ACE and colorectal cancer: A dose response meta-analysis of 7 observational studies, including case-control and cohort studies (total cases=15,220, total controls=1,565,018) found an association of ACE inhibitor use with reduced colorectal cancer risk (RR: 0.81, 95% CI: 0.70, 0.92), however there was substantial heterogeneity between studies (I2=71.1%) (41).