Ovarian clear cell carcinoma: open questions on the management and treatment algorithm

Ovarian clear cell carcinoma (OCCC) accounts for ~10% of all epithelial ovarian cancers and is considered a different entity from the more common high-grade serous ovarian carcinoma (HGSC), with distinct clinical presentations, different risk, and prognostic factors, and specific molecular features. Most OCCCs are diagnosed at an early stage and show favorable outcomes, in contrast to those diagnosed at advanced stages, which exhibit intrinsic resistance to platinum-based chemotherapy regimens and a very poor prognosis. The standard treatment of advanced OCCC is currently based on primary debulking surgery followed by platinum-based chemotherapy according to recent international guidelines. However, these recommendations are extrapolated from several trials mainly featuring a large cohort of HGSC, with only a small minority of OCCC. Because of its rarity, many questions remain unanswered regarding the surgical and medical treatment. Lymph node staging, fertility-sparing treatment, the use of targeted therapies and radiotherapy as well as the adjuvant treatment for early-stage disease and second or further lines of chemotherapy are still under debate. This review aims to address these unresolved issues, by providing a comprehensive overview of the current data on this disease, and to suggest possible directions for future research.