Expression and mutation analysis of the p53 gene in uterine papillary serous carcinoma

Background. The status of p53 protein expression was determined by immunohistochemistry and correlated with genetic analysis and clinical outcome in patients with uterine papillary serous carcinoma (UPSC). Methods. Twenty-two patients with UPSC were identified and immunohistochemical staining of p53 protein was performed. Staining was analyzed by quantitating nuclear reactivity in 500 randomly counted cells per specimen. DNA analysis was performed on the tumors using single-strand conformation polymorphism (SSCP) analysis of exons 4-10 of the p53 gene, followed by DNA sequencing of all variants. Clinical data and patient status were ascertained from chart reviews. Results. Sixteen of the 22 (73%) tumors were scored as p53-overexpressing as determined by immunohistochemical analysis. Patients whose tumors overexpressed p53 had a statistically significant shorter survival than those whose tumors did not (P < 0.022). DNA analysis of the 22 tumors revealed five with mutations of the p53 gene. Only three of these mutations were observed in tumors that overexpressed p53. Conclusions. A relatively large percentage of UPSC tumors exhibited high p53 immunoreactivity. Overexpression is correlated with poor prognosis. Positive immunohistochemistry for p53 protein in UPSC is not necessarily indicative of a genetic mutation