Objective: We sought to perform a systematic review and meta-analysis of published CT colonography (CTC) studies assessing lesion detection in senior-age (≥ 65 years old) cohorts.
Materials and methods: We conducted a systematic review of CTC studies published between January 1994 and August 2017 containing data on senior-age adults. The primary endpoint was the CTC-positive rate for large colorectal polyps (≥ 10 mm) and masses. Secondary endpoints included lesions ≥ 6 mm, proven advanced neoplasia, and colorectal cancer (CRC). Study authors were contacted for additional missing data. Random-effects and meta-regression analyses were used to generate pooled estimates and explore contributing factors.
Results: A total of 34 studies with 41,680 (18,798 senior-age) subjects were included. Pooled CTC-positive rates among senior-age patients using the 10-mm size threshold were significantly lower in cohorts of patients with no symptoms (8.2%; 95% CI, 6.0-11.1%) compared with cohorts of patients with positive fecal occult blood tests (32.8%; 95% CI, 15.4-56.7%) and other symptoms of CRC (14.0%; 95% CI, 12.0-16.1%). However, a uniformly high positive predictive value for advanced neoplasia at colonoscopy was seen for all senior-age cohorts using a 10-mm threshold (84.3%; 95% CI, 79.3-88.3%; I2 = 0.0) where such data were available. CTC sensitivity for CRC was 93.0% (95% CI, 89.0-95.0%) in senior-age patients compared with 92.0% (95% CI, 84.0-93.0%) in younger patients. Overall, CTC detection rates were higher in senior-age adults compared with younger adults.
Conclusion: On average, one in every 12 senior-age adults without symptoms of CRC who underwent screening would be referred to colonoscopy using the 10-mm threshold, with a high yield for advanced neoplasia and high sensitivity for cancer detection. As expected, CTC-positive rates were higher in cohorts of patients 65 years old or older with symptoms of CRC. These results should help inform the Centers for Medicare & Medicaid Services regarding coverage determination of CTC screening for Medicare beneficiaries.
Keywords: CT colonography; Medicare; colorectal cancer screening; meta-analysis; virtual colonoscopy.