The emergence of cholesterol lowering drugs called statins may have had an unexpected but welcome side-effect: lowering the death rate from prostate cancer.
American researchers raised this possibility after they looked for factors that might explain a fall in prostate cancer deaths between 1993 and 2003. During this decade the mortality rate fell from 131 to 88 deaths per 100,000 white American men older than 50 years.
“Advances in prostate cancer treatments are a part of this, but may not be the whole answer,” says Dr. Janet Colli, a study co-author and assistant professor of surgery at the University of Alabama at Birmingham.
Colli and her team used a national statistical database to track various trends over the same decade. These included changes in prostate cancer screening, health insurance coverage, obesity, physical inactivity, diabetes and cholesterol levels. Prostate cancer mortality in white males correlated most strongly with elevated cholesterol and, to a lesser extent, with prostate cancer screening levels.
Colli notes that statins have been shown to decrease the growth of prostate cancer cells in laboratory tests, but she says the results of the new study were nevertheless unexpected and require confirmation.
However, another recent study lends support to this potential benefit of statins. Dr. Robert Hamilton and his colleagues at the Durham Veterans Affairs Medical Center in North Carolina measured levels of prostate-specific antigen (PSA) in more than 1,500 men who were prescribed statins. PSA is a protein that may signal prostate cancer if it is present at high levels in the blood.
“We found that the average patient experienced a 4.1 per cent decline in PSA. When you look at the results, you may start to believe that statins can influence the prostate’s biology,” Hamilton says. But it is not clear whether this result means statins reduce the risk of prostate cancer or could simply mask the presence of an existing tumour.