Daily Aspirin Prevents Many Cancers

Although past research suggested that regular aspirin use reduced the likelihood of developing colon cancer, the findings were inconsistent. And because many of these studies were observational rather than clinical trials, they were considered less reliable. Now a meta-analysis of clinical trials confirms that taking low-dose aspirin daily is preventative for some types of cancer. 

Benefits of long-term aspirin treatment confirmed

A report in a recent issue of Lancet pooled the data from seven trials with 23,535 participants and showed that a small daily dose of aspirin prevented deaths from colon and several other cancers. The aspirin treatment in the various trials lasted for 4 to 8 years, but the protection continued for at least 20 years in both men and women.

Even more impressive, the benefit increased with the duration of aspirin treatment during the trial. The overall 20-year risk of death from all solid cancers was reduced by 20 percent in those taking aspirin. Significant reductions in death were seen for cancers of the esophagus (60 percent), colon and rectum (40 percent), stomach (30 percent), and lung (30 percent). The 10 percent lower death rate for prostate cancer was not statistically significant. Unfortunately, there was no significant protection against pancreatic cancer, and too few women were enrolled in the trials to determine the effects of aspirin treatment on breast or ovarian cancer.

Benefits outweigh risks

These decreases in cancer deaths (as well as the possible protection against cardiovascular events such as heart attacks and strokes) appear to considerably outweigh gastrointestinal bleeding, the major risk of aspirin treatment, especially since the cancer benefit did not require aspirin doses greater than 75 mg per day. In addition, the benefits were unrelated to smoking and even increased with greater age of the participants.

Talk with your doctor about taking daily aspirin after age 45

The lead author of this study, Professor Peter Rothwell, from Oxford, England, suggested that the results might actually underestimate the protective effects of aspirin since it was taken for no longer than eight years in any of the trials. He also stated that it would be sensible to consider starting daily aspirin between 45 and 50 years of age and to stop taking aspirin after 25 years when the risk of gastrointestinal bleeding is greater and more dangerous. And, of course, people should not start taking aspirin without first consulting with their physician, who would probably warn them against regular aspirin use if they have a history of significant gastrointestinal bleeding.