Overexpression of p53 is not a feature of ovarian granulosa cell tumors.

The p53 tumor suppressor gene has been extensively studied in various human tumors including epithelial ovarian cancers. However, little is known about the expression of this gene in ovarian granulosa cell tumors, the most common histologic type of sex cord-stromal tumors. We investigated whether overexpression of the p53 gene product occurs in this specific ovarian tumor. Nineteen patients with ovarian granulosa cell tumors were recruited in this study. Immunohistochemical staining for the p53 protein with monoclonal antibody PAb 1801 was performed in the paraffin-embedded tissue of each case to screen for p53 overexpression. Among the 19 ovarian granulosa cell tumors, there was only one well-differentiated tumor found to have nuclear immunoreactivity in a small fraction of tumor cells. Polymerase chain reaction--single-stranded conformation polymorphism was used to study the tumor showing focal p53 positivity, but no mobility shift was noted from exon 4 through exon 9 of the p53 gene. On the basis of this observation, we propose that alteration of the p53 tumor suppressor gene is not a common finding in ovarian granulosa cell tumors.