A Comparative Study of the Treatment of Real-world Patients With Clear Cell Carcinoma of the Ovary
The goal of this observational study is to learn about the treatment effectiveness of physician's choice of chemotherapy and the immune checkpoint inhibitor (ICI)-based therapy in patients with relapsed/refractory ovarian clear cell carcinoma (OCCC), and compare the treatment response with the phase II, single-arm clinical trial INOVA to investigate the efficacy of combinational therapy of sintilimab plus bevacizumab. The main questions it aims to answer are:

What is the efficacy of physician's choice of chemotherapy in relapsed/refractory OCCC patients in the real world?
Is ICI-based therapy more effective than physician's choice of chemotherapy in real-world for relapsed/refractory OCCC patients?
Dose the combinational regimens of sintilimab plus bevacizumab in Sintilimab Plus Bevacizumab in Recurrent/Persistent Ovarian Clear Cell Carcinoma (INOVA) trial more effective than physician's choice of chemotherapy?

Participants will be respectively retrieved and extracted de-identified, longitudinal electronic health records (EHR)-derived data.
- EligibilityCriteria: Inclusion Criteria:  Female patients with age ≥ 18 years old and ≤ 75 years old. There must be a histological diagnosis of ovarian clear cell carcinoma. Patients with recurrent or persistent ovarian clear cell carcinoma must have at least one-line pretreated platinum-containing chemotherapy. Eastern Cooperative Oncology Group (ECOG) performance status score ≤ 2. Expected survival time ≥ 12 weeks.  Exclusion Criteria:  1.Histological evidence of non-ovarian clear cell carcinoma. - HealthyVolunteers: No - Gender: Female - MinimumAge: 18 Years - MaximumAge: 75 Years - StdAgeList: Adult, Older Adult - StudyPopulation: Patients with relapsed/persistent OCCC were extracted de-identified, longitudinal electronic health records (EHR)-derived data from 12 tertiary hospitals in China since October 2008. Consecutive patients were enrolled with no restriction on treatment regimens. - SamplingMethod: Non-Probability Sample