Cholesterol-lowering drugs called statins may prevent various forms of cancer, including prostate and colon cancer, two teams of researchers said this week.

Israelis who took statins had a 51 percent lower risk of developing colon cancer than those who did not take the drugs, Dr. Stephen Gruber of the University of Michigan told a meeting of the American Society of Clinical Oncology.

A second study at Oregon Health & Science University Cancer Institute showed that men who took statins had a 58 percent lower risk of prostate cancer.

Combined, the studies suggest that statins, which reduce how much cholesterol the body makes, may also affect some the of the processes that underlie cancer.

But Gruber warned his study was “observational,” or based on questionnaires rather than strict scientific controls, so it is far too early to definitively conclude that statins can prevent cancer.

His team studied 3,342 Israeli patients, about half of them with colorectal cancer, comparing them to a similar number of people matched for age, gender, and ethnicity.

They were all asked whether they had taken a statin for at least five years.

Statins greatly reduce the risk of stroke and heart attack and may help patients with multiple sclerosis and even Alzheimer’s disease.

Prostate cancer prevention
Statins - which include Pfizer Inc.‘s $10 billion-a-year Lipitor, Bristol-Myers Squibb Co.‘s Pravachol and Merck and Co. Inc’s Zocor - interfere with an enzyme called HMG-CoA reductase that enables the liver to produce cholesterol.

In laboratory studies they also interfered with the growth of cancer cells.

“Pravastatin (Pravachol) and simvastatin (Zocor) had similarly protective effects” against colorectal cancer,” Gruber said, suggesting all members of the statin class somehow interfere with development of tumors.

Gruber said other types of medicines that help control buildup of artery-clogging fats did not appear to have reduced the cancer risk.

He speculated statins, besides cutting cholesterol production, also interfere with a number of genes that promote tumors and therefore probably protect against other forms of cancer.

Oregon Health & Science University researcher Jackilen Shannon agrees.

“We were interested in the relationship between statin use and prostate cancer because recent research has demonstrated that in a number of tumor types, statins also induce cancer cell death and growth arrest,” Shannon said in a statement.

“If these results are confirmed in a larger prospective study, they may provide necessary evidence to consider the use of cholesterol-lowering drugs in prostate cancer prevention. Currently, no preventive measures are available for prostate cancer.”

Her team reviewed the records of men who got prostate biopsies, a test for cancer, at a Veterans Affairs Medical Center. They included 72 men diagnosed with prostate cancer, 150 with negative biopsies, and compared them to 208 men whose prostate antigen tests, a measure of potential cancer, were normal.

They looked to see which men had taken statins, any statins, for any length of time.

Men with a cumulative dose of more than 19 grams had lower risk of prostate cancer. Those with an average daily dose of more than 40 milligrams were less likely to have an elevated PSA.

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SOURCE: American Journal of Public Health