Background: The clinical significance of p53 suppressor gene nucleoprotein immunostaining in ovarian epithelial cancer has not been determined.
Methods: p53 protein expression was studied by immunohistochemistry from paraffin embedded tissue in a series of 136 patients with malignant ovarian epithelial tumors. The median follow-up time of the patients still alive was 10 years.
Results: Sixty (44%) carcinomas stained clearly positive for p53 protein. Positive staining for p53 protein was associated with the serous histologic type (P = 0.0006), a higher than the median S-phase fraction size determined by DNA flow cytometry (P = 0.02), and poor histologic grade of differentiation (P = 0.04), but not with the International Federation of Gynecology and Obstetrics (FIGO) stage, age at diagnosis, or DNA ploidy. Cancers with positive staining had only 17% 5-year and 9% 15-year survival rates compared with 42% 5-year and 36% 15-year survival rates corrected for intercurrent deaths among the rest of patients (P = 0.002). In a multivariate analysis, positive p53 staining was associated with poor survival (relative risk of death, 1.8, 95% confidence interval [CI], 1.2-2.9) together with less than radical surgery (nonradical vs. radical: RR, 5.5; 95% CI, 2.2-13.6), and advanced FIGO stage (RR, 1.4; 95% CI, 1.0-2.0).
Conclusion: Although p53 protein immunostaining is associated with several other prognostic factors in epithelial ovarian cancer, it may also have independent prognostic value in this disease.