Neu antibody was positive in two cases (5.4%). Conclusion: The low prevalence of Her-2/Neu observed in these southern brazilian cases is probably due to the great number of poorly differentiated cancers in this serie.

Objetivo: Determinar a prevalência do Her-2/Neu-CerbB-2 na mucosa de pacientes com adenocarcinoma de estômago em um grupo de doentes brasileiros. Métodos: A expressão imunoistoquímica do Her-2/Neu foi estudada em 37 amostras de tecidosfixados em formalina e embebidos em parafina. Resultados: A reação imunoistoquímica produzida pelo anticorpo HER-2/Neu foi positiva em dois pacientes (5.4%). Conclusão: A baixa prevalência Her-2/Neu observada neste grupo de pacientes é provavelmente devida ao grande número de tumores pouco diferenciados encontrados nesta série.

Immunohistochemical expression of HER-2/NEU-CERBB-2 in patients with adenocarcinoma of the stomach.

OBJECTIVES: To determine the prevalence of Her-2/Neu-cerbb-2 in the gastric mucosa of patients with gastric adenocarcinoma in a brazilian patient group. METHODS: The immunohistochemical expression of Her-2/Neu was studied in 37 formalin-fixed paraffin-embedded tissue sections. RESULTS: The immunohistochemical reaction produced by the anti-HER-2/Neu antibody was positive in two cases (5.4%). CONCLUSION: The low prevalence of Her-2/Neu observed in these southern brazilian cases is probably due to the great number of poorly differentiated cancers in this series.

pRB expression in esophageal mucosa of individuals at high risk for squamous cell carcinoma of the esophagus.

AIM: To investigate the pRb expression in a large group of patients with history of chronic exposure to the main risk factors for development of squamous cell carcinoma of the esophagus. METHODS: One hundred and seventy asymptomatic individuals at high risk for esophageal squamous cell carcinoma (consumption of more than 80 g of ethanol and 10 cigarettes/d for at least 10 years) underwent upper gastrointestinal endoscopy with biopsies of the esophageal mucosa. As a control group, specimens of esophageal mucosa obtained from 20 healthy subjects were also studied. Immunohistochemical assessment of the tissues was performed using a monoclonal antibody anti-pRB protein. RESULTS: Absence of the pRB staining, indicating loss of RB function, was observed in 33 (19.4%) of the individuals at risk for esophageal cancer, but in none of the healthy controls (P < 0.02). Loss of pRb expression increased in a stepwise fashion according to the severity of the histological findings (P < 0.005): normal mucosa (11/97 or 11.3%), chronic esophagitis (17/60 or 28.3%), low-grade dysplasia (3/10 or 30%), high-grade dysplasia 1/2 or 50%) and squamous cell carcinoma (1/1 or 100%). CONCLUSION: Our findings suggest that abnormal expression of the pRB protein may be implicated in the process of esophageal carcinogenesis. Additional studies are warranted to define the role of the pRB protein as a biomarker for development of esophageal squamous cell carcinoma in individuals at high risk for this malignancy.

Bcl-2 expression in rectal cancer

BACKGROUD: Proteins involved in apoptosis process seem to play an important role in colorectal carcinogenesis AIM: To determine the prevalence of bcl-2 protein immunohistochemical expression and its relation with clinical and histopathological variables of rectal adenocarcinoma. PATIENTS AND METHODS: One hundred and thirty-two patients operated at "Hospital de Clínicas de Porto Alegre", Porto Alegre, RS, Brazil, between 1988 and 1999 were studied through immunohistochemical reaction using a monoclonal antibody anti-bcl-2 on formalin-fixed, paraffin-embedded tissue samples RESULTS: The prevalence of bcl-2 protein was 29.5 percent. There was a significant increased number of positive bcl-2 cases among women as compared to men. There was no significant association between bcl-2 and age, tumour site, histological grade, mucin production, depth of invasion, lymphatic involvement, distant metastasis or stage, despite a trend showing decreased immunoreactivity to bcl-2 among poorly and moderately differentiated tumours, as well as disseminated disease CONCLUSIONS: Analysis of bcl-2 protein expression in tumour tissues, as well as other oncoproteins, may have a role in predict therapeutic response and prognosis of colorectal cancer. However, the potential use of bcl-2 protein assessment in the clinical set for management of rectal cancer remains to be determined.

RACIONAL: As proteínas envolvidas no processo de apoptose parecem desempenhar papel importante na carcinogênese colorretal. OBJETIVOS: Determinar a prevalência da expressão imunoistoquímica da proteína bcl-2 e sua relação com variáveis clínicas e histopatológicas do câncer de reto. PACIENTES E MÉTODOS: Cento e trinta e dois pacientes operados no Hospital de Clínicas de Porto Alegre, RS, entre 1988 e 1999 foram estudados através de reação imunoistoquímica, utilizando um anticorpo monoclonal anti-bcl-2 em amostras teciduais fixadas em formalina e parafinizadas. RESULTADOS: A prevalência da proteína bcl-2 foi de 29,5 por cento. Houve aumento significativo no número de casos bcl-2 positivo entre mulheres quando comparado aos homens. Não houve associação significativa entre bcl-2 e idade, sítio do tumor, grau histológico, produção de muco, profundidade de invasão, envolvimento linfático, metástases distantes ou estágio, apesar de uma tendência demonstrando imunorreatividade ao bcl-2 diminuída entre os tumores pouco e moderadamente diferenciados, bem como para doença disseminada. CONCLUSÕES: A análise da expressão da proteína bcl-2 em tecidos tumorais, bem como outras oncoproteínas, pode ter um papel em predizer a resposta terapêutica e o prognóstico do câncer colorretal. Entretanto, o uso potencial da avaliação da proteína bcl-2 na prática clínica no manejo do câncer de reto permanece a ser determinado.

Bcl-2 expression in rectal cancer.

BACKGROUND: [corrected] Proteins involved in apoptosis process seem to play an important role in colorectal carcinogenesis AIM: To determine the prevalence of bcl-2 protein immunohistochemical expression and its relation with clinical and histopathological variables of rectal adenocarcinoma. PATIENTS AND METHODS: One hundred and thirty-two patients operated at "Hospital de Clínicas de Porto Alegre", Porto Alegre, RS, Brazil, between 1988 and 1999 were studied through immunohistochemical reaction using a monoclonal antibody anti-bcl-2 on formalin-fixed, paraffin-embedded tissue samples RESULTS: The prevalence of bcl-2 protein was 29.5%. There was a significant increased number of positive bcl-2 cases among women as compared to men. There was no significant association between bcl-2 and age, tumour site, histological grade, mucin production, depth of invasion, lymphatic involvement, distant metastasis or stage, despite a trend showing decreased immunoreactivity to bcl-2 among poorly and moderately differentiated tumours, as well as disseminated disease CONCLUSIONS: Analysis of bcl-2 protein expression in tumour tissues, as well as other oncoproteins, may have a role in predict therapeutic response and prognosis of colorectal cancer. However, the potential use of bcl-2 protein assessment in the clinical set for management of rectal cancer remains to be determined.

p53 immunoexpression: an aid to conventional methods in the screening of precursor lesions of squamous esophageal cancer in patients at high-risk?

INTRODUCTION: Squamous cell carcinoma of the esophagus (SCCE) is diagnosed late and carries a poor prognosis. Lugol chromoendoscopy (LC) has being shown a useful tool in the management of patients at high risk for SCCE. Biomarkers such as p53 protein expression may be present in the esophageal mucosa long before esophageal symptoms or lesions appear and may aid in early diagnosis. This study was carried out to investigate the p53 immunoexpression in esophageal mucosa of smokers and alcohol consumers and study its relationship with different degrees of histological findings and the role of LC to detect areas that express p53. METHODS: Group 1: One hundred and eighty-two asymptomatic subjects at high risk for SCCE (consumption of more than 80 g of ethanol and 10 cigarettes/day for at least 10 years). Group 2: Twenty healthy volunteers who neither smoked nor consumed alcohol. Both groups underwent upper GI endoscopy plus LC, with biopsies of the esophageal mucosa. Expression of p53 protein was compared to histological findings. RESULTS: Group 1: There was 25/182 (14%) Lugol's unstained areas. p53 protein was expressed in a stepwise fashion according to the severity of the histological findings: normal mucosa (12/103 or 12%), mild esophagitis (6/43 or 14%), moderate esophagitis (4/18 or 22%), severe esophagitis (1/3 or 33%), low-grade dysplasia (4/11 or 36%), high-grade dysplasia (2/2 or 100%) and squamous cell carcinoma (2/2 or 100%) (p=0.001). Nine in 25 (36%) patients with Lugol's unstained areas and 22/157 (14%) with normal appearing Lugol's stained mucosa expressed p53. Group 2: There was no Lugol unstained areas. The histological analysis and immunohistochemistry for p53 were normal with the exception of two patients that presented mild esophagitis and expressed p53. Unstained areas were 3.5 times (95% CI: 1.2-9.6) more likely to express p53 then stained ones. Alcoholics/smokers were 1.9 (95% CI: 0.4-8) times more likely to express p53 than non-alcoholics/non smokers. CONCLUSIONS: In this study, we find an association between histological alterations, p53 expression and Lugol's unstained areas. It may point to a higher risk for SCCE. Smokers and alcohol drinkers with normal mucosa or chronic esophagitis that express p53 protein may represent an unrecognized sub-group of individuals that may benefit from surveillance or intervention.

Nuclear chromatin texture in rectal carcinoma. Prognostic value.

OBJECTIVE: To investigate the prognostic value of nuclear features in rectal carcinoma. STUDY DESIGN: High-resolution imagery of 3,635 nuclei from 51 patients operated on for rectal cancer at various Dukes' stages was digitally recorded. A set of 93 features descriptive of the spatial and statistical distribution of nuclear chromatin was computed for each nucleus to derive a digital signature. Karyometric features were analyzed for correlation with progression of disease and death. RESULTS: Multivariate analysis of main karyometric features in comparison with cancer staging demonstrated that total optical density and clumpness, as well as average nuclear signature, had significant prognostic value in predicting cancer-related death. CONCLUSION: Digital signature seems to have a role as prognostic factor in rectal cancer. The method could be a useful parameter in deciding whether to perform adjuvant therapy in particular subgroups of patients, independently of tumor staging. However, these observations need to be substantiated with additional studies, including larger numbers of patients.

Nuclear chromatin texture in rectal cancer. Relationship to tumor stage.

OBJECTIVE: To characterize, by morphometric and chromatin texture analysis, a series of rectal carcinomas classified according to Dukes staging. STUDY DESIGN: High-resolution imagery of 6,001 nuclei from 51 specimens of rectal carcinoma and 22 specimens of normal rectal tissue was digitally recorded. A set of 93 features descriptive of the spatial and statistical distribution of nuclear chromatin was computed for each nucleus to form a characteristic signature. RESULTS: Rectal carcinomas were significantly different from normal rectum in their digital signature. Eleven karyometric features, such as nuclear area and total optical density, were clearly different between the groups, with significant differences found in analysis of 8 of those features. The most distinctive pattern in lesion signatures in comparison with normal rectal tissue was observed at Dukes' stage D. However, the highest average signature values were seen at Dukes' stage B. The lesion signatures and total optical density observed in cancer specimens deviated markedly from values in the normal group. CONCLUSION: Chromatin texture signature proved to be a useful method of identifying and characterizing nuclear differences between rectal carcinoma and normal rectal tissue.