Heart drug digoxin may provide prostate cancer treatment
A heart failure drug derived from the foxglove plant, called digoxin (also known as digitalis), may provide a new treatment for prostate cancer, US scientists say.
Researchers at Johns Hopkins University set out to identify existing drugs for other diseases that could be used for prostate cancer - a process known as 'drug repositioning' - using a combination of laboratory science and population studies (epidemiology).
To begin with, scientists screened 3,187 chemicals for toxicity against prostate cancer cells in the laboratory.
Digoxin - a drug routinely used to treat heart conditions such as atrial fibrillation - was found to be effective at preventing the development of prostate cancer cells in lab-grown samples.
Epidemiologists then looked at prostate cancer rates among 47,884 men, all of whom were followed from 1986 to 2006.
They found that those who regularly took digoxin had a 25 per cent lower risk of prostate cancer than those who did not.
Meanwhile, population studies showed that there was an average 46 per cent reduced risk of the disease among men who had used digoxin for more than ten years.
The researchers, whose findings are published in the journal Cancer Discovery, are now trying to work out exactly how digoxin affects prostate cancer cells.
Dr Elizabeth Platz, professor of epidemiology and a cancer prevention researcher at Johns Hopkins University, revealed: "If you use drugs that are already available then you have a long history of safety research that does not necessarily need to be redone, and we can move more quickly to testing whether the drug will actually work in a new setting."
Oliver Childs, senior science information officer at Cancer Research UK, said: "Although it's far too early to think about using digoxin to treat men with prostate cancer, this is a fascinating and unique approach to finding potential cancer drugs. By closely linking lab findings with studies following large groups of people, this research illustrates the power of different specialists working together.
"The next step will be further lab studies to see how the drug works in cancer cells, along with clinical trials to work out if the 25 per cent reduction in prostate cancer risk seen in this study translates into improved survival."