Level 2: Mid-level evidence
In a systematic review, cancer outcomes were analyzed in 35 randomized trials of statins studied for cardiovascular benefits in a total of 109,143 patients (J Clin Oncol. 2006;24:4808-4817). The Prospective Study of Pravastatin in the Elderly at Risk (PROSPER) trial was the only one to show a statistically significant increase in cancer risk with statins, but it was also the only one in the elderly (aged 70-82 years).
Subgroup analyses of the Long-Term Intervention with Pravastatin in Ischaemic Disease (LIPID) trial found pravastatin was associated with an increased risk for cancer in older patients (aged 65-75 years) and decreased risk for cancer in younger patients (aged 31-64 years). The results were almost statistically significant. Statins were not associated with cancer risk in an overall meta-analysis of 35 trials, but the relative risk for cancer with statins increased by 1.14 (95% CI 1.05-1.23) for every 10-year increase in mean age of patients, which suggests an increased risk in the elderly and a decreased risk in younger patients.