Current smoking is as strong a risk factor for colorectal polyps as a positive family history for colon cancer, according to findings presented at the 67th Annual Scientific Meeting of the American College of Gastroenterology.

When Rajeev Attam, M.D., and his American colleagues analyzed records of 1,566 consecutive patients who had a screening colonoscopy at one university center over slightly more than 2 years, they found that the incidence of polyps was higher among current smokers than ex-smokers or non-smokers (354 current smokers, 364 ex-smokers, 848 non-smokers). Ex-smokers were defined as people who had quit more than 10 years before the screening test but who had smoked for more than 10 years.

In addition to noting the colonoscopy results, the researchers examined data for age, sex, family history and personal history of colon cancer, smoking habits, alcohol and wine consumption habits, fruit and vegetable intake, body mass index, weekly exercise habits, and history of inflammatory bowel disease.

"It is well established that family history of colon cancer is predictive of colorectal polyps, but our statistical analysis indicates that being a current smoker is equally predictive," said Attam, the lead author of the study. "Polyps were found in about 19 percent of ex-smokers and about 17 percent of non-smokers, whereas 25 percent of smokers had polyps."

"Perhaps an even more important finding is that a much larger proportion of the smokers had more than two polyps, had a polyp larger than 1 centimeter, or had a polyp with a greater potential for malignancy. These differences had high statistical significance," said Attam. "Although current guidelines recommend that people with average risk start screening colonoscopy at age 50, our results suggest that physicians should consider performing screening colonoscopy in current smokers before age 50."