The renin–angiotensin system blockers and survival in digestive system malignancies

BACKGROUND: Accumulating pre-clinical and clinical studies suggested that the renin-angiotensin system blockers (RASBs) possess anti-carcinogenic properties, and their use is associated with favorable outcomes in many types of cancers. METHODS: A systematic literature search of relevant databases through January 2019 was conducted to identify studies assessing the RASBs on prognostic outcomes in digestive system malignancies patients on the basis of predetermined selection criteria for pooled hazard ratio (HR) with 95% confidence intervals (CIs). A total of 13 studies were included in the meta-analysis. RESULTS: The meta-analysis showed that the use of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) resulted in a significant improvement in overall survival (HR 0.79; 95%CI 0.70-0.89; P < .000), cancer-specific survival (HR 0.81; 95%CI 0.73-0.90; P < .000) and recurrence-free survival (HR 0.68; 95%CI 0.54-0.85; P = .001), but not progression-free survival (HR 0.88; 95%CI 0.73-1.07; P = .183) and disease-free survival (HR 0.50; 95%CI 0.11-2.39; P = .103). Subgroup analysis indicated that the use of RASBs has a significant improvement of overall survival (OS) in pancreatic cancer, liver cancer, and gastric cancer. Two studies evaluated the dose-response relationship between ACEIs/ARBs therapy and survival and showed higher doses and better survival [(1-364 defined daily doses: odds ratio (OR) 0.89, 95%CI 0.78-1.01, P = .076), (≥365 defined daily doses: OR 0.54, 95%CI: 0.24-1.24, P = .148]. CONCLUSIONS: Meta-analysis of studies supports a beneficial association between use of RASBs and survival of digestive system malignancies.