Ovarian cancer is the most lethal disease among all gynaecological malignancies. It can be categorized into three major groups according to the origins of the ovarian tumors: (1) epithelial tumors, (2) stromal tumors and (3) germ cell tumors. Among these three groups, Epithelial Ovarian Cancer (EOC) accounts for approximately 90% of ovarian malignancies and can be divided into four major histological subtypes based on morphological and appearance criteria: serous, mucinous, endometrioid and clear cell carcinoma. Each of these histologic subtypes is further subdivided into benign, borderline and malignant according to their malignant potential.
Ovarian Clear Cell Carcinoma (OCCC) is distinct histopathologically and clinically from the other EOC subtypes. This tumor has a high incidence at stage I and usually present as a large pelvic mass, rarely exist bilaterally, associated with endometriosis, hypercalcemia as well as thromboembolic vascular complications. While the incidence of OCCC is not high and accounts 3.7- 12.1% of all EOC, patients with OCCC have a poorer prognosis and higher recurrences than patients with other EOC subtypes. The recent clinical management of advanced EOC includes maximal cytoreduction and platinum plus paclitaxel–based combined chemotherapy. However, the survival rates of OCCC patients are much lower than other advanced EOC such as endometrial subtype. The poor response of OCCC to platinum-based regimens may be due to the intrinsic chemo-resistance. Therefore, novel treatment approaches such as molecular-targeted therapies plus more effective combinations of new chemotherapeutic agents should be investigated in a prospective clinical trial in OCCC.