Long-term Use of Statins and Risk of Renal Cell Carcinoma: A Population-based Case-Control Study

Abstract

Background: Use of statins has been suggested to protect against renal cell carcinoma (RCC); however, studies have typically been underpowered, and the results are conflicting.

Objective: To determine whether the use of statins is associated with a reduced risk of RCC using high-quality registry data.

Design, setting, and participants: We conducted a nationwide case-control study based on all histologically verified cases of RCC in Denmark between 2002 and 2012 (n=4606) matched 1:10 to cancer-free controls. Data on drug use, comorbidity, and educational level were obtained from Danish nationwide prescription, patient, and demographic registries.

Outcome measurements and statistical analysis: Odds ratios (ORs) and 95% confidence intervals (CIs) for RCC associated with long-term use (≥5 yr) of statins were estimated using conditional logistic regression, adjusting for potential confounders.

Results and limitations: The adjusted OR for RCC associated with long-term use of statins was 1.06 (95% CI, 0.91-1.23). Analyses stratified by duration of statin use, type of statin, and patient characteristics all yielded ORs close to unity, except for a slightly increased OR for RCC associated with long-term statin use among women (OR: 1.25; 95% CI, 0.96-1.62). The main limitation of our study was lack of information on lifestyle factors, notably obesity, which may have biased the risk estimates upward.

Conclusions: Our study does not support an important chemopreventive effect of long-term statin use against RCC. The marginally increased and statistically insignificant risk estimates can readily be interpreted as a null finding, considering the lack of control for obesity and other lifestyle risk factors.

Patient summary: Previous studies have shown that the use of cholesterol-lowering drugs (statins) may protect against renal cancer. In a large study including all Danish renal cancers during an 11-yr period, we found no evidence of such an effect.

Keywords: Case–control study; Pharmacoepidemiology; Renal cancer; Statin.