Online Reporter
LONDON.— The 4,000-year-old drug, most commonly used to treat pain, prevents certain tumours from forming and spreading across the body — findings that are already changing health policies.
Nick James, a British furniture maker in his mid-40s, first became concerned about his health after his mother died from cancer and his brother, along with several other family members, later developed bowel cancer. He opted to undergo genetic testing, and was found to be carrying a faulty gene which causes Lynch Syndrome, a condition that significantly increases the risk of developing that type of cancer.
Help came from an unexpected place, however, when James became the first person to sign up for a clinical trial that set out to test whether a daily dose of aspirin— the over-the-counter painkiller —could protect against developing cancer.
Depending on the type of gene mutation, 10-80percent of people with Lynch syndrome will get bowel cancer during their lifetime. But so far, things are looking good for James. “He’s been on aspirin now with us for 10 years without any cancer so far,” says John Burn, a professor of clinical genetics at Newcastle University, who led the trial.
It sounds almost impossible to believe, yet there have long been indications that the drug might reduce the chances of colorectal cancer spreading, or even occurring in the first place. In the past year, a string of trials and studies have strengthened such evidence. Some countries have already changed their medical guidelines to include the pill as a first line of protection for those who are most at risk (though experts stress that this should only be done under your doctor’s supervision). And we’re finally beginning to understand the reasons why it has such a mysterious effect.
Ancient roots
The latest findings offer a remarkable new twist in the tale of one of our oldest and most effective medications. In the late 19th Century, archaeologists uncovered 4,400-year-old clay tablets from the ancient Mesopotamian city of Nippur — in what is now Iraq — offering lists of a range of medicines crafted from botanical, animal and mineral compounds. Among them were instructions for a substance derived from the willow tree. We now know that this contains a chemical called salicin, which the body can convert into salicylic acid that helps to calm pain. It is very similar in structure to modern aspirin — acetylsalicylic acid —but more irritating for the stomach. Other ancient civilisations—including the Egyptians, Greeks and Romans — also used the remedy.
The modern study of the compound kicked off in 1763, when the English cleric Edward Stone wrote to the Royal Society to describe the fever-fighting properties of dried and powdered willow bark. About a century later, scientists managed to synthesise salicylic acid into the less corrosive acetylsalicylic acid, and put it on the market under the brand name Bayer.
Fast forward yet another century, and scientists started noticing some unexpected benefits of aspirin on preventing cardiovascular disease— reducing the risk of blood clots by making the blood thinner and the blood platelets less sticky. For this reason, organisations like the UK’s National Health Service recommend low daily doses for people with a high risk of heart attack or stroke.
By 1972, the potential benefits had extended to the prevention of cancer, with an attention-grabbing study of mice injected with tumorous cells.
The American scientists found that lacing the animal’s drinking water with aspirin significantly reduced the risk that the cancer would spread across the body —a process called metastasis — compared to mice who were not given the drug.
While discovery generated some excitement, “it wasn’t immediately clear how this would impact clinical practice,” says Ruth Langley, a professor of oncology and medical trials at University College London. It wasn’t obvious if the drug would have the same effect in humans, after all —meaning that the finding remained an obscure fascination rather than a potentially life-changing treatment.
A turning point came in 2010, when Peter Rothwell, a professor of clinical neurology at the University of Oxford in the UK, went back and re-investigated the much more abundant data on aspirin as a prevention of cardiovascular disease. In his analyses, the drug appeared to reduce both the incidence and spread of cancer, prompting renewed interest in both the power of aspirin to help fight the disease, and the reasons that it does so.Proving that aspirin can prevent cancer in the general population is a challenge, however. In an ideal world, researchers would recruit a large sample of people.
Half would take aspirin, while the rest would take a placebo pill — and you would then compare which had the highest rates of the disease. It can take many decades for cancer to occur in the first place, however, meaning that a randomised controlled trial would take a very long time to conduct at a huge expense. “It’s almost impossible, actually,” explains Anna Martling, a professor of surgery at the Karolinska Institute in Sweden.
For this reason, scientists have turned their attention to specific groups, such as those who have already had cancer or those who are genetically susceptible to developing it. —BBC
