Prognostic importance of DNA ploidy and p53 in early stages of epithelial ovarian carcinoma.

ABSTRACT

Patients with early stages (FIGO stages IA-IIC) of ovarian cancer continue to experience tumor relapses and they succumb due to their disease after seemingly adequate adjuvant therapy. In a series of 113 patients treated with adjuvant radiotherapy 4-6 weeks after primary surgery, the DNA content and p53 status of the tumors were studied and related to other known prognostic factors (age, FIGO stage, histopathologic type, and tumor grade). The DNA analyses were done by flow cytometry and p53 expression was studied by immunohistochemistry on formalin-fixed and paraffin-embedded tissue. DNA analyses of 103 tumors could be made and the p53 status was determined in 106 cases. Univariate analyses showed that both p53-positivity and aneuploidy of the ovarian tumors were strongly associated with tumor grade. There was also a strong association between p53 expression of the tumors and DNA aneuploidy (DNA index >1.10 and S-phase fraction >11.5%). P53-positivity and tumor grade were the only significant factors for the risk of tumor recurrence. DNA and p53 status alone were not adequate predictive factors to identify clinically relevant subgroups of patients who would benefit from adjuvant postoperative therapy. Tumor grade remains the most important prognostic factor with regard to the risk of tumor recurrence and the cancer-specific survival rate in early stage ovarian carcinoma. Overexpression of p53 also increases the risk of tumor recurrence.