With the widespread use of PARP inhibitors (PARPi) as maintenance therapy in ovarian cancer, there is still a lack of real-world data from large samples regarding their impact on survival outcomes in advanced and recurrent ovarian cancer. This study aims to conduct a pragmatic cohort study to evaluate the impact of first-line and second-line maintenance treatment with PARPi on survival rates in patients with advanced and recurrent ovarian cancer. The genetic status, different PARPi drugs, and the use of anti-angiogenic inhibitor maintenance therapy or not is used as confounding factors.

Inclusion Criteria:

Group 1:

• Patients newly diagnosed with stage IIIC or IV primary epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer between December 2013 and December 2024.
• Complete data on first-line treatment and maintenance therapy.
• Availability of follow-up data.

Group 2:

• Patients with platinum-sensitive first recurrence of any stage of epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer, diagnosed between December 2013 and December 2024.
• Disease progression occurring at least 6 months after the completion of the last platinum-based chemotherapy regimen.
• Complete data on second-line treatment and maintenance therapy.
• Availability of follow-up data.

Exclusion Criteria:

Group 1:

• Non-epithelial tumors, borderline tumors, clear cell carcinoma, mucinous carcinoma.
• Missing first-line or follow-up data.

Group 2:

• Non-epithelial tumors, borderline tumors, clear cell carcinoma, mucinous carcinoma.
• Patients with second relapse.
• Platinum-resistant patients, such as those who had disease progression during chemotherapy or within 6 months after platinum-based chemotherapy.
• Missing second-line or follow-up data.

Patients who were newly diagnosed with stage IIIC or IV primary epithelial ovarian cancer or had platinum-sensitive first relapsed ovarian cancer between December 2013 and December 2024.