Tumor Cholesterol Synthesis, Statin Use, and Lethal Prostate Cancer

Prostate tumor cells produce cholesterol de novo, and statin therapy targets the initial rate-limiting enzyme in this process, 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR). The extent to which the expression of HMGCR in prostate tumors could influence progression and predict the potential antineoplastic effects of statins remains unclear. In a prospective cohort study of 1,098 men diagnosed with primary prostate cancer from 1982 to 2009 in the Health Professionals Follow-up Study and Physicians' Health Study, 16% of prostate tumors showed strong HMGCR staining intensity, and 31% showed no staining. HMGCR expression was higher in tumors with PTEN loss but did not differ by statin use or long-term dietary cholesterol or saturated fat intake. Participants were followed for lethal events (distant metastases or prostate cancer-related death) over up to 32 years, and 96 lethal events occurred in those without metastases at diagnosis. Strong HMGCR expression was associated with higher rates of lethal prostate cancer (HR, 2.2; 95% confidence interval, 1.3-3.7), adjusting for age at diagnosis and Gleason score but without a linear dose response. In vitro, in the LNCaP human prostate cancer cell line, atorvastatin affected tumor cell viability in cells with experimentally lowered HMGCR expression. This study corroborates that high cholesterol synthesis in prostate tumor cells is associated with PTEN loss, aggressive tumor characteristics, and a greater risk of lethality. IMPLICATIONS: High expression of HMGCR, the first rate-limiting enzyme of cholesterol synthesis, is a feature of prostate tumors that are more likely to progress to metastatic disease or death from prostate cancer.