Sunday, February 10, 2008

Cholesterol Lowering Drugs and Cancer

By: Shane Ellison, M.Sc.


The use of cholesterol-lowering drugs for the prevention of heart disease may increase your chances of suffering from the pandemic killer known as cancer. Few doctors are aware of this real and present danger.

Well-designed studies have shown the link between cholesterol-lowering drug use and cancer. In a study published in the Journal of the American Medical Association (JAMA), Thomas B. Newman MD, MPH and co-workers show that all cholesterol-lowering drugs, both the early drugs known as fibrates (glofibrate, gemfibrozil) and the newer drugs known as statins (Lipitor, Pravachol, Zocor), cause cancer in rodents at the equivalent doses used by man.

The extrapolation of evidence of cancer from rodent to human is very uncertain. This is the argument of those in favor of using cholesterol-lowering drugs. The argument would only be plausible if human studies also showed an increase in cancer rates. And in fact, that is what science is showing.

Evidence from the cholesterol-lowering drug trial known as CARE (Cholesterol And Recurrent Events) showed that Pravachol(a cholesterol-lowering drug made by Bristol-Myer Squib) reduced the chance of suffering from a heart attack by an absolute reduction rate of 1.1%. This miniscule benefit was accompanied by a 1500% increase in breast cancer among women taking Pravachol.

It is rare that cancer would show up in most other cholesterol-lowering drug trials. Drug company-funded studies for these drugs are conveniently short in nature, typically 5 years or less. It can take decades for cancer to develop. Therefore, cancer rarely shows up. In fact, even heavy smoking will not cause lung cancer within 5 years. Yet it is a well-known fact that smoking leads to lung cancer. Therefore, as long as statin drug trials last only 5 years, this side effect will continue to fly below the radar.

If cancer were to show up as a negative side effect, there is concern whether or not it would be reported. The British Medical Journal (BMJ) has reported that of 164 statin drug trials reviewed, only 48 reported the number of participants with one or more negative side effects caused by the drug.

start quoteStatins have killed and injured more people than the government has acknowledgedend quote
-- USA Today

As if in recognition of this, attempts have been made to warn the public. Dr. Gloria Troendle, deputy director for the Division of Metabolism and Endocrine Drug Products for the FDA, noted that the cholesterol-lowering drug gemfibrozil belonged to a class of drugs that has repeatedly been shown to increase death rates among users. Moreover, Dr. Troendle stated that she does not believe the FDA has ever approved a drug for long-term use that was as cancer causing at human doses as gemfibrozil. Elizabeth Barbehenn, PhD, concluded to the FDA, "fibrates must be considered as potential human carcinogens and their carcinogenic potential should be part of the risk benefit equation for evaluating gemfibrozil."

Historically, FDA advisors were reluctant to approve the cholesterol-lowering drugs. When asked to vote whether or not the cholesterol-lowering drug gemfibrozil should be approved for the prevention of heart disease, only 3 out of 9 members of the FDA advisory committee voted in favor of approval. Unfortunately, these votes are only "advisory" and the FDA decided to approve gemfibrozil for human consumption against the better judgment of the committee.

One mechanism by which cholesterol-lowering drugs may cause cancer has been identified. Published in Nature Medicine, Dr. Michael Simons of Beth Israel Deaconess Medical Center in Boston shows that statin drugs mimic a substance known as vascular endothelial growth factors (VEGF). The biochemical VEGF promotes the growth of new blood vessels, a process known as angiogenesis. While angiogenesis may help the growth of arteries, the benefit is quickly negated by the potential for growth of cancer. The British Journal of Cancer reports that VEGF plays an important role in the spread of colorectal cancer. Further, for those who already have tumors, VEGF and compounds that mimic VEGF significantly diminishes that person's survival time.

Benefits associated with cholesterol-lowering drugs do not exceed risk. Looking at the statin-drug trials,only two of the many cholesterol-lowering trials prevented absolute total mortality rates when compared to a placebo, all others provided no benefit.

The Long Term Intervention with Pravastatin (Pravachol) in Ischemic Heart Disease (LIPID) trial showed a contemptible 3.1% reduction in absolute total mortality rates. Similarly, the 4S trial showed a minimal 3.3% reduction in absolute total mortality rates among those taking 20-40mg/day of Zocor.

USA Today reported that, "Statins have killed and injured more people than the government has acknowledged." Oblivious to their dangers, medical doctors are calling cholesterol-lowering drugs the "new aspirin" and are even recommending that children be prescribed cholesterol-lowering drugs.

The medical community failed to protect the public from Vioxx. Now they are failing to protect them from the dangers of cholesterol-lowering drugs.

Health and longevity was not meant to be risky, complicated or expensive. To attenuate the risk of using cholesterol-lowering drugs while preventing heart disease, the general public must utilize healthy lifestyle habits.


References:

1. Newman, Thomas B. et al. Carcinogenicity of Lipid-Lowering Drugs. JAMA. January 3, 1996-Vol 275, No. 1.
2. Ravnskov, Uffe. Statins as the new aspirin. Letters. BMJ. 2002; 324:789 (30 March).
3. Law, M.R. et al. Quantifying effect of statins on low-density lipoprotein cholesterol, ischaemic heart disease, and stroke: systematic review and meta-analysis. BMJ. 2003 June 28; 326 (7404): 1423.
4. Akagi K. et al. Vascular endothelial growth factor-C (VEGF-C) expression in human colorectal cancer tissues. Br J Cancer. 2000 Oct; 83 (7):887-91.
5. Nature Medicine September, 2000;6:965-966, 1004-1010.
6. Sternberg, Steve. USA Today. 08/20/2001.