Colon Cancer Develops Earlier in Drinkers, Smokers

Screening Should Be Done Earlier, Study Says

Colorectal cancer, the second leading cause of cancer death in the United States, seems to develop years earlier in people who drink alcohol, smoke cigarettes and are males, according to research conducted at Evanston Northwestern Healthcare.

Evanston Northwestern Healthcare researchers studied the records of 161,172 colorectal cancer patients nationwide to assess whether alcohol and tobacco use, should also be considered in screening decisions. They analyzed the relationship between drinking and smoking and the age of onset of colon cancer as well as location of onset -- distal or proximal colon.

According to a ENH news release, "distal tumors, including those in the lower left part of the colon and the rectum, can generally be detected by flexible sigmoidoscopy; while proximal tumors in the right side of the colon can be missed by methods other than colonoscopy."

"The data clearly show that screening for colorectal cancer in people who smoke and drink should start earlier," said lead author of the study Hemant K, Roy, MD, Evanston Northwestern Healthcare. "If confirmed after further research, these factors should guide recommendations regarding the timing of colorectal cancer screening."

"Our report provides compelling evidence that smoking and alcohol consumption are associated with an earlier age of diagnosis and likelihood for distal colorectal cancers," said Dr. Roy. "This data underscores the need for tobacco and alcohol cessation as an integral part of a colon cancer prevention program."

7.8 Years Earlier Onset

Here are some of the key findings of the study:

• Alcohol and tobacco users developed cancer an average of 7.8 years earlier than those who had never drank or smoked.

• Those who had never smoked but drank or who had never drank but smoked were each an average of 5.2 years younger at cancer diagnosis than those who neither smoked nor drank.

• The effect of smoking appeared to be particularly larger for women. Women who smoked but never drank developed cancer 6.3 years younger than those who never drank or smoked, compared with 3.7 years in men.

• Current alcohol and tobacco consumption was associated with an increased likelihood of distal colorectal cancer, although women in all categories were less likely to have distal cancer than men.

The researchers said that women who do not smoke or drink may be at increased risk for proximal colon cancer and may want to consider undergoing a colonoscopy instead of flexible sigmoidoscopy.

"In the future, we envision the development of risk scores with exogenous factors to tailor an individual's colorectal cancer screening program," said Roy.

Source: Roy's study was published in the March 27, 2006 issue of the Archives of Internal Medicine. See also the Evanston Northwestern Healthcare news release.