ARBs may increase risk of cancer development, according to meta-analysis

Key Points

A systematic review and meta-analysis conducted by researchers at Case Western Reserve University School of Medicine and University Hospitals Case Medical Center, Cleveland, suggests that angiotensin-receptor blockers (ARBs) are associated with "a modestly increased risk" of developing cancer (RR increase of 8%, P=.016).

The meta-analysis which, systematically pooled available literature through November 2009, recently was published in the July 2010 Lancet Oncology.

While not detected in early-stage development, results of clinical evaluations (including a prior meta-analysis published in 2008 by researchers at the University of Connecticut) have suggested that ARBs may have a propensity to increase cancer risk since angiotensin II type-1 and type-2 receptors (AT1R and AT2R) play an important role in cellular proliferation, angiogenesis, and consequently tumor progression.

For this most recent meta-analysis, investigators conducted a systematic literature search of MEDLINE, SCOPUS, CENTRAL, the Cochrane Database of Systematic Reviews, and FDA website in order to identify randomized trials evaluating an ARB, with a follow-up of at least 1 year; and that enrolled at least 100 patients.

The search identified 5 trials (n=61,590 patients) reporting data on the development of new cancer. Of note, nearly 86% of these patients received telmisartan. Upon meta-analysis, patients randomly assigned to receive an ARB had a significantly increased risk of new cancer occurrence compared with patients in control groups (7.2% vs 6.0%, RR, 1.08, 95% CI, 1.01–1.15; P=.016). Despite more new cases of cancer in the patients treated with an ARB, no statistically significant difference in cancer deaths was seen (1.8% vs 1.6%, RR, 1.07, 0.97–1.18; P=.183).

Investigators stated, "The increased risk of new cancer occurrence is modest but significant. However, the clinical significance of this potential excess cancer risk is unknown."

The paper concluded by cautioning readers that due to limitations in available data, it was impossible to draw conclusions about the exact risk of cancer associated with each individual ARB. Furthermore it suggested that further investigation is warranted.

This study was unfunded.