Sleeping with the enemy

▶ Sipahi I, Debanne SM, Rowland DY et al. Angiotensin-receptor blockade and risk of cancer: meta-analysis of randomised controlled trials. Lancet Oncol 2010;11:627–36.

Angiotensin-receptor blockers (ARBs) are a widely used drug class approved for treatment of hypertension, heart failure, diabetic nephropathy and, recently, for cardiovascular risk reduction. Animal experimental studies implicate the renin–angiotensin system in hepatic myofibroblasts as a powerful stimulator of fibrosis. Hence, randomised clinical trials are underway to investigate the efficacy of ARBs in non-alcoholic fatty liver disease and portal hypertension. However, angiotensin II type 1 and type 2 receptors, in particular, are also involved in the regulation of cell proliferation, angiogenesis and tumour progression.

Sipahi et al assessed whether ARBs affect cancer occurrence with a meta-analysis of randomised controlled trials of these drugs. Randomised controlled trials with a follow-up of at least 1 year, which enrolled at least 100 patients were included. Authors found that the patients assigned to receive ARBs had a significantly increased risk of new cancer occurrence compared with the control groups (7.2% vs 6.0%, RR=1.08, 95% CI 1.01 to 1.15; p=0.016). When analysis was limited to trials where cancer was a pre-specified end point, the RR was 1.11 (95% …