Contrast-enhanced computed tomography colonography in preoperative distinction between T1-T2 and T3-T4 staging of colon cancer

Rationale and Objectives: To predict the T stage of nonrectal colon cancer using contrast-enhanced computed tomography colonography. Materials and Methods: Sixty-one patients with 67 nonrectal colon cancers consecutively underwent contrast-enhanced computed tomography colonography after an incomplete colonoscopy. Two readers evaluated wall deformity and perilesional fat abnormality on three-dimensional double contrast enema-like views and multiplanar reconstructions. Pathology was used as the standard of reference. McNemar, Fisher, and Cohen κ statistics were used. Results: At pathologic examination, we found the following stages: T1 (n = 5), T2 (n = 10), T3 (n = 41), T4a (n = 6), and T4b (n = 5). Intraobserver and interobserver reproducibilities were almost perfect for wall deformity (κ = 1.00 and κ = 0.88, respectively), substantial for perilesional fat abnormality (κ = 0.79 and κ = 0.74, respectively). Using the results of the more experienced reader, accuracy of wall deformity ≥50% (apple-core) alone for T ≥ 3 was 62 of 67 (0.93, 95% confidence interval [CI] 0.83-0.97) and that of perilesional fat abnormality alone was 37 of 67 (0.55, 95% CI 0.43-0.67) (P <.001). Predictive value for ≥ T3 of the association wall deformity ≥50% with perilesional fat abnormality was 22 of 22 (1.00, 95% CI 0.85-1.00), higher, but not significantly, than that of wall deformity ≥50% with normal perilesional fat 29 of 33 (0.88, 95% CI 0.72-0.97) (P = .148, Fisher exact test). Conclusions: The presence of apple-core wall deformity, regardless of perilesional fat abnormality, is highly predictive of stage T3 or higher.