A provocative press release crossed my desk today, “Study Finds Association Between Low Cholesterol Levels and Cancer” with subtitle: “Benefits of Statin Therapy Outweigh Small Risk.” Well that’s fairly terrifying, isn’t it? It sounds as if they’re saying that taking a statin (like lipitor or zocor) is good for your heart but might carry with it the “small” risk of developing cancer.
First of all, let me assure you that this is a gross misinterpretation of the metanalysis. The authors themselves never postulated a cause and effect between statins and cancer, and in fact did all they could to avoid drawing this conclusion. They merely observed that there was a slight trend towards higher cancer rates among people with low LDL cholesterol.
There are two very good explanations for the higher cancer rates in people with low cholesterol:
1. Everyone knows that “unexplained weight loss” is an ominous sign. Often times a patient’s first clue that they have cancer is sudden weight loss – since cancer has a voracious appetite and steals nutrients from the rest of the body. When people lose weight, their cholesterols decrease. So it’s possible that low LDL cholesterol is really just a surrogate marker for those who already have very early stages of cancer that have not yet been detected otherwise.
2. Statins are well known to reduce cholesterol and the atherosclerotic plaques that put people at risk for heart attacks and strokes. Lower cholesterol levels can reduce overall mortality risk/year by 30%, and so people live longer when they have lower cholesterol levels. People who live longer extend their opportunity to develop cancer. And so lower cholesterol levels inadvertently raise your cancer risk simply because they may extend your life.
Why else do I think the link between cancer and statins is faulty? Because the observed increase in cancer rates was in ALL cancer types – the genetics of cancer is so complex, and the reasons why certain cell types begin to divide in an uncontrolled manner is so diverse, that it’s hard to imagine any possible trigger could stimulate all cells to become cancerous. Also, most cancers develop very slowly, and the 5 year window in which the authors observed people taking statins and developing cancers is too short to be a cause and effect. And finally, previous statin safety studies showed no link between them and the development of any form of cancer.
The Journal of the American College of Cardiology admits in an
accompanying editorial, “In the 5 years that we have been stewards of
the Journal, no other manuscript has stimulated such intense scrutiny
or discussion.” Do I think they should have published this study? Yes – but to me the most interesting question out of all of this is: could cholesterol screening be used for early cancer detection? If an extra low LDL is observed, maybe that should prompt some additional investigations to rule out occult malignancies?
Obviously, more studies are needed to determine the potential validity of such an approach… but for now, there is absolutely no reason (based on this study) to cease statin therapy for fear of developing cancer. Hope that allays some fears!This post originally appeared on Dr. Val’s blog at RevolutionHealth.com.