Statins are cholesterol-lowering medications used by millions of people to lower their risk of heart disease and associated mortality. There has been growing interest in the potential anticancer activity of statins, based on preclinical studies showing that these drugs inhibit cancer cell proliferation and angiogenesis (new blood vessel growth), and that they may sensitize some types of cancerous tumors to radiation therapy.
A new study conducted by researchers at the University of Chicago and published in the Journal of Clinical Oncology sought to determine whether statin use is associated with improved clinical outcomes in patients treated with radiotherapy (RT) for prostate cancer. In total, 691 men with non-metastatic prostate adenocarcinoma treated with RT with the intent to cure the disease, between 1988 and 2006, were included in the retrospective analysis. Of those, 189 patients (27%) were using statins, either during initial consultation or during follow-up examinations. Lipid panels to measure blood cholesterol levels were collected in 298 patients with a median of 5 months before the initiation of RT. Median follow-up was 50 months after RT.
The researchers found that patients who were taking statins had significantly improved relapse-free survival—the time patients lived without their cancer returning—and were less likely to have failure of biochemical therapy (defined as the lowest measured PSA level plus 2 ng/mL) and salvage androgen deprivation therapy, consisting of a gonadotropin-releasing hormone with or without a concurrent antiandrogen. In this study, statin use did not affect the overall survival time of the patients or the risk for metastases.
There may be multiple mechanisms by which statins lower the risk of cancer and its recurrence. Inhibition of angiogenesis may be a direct effect. An indirect effect may be lowering of cholesterol. Cholesterol, which statins inhibit, is a precursor for androgen formation. Therefore lowering cholesterol levels may reduce levels of androgens in the prostate. Statins also inhibit the proliferation of cancer cells, and have synergistic effects when combined with RT. Further prospective studies are warranted in order to validate the benefits of statins for prostate cancer.