An estimated 90 million Americans are at risk of developing colorectal cancer, the second-leading cancer killer in the United States. About 145,000 Americans will be diagnosed with the disease this year-and 57,000 will die from it. In many cases, the cancerous tumors are discovered too late, mainly because screening was not taken seriously. The fact is, screening can prevent many cases of this disease because most colorectal cancers evolve from benign adenomatous polyps that develop during a 10-year silent window. A single colonoscopy exam can remove polyps when they are still harmless and decrease the life-long risk of colon cancer death by 31 percent. And that's just one exam. Repeating the exam every 10 years does much more. Relatively few people, however, are properly screened for colon cancer. While roughly 80 percent of U.S. women are screened for breast cancer with mammography, fewer than 20 percent of Americans over age 50 have even had the least invasive colon cancer screening test-a fecal occult blood test-in the past five years. According to experts, the barriers to proper screening for colon cancer involve misperceptions, money, manpower and mind-set. The misperceptions include the thought that this disease only strikes older men. The reality is, if you are male or female, age 50 or older, you're well within striking distance. Another misperception: screening for colon cancer is terribly painful and uncomfortable. The reality: The bowel prep is somewhat annoying but quite manageable at home, and colonoscopy with light sedation is painless. The expense of the tests can be a roadblock, but insurance companies are coming on board, as colonoscopy screenings for this cancer have been proven to be as cost effective as mammography for breast cancer. Manpower issues exist since special training is required to do colonoscopies, and a specially designed setting, equipment and sedation are all required, but ease and efficiency have greatly increased in the past decade. The first step? Focus on baseline colonoscopy for everyone over age 50. If a polyp or tumor is detected, it can be addressed early and directly. If your exam is clean, you're good for 10 years. All in all, it seems a relatively small price to pay. How many other bad cancers allow a 10-year window for detection? Fewer, still, have relatively painless detection technology and skilled clinicians already in place to ensure success. Mike Magee, M.D., is a former Senior Fellow in the Humanities to the World Medical Association, director of the Pfizer Medical Humanities Initiative and host of the weekly Web cast "Health Politics with Dr. Mike Magee."