Anticancer Effects of Aspirin: FAQ
Top 4 Questions About Aspirin and Cancer
Feb. 19, 2010 - Aspirin has anticancer effects, new studies confirm.
The latest of these studies shows that after successful treatment for breast
cancer, women who take aspirin regularly have a significantly lower risk of
dying from recurrent cancer. Aspirin also cut their risk of having their cancer
spread to other sites.
What does this mean for people treated for cancer? What does it mean for
people worried about their cancer risk? Here are answers to these and other
frequently asked questions about aspirin and cancer.
Does aspirin really improve breast cancer survival?
Only a clinical trial, in which randomly assigned treatment is tested
against an inactive placebo, can prove that a treatment is truly effective.
Until such proof is available, the next best thing is a study in which
people taking the treatment are observed over time. The Nurses Health Study
followed more than 4,000 nurses who had been treated for breast cancer at
least 12 months earlier.
The result: Nurses who took aspirin were significantly less likely to die of
breast cancer and to have cancer recur at another site. After adjusting for
cancer stage, menopausal status, body mass, and hormone sensitivity of the
tumor, women who took aspirin seven days a week were 43% less likely to die of
The findings may apply only to women who survive at least four years after
breast cancer treatment. But since 90% of women diagnosed with breast cancer
survive at least five years, "our findings have considerable clinical
importance," conclude researchers Michelle D. Holmes, MD, DrPH, and colleagues
at Boston's Brigham & Women's Hospital. Their study is published online in
the Journal of Clinical Oncology.
Can aspirin take the place of other breast cancer treatments?
No. If aspirin truly helps prevent breast cancer recurrence, it does so only
when combined with recommended cancer therapies.
Can aspirin prevent breast cancer?
Some studies suggest that aspirin can
cut breast cancer risk in women who do not have the disease. Other studies
reach the opposite conclusion.
When data from several studies are combined,
there is a hint that aspirin or other nonsteroidal anti-inflammatory drugs
(NSAIDs, such as ibuprofen) may slightly decrease breast cancer risk.
Most women do not get breast cancer. Taking aspirin every day for a long
time carries risks, especially the risk of stomach or intestinal bleeding. This
means that for most women, the risks of taking aspirin may exceed the benefit
of preventing breast cancer.
However, when taken under a doctor's supervision, regular low-dose aspirin
use does cut the risk of heart disease. It's not yet clear whether women at
higher risk of breast cancer might get an extra benefit from aspirin.
Can aspirin prevent other kinds of cancer?
Aspirin may be sold over the counter, but it's a very powerful drug. It has
at least two effects that, in animal studies, fight cancer.
Aspirin is most studied in colon cancer. Human studies strongly suggest that
aspirin improves survival in patients treated for colon cancer. Studies
also suggest that aspirin decreases the risk of new polyps in patients who have
had precancerous intestinal polyps removed, and that regular aspirin use lowers
colon cancer risk.
However, the U.S. Preventive Services recommends against the widespread use
of aspirin to prevent colon cancer. Again, the risks of aspirin outweigh the
benefit for people at normal risk of colon cancer.
Aspirin may also lower the risk of other cancers, particularly prostate
cancer and esophageal cancer.
As with breast and colon cancer, the strongest benefits appear to be in
patients already treated for cancer. While there is evidence that aspirin has
broad anticancer effects, there is no good evidence that this benefit -- even
when combined with the benefit of low-dose aspirin in preventing heart disease
-- outweighs the risk for people at normal risk of cancer.