If aspirin does have this effect, that doesn't mean other NSAIDs don't also work this way. Tang said that the women in the study tended to take aspirin more regularly and frequently than other NSAIDs, so this may have affected the results. Study authors also did not differentiate between women who took painkillers twice a week and those who took them more often.
Other researchers are studying aspirin and other NSAIDs for possible anti-cancer effects, she said.
Information about the women's sun exposure was self-reported, and their activities were not controlled in an experimental setting.
This was also restricted to postmenopausal women; it is unclear what the benefits would be, if any, if women started taking anti-inflammatory drugs earlier in life.
"The results of this study add to the results found by other studies that strongly suggest that aspirin may have anti-cancer properties," Tang said.
But the research is not at the point of recommending that everyone take aspirin every day. Stronger evidence would come from a long, expensive clinical trial to examine aspirin against a placebo for cancer risk prevention, which is hard to come by in the current stringent government funding environment, she said.