Hypertension is without doubt a leading cause of morbidity and mortality, especially prevalent in the developed world. Unsurprisingly, the search for newer, better antihypertensive therapy is ever ongoing, whereas the older, more established drug treatments such as diuretics, beta-blockers, calcium antagonists and angiotensin-converting enzyme inhibitors continue to be the mainstay of current treatment guidelines for hypertension. In the main, as a group of drugs, their profiles and complications have been well established from decades of use as well as the many large trials conducted 1-3 that provide unassailable evidence that antihypertensive therapy lowers cardiovascular morbidity and mortality. What is less clear is the relationship between hypertension treatment and overall mortality; indeed, not all studies demonstrate a significant decrease in overall mortality, 4 whereas others report a reduction which is negated over time. 2 One possible reason for this could be the longerterm non-cardiovascular effects of antihypertensive therapy. Indeed, some researchers suggest a link between some antihypertensive drugs and malignancy. The very possibility of there being a relationship is worth considering, not least because as a group of drugs they are among the most frequently prescribed and usually for the longer term.The very idea of a relationship between antihypertensive drugs and cancer is not a new one, with Dyer et al. 5 providing the seminal prospective study investigating the relationship between systolic and diastolic blood pressure with mortality. The study excluded reserpine (an adrenergic antagonist) and implicated hypertension instead as a contributing factor in breast cancer development, contrary to the conclusions of three prior studies. 6-8 Since then, there have been many studies reporting a putative link between antihypertensive drugs and cancer, with diuretics being the most frequently cited culprit, with renal carcinoma being the most common site-specific cancer. 9 In this issue of the Journal of Human Hypertension, Largent et al. 10 describe associations between breast cancer and hypertension, as well as diuretics, in a population-based case-control study. Their study was based on self-administered questionnaires and telephone interviews -rather than clinical observations -and suffers from the inevitable problems of recall bias, as well as an ambiquous definition of antihypertensive drugs and hypertension diagnosis. Despite the limitations, the findings of a small but significant association between hypertension and breast carcinoma (odds ratio (OR) 1.77; 95% confidence interval (CI) 1.0-3.0), as well as diuretic use (OR ¼ 1.79; 95% CI 1.0-3.0) merit careful consideration. Confounding variables appear to have been adequately adjusted for, and even with stratified analyses, an increased risk with hypertension was maintained. Perhaps unsurprisingly, the authors also report an increased breast cancer risk coinciding with greater body mass index (BMI) scores, when seen in conjunction with hyperten...