Add Cancer of Colon and Rectum to List of Cigarette Crimes
Dec. 5, 2000 -- People who claim that there is no link between cigarettes and colorectal cancer are just blowing smoke, suggest researchers from the American Cancer Society, who found that about 12% of all deaths from colorectal cancer in the U.S. in 1997 were attributable to smoking.
"Our main finding is that men and women who smoked cigarettes for 20 or more years at study enrollment experienced higher colorectal cancer death rates," write Ann Chao, PhD, and colleagues in the Dec. 6 issue of the Journal of the National Cancer Institute. Long-time smokers were more likely to die from colorectal cancers than nonsmokers even when other factors such as diet, family history of colorectal cancers, alcohol use, and age were taken into consideration.
Chao tells WebMD that among current smokers "men had about a 30% increase in colorectal cancer deaths." Chao, a research scholar in the epidemiology and research surveillance division of the American Cancer Society (ACS), also found that women who had smoked for less than 20 years had only a slightly increased risk for colorectal cancer, but those who had been puffing away for two decades or more had a risk for colorectal cancer approaching that of male smokers.
Death rates from colorectal cancer were highest among current smokers, intermediate in former smokers, and lowest in those who never took up the addictive habit. Death rates from colon and rectal cancer rose in step with the number of years of smoking in both men and women and with number of cigarettes smoked per day. People who started smoking at age 15 or earlier had a nearly 50% greater risk for colorectal cancer than their counterparts who never smoked.
The study also confirmed that the sooner smokers quit, the better. "Among former smokers, risk decreased with the number of years since smoking cessation. Former smokers who quit smoking at least 20 years before study enrollment were not at demonstrably increased risk compared with never smokers," the researchers write. The results highlight the importance of never taking up the habit or at least quitting early, they emphasize.