TUESDAY, March 28, 2006 (HealthDay News) -- Drinking and smoking may contribute to developing colorectal cancer years earlier than average, a new study found.
Colorectal cancer is the second leading cause of cancer deaths, and doctors generally recommend that patients begin screening for the disease at age 50. However, for patients with a family history of colorectal cancer, doctors often recommend earlier screening. Typically, the disease is diagnosed in people in their late 60s, the researchers said.
Given this new data, doctors may want to screen patients who drink or smoke, or both, at an earlier age, the Northwestern University researchers said.
"For people who smoke and drink, their age of onset of colon cancer was dramatically earlier than people who did not smoke and drink," said lead researcher Dr. Hemant K. Roy, an associate professor of gastroenterology.
"Our data suggests that current tobacco and alcohol consumption would be a marker for people who are at risk for developing earlier disease, and maybe screening for these folks should start earlier than age 50," Roy added.
The researchers also found that smoking or drinking can influence the location of the disease -- distal or proximal colon. Distal tumors, such as 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 researchers said.
Screening methods for colorectal cancer include flexible sigmoidoscopy, which involves inserting a flexible optical instrument through the rectum into the lower portion of the large intestine. Colonoscopy involves inserting a longer flexible optical instrument through the rectum and into the entire colon, a procedure that's more expensive and can have higher complication rates, the study authors said.
In its study, Roy's team collected data on 161,172 patients with colorectal cancer. They found that current drinking or smoking, and smoking plus drinking, were associated with an earlier onset of disease. The appearance of cancer was 5.2 years earlier among those who either smoked or drank, and 7.8 years earlier among those who both smoked and drank -- 63.2 years in women and 62.1 years in men.
In addition, 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, Roy's group found.
The findings appear in the March 27 issue of the Archives of Internal Medicine.
Roy believes that in addition to family history, smoking and drinking should be taken into account when considering when patients should be screened for the disease. "People need to get colon cancer screening," he said. "They need to tell their doctors all their potential risk factors for colon cancer."
"The typical age for developing colon cancer is the late 60s," Roy added. "The reason for people who smoke and drink to be screened earlier is to find potential cancers earlier and prevent them from developing into cancers."
Dr. Durado Brooks, director of colorectal cancer at the American Cancer Society, said far too few people get screened for the disease.
"We already knew that alcohol and tobacco were risk factors for developing colorectal cancer," Brooks said. "This is the first study to indicate that they may contribute to an earlier age of onset."
But Brooks doesn't think these findings mean that the age of screening needs to change. "The recommendation is to begin screening at age 50, and the median age for diagnosis in this group was in their 60s and early 70s," he said.
Brooks said 45 percent of people at risk for colorectal cancer aren't being screened. "I'm not sure screening before 50 is the key," he said. "The key is to get everyone screened at age 50."
More information
The American Cancer Society can tell you more about colorectal cancer.
