Supplementary Material for: How Does Inhibition of the Renin-Angiotensin System Affect the Prognosis of Advanced Gastric Cancer Patients Receiving Platinum-Based Chemotherapy?

Background: The renin-angiotensin system (RAS) is related to the regulation of cell proliferation, angiogenesis, and tumor progression. Patients and Methods: We retrospectively analyzed the effect of angiotensin I-converting enzyme inhibitors (ACEIs) and angiotensin II type-1 receptor blockers (ARBs) in 63 patients with advanced gastric cancer (AGC) with platinum-based chemotherapy. All patients analyzed had received medications for hypertension at the diagnosis of AGC. Patients were divided into two groups: an ACEI/ARB group (n = 30) and a non-ACEI/ARB group (n = 33). Results: Patient characteristics were not different between patients with and without ACEI/ARB. The response rate for all patients was 25.4% and the disease control rate was 77.8%. The median progression-free survival (PFS) for first-line chemotherapy was 5.5 months (95% CI 3.71–7.29) in the ACEI/ARB group and 4.3 months (95% CI 2.39–6.21) in the non-ACEI/ARB group (p = 0.506). There was a significant difference in overall survival (OS) in the ACEI/ARB group compared to the non-ACEI/ARB group (median OS: 8.2 vs. 13.9, p = 0.0095). In multivariate analysis, the use of ACEI/ARB was a significant independent prognostic factor for OS (p = 0.039) but not for PFS. Conclusion: ACEI/ARB in combination with standard chemotherapy might improve survival in patients with AGC and hypertension. These results support further investigation into the anticancer effects of ACEL/ARB.