Conversion surgery for stage IV gastric cancer: Real-world insights with a focus on elderly patients (OGSG2301).

311 Background: Recent advances in systemic chemotherapies, especially molecular targeted drugs and immune checkpoint inhibitors (ICIs), have improved survival outcomes for patients with Stage IV gastric cancer. However, their impact on conversion surgery rates remains unclear, particularly in elderly patients. Methods: This study retrospectively analyzed 376 Stage IV gastric cancer patients treated with chemotherapy across 36 institutions in 2022. The primary endpoint was the overall conversion surgery rate, defined as any surgery performed after chemotherapy. The conversion surgery rate according to the JCOG criteria was also evaluated as a secondary endpoint; this refers to surgery performed on patients whose tumors were converted from unresectable to resectable status as a result of chemotherapy. Additionally, the following data were compared between the elderly (≧75 y.o.) and non-elderly groups (