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Computerized tomographic (CT) colonography, also known as virtual colonoscopy, accurately detects cancer and precancerous polyps in persons aged 65 years and older, indicate the results of a secondary analysis involving participants from the National CT Colonography Trial.

In 2008, C. Daniel Johnson, MD, MMM, of Mayo Clinic Arizona in Scottsdale, and colleagues recruited 2,600 asymptomatic persons aged 50 years and older, who were at average risk for colorectal cancer, to compare noninvasive CT colonography with colonoscopy in detecting the disease. Screening CT colonography identified adenomas or cancer measuring at least 10 mm in diameter in 90% of participants (N Engl J Med. 2008;359[12]:1207-1217). 

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More recently, Johnson’s team compared the sensitivity and specificity of CT colonography in participants of the earlier trial who were younger and older than 65 years. The difference between senior-aged participants and those younger than 65 years was not statistically significant for most measures. 

Of 2,531 evaluable enrollees from the original study, complete data were available for 477 participants aged 65 years and older. A total of 33 (6.9%) of these patients had adenomas of 1 cm or larger, compared with 76 (3.7%) of the 2,054 younger patients. For large neoplasms, mean estimates for CT colonography sensitivity and specificity for the older group were 0.82 and 0.83, respectively. Sensitivity and specificity for large neoplasms among the younger participants were 0.92 and 0.86, respectively. ONA