SEATTLE, July 3 (UPI) -- The protective effect of aspirin or nonsteroidal anti-inflammatory drugs against colorectal cancer does not extend to long-term smokers, says U.S. study.
Researchers at Fred Hutchinson Cancer Research Center in Seattle conducted a large, population-based study comparing risk factors in people with and without colorectal cancer.
The highest risk of colon cancer proved to be among long-term smokers of 20 or more years who had never used NSAIDs, according to the study published in Cancer Research.
First author Victoria Chia said the research team also found that smokers who used NSAIDs were still at an approximate 30 percent higher risk of colon cancer than nonsmokers.
"Given the damage that smokers receive over their lifetime, even strong anti-progression agents, like NSAIDs, may be ineffective," said Chia. "NSAIDs may not be able to counteract the long-term effects of smoking, as evidenced by our observation that long-term smokers are at increased risk of colorectal cancer, despite current NSAID use."
Previous studies have shown that aspirin or NSAIDS reduce the risk of colorectal cancer by up to 40 percent.
