P53 EXPRESSION IN EPITHELIAL OVARIAN NEOPLASMS - RELATIONSHIP TO CLINICAL AND PATHOLOGICAL PARAMETERS, KI-67 EXPRESSION AND FLOW-CYTOMETRY

Epithelial ovarian tumors of varying malignancy as well as normal ovar ies were examined for their expression of p53 with the monoclonal anti body PAb1801. Immunohistochemical detection of p53 protein is possible when the gene has been mutated, but not when the normal gene product alone is present. Our results indicate that this tumor suppressor gene may be involved in tumorigenesis, as its expression was detected in b oth borderline and malignant tumors while normal ovaries and benign ov arian tumors were unstained with the p53 antibody. The presence of p53 was also related to dissemination of disease, residual tumor bulk, an d poor differentiation as well as the presence of the proliferation va riable Ki-67, another negative prognostic variable. No significant rel ation could be detected to S-phase fraction or DNA ploidy. Furthermore , the presence of p53 in malignant epithelial ovarian tumors was relat ed to significantly decreased patient survival, with only 36% alive co mpared.to 70% in the p53-negative group (P = 0.002). In the subgroup o f patients with residual tumor burden after surgery, those with p53-po sitive tumors had a significantly (P = 0.05) decreased survival compar ed to those with p53-negative neoplasms, which further supports an ind ependent role in ovarian cancer malignancy. (C) 1994 Academic Press, I nc.