WASHINGTON - People who smoke cigarettes over a long period of time have
an increased risk for developing colorectal cancer, says a new study.
“This provides one more reason not to smoke, or to quit as soon as possible,”
said senior author Michael J. Thun, M.D., M.S., vice president emeritus,
epidemiology and surveillance research at the American Cancer Society.
The expert added: “Colorectal cancer should be added to the list of cancers
caused by smoking.”
Findings are published in the December issue of Cancer Epidemiology, Biomarkers
and Prevention, a journal of the American Association for Cancer Research, as
part of a special focus on tobacco.
To
reach the conclusion, Thun and colleagues tested the association between
long-term cigarette smoking and colorectal cancer after adjusting for multiple
other factors that are generally associated with risk, including screening. From
1992 through 2005 the researchers followed almost 185,000 participants aged 50
to 74 years old; participants described their behaviors and medical conditions.
Participants who smoked cigarettes for 40 or more years, or who did not quit
before age 40, had a 30 percent to 50 percent increased risk of developing colon
or rectal cancer during the follow-up, even in analyses that adjusted for 13
other potential risk factors, according to Thun.
After 13 years of follow-up, the researchers identified 1,962 cases of invasive
colorectal cancer. (ANI)
