Cigarettes List

Most people don’t need another reason to quit smoking, with study after study linking the deadly habit to 16 different types of cancer as well as high blood pressure and emphysema.

A new study released this week, however, adds one more reason to quit, says the study’s author. Long-term cigarette smokers who have smoked for 40 years or more, or who have not quit before the age of 40, are more likely to develop colon cancer.

“This provides one more reason not to smoke, or to quit as soon as possible,” said senior author Dr. Michael J. Thun, vice president emeritus, epidemiology and surveillance research at the American Cancer Society.

“Colorectal cancer should be added to the list of cancers caused by smoking.”

Thun and colleagues studied the association between long-term cigarette use and colorectal cancer after adjusting for risk factors, including screening. Researchers followed 185,000 participants aged 50 to 74 from 1992 to 2005.

Those participants who smoked for 40 years or did not quit by the age of 40, had a 30 to 50 percent increased risk of developing colon or rectal cancer during the follow up, even when adjusting for 13 other potential risk factors, Dr. Thun said.

After 13 years of follow- up, researchers identified 1,962 cases of invasive colorectal cancer.

“These findings contributed to the evidence recently reviewed by the International Agency on Cancer (IARC) in October of this year,” said Thun. “IARC upgraded the evidence that smoking causes colorectal cancer from ‘limited’ to ’sufficient’.”

While Dr. Thun said previous studies have shown similar results, this study was the first to control for screening of all of the suspected risk factors for colorectal cancer, such as alcohol consumption, physical inactivity, and consumption of red or processed meat.

The IARC classification brings the number of cancer organ sites that are causally related to cigarette smoking to 17, according to the study.

Cigarette smoking has been related to cancers of the oral cavity, pharynx, nasopharynx, nasal cavity, paranasal sinuses, larynx, lung, esophagus, stomach, colorectum, liver, pancreas, kidney (both renal cell and transitional cell carcinoma), urinary bladder and lower urinary tract, uterine, cervix and myeloid leukemia.

Source URL: http://www.foodconsumer.org/newsite/Non-food/Lifestyle/smoking_linked_to_colorectal_cancer_051220090212.html