Tuesday, 25 December 2012

Anti-cholesterol drugs [Statins] may prevent cancer deaths

reposted from:
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Can Statins Be Used to Prevent or Treat Cancer?

The safety and efficacy of statins, coupled with the recognition of the importance of maintaining low LDL cholesterol to prevent cardiovascular disease, has resulted in these medicines becoming some of the most widely prescribed drugs of all time. Millions of patients have been taking statins for as long as two decades and, as a result, an enormous database exists in terms of the long-term benefits and risks these agents might have. This information continues to be mined resulting in various hypotheses of other potential effects that statins may have beyond lowering LDL cholesterol. A study last week, reported in the New England Journal of Medicine is typical. These Danish authors believed that since cholesterol is essential for cell proliferation, perhaps statins could reduce cholesterol availability thereby leading to decreased proliferation and migration of cancer cells (metastasis).

To test their theory, these scientists assessed cancer mortality among patients in the entire Danish population who received a diagnosis of cancer between 1995 and 2007, with a follow-up until the end of 2009. They found that 18,721 (out of 277,204) of these cancer patients had used statins regularly and that these patients were 15% less likely to die from their disease than their non-statin treated counterparts. The study didn’t look at whether statins could prevent cancer, but only at the results after cancer has been diagnosed.

This is not the first hint that statins may have a beneficial impact in the treatment of cancer. At this year’s American College of Gastroenterology meeting in Las Vegas, researchers at the Mayo Clinic spoke of their meta-analysis of 13 studies involving a total of 1,132,969 patients of which 9,285 were diagnosed with esophageal cancer. Those who were on statins were 28% less likely to get esophageal cancer than those not on statins.

However, anyone experienced in the conduct of clinical trials will be able to tell you that meta-analyses just provide a signal, not a conclusion. Because they are retrospective in nature, meta-analyses have flaws. For example, in these studies patients are also taking other drugs, so you don’t know if he observation is due to the statin or the other drugs also being administered. Similarly, statin users may be people who tend to take better care of themselves in terms of diet and exercise and so the beneficial effects may not have anything to do with the statin use. This is why you cannot get FDA approval for a drug indication based on meta-analyses. Rather, you need to carry out highly controlled clinical trials so that the ONLY variable in the study is statin use vs. non-statin use. Only then will you be able to ascertain whether statins are delivering a benefit.

So, are there any clinical trials underway to test whether statins can, in fact, be useful in cancer treatment? Actually, the National Cancer Institute (NCI) is funding a variety of studies in this area. A check of shows there are at least a dozen such studies ongoing. One example, a study being carried out at the M.D. Anderson Cancer Center, is exploring the use of atorvastatin (Lipitor) in preventing breast cancer in women at high-risk for getting this disease. Another is a trial studying rosuvastatin (Crestor) in the prevention of colorectal cancer recurrence in patients whose cancer was surgically removed. Studies are also underway exploring statins in others cancers including prostate, melanoma and acute leukemia.

The downside to all of this is that these studies won’t be completed for a number of years. However, if any of these trials are successful, it is possible that relatively inexpensive generic drugs designed to reduce heart attacks and strokes could turn out to be an important addition to battling a tough disease.

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