Lack of correlation between p53 codon 72 polymorphism and anal cancer risk.

AIM: To investigate the potential role of p53 codon 72 polymorphism as a risk factor for development of anal cancer. METHODS: Thirty-two patients with invasive anal carcinoma and 103 healthy blood donors were included in the study. p53 codon 72 polymorphism was analyzed in blood samples through polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing. RESULTS: The relative frequency of each allele was 0.60 for Arg and 0.40 for Pro in patients with anal cancer, and 0.61 for Arg and 0.39 for Pro in normal controls. No significant differences in distribution of the codon 72 genotypes between patients and controls were found. CONCLUSION: These results do not support a role for the p53 codon 72 polymorphism in anal carcinogenesis.

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.