The scientists looked at the seven gene variants among the two groups. They found that four of seven variants were associated with an increased risk for advanced distal colorectal adenomas. The frequency of these variants was higher among those with polyps than among controls.
The researchers also compared ibuprofen use among the two groups. Studies have shown that non-steroidal anti-inflammatory drugs such as ibuprofen can reduce the risk of adenomas and colorectal cancer.
"We found that regular use of ibuprofen had a slight protective effect in the development of advanced distal colorectal adenomas ?a 20 percent reduction in risk, which was not statistically significant," Daugherty said.
When they looked further at the association between ibuprofen use and colorectal adenomas, they found that a subgroup of individuals who had two copies of one variant showed a statistically significant reduction of nearly 70 percent in the risk for developing adenomas. Among the other individuals who did not have this genotype, regular use of ibuprofen had little effect on risk of colorectal adenomas.
"Our data are the first to show a link between these genotypes and effectiveness of ibuprofen in protecting against adenomas," Daugherty said. She noted that previous research in animals has shown that AMACR modifies a component of ibuprofen that enhances its chemopreventive effects.
"This is the first study to corroborate the biological data at a statistical level in humans,
Source:American Association for Cancer Research