The Impact of Statins on Colon Cancer Risk

Statins are commonly used to treat high LDL cholesterol levels. They lower cholesterol production in the liver by inhibiting an factor in the mevalonate pathway. A negative side effect of statins is that they have the potential to cause liver damage. A positive side effect is that they may reduce a person's risk of developing colon cancer.

Examples

Examples of statins include Lipitor (atorvastatin), Lescol (fluvastatin), Mevacor (lovastatin), Pravachol (pravastatin), Crestor (rosuvastatin), and Zocor (simvastatin).

How Statins Might Inhibit Cancer Growth

Statins have several effects in the body. They are pro-apoptotic, supporting the process of breaking down cells, including tumor cells. They are anti-angiogenic, acting to prevent cancers from developing a blood supply. Without a blood supply, tumors cannot grow and invade other tissues. They sensitize tumor cells to natural killer (NK) cell activity. This would enhance your body's own immune function in attacking and killing tumors by recognizing them as foreign cells that shouldn't be allowed to continue growing in the body. All of those would seem like characteristics that might have an effect on tumors and cancers in general. The question then is whether there is any convincing evidence that statins actually have an effect on preventing cancer growth and spread in your body.

Research That Supports This Claim

An Israeli study found that using statins for more than five years could reduce the risk of developing colon cancer by almost 50%. This study included more than 3,000 people, about half of whom had colon cancer. That certainly appeared to be a significant finding.

A Canadian study found that using statins significantly lowered the risk of developing colon cancer. But, the authors pointed out that approximately 4,814 people would need to be treated with statins for five years to prevent one case of colon cancer. That is a very large amount of medication being done in the hopes of preventing only a small number of actual cases of cancer.

Research That Doesn't Support This Claim

An American study examined the association between cholesterol-lowering drugs and the incidence of colon cancer in more than 130,000 people. Researchers found that cholesterol-lowering drugs, in general, don't impact colon cancer risk. They specifically noted that the study didn't support the idea that statins, as a class of drugs, strongly reduce the risk of developing cancer of the colon or rectum.

However, since the study didn't examine specific types of statins, it couldn't rule out the possibility that specific types and doses of statins could potentially reduce a person's risk of developing colon cancer.

A 2015 review of studies concluded, "it has not yet been confirmed that statins influence the risk of developing colorectal cancer, breast cancer, or lung cancer."

Bottom Line

Do statins reduce a person's risk of developing colon cancer or not? Unfortunately, the jury is still out on that question. For now, we'll have to settle for "maybe" and keep an eye out for more research. The question may be proven one way or another in the future.