Hypertension, antihypertensive therapy and renal-cell cancer: a meta-analysis

The relationship between hypertension, antihypertensive treatments and the risk of renal-cell cancer (RCC) remains still controversial. To evaluate the strength of the evidence provided by the epidemiological literature on this topic, a MEDLINE search of the papers published from 1966 to 2006 was performed. A total of 18 studies were included in the analysis. Pooled estimates of the effects of interest were obtained by fitting random effect models to the original data. The effects of some characteristics of the studies were considered as putative sources of heterogeneity of the estimates. Significant increased risks of RCC associated with hypertension (pooled odds ratio 1.62; 95% confidence interval: 1.24 to 2.12), as well as with the use of both diuretics (1.43; 1.12 to 1.83) and no diuretics (1.51; 1.21 to 1.87) antihypertensive drugs were observed. The effect of diuretics was significant in women (1.92; 1.59 to 2.33), but not in men (1.18; 0.93 to 1.49). Allowance for the known risk factors of RCC appreciably modified the effect of no diuretic antihypertensives making its pooled estimate not significant (1.17; 0.94 to 1.46). Although the pooled estimates show that both, hypertension and hypertensive therapy, are statistically associated with increased risk of RCC, experimental data and a closer look on the original data from epidemiologic literature, show that available evidence are still uncertain and need to be further investigated.