BACKGROUND & AIMS: We developed a risk index to identify low-risk patients who may be screened for colorectal cancer with computerized tomographic colonography (CTC) instead of colonoscopy. METHODS: Asymptomatic persons aged 50 years or older who had undergone screening colonoscopy were randomized retrospectively to derivation (n = 1512) and validation (n = 1493) subgroups. We developed a risk index (based on age, sex, and family history) from the derivation group. The expected results of 3 screening strategies--universal colonoscopy, universal CTC, and a stratified strategy of colonoscopy for high-risk and CTC for low-risk patients--were then compared. Outcomes for the 3 strategies were extrapolated from the known colonic findings in each patient, using sensitivity/specificity values for CTC from the medical literature. Results were validated in the validation subgroup. RESULTS: In the derivation subgroup, universal colonoscopy detected 94% of advanced neoplasia and universal CTC detected only 70% and resulted in the largest total number of procedures and number of patients undergoing both procedures. The stratified strategy detected 92% of advanced neoplasia, requiring colonoscopy in 68% and CTC in 36% of patients, with only 4% having to undergo both procedures. In the validation subgroup, universal colonoscopy detected 94% and universal CTC detected 71% of advanced neoplasia, whereas the stratified strategy detected 89%, requiring colonoscopy in 64% and CTC in 40%. Unlike universal CTC, the stratified strategy was independent of assumptions for CTC sensitivity, specificity, and threshold for colonoscopy. CONCLUSIONS: The stratified strategy based on our risk index may optimize the yield of colonoscopic resources and reduce the number of patients undergoing colonoscopy.
BACKGROUND & AIMS: We developed a risk index to identify low-risk patients who may be screened for colorectal cancer with computerized tomographic colonography (CTC) instead of colonoscopy. METHODS: Asymptomatic persons aged 50 years or older who had undergone screening colonoscopy were randomized retrospectively to derivation (n = 1512) and validation (n = 1493) subgroups. We developed a risk index (based on age, sex, and family history) from the derivation group. The expected results of 3 screening strategies--universal colonoscopy, universal CTC, and a stratified strategy of colonoscopy for high-risk and CTC for low-risk patients--were then compared. Outcomes for the 3 strategies were extrapolated from the known colonic findings in each patient, using sensitivity/specificity values for CTC from the medical literature. Results were validated in the validation subgroup. RESULTS: In the derivation subgroup, universal colonoscopy detected 94% of advanced neoplasia and universal CTC detected only 70% and resulted in the largest total number of procedures and number of patients undergoing both procedures. The stratified strategy detected 92% of advanced neoplasia, requiring colonoscopy in 68% and CTC in 36% of patients, with only 4% having to undergo both procedures. In the validation subgroup, universal colonoscopy detected 94% and universal CTC detected 71% of advanced neoplasia, whereas the stratified strategy detected 89%, requiring colonoscopy in 64% and CTC in 40%. Unlike universal CTC, the stratified strategy was independent of assumptions for CTC sensitivity, specificity, and threshold for colonoscopy. CONCLUSIONS: The stratified strategy based on our risk index may optimize the yield of colonoscopic resources and reduce the number of patients undergoing colonoscopy.
Authors: Thomas F Imperiale; Menggang Yu; Patrick O Monahan; Timothy E Stump; Rebeka Tabbey; Elizabeth Glowinski; David F Ransohoff Journal: J Natl Cancer Inst Date: 2016-08-31 Impact factor: 13.506
Authors: Thomas F Imperiale; Patrick O Monahan; Timothy E Stump; Elizabeth A Glowinski; David F Ransohoff Journal: Ann Intern Med Date: 2015-09-01 Impact factor: 25.391