Antihypertensive therapy and the risk of malignancies

To assess the relationship between antihypertensive therapy and malignancy.

A MEDLINE search for English-language articles published between January 1966 and August 1999 identified 29 prospective studies that reported cancer incidence or mortality and 28 case-control studies that reported specific drug use in cancer patients and controls. The association between rauwolfia derivatives and breast cancer was analysed in 5852 cases and 9776 controls, yielding an odds ratio (OR) of 1.25 (95% CI, 1.09-1.44). The association between diuretics and renal cell carcinoma was analysed in 4389 cases and 6566 controls, yielding a pooled OR of 1.54 (95% CI, 1.41-1.68). The association between atenolol and cancer death was analysed pooling three randomized controlled studies, including 1879 treated patients and 3078 non-treated patients, yielding a pooled OR of 1.36 (95% CI, 1.02-1.82); however, data from non-randomized studies did not confirm the latter. The association between calcium antagonists and malignancy was analysed pooling five randomized controlled studies, including 5451 treated patients and 5207 untreated ones, yielding a pooled OR of 0.78 (CI, 0.60-1.00). A meta-analysis of an additional five longitudinal studies, including 9087 treated patients and 15 559 non-treated patients, yielded a pooled OR of 1.04 (CI, 0.91-1.19). The association between ACE inhibitors and malignancy was analysed pooling two randomized controlled trials involving 1585 treated patients and 1567 non-treated patients, yielding a pooled OR of 1.57 (95% CI, 0.97-2.57); however, non-randomized studies showed no association or a decreased risk for malignancy with ACE inhibitors.

With the exception of diuretics and renal cell carcinoma, the association between antihypertensive drugs and malignancy was either low grade (rauwolfia), uncertain (atenolol), absent (ACE inhibitors), or absent with a yet to be investigated inverse association (calcium antagonists). Ongoing long-term prospective studies with cardiovascular drugs should carefully monitor the risk of malignancy.