The FDA ( Food and Drug Administration ) is conducting a review of the class of medications known as angiotensin receptor blockers ( ARBs ) after a recently published study suggested they may be associated with a small increased risk of tumor.

FDA's review is ongoing and the Agency has not concluded that ARBs, also known as sartans, increase the risk of cancer.
At this time, FDA believes that the benefits of these medicines continue to outweigh their potential risks.
FDA recommends that these drugs continue to be used as recommended in their approved labels.

Sartans are used in patients with high blood pressure and other conditions. Brand names include Atacand ( Candesartan ), Avapro ( Irbesartan ), Benicar ( Olmesartan ), Cozaar ( Losartan ), Diovan ( Valsartan ), Micardis ( Telmisartan ), and Teveten ( Eprosartan ). ARBs are also sold in combination with other medications: Atacand HCT ( Candesartan and Hydrochlorothiazide ), Avalide ( Irbesartan and Hydrochlorothiazide ), Azor ( Olmesartan and Amlodipine ), Benicar HCT ( Olmesartan and Hydrochlorothiazide ), Diovan HCT ( Valsartan and Hydrochlorothiazide ), Exforge ( Valsartan and Amlodipine ), Exforge HCT ( Valsartan, Amlodipine, and Hydrochlorothiazide ), Hyzaar ( Losartan and Hydrochlorothiazide ), Micardis HCT ( Telmisartan and Hydrochlorothiazide ), Teveten HCT ( Eprosartan and Hydrochlorothiazide ), Twynsta ( Telmisartan and Amlodipine ), Valturna ( Valsartan and Aliskiren ).

The Agency plans to review the available data on these medications, and evaluate additional ways to better assess a possible link between use of sartans and cancer.

The published study was a meta-analysis combining cancer-related findings from several clinical trials. The study found a small increased risk of reported new tumors in patients taking an angiotensin receptor blocker compared to those not taking an ARB. No statistically significant difference in the number of cancer deaths was observed.

These clinical trials were not designed to study the effects of sartans on cancer risk. The findings need close examination for more detailed information about the patients who were reported to have tumor so that it can be determined whether this cancer was in fact new. Angiotensin receptor blockers have been shown to provide significant benefit in many patients with certain heart-related conditions such as high-blood pressure and heart failure.

The meta-analysis included data from over 60,000 patients in several long-term, randomized, controlled clinical trials evaluating angiotensin receptor blockers for which adverse events related to cancer were captured during the study. The mean duration of follow-up ranged from 1.7 to 4.8 years.
The study reported the frequencies of new cancer occurrence to be 7.2% for patients receiving sartans compared to 6.0% for those not receiving sartans ( risk ratio, RR= 1.08 ). No statistically significant difference in cancer deaths was noted.

The meta-analysis had several limitations that make it difficult to determine the validity of the findings without further examination of the underlying data. The limitations include: a) the analysis included data from trials where there was no adjudication of cancer-related adverse events. In these trials, there was no way to determine whether the events represented new diagnoses of cancer, or events related to a preexisting cancer. Thus, the actual number of new cancer occurrences is unknown; b) the analysis may not have included all relevant clinical trials of sartans; c) the analysis is not based on patient-level data. Knowledge of the specific timing and nature of events in individual patients would aid in interpretation of the findings; d) the majority of patients included in the studies reviewed were receiving the Telmisartan; therefore the applicability of the cancer-related findings to all sartans is uncertain; e) the meta-analysis was planned to examine a hypothesis raised by cancer-related trends in three outcome studies. Because the meta-analysis included two of these studies, the results of the meta-analysis do not provide a fully independent confirmation of the hypothesis raised by the earlier studies.

Source: FDA, 2010

XagenaMedicine2010


Link: Xapedia - Medical Encyclopedia