FRIDAY, March 11 (HealthDay News) -- Taking aspirin to protect
against colorectal cancer may be effective, but mostly in people at
increased risk for the disease due to elevated levels of an
inflammatory biomarker in their blood, according to a new
study.
Previous research has found that people who take aspirin or
other nonsteroidal anti-inflammatory drugs (NSAIDs) have a reduced
risk of colorectal cancer. Other studies have noted that
inflammation contributes to the development of conditions such as
cardiovascular disease and several types of cancer.
In this new study, researchers at Massachusetts General Hospital
and the Dana-Farber Cancer Institute found that elevated baseline
levels of an inflammatory marker called "soluble tumor necrosis
factor receptor-2 (sTNFR-2)" were associated with increased risk of
colorectal cancer and also predicted who might benefit from taking
aspirin or other NSAIDs, such as ibuprofen or naproxen.
The researchers analyzed data from 280 participants in the
Nurses' Health Study who were cancer-free when they provided a
blood sample in 1989 and 1990, but developed colorectal cancer over
the next 14 years. These patients were compared to 555 age-matched
participants who did not develop colorectal cancer.
The researchers analyzed baseline levels of three inflammatory
markers -- sTNFR-2, c-reactive protein (CRP), and interleukin-6
(IL-6). There was no association between levels of CRP or IL-6 and
risk of developing colorectal cancer. But people with the highest
levels of sTNFR-2 were 60 percent more likely to develop colorectal
cancer than those with the lowest levels of the factor.
The researchers also found that the reduced risk of colorectal
cancer associated with regular use of aspirin or other NSAIDs was
primarily seen among people with high baseline levels of
sTNFR-2.
The study appears in the March issue of the journal
Gastroenterology.
"These findings suggest that a blood biomarker may be helpful in deciding whether individuals should take aspirin or NSAIDs to reduce their cancer risk," lead author Dr. Andrew Chan, of the gastrointestinal unit at Massachusetts General Hospital, said in a hospital news release.
"They also indicate that chronic inflammatory pathways are quite complex, and further studies are needed to understand which facets of the inflammatory response are most associated with the development of colorectal cancer," he added.
More information
The U.S. National Cancer Institute has more about
colorectal cancer prevention.