People who smoke and drink should start screening for colon cancer earlier because they tend to contract the disease at a younger age than those who abstain from cigarettes and alcohol, a study reported on Monday.
Screening for colon cancer is generally recommended for anyone 50 or older, and 90 percent of cases occur after that age.
Men have a 1-in-17 chance of contracting the disease in their lifetimes, according to the American Cancer Society. Use of alcohol and cigarettes are known to heighten the risks of all types of cancer, including colon cancer.
An analysis of 161,000 colon cancer victims found those who had smoked and drunk alcohol in the previous year contracted the disease an average of eight years earlier than people who never smoked and never drank.
The average age of initial diagnosis was 62 for male smokers and drinkers, 63 for women.
Female smokers at highest risk
In the study, those who smoked but did not drink, or the reverse, developed the disease an average of five years earlier than abstainers, with female smokers particularly at risk of getting the disease earlier.
A family history is another important risk factor for colon cancer, which often produces symptoms such as bleeding only after it has progressed, said the study published in the Archives of Internal Medicine.
"In the future, we envision the development of risk scores with exogenous (e.g., alcohol and tobacco use, age, body mass index, diet and calcium consumption) and hereditary factors to tailor an individual's colorectal cancer screening program," wrote study author, Dr. Anna Zisman of Northwestern University.
Screening involves either a sigmoidoscopy that checks for tumors in the lower portion of the large intestine, or a more extensive colonoscopy in which a longer flexible optical instrument is threaded through the entire colon.
Colon cancer is the second-leading cause of cancer deaths after lung cancer, killing nearly 500,000 people annually.