Known as aberrant crypt foci (ACF), these abnormal cell clusters are thought
to develop into colon cancer. Findings from animal studies have suggested that
aspirin suppresses ACF, but no study has ever looked at aspirin's effect on ACF
in humans.
To investigate, Dr. B. Shpitz, from the Meir General Hospital in Kfar Sava,
Israel, and colleagues tested for ACF in samples obtained from 194 colon cancer
patients during colon removal. Fifty-nine of the subjects reported regular use
of low-dose aspirin for at least 1 year before surgery.
As the researchers report in the medical journal Gut, nearly 76 percent of
the samples from non-aspirin users contained ACF, compared with only 36 percent
of the samples from aspirin users.
When the analysis was limited to samples from the last portion of colon -- a
common site for cancer -- aspirin use was tied to a 53 percent drop in the rate
of ACF.
Moreover, the investigators found that aspirin use seemed to reduce ACF
density, especially in the last portion of colon. Also, such therapy was linked
to a reduction in dysplastic ACF--the type most strongly linked to cancer.
"This study has provided the first evidence of (a preventive) effect of
low-dose aspirin on ACF in humans," the authors note. Further studies are needed
to determine how aspirin achieves this effect, they add.
SOURCE: Gut, November 2003.
