p53 alterations but no human papillomavirus infection in preinvasive and advanced squamous esophageal cancer in Italy

Geographic differences in exposure to suspected carcinogens have been identified in esophageal carcinogenesis, and both p53 alterations and human papillomavirus (HPV) infection have been reported in esophageal squamous carcinoma (ESC) from high-risk areas, including China and South Africa. The status of p53 alterations and HPV infection in ESC has not been determined in northern Italy, where the incidence of ESC is low. Formalin-fixed paraffin-embedded esophageal samples containing normal, dysplastic, and carcinomatous tissue from 18 patients were examined for p53 protein accumulation with immunohistochemistry, p53 mutation (exons 5-8) with PCR-single-strand conformation polymorphism analysis and DNA sequencing, and HPV infection with PCR using general primers to amplify the L1 gene. Accumulation of p53 protein was observed in both precancerous and carcinomatous lesions. p53 mutations were rare in dysplastic lesions but were detected in 9 of 18 carcinomas, a finding consistent with reports from other geographic areas. Examination of the p53 mutation spectrum revealed no hot spot mutation. In contrast, HPV was not found in any of these 18 cases. This is consistent with the findings from other low ESC risk areas in which HPV infection may not play a crucial role in esophageal oncogenesis, whereas the high risk of ESC in China and South Africa may be attributed to frequent HPV infection.