Prevalence and clinical significance of abnormal p53 gene in patients with ampullary adenocarcinoma / 대한내과학회지

ABSTRACT

BACKGROUND: Although abnormalities of p53 gene and their relation to clinicopathologic parameters have been identified in some human malignancies, there is little published data on their prevalence and clinical significance in ampullary adenocarcinoma (AAC). The aim of this study is to determine the prevalence of p53 abnormalities in AAC and to evaluate their relation to clinicopathologic features. METHOD:35 formaline-fixed paraffin-embedded tissues of AAC were examined for detection of p53 abnormalities by both single-strand conformation polymorphism (SSCP) analysis of polymerase chain reaction- amplified DNA fragments corresponding to exons 5-8 and immunohistochemistry (IHC) using monoclonal antibody to p53 protein (Novocastra, DO7), and the association between the p53 abnormalities and clinicopathologic parameters was analyzed. RESULT: In 22.9% of AAC, p53 gene muation was demonstrated by SSCP analysis, mainly at PCR-amplified exon 8 and exon 7. The p53 protein overexpression by IHC was 48.6% of AAC. Six SSCP and IHC-positive (17.2%) cases and 16 normal (45.7%) cases showed concordant results between the methods, although 13 cases (37.1%) showed discordance, including 11 IHC-positive (31.4%) and 2 SSCP-positive (5.7%) cases. Overall, the prevalence of p53 abnormalities was 54.3%. No significant associations between the p53 abnormalities and clinicopathological parameters such as clinical manifestations, histologic differentiation, and tumor stage were observed. CONCLUSION: The p53 abnormalities detected in 55% of AAC are not associated with prognostic factor, suggesting that abnormal p53 gene may play a role in the development of AAC, but not in its invasiveness.