A population-based outcomes study of patients with metastatic gastric cancer receiving second-line chemotherapy: A nationwide health insurance database study

Purpose: The survival benefit of second-line chemotherapy in patients with metastatic gastric cancer (MGC) has recently been established. We conducted a nationwide population-based outcomes study of patients with MGC receiving second-line chemotherapy to better understand real-world treatment patterns and outcomes. Materials and methods: Data were collected from the Health Insurance Review and Assessment Service database. We identified 509 newly diagnosed patients with MGC in 2010 who received second-line chemotherapy. These patients were divided into three groups for analyses: Group A comprised all patients who received second-line chemotherapy (N = 509); Group B comprised those who received fluoropyrimidine (Fp) plus platinum as first-line treatment, followed by irinotecan-based or taxane-based regimens as second-line chemotherapy (N = 284); and Group C comprised those who received Fp plus cisplatin as first-line treatment, followed by 5-fluorouracil (5-FU)/oxaliplatin, irinotecan-based, or taxane-based regimens as second-line chemotherapy (N = 184). Results: Among patients who received first-line chemotherapy, 47.2% (509/1,078) continued to receive second-line chemotherapy. The most commonly used second-line chemotherapy regimens were 5-FU/irinotecan, 5-FU/oxaliplatin, and docetaxel. The median overall survival (OS) of all 509 patients was 5.2 months. The time from the start date of first-line chemotherapy to the start date of second-line chemotherapy > 6.1 months was an independent prognostic factor for improved OS. The type of chemotherapy regimen was not a significant factor affecting OS. Conclusion: The findings provide a better understanding of second-line treatment patterns and outcomes in patients with MGC and will help guide treatment decisions in real-world clinical practice.