Mutation and overexpression of p53 in early-stage epithelial ovarian cancer

To investigate whether mutation and overexpression of p53 is a feature of early-stage ovarian cancers.

Because early-stage ovarian cancers are relatively uncommon, we adapted p53 immunostaining and DNA sequencing methods for use in paraffin-embedded tissue blocks. Early-stage ovarian cancers from 52 patients treated at Duke University between 1980-1991 were analyzed.

Immunostaining for p53 consistent with overexpression was seen in 29% of early-stage (I/II) ovarian cancers overall. The incidence of p53 overexpression was lower in cancers confined to the ovaries (stage IA/IB) (15%) than in cancers that had spread outside the ovaries (stage IC/II) (44%) (P = .03). Although p53 overexpression was seen more frequently in large tumors (diameter greater than 10 cm) and in tumors with "high-risk" features (stage IC or II, or grade 3), these relationships were not statistically significant. Recurrent disease developed in 35% of the patients in this series, but there was no relationship between p53 overexpression and recurrence rate or survival. The presence of point mutations in the p53 gene was confirmed by DNA sequencing in eight cancers that overexpressed p53.

Mutation and overexpression of p53 are less frequent in early-stage ovarian cancers than in advanced-stage cases. P53 overexpression is not associated with adverse outcome in early-stage ovarian cancer.