They found that, with a mean follow-up of 6.5 years, allocation to aspirin reduced risk of cancer with distant metastasis by 36%, risk of adencarcioma (common solid cancers including colon, lung, and prostate cancers) by 46%, and of other solid cancers (eg bladder, kidney) by 18%.

FORBES: Meta-Analysis Adds New Evidence For Cancer Benefits Of Daily Aspirin

"These findings provide the first proof in man that aspirin prevents distant cancer metastasis, " the second study's authors concluded.

WSJ: Studies Find New Evidence Aspirin May Prevent Cancer