aspirin effect on cancer.

Many Americans take aspirin to lower their risk of heart disease, but a new study suggests a remarkable added benefit, reporting that patients who took aspirin regularly for a period of several years were 21 percent less likely decades later to die of solid tumor cancers, including cancers of the stomach, esophagus and lung.

The risk of lung cancer death was 30 percent lower, the risk of colorectal cancer death was 40 percent lower and the risk of esophageal cancer death was 60 percent lower, the study reported.
“Many people may wonder if they should start taking daily aspirin, but it would be premature to recommend people starting taking aspirin specifically to prevent cancer,” said Eric J. Jacobs, an epidemiologist with the American Cancer Society.

Observational studies have reported that people who took aspirin were at lower risk for colorectal cancer recurrences, while other studies have pointed to similar reductions in cancers of the lung, stomach and esophagus.

“Randomized controlled trials carry more weight.”
The strong results “add to the accumulating evidence that aspirin may be protective against various cancers,” Dr. Arslan said.

There are several ways in which aspirin may work to slow the development of cancers, experts say. Aspirin may also induce the death of early cancer cells before they become aggressive, Dr. Arslan suggested.

Aspirin is already known to be beneficial for those at high risk of heart disease. "Previous guidelines have rightly cautioned that in healthy middle aged people the small risk of bleeding on aspirin partly offsets the benefit from prevention of strokes and heart attacks, but the reductions in deaths due to several common cancers will now alter this balance for many people."
The results, published in the Lancet, showed that aspirin reduced death due to any cancer by around 20% during the trials. After 5 years of taking aspirin, the data from patients in the trials showed that death rates were 34% less for all cancers and as much as 54% less for gastrointestinal cancers, such as oesophagus, stomach, bowel, pancreas and liver cancers.

It took about 5 years to see a benefit in taking aspirin for oesophagus, pancreatic, brain, and lung cancer; about 10 years for stomach and bowel cancer; and about 15 years for prostate cancer. The 20-year risk of death was reduced by about 10% for prostate cancer, 30% for lung cancer, 40% for bowel cancer and 60% for oesophagus cancer.

Professor Rothwell estimates that in terms of cost-effectiveness, taking low-dose aspirin daily is likely to be much more cost-effective than those interventions already used for preventing cancer, such as screening for breast or prostate cancer.
He does note that more research is necessary to understand more about the effect aspirin has on cancer.
While this study looked at how aspirin affected deaths from cancer, Professor Rothwell and colleagues now aim to look at any protective effect of aspirin on the incidence or progression of cancer. The researchers also point out that more trial data are needed on breast cancer and other cancers that particularly affect women.
Taking a daily aspirin may do more than lower your heart disease risk -- it could lower your risk of death from cancer as well.
Researchers found that after five years, cancer death rates were 21 percent lower in patients assigned to take an aspirin a day -- a reduction in cancer risk that persisted for 20 years -- according to pooled data on a total of 25,570 individuals participating in eight randomized studies.
The researchers called the results "the first reliable evidence that aspirin prevents non-colorectal cancer in humans" -- a possibility to which earlier studies had pointed -- though the preventive effect was evident mainly in deaths from gastrointestinal cancers.
Rothwell and colleagues also cautioned, however, that the findings by themselves do not prove that aspirin prevents cancer or even cancer death.