Aspirin, the century-old drug that is used to treat headaches and prevent heart attacks and stroke, may also help to fight prostate cancer, scientists said Tuesday.
New research by doctors at the Prostate Biology Group at Imperial College and Hammersmith Hospital in London shows that the drug may stop or slow down an enzyme called cox-2 that is involved in the growth of cancerous tumors.
In a report in the British Journal of Urology, Dr. Paul Abel and his colleagues said laboratory tests of 112 samples of cancerous and benign prostate tissue showed an increase in cox-2 in the cancerous tissue.
Anti-inflammatory drugs such as aspirin, which was launched more than 100 years ago as a painkiller, blocked the action of the enzyme.
"Aspirin may work in this situation and it may be an appropriate drug to use, but we don't know that, and aspirin is more likely to have side effects," Abel said in an interview.
"There are two forms of this enzyme, and aspirin affects both of them, but in prostate cancer, the only one that is increased is cox-2. We only need to get the cox-2 levels back down."
Abel warned that people should not rush to take aspirin to fight prostate cancer. He said the research is the first piece in a large jigsaw puzzle. A more likely treatment could be aspirinlike drugs, so-called specific cox-2 inhibitors, used to treat arthritis.
Vioxx, made by drug giant Merck & Co. and Celebrex, produced by Swiss-U.S. pharmaceutical group Pharmacia Corp, are two cox-2 inhibitors for arthritis.
"There are suggestions in the literature that one of the things this enzyme could do is switch on genes that are responsible for giving cells immortality," said Dr. El-NasirLalani, who contributed work on the research.
Uncontrolled cell division is a hallmark of cancer.
Eating too much fatty food is linked to an increased risk of developing cancer. Cox-2 is an enzyme that is pivotal in the conversion of fats in prostagladins, which may mediate the effects that trigger or exacerbate cancer.
Abel and Lalani said they hope to begin trials of cox-2 inhibitors to determine their impact on prostate tumors.
Though aspirin, when taken in small daily doses less than the normal size, has been shown to prevent heart attacks and strokes, it can produce stomach bleeding.
People with liver or kidney disease, bleeding disorders, asthma and uncontrolled high blood pressure are advised to avoid using aspirin.
In addition to a possible role in treating prostate cancer, the scientists said aspirinlike drugs may also have a role to play in fighting colon cancer.
Prostate cancer affects an estimated 10 million men older than 50, and many may not realize that they have the disease. It is the most common male cancer and the second-leading cause of cancer deaths.