Background & aims: Screening rates for colorectal cancer remain low compared with screening rates for other cancers. The size of the unscreened population and the capacity to provide widespread screening are unknown. We estimated the number of average-risk persons aged 50 years or older not screened for colorectal cancer, the number of procedures required for this population, and the endoscopic capacity to satisfy this unmet need.
Methods: Using data from the US Census Bureau and the Centers for Disease Control and Prevention's National Health Interview Survey, we designed a forecasting model to estimate the number of persons in the United States currently not screened for colorectal cancer and the number of examinations needed to screen these persons. Test need was compared with available capacity, based on results from the national Survey of Endoscopic Capacity, assuming different proportions of available capacity were used for colorectal cancer screening.
Results: Approximately 41.8 million average-risk people aged 50 years or older have not been screened for colorectal cancer according to national guidelines. Sufficient capacity exists to screen the unscreened population within 1 year using fecal occult blood testing followed by diagnostic colonoscopy for positive tests. Depending on the proportion of available capacity used for colorectal cancer screening, it could take up to 10 years to screen the unscreened population using flexible sigmoidoscopy or colonoscopy.
Conclusions: The capacity exists for widespread screening with fecal occult blood testing. The capacity for screening with flexible sigmoidoscopy or colonoscopy depends on the proportion of available capacity used for colorectal cancer screening.