COLUMBUS, Ohio – Smokers may have a greater risk for developing a type of colorectal polyp that could increase their risk of colon cancer, according to researchers here.
“These findings are important, because it’s more evidence of the dangers of smoking,” says principal investigator Electra Paskett, associate director for population sciences at The Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute(OSUCCC – James).
Electra D. Paskett, Ph.D.
“This is yet another reason to stop smoking.”
The findings, part of the multi-center Polyp Prevention Trial, were reported in a recent issue of the journal Cancer Causes and Control.
Polyps are abnormal growths in the lining of the large intestine, or colon. They are usually classified as either adenomatous polyps, also called adenomas, or hyperplastic polyps. Adenomas generally occur in older people and often precede the development of colon cancer. Hyperplastic polyps, on the other hand, tend to occur in younger people and are generally considered benign and not associated with colorectal cancer.
The study led by Paskett, confirms other recent studies that link hyperplastic polyps to colorectal cancer. Paskett is reporting on work she began while at the Wake Forest School of Medicine before coming to Ohio State in 2002.
“Adenomas have been shown to directly turn into colon cancer, so we expected that,” says Paskett, who is also a professor in the School of Public Health. “What was surprising, however, was the risk associated with hyperplastic polyps and colon cancer. Some people think that hyperplastic polyps signal the development of polyps that could become adenomas, which could lead to colon cancer.”
A total of 1,872 men and women completed Paskett’s study as part of the Polyp Prevention Trial, which examined the effect of a low-fat, high-fiber diet.
To participate, each patient had at least one adenoma removed during a baseline colonoscopy within six months of joining the study. Participants then underwent follow-up colonoscopies after one year, and again after four years. All detected polyps – whether adenomas or hyperplastic – were removed.
Participants were categorized as current smokers, former smokers and never smokers. The study also took into account other variables, including family history of colorectal cancer, body mass index, alcohol and fiber intake, physical activity, use of non-steroidal anti-inflammatories, and for women, use of hormone replacement therapy. In addition, demographic variables of gender, age, race and education were included.
The study found that current and former smokers had significantly greater odds of developing hyperplastic polyps – both at baseline and after four years –compared with non-smokers.
“Smokers often worry about oral cancer or lung cancer, but they don’t usually worry about colon cancer,” Paskett says. “If these findings are verified, smokers may need to make sure they get regular screenings for colorectal cancer.”
The Ohio State University Comprehensive Cancer Center is a network of interdisciplinary research programs with more than 200 investigators in 13 colleges across the OSU campus, the Arthur G. James Cancer Hospital and Richard J. Solove Research Institute and Children’s Hospital, in Columbus. OSUCCC members conduct research on the prevention, detection, diagnosis and treatment of cancer, generating more than $100 million annually in external funding.###
Medical Center Communications