Earlier onset of colorectal cancer appears to be associated with alcohol use, tobacco use and male gender, according to research conducted at Evanston Northwestern Healthcare (ENH) and published in the March 27 issue of the Archives of Internal Medicine.
Colorectal cancer is the second leading cause of cancer death in the United States yet it is one of the most preventable forms of the disease. Screening not only helps diagnose it at an early stage when it is most curable, it also can locate polyps before they become cancer. However, once patients experience symptoms, the disease has already spread beyond the point where it can be cured. This is why physicians recommend everyone 50 years of age and older get screened for colorectal cancer and sooner for individuals who have a family history or other risk factors.
ENH researchers examined the records of 161,172 colorectal cancer patients from 350 teaching and community hospitals nationwide to assess whether alcohol and tobacco use, should also be considered in screening decisions. They analyzed the relationship between use of these substances and age of onset of colon cancer as well as location of onset--distal or proximal colon. 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."
The data showed that 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. Also, 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.
"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."
These findings also suggest 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.