March 21, 2012
Do Daily Doses Of Aspirin Reduce Risk Of Cancer?
Two new studies published this week have found that taking aspirin every day may significantly reduce the risk of many cancers and prevent tumors from spreading. The cheap drug not only appears to stop cancers developing in the first place, but also prevents them from spreading to other parts of the body, the study, published in the medical journal The Lancet, says.
Researchers from the University of Oxford found that after three years of daily aspirin use, the risk of developing cancer was reduced by almost 25 percent when compared with a control group not taking aspirin.
Professor Peter Rothwell, of Oxford University´s Stroke Prevention Research Unit explained the findings, “These data do push the argument in favor of taking daily low-dose aspirin, particularly if you have a family history of heart disease or cancer.”
“We showed previously that daily aspirin substantially reduces the long-term risk of some cancers, particularly colorectal cancer and esophageal cancer, but that these effects don´t appear until about eight to 10 years after starting treatment.”
“The delay is because aspirin is preventing the very early development of cancers and there is a long delay between this early stage and the eventual clinical presentation with a cancer.
“What we have now shown is that aspirin also has short-term effects, which are manifest after only two to three years.”
A second paper that analyzed five large randomized controlled studies in Britain found that over six and a half years on average, daily aspirin use reduced the risk of metastatic cancer by 36 percent and the risk of adenocarcinomas – common solid cancers including colon, lung and prostate cancer – by 46 percent, writes Roni Caryn Rabin for the New York Times.
Daily aspirin use also reduced the risk of progressing to metastatic disease, particularly in patients with colorectal cancer, the studies reported.
These positive findings however puts health providers in a quandary. Aspirin increases the risk of not just of gastrointestinal bleeding, but of hemorrhagic strokes. The new studies, however, also found that the risk of bleeding in aspirin users diminished over time, and that the risk of death from brain bleeds was actually lower in the aspirin users than in the comparison group.
“I think he´s on to something. I just want to be cautious, and I don´t want to exaggerate,” Dr. Otis W. Brawley, chief medical officer and executive vice president of the American Cancer Society, told Rabin. “I´m not ready to say that everybody ought to take a baby aspirin a day to prevent cancer.”
The trials that the Oxford investigators examined were originally intended to study the effects of aspirin on preventing heart disease, not cancer prevention and so the application of the findings to cancer prevention may be flawed, some experts explained.
In the United States, two major studies of low-dose aspirin to prevent cancer did not find reductions in cancer with aspirin use. Those findings were excluded from analysis by the Oxford researchers because they involved use of aspirin every other day, rather than daily use.
Though many Americans use baby aspirin daily to reduce their risk of heart disease, patients are generally advised to do so only when their cardiac risk is presumed to outweigh the risks of taking aspirin. Physicians remain extremely reluctant to recommend long-term use of aspirin in a healthy population.