Statins or HMG-CoA reductase inhibitors are pharmacological agents used in the control and management of hyperlipidemia or high cholesterol levels. The most popular statins are Lipitor (atorvastatin) and Zocor (simvastatin).
According to the US Food and Drug Administration (US FDA), statins work in the liver to prevent formation of cholesterol
- are effective in lowering bad cholesterol levels and raising good cholesterol
- are not recommended for pregnant patients or those with active or chronic liver disease
- can cause serious muscle problems
Currently available statin drugs are:
- Lovastatin (Mevacor, Altoprev)
- Pravastatin (Pravachol)
- Simvastatin (Zocor)
- Fluvastatin (Lescol)
- Atorvastatin (Lipitor)
- Rosuvastatin (Crestor)
Several studies in recent years indicate that the use of statins can go beyond the therapeutic area of cardiovascular medicine. One of the therapeutic areas is oncology and here are some of the studies:
The study tracked 1214 men who were taking statins between 1990 and 2006 and monitored the levels of prostate-specific antigen (PSA), a known biomarker for cancer risk. Those who were on statins had lower PSA levels and effect of statins on PSA was dose-dependent. Whether the effect of statins on the PSA levels translates into anticancer properties is not yet clear. It is also not clear statins interact with prostate biology. However, the anti-inflammatory properties of statins may play a role.
Researchers at the Albert Einstein Medical Center in Philadelphia reported statins lower the incidence of blood clots in cancer patients. It is possible that statins “may have a future in preventing blood clots in patients with breast, lung, colon and other solid-organ cancers…Statins could improve endothelial function, and this could reduce the chance of venous thrombosis. Conceivably, statins could have some benefits on clotting factors. It is known that statins can have platelet effects, but this should help arterial thrombosis and would not be expected to help venous thrombosis.” Blood clots in the form of venous thromboembolism (VTE) are conditions that results when patients stay immobile for long periods of time (e.g. after surgery).However, the results are very preliminary and need to be confirmed in bigger studies.
Breast cancer and statins
A more recent research, however, demonstrated that statins do not prevent cancer. This was published in an article in the February issue of the American Association for Cancer Research (AACR) journal Cancer Prevention Research.
The results of previous studies on breast cancer and statin were a bit controversial, even inconclusive because they were mostly restrospective studies, e.g. studies that look at data in retrospect. In clinical research however, prospective studies carry more weight when it comes to providing evidence.
The current study compared the effectiveness of statins atorvastatin and lovastatin in laboratory animals with proven anti-tumor drugs on preventing breast tumors.
Atorvastatin orally administered at a dose of 125 and 500 mg/kg body weight did not influence the incidence of estrogen receptor-positive or estrogen-receptor negative breast cancers in mice. Similarly, lovastatin orally administered at 100 and 500 mg/kg body weight also did not show any significant effects. In contrast, 0.4 mg of tamoxifen or 80 mg of bexarotene induced a significant reduction in the multiplicity of mammary tumors. Combining statins with the anti-tumor drugs did not show any augmentation effect.
According to researcher Dr. Ronald Lubet
“We saw no real efficacy from either statin…Prior studies have shown some but limited efficacy in breast cancer models when these drugs were given through a method that would be the equivalent of intravenously in humans. However, that is not the way people take statins… There is always the question of whether there will be a subset of breast cancer where this class of agents will be effective, but the answer at this point is that the present preclinical studies do not support the use of statins as general breast cancer preventive agents.”
Statins are the blockbusters of the pharmaceutical industry, earning billions of dollars in revenues. One the most successful statins is Lipitor (atorvastatin) of Pfizer, supposedly the bestselling drug globally. However, many popular drugs have gone or are about to go off patent, thus exposing big pharma companies to competition from generic companies. Lipitor goes off patent in 2011. Finding new therapeutic applications for statins could be a way for many big companies to keep their hold on their bestsellers.
Some people might think that pharmaceutical companies are simply clutching straws when testing statins in other therapeutic areas. I believe this is not so. The wonder drug aspirin (acetylsalicylic acid), for example, was initially developed to treat fever and headaches. Nowadays, it occupies a major role in cardiovascular medicine as an anticoagulant agent and is also being tested in treating different kinds of cancer. Another blockbuster drug, Viagra, was initially developed as a cardiovascular drug before its rather “profitable and beneficial” side effect” was discovered.