A Lancet Oncology meta-analysis of 61,590 patients found a modest 8% increase in new cancer diagnoses with ARB use, particularly lung cancer, though no increase in cancer deaths was seen.
RR 1.088% relative increase in new cancer diagnoses with ARB use versus controls, though absolute risk difference was small (~1.2 percentage points)
What the researchers found
A meta-analysis of randomized controlled trials involving 61,590 patients found that angiotensin receptor blockers (ARBs) were associated with a modestly increased risk of new cancer diagnosis: 7.2% in ARB groups versus 6.0% in control groups (RR 1.08, P=0.016). When limited to trials with cancer as a prespecified endpoint, the risk was slightly higher (RR 1.11, P=0.001).
Among specific cancers, only lung cancer showed a significantly increased risk with ARB use (0.9% vs 0.7%, RR 1.25, P=0.01). No significant increase in cancer deaths was observed (1.8% vs 1.6%, P=0.183). Telmisartan was the ARB used in 85.7% of patients in the cancer analysis, so the signal was heavily driven by this specific drug.
Why it matters
ARBs are among the most widely prescribed drugs worldwide for hypertension, heart failure, and diabetic kidney disease. The angiotensin II peptide system — which ARBs block — plays roles in cell growth, blood vessel formation, and tumor progression. This Lancet Oncology meta-analysis raised an important safety signal that generated considerable debate and led to regulatory review. While subsequent analyses have largely been reassuring, the study highlights how peptide signaling systems (like the renin-angiotensin system) can have unexpected effects across different organ systems.
The numbers in context
n=61,590 for new cancer · n=93,515 for cancer deaths · new cancer: 7.2% vs 6.0% (RR 1.08, P=.016) · lung cancer: 0.9% vs 0.7% (RR 1.25, P=.01) · cancer deaths: NS · telmisartan = 85.7% of ARB patients
How the study worked
Systematic meta-analysis of randomized controlled trials identified through Medline, Scopus, Cochrane databases, and FDA records. Included trials with at least 100 patients, ≥1 year follow-up, and ARB in at least one arm. Separate analyses were conducted for new cancer occurrence, specific solid organ cancers, and cancer mortality.
Who was studied
Up to 93,515 patients from RCTs of angiotensin receptor blockers, primarily for hypertension and cardiovascular conditions
What this study cannot tell us
The cancer signal was heavily driven by telmisartan (85.7% of ARB patients), making it difficult to generalize to all ARBs. Cancer was not the primary endpoint in most included trials, raising concerns about ascertainment and reporting bias. The absolute risk increase was small (~1.2 percentage points). No increase in cancer deaths was observed, suggesting the cancers detected may have been early-stage or incidental. Subsequent larger meta-analyses and regulatory reviews have not confirmed a consistent cancer risk with ARBs as a class.
How to read the evidence
This is a meta-analysis of randomized controlled trials published in Lancet Oncology — one of the highest evidence levels possible. The 'Strong' grade reflects the meta-analytic design and large patient numbers, though the finding has been debated and not consistently replicated.
When this study was published
Published in 2010, this was a highly influential but controversial study. The FDA reviewed the data and concluded there was insufficient evidence to confirm a causal link between ARBs and cancer. Subsequent larger meta-analyses have been largely reassuring, though the question stimulated important research on angiotensin's role in tumor biology.
The bigger picture
The renin-angiotensin system is one of the body's most important peptide signaling pathways. Angiotensin II doesn't just control blood pressure — it also influences cell growth, blood vessel formation, and inflammation, all of which are relevant to cancer biology. This meta-analysis highlighted that blocking peptide receptors intended for one purpose can have unexpected effects elsewhere. While the cancer signal has not been consistently replicated, it underscores the importance of long-term safety monitoring for drugs that modulate peptide signaling systems.
Questions still open
- Is the cancer signal specific to telmisartan, or does it apply to all ARBs?
- How does blocking angiotensin II type-1 receptors potentially promote tumor growth at the mechanistic level?
- Have subsequent larger studies confirmed or refuted this association?
Common questions
Should I stop taking my ARB blood pressure medication because of this study?
How could a blood pressure drug affect cancer risk?
Read the original research
Angiotensin-receptor blockade and risk of cancer: meta-analysis of randomised controlled trials.
The Lancet. Oncology, 11(7), 627-36
Citation
Sipahi, Ilke; Debanne, Sara M; Rowland, Douglas Y; Simon, Daniel I; Fang, James C. (2010). Angiotensin-receptor blockade and risk of cancer: meta-analysis of randomised controlled trials.. The Lancet. Oncology, 11(7), 627-36. https://doi.org/10.1016/S1470-2045(10)70106-6