Colorectal cancer is the third most common cancer in the U.S. and represents the second leading cause of cancer deaths. Each year, 50,000 die from the cancer and three times that number are newly diagnosed. The adenoma is a common type of polyp, or abnormal growth of tissue in the lining of the colon, that can develop over time into a colorectal cancer. Although screening is widely available and methods continue to be developed, screening rates remain relatively low. Moreover, a central registry with uniform guidelines is lacking.
A panel of experts assembled by the NIH to examine how best to enhance the use and quality of colorectal cancer screening recently published its recommendations.1 Although the panel found substantial progress in the past decade towards higher screening rates, increasing from 20 to 30 percent in 1997 to nearly 55 percent in 2008, screening rates in the at-risk population - adults age 50 and older - still fall short of goals and continue to reflect serious gaps in subgroups of the population. The panel recommends specific actions to address these shortcomings in order to reduce sickness and death from colorectal cancer, namely:
- Eliminate financial barriers to screening and follow-up. The most important factors related to screening are insurance coverage and access, and income and education level are highly related to both.
- Implement interventions proven to be effective in triggering screening, including patient reminder systems.
- Conduct research to improve tailoring programs for targeted groups who experience sub-optimal screening rates.
- Implement systems to ensure appropriate follow-up in patients whose screening test suggest possible cancer and to improve the quality of screenings in general.
- Conduct studies to determine the effectiveness of various screening methods, weighing comparisons against costs.
No doubt, it will still take years to see the effects of these steps. In the meantime, you as an individual can initiate your own screening if your regular doctor fails to remind you or you don't see your primary care doctor routinely. For all adults 50 years and older, current recommendations from the American Cancer Society call for a fecal occult blood test annually and a sigmoidoscopy every five years or a colonoscopy every ten years. A colonoscopy may be repeated more often if polyps are found that warrant removal.
While a high definition colonoscopy delivering a sharper and more detailed image through its scope may find a very small percentage of more adenomas than a standard colonoscopy, studies show they are very small and it's not known the proportion likely to become cancer. Michael B. Wallace, chief of gastroenterology and hepatology at the Mayo Clinic in Jacksonville advises patients to seek a doctor with good technique, someone who goes "slowly during the exam, washing the colon frequently and looking behind folds of skin." He maintains this is more important than the type of scope used. Also, ask your doctor what his or her adenoma detection rate is: doctors should be finding at least one adenoma in 25% of male patients and 15% of female patients, Dr. Wallace adds. 2