Meta-analysis of randomized controlled trials on effect of angiotensin-converting enzyme inhibitors on cancer risk

The renin-angiotensin system is an important mediator of tumor progression and metastasis. A recent meta-analysis of randomized controlled trials reported an increased risk of cancer with angiotensin receptor blockers. It is unknown whether angiotensin-converting enzyme (ACE) inhibitors may have a similar effect. Our primary objective was to determine the effect of ACE inhibitors on cancer occurrence and cancer death. Our secondary objective was to determine the effect of ACE inhibitors on occurrence of gastrointestinal (GI) cancers given previous concerns of increased risk. Systematic searches of SCOPUS (covering MEDLINE, EMBASE, and other databases) and the Food and Drug Administration official web site were conducted for all randomized controlled trials of ACE inhibitors. Trials with ≥1 year of follow-up and enrolling a minimum of 100 patients were included. Fourteen trials reported cancer data in 61,774 patients. This included 10 trials of 59,004 patients providing information on cancer occurrence, 7 trials of 37,515 patients for cancer death, and 5 trials including 23,291 patients for GI cancer. ACE inhibitor therapy did not have an effect on occurrence of cancer (I(2) 0%, risk ratio [RR] 1.01, 95% confidence interval [CI] 0.95 to 1.07, p = 0.78), cancer death (I(2) 0%, RR 1.00, 95% CI 0.88 to 1.13, p = 0.95), or GI cancer (RR 1.09, 95% CI 0.88 to 1.35, p = 0.43). In conclusion, ACE inhibitors did not significantly increase or decrease occurrence of cancer or cancer death. There was also no significant difference in risk of GI cancer.