Although the findings of this study are limited by the fact that the pooled results come from trials not designed to explore cancer outcomes as the primary end point and by the lack of individual patient-level cancer data, “meta-analysis can be useful in providing insights into issues of safety and rare adverse events that might provide the hypothesis for a prospective trial,” the authors wrote, noting that the findings “warrant further investigation.”
My Take
This Raises Crucial Safety Questions
The meta-analysis linking angiotensin receptor blockers with an increased risk of incident cancer raises crucial drug safety questions. “Are angiotensin-receptor blockers associated with increased risk of incident malignancies? Should we be concerned about all ARBs or a single drug, telmisartan? How can this uncertainty best be resolved? What actions should practitioners take while this concern undergoes further examination and analysis?”
While the meta-analysis has its strengths—particularly its size, the thoroughness of the literature search, and the application of appropriate filters to exclude potentially unreliable data, “there are also important weaknesses, which the investigators acknowledge—including the post hoc nature of this investigation and the fact that the trials were not designed to explore cancer outcomes,” leading the investigators to be “appropriately cautious” in their interpretation of the data.
Until regulators review the possible association between ARB use and cancer and report their findings, “we should use ARBs, particularly telmisartan, with greater caution. These drugs are often overprescribed, as a result of aggressive marketing and in the absence of evidence that they are better than angiotensin-converting enzyme inhibitors. ARBs can be reserved for patients with intolerance to ACE inhibitors.” Using ARBs more selectively will also save money, “since nearly all ARBs are proprietary while ACE inhibitors are generic.”
STEVEN E. NISSEN, M.D., is chair of the department of cardiovascular medicine at the Cleveland Clinic. His remarks were made in an editorial (Lancet Oncol. 2010 [doi:10.1016/S1470-2045(10)70142-X]). He has received research support from Pfizer, Astra Zeneca, Novartis, Novo Nordisk Roche, Daiichi-Sankyo, Takeda, Sanofi-Aventis, Resverlogix, and Eli Lilly. He consults for many pharmaceutical companies, but donates all related money to charity.
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