p53, c-erbB2, and PCNA status in benign, proliferative and malignant ovarian surface epithelial neoplasms: a study of 75 cases.

Low malignant potential tumors of the ovary are believed to behave in a manner intermediate to their benign and malignant counterparts. However, recent evidence suggests these lesions are in fact benign and better classified as proliferative. Based on our previous work and evaluating p53, c-erbB2, and PCNA status in a full spectrum of ovarian surface epithelial tumors, with emphasis on low malignant potential tumors, we tested this hypothesis. Immunohistochemical stains with monoclonal antibodies were used on 75 archival ovarian neoplasms. The results demonstrated anti-p53 reactivity in 30 carcinomas (40%), 2 of which were proliferative, and no reactivity in the benign tumors. Overexpression of c-erbB2 was seen in 31 malignant neoplasms (64.5%), 4 of which were proliferative (22.1%), and none in benign tumors. The PCNA proliferative index showed means of 42.8%, 22.8%, and 14.9% with benign, low malignant potential, and malignant tumors, respectively. Predicting immunoreactivity in carcinomas for anti-PCNA (Student t test), anti-p53, and anti-c-erbB2 (Pearson chi2 test) versus a lack of immunoreactivity in proliferative tumors indicate P values of .001, <.001, and <.001, respectively. These data show significant differences in the expression of these markers in ovarian tumors and suggest a possible role for these oncogenes as supplemental tools in diagnostic pathology. Further, our findings also support the designation of proliferative as opposed to the current nomenclature of low malignant potential tumors.