Angiotensin-converting enzyme inhibitors/angiotensin receptor blockers therapy and colorectal cancer: a systematic review and meta-analysis

We aim to investigate the association between angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs) therapy and colorectal cancer (CRC) by conducting a systematic review with meta-analysis. Literature was searched on PubMed, Scopus, and the Cochrane library to identify relevant studies evaluating ACEIs/ARBs therapy and risk of CRC incidence or survival of CRC patients. Pooled risk ratio (RR) with 95 % confidence intervals was calculated for the association between ACEIs/ARBs and CRC risk and mortality. Eleven observational studies were included in the systematic review. A meta-analysis of six studies totaling 113,048 individuals indicated a 6 % decreased risk of CRC in ACEIs/ARBs users compared to non-users (95 % CI 0.89-0.98). In the four case-control studies, individuals using ACEIs/ARBs were associated with a 6 % decreased risk of CRC (95 % CI 0.90-0.99). The meta-analysis of three studies investigating the relationship between ACEIs/ARBs and survival of CRC did not show a significantly decreased mortality in ACEIs/ARBs users (RR 0.81, 95 % CI 0.60-1.09). Seven studies evaluated the dose-response relationship between ACEIs/ARBs therapy and CRC, and two of them showed that the association was related to longer duration and higher dose. CEIs/ARBs therapy might be associated with a reduce risk of CRC development, but whether use of these medications improves the outcomes of CRC remains unknown. Large-scale and more robust studies are needed to further explore this association.