p53 protein accumulation in oesophageal squamous cell carcinomas and precancerous lesions.

AIMS: To investigate the immunohistochemical expression of p53 protein in oesophageal squamous cell carcinomas and in dysplastic areas of the oesophageal mucosa surrounding the tumours. METHODS: Biopsy samples were obtained from 20 patients with an oesophageal squamous cell carcinoma. Blocks of the tumours and of the surrounding mucosa were immunostained with the monoclonal antibody DO-7. RESULTS: Fourteen of the 20 carcinomas were positive for p53 (70%). The frequency of p53 overexpression increased with the differentiation of the tumour. Nine out of 13 dysplastic specimens were positive for p53 (69%): eight cases with severe dysplasia and one case with moderate dysplasia. No p53 immunostaining was detected in normal oesophageal epithelium. All p53 positive dysplastic specimens were taken from the mucosa adjacent to tumours that were also immunostained. In moderate dysplastic mucosa the p53 positive cells were located in the proliferative basal zone, whereas in severe dysplasia the immunostained cells increased in number and spread to upper cell layers of the epithelium. CONCLUSION: This study supports the hypothesis that TP53 gene is frequently involved in the development of oesophageal squamous cell carcinoma and that p53 protein accumulation is an early event in human oesophageal carcinogenesis.

[Gastroduodenal metastases: an unusual manifestation of lung cancer. Study of two cases and review ot the literature]. / Métastases gastroduodénales: un mode de révélation exceptionnel du cancer du poumon. Etude de deux cas et revue de la littérature.

INTRODUCTION: Diagnosis of gastroduodenal metastases is rare. Primary tumors are essentially melanomas and breast cancer, and exceptionally lung cancer. EXEGESIS: We report two patients who have a diagnosis of gastroduodenal metastases as initial manifestation of lung cancer. In one case, the patient died 3 weeks after the diagnosis. In the other case, chemotherapy was performed and complete response was obtained for the gastric metastasis. After a few months, node recurrence was diagnosed and the patient died 8 months after the diagnosis. CONCLUSION: We review the endoscopic and non-endoscopic literature and discuss the different histological types and therapeutic strategies concerning these unusual manifestations of lung cancer.

TP53 and oesophageal cancer.

Mutations of the tumor suppressor gene TP53 have been detected in tumor tissues of a large variety of human malignancies and contribute to the development, progression and probably the prognosis of the disease. The pattern of somatic mutations in the TP53 gene in human tumors most often consists of a point mutation in one allele accompanied by loss or rearrangement of the second allele. Esophageal cancer is one of the most commonly mutated cancer, p53 mutations having an incidence greater than 80% in squamous cell carcinoma. The profile of distribution of these mutations in the TP53 gene is of interest to establish correlation between the exposure to carcinogens responsible for DNA mutations. The other form of esophageal cancer, Barrett's esophageal is a good model to study the role of TP53 in mammalian tumorigenesis.