The goal of this observational study is to determine the risk of recurrence in early-stage OCCC (Ovarian Clear Cell Carcinoma) patients who received postoperative adjuvant treatment.

Participants were received platinum-based adjuvant therapy following debulking surgery will be included for the study.

This is a retrospective, global multicenter, single-arm, study for early-stage OCCC (Ovarian Clear Cell Carcinoma) patients at risk of recurrence following the first-line treatment. This study is planned to enroll 272 patients eligible for participation from two study sites in Taiwan, one in Korea, and one in Japan. The study will use archival Formalin-Fixed Paraffin-Embedded (FFPE) samples from patients who have received adjuvant therapy following debulking surgery. The study is designed to identify OCCC patients at risk for relapse and apply clinical stratification by IHC staining of 3 selected markers (CD45, CD8, tryptase) to prepare as clinical assays.

Inclusion Criteria:

• Women aged ≥20 years old.
• Participant with histologically confirmed OCCC of stage IC2, IC3, IIA and IIB by International Federation of Gynecology and Obstetrics (FIGO) 2014 system.
• Participant has received platinum-based regimens for 3 to 6 cycles combined with paclitaxel, gemcitabine, cyclophosphamide, or bevacizumab adjuvant therapy following debulking surgery.
• Formalin-fixed paraffin-embedded (FFPE) tissue samples available.

Exclusion Criteria:

• Absence of histological confirmation of the diagnosis.
• Unusable sample or biologically deteriorated.

A cohort of 272 women with a diagnosis of FIGO stage IC2, IC3, IIA and IIB of OCCC, diagnosed between 2011 and 2021. Patients were received platinum-based adjuvant therapy following debulking surgery will be included for the study. Adjuvant therapy was given according to the NCCN guideline and Institutional Tumor Board.