Clinical and biological characteristics of clear cell carcinomas of the ovary in FIGO stages I-II.

Clear cell carcinoma of the ovary is considered to be a specific subtype among the epithelial ovarian malignancies. To characterize clear cell carcinomas in early FIGO stages (I-II) with regard to clinical and biological properties, a retrospective study was performed to compare these tumors with other histological subtypes. From a complete series of 226 patients with epithelial ovarian carcinomas in FIGO stages I-II, 28 patients with clear cell carcinomas were selected and the clinical and biological characteristics of these tumors were compared with the remaining non-clear cell carcinomas. All patients underwent primary staging laparotomy followed by adjuvant radiotherapy or chemotherapy. The apoptosis regulators p53, bcl-2 and bax, and the growth factor receptors EGFR and HER-2/neu were analyzed by immunohistochemical techniques and DNA analysis was performed by flow cytometry. Clear cell carcinomas stained negative for p53 significantly more often than other histological subtypes. Positive EGFR staining was seen more frequently in serous carcinomas than in the clear cell carcinomas. Aneuploid DNA status was seen more frequently in clear cell carcinomas than in other histological subtypes and tetraploid tumors made up 50% of the non-diploid tumors. Clear cell tumors were frequently (64%) found in FIGO stages IC and IIC and this was more common than for non-clear cell tumors. No difference was found in the rate of tumor recurrences or survival for patients with clear cell and non-clear cell carcinomas. Clear cell carcinomas of the ovary should be regarded as a separate entity among the epithelial ovarian carcinomas and they differ with regard to both clinical and biological characteristics when compared with non-clear cell tumors.