Table 1 CTC as a follow-up test

People with small polyps (6–9 mm) detected at CTC screening

CTC with or without polyp size reporting threshold (6-mm) vs COL + polypectomy FSIG No screening

(<=5 mm polyps,6-9 mm, > = 10 mm, CRC) CTC Se (48%, 70%, 85%, 95%) Sp 86% COL Se(80%, 85%, 90%, 95%) Sp 90% FSIG (45%, 45%, 60-65%, 90%)

I 65% [1–100] R 80% [1–100]

Compared with No screening; $4361per LYG (CTC with a 6-mm threshold), $7138 per LYG (CTC with no threshold), $7407 per LYG (FSIG), $9180 per LYG (COL).

Compared with COL, CTC with a 6-mm threshold resulted in a 77.6% reduction in invasive endoscopic procedures and 1112 fewer reported COL-related complications from perforation or bleeding.

CTC with non-reporting of diminutive lesions was found to be the most cost-effective and safest screening option evaluated.

60 years old asymptomatic polyps; diminutive (≤5 mm), small (6-9 mm), large (≥10 mm)

CTC then COL with polypectomy vs CTC only

polyps (≤5 mm, ≥6 mm, ≥10 mm,) CTC Se (48%, 89%, 94%) CTC Sp (80%, 8%, 96%)

100% (assumption)

Estimated 10Y CRC risk for unresected diminutive (0.08%), small (0.7%) and large polyps (15.7%). ICER of removing all diminutive polyps was $465,407/LYG, and small CTC-detected polyps $59,015 per LYG. Polypectomy for large CTC-detected polyps yielded a cost-saving of $151 per person screened.

60 years old asymptomatic individuals with small polyps (6- to 9-mm) detected at CTC screening

3-yearly CTC surveillance vs Immediate polypectomy

CTC Se( polyps 6-9 mm) 89%, Sp 80% COL Se( 6-9 mm polyps) 85%, Sp 100%

Not stated

Without any intervention, the estimated 5-year CRC death rate from 6- to 9-mm polyps in this concentrated cohort was 0.08%, which is a sevenfold decrease over the 0.56% CRC risk for the general unselected screening population. The death rate was further reduced to 0.03% with the CTC surveillance strategy and to 0.02% with immediate colonoscopy referral. However, for each additional cancer-related death prevented with immediate polypectomy versus CTC follow-up, 9,977 COL referrals would be needed, resulting in 10 additional perforations and an incremental CE ratio of $372,853.

Individuals with a positive FOBT

CTC vs COL

Se,% (CRC-polyps ≥10 mm - polyps 6-9 mm) CTC Se (89 [70–98]-63 [59–85] - 51 [41–60]) Sp CTC lesions ≥6 mm 90% [88–92] COL Se (96[80–100]-95[90–98]-99[95–100]) Sp COL lesions ≥6 mm 99.6[99.2-100]

Not stated

Australian dollars/LYG

CTC is less effective and more costly than COL; if CTC was more sensitive than COL, CTC was more effective, at higher cost.