Long-term use of angiotensin II receptor blockers and risk of cancer: A population-based cohort analysis

Background: The risk of incident cancer after angiotensin II receptor blockers (ARBs) exposure was controversially reported by analyses of clinical trials and database. We assessed the occurrence of overall and site-specific cancers among ARB users and nonusers in the cohort with indications for ARB treatment. Methods: Data were obtained from the Taiwan National Health Insurance research database. Subjects exposed to ARBs >= 180 days with no cancer prior to the first year of ARB initiation were identified; age-, sex-, comorbidity- and time-matched nonusers without cancer before the index date plus 1 year were selected. Incidences of overall and the most common cancers between users and nonusers were compared. Results: There were 42,921 subjects enrolled in each group. During the mean follow-up of 4.8 +/- 2.4 years, the cumulative incidence of cancer was 4% (ARB users) and 6% (ARB nonusers) (hazard ratio: 0.58, 95% confidence intervals 0.55-0.62; P<0.001). All ARBs significantly correlated with lower rates of cancer. Malignancies from the 7 most common sites were fewer in ARB users with the relative risk reduction of 28 to 49%. ARBs were associated with a decrease in incident cancer across subgroups including prior and concomitant exposure to angiotensin-converting enzyme inhibitors. Conclusions: In the cohort with indications for ARB treatment, exposure to ARBs was associated with lower risk of overall and site-specific cancers compared to nonusers. These findings reassure the safety of ARBs and support further investigations on ARBs and cancer prevention at the molecular level. (C) 2012 Elsevier Ireland Ltd. All rights reserved.