DIFFERENTIATION MARGINS OF OVARIAN TUMOR PATHOLOGY - FIRST INCIDENCESOF EPITHELIAL OVARIAN-TUMORS MONITORED BY MARKER ANTIBODIES

The first incidence of ovarian tumors in The Netherlands was analyzed using the PALGA data. The first incidences of benign epithelial ovaria n tumors reach a plateau, at a level of 60 to 65 cases per 100,000 wom en beyond the age of 40 years. The borderline malignant epithelial ova rian tumors account for 10 per 100,000 women aged 30 to 85, while the ovarian carcinomas reach a plateau level of 25 to 35 per 100,000 women after the age of 50. Despite the long lag period (+/- 10 years) betwe en benign and malignant ovarian tumors, the question of whether or not all epithelial ovarian cancers develop via an intermediate step of cy stadenomas is still unanswered. Therefore, we examined whether the exp ression pattern of intermediate filaments and tumor antigens in normal , benign, and malignant ovarian tissues might contribute to this quest ion. The following changes in expression pattern were observed: genera lly, all tumor cells retained the keratin profile of the corresponding original cell type. However, in a limited number of tumor samples ect opic keratin types, such as nos. 4, 10, 13, and 14, became expressed a dditionally. Most epithelial ovarian tumors and mesothelial cells coex pressed vimentin. The panepithelial marker BW495/36 clearly distinguis hed between negatively stained normal ovarian surface mesothelium and the positively stained (inclusion) cystic epithelium. TAG-72 as well a s OV-632 marked a subsequent tumor stage by discriminating between neg ative serous adenomas and positive serous carcinomas. TAG-72, however, stained both mucinous adenomas and carcinomas. The ovarian tumor mark ers (OC125, OV-TL 3, OV-TL16, MOv18), all showed an increasing express ion level in the sequence order from normal cells to benign and malign ant ovarian tumors. Both our epidemiological and our immunohistochemic al data have shown that in the Dutch population there is a lag period of at least 10 years between the plateau levels of benign and malignan t ovarian tumors. The early transformation of mesothelial cells to ben ign and/or malignant tumors is clearly marked by a switch on of the BW 495/36 marker. Although no general transformation or progression marke r from adenomas to carcinomas emerged from this study, TAG-72 might be considered a (progression) marker between the subgroup of benign and malignant serous ovarian tumors.