The risk of developing colorectal polyps among smokers

Published on March 7, 2008 8:28 AM

Colorectal cancer is the third most commonly diagnosed cancer among men and women in the United States. Family history of the disease and a personal history of inflammatory bowel disease or polyps are the factors known to increase a person's risk of colorectal cancer. And not only a diet high in fat and low in dietary fiber, but also smoking may increase a person's risk.

Cancer researchers showed that cigarette smoking is a big risk factor for developing colorectal adenomas. Inherited variation in two genes (NQO1 and CYP1A1), which influence the activation of cancer-causing substances in tobacco smoke, were found to increase risk for developing colorectal adenomas.

Researchers indicated that approximately 20 to 25 percent of colorectal polyps may be caused by smoking. Smoking also can transform the polyps into cancer.

According to the study, smokers have a 13 percent higher risk of polyps in comparison to never smokers.

"While the harmful health effects of tobacco smoking are well known, smoking so far has not been considered in the stratification of patients for Colorectal Cancers (CRC) screening. Our findings could support lowering the recommended age for smokers to receive colorectal cancer screening," said Albert B. Lowenfels, MD, senior author of the study, from New York Medical College, Valhalla, New York.

Over the years researchers have shown a link between cigarette smoking and pre-cancerous colorectal polyps. They found that current smokers double their risk for adenoma with the possibility of becoming a cancer. They showed that a previous smoker can also have a risk of colorectal polyps.

This study provides strong evidence of the detrimental effect of cigarette smoking on the development of adenoma polyps.