Abstract / Summary
Background/Objectives: Computed tomography (CT) informs preoperative staging in colon cancer, yet its diagnostic accuracy for lymph node involvement relative to pathological staging remains uncertain. We examined nodal concordance and multicentre variation in Poland. Methods: This retrospective diagnostic accuracy study included adults who underwent upfront resection for nonmetastatic colon cancer at five centres between January 2022 and August 2025. All underwent preoperative CT; recorded cN categories were dichotomised as cN0 versus cN+ (any positive cN category), and pathological pN was the reference. We estimated accuracy, sensitivity, specificity, predictive values, and kappa with 95% confidence intervals. A centre-adjusted exploratory analysis examined the association between cT3–4 and occult pN+ among cN0 patients. Results: Of 662 otherwise eligible patients, 590 had evaluable cN and pN. CT and pathology agreed in 386 (65.4%; 95% CI, 61.5–69.2; κ = 0.276; 95% CI, 0.199–0.353). Occult pN+ occurred in 73 of 335 cN0 patients (21.8%; 95% CI, 17.7–26.5); 131 of 255 cN+ patients were pN0 (51.4%; 95% CI, 45.3–57.4). Sensitivity was 62.9% and specificity 66.7%. Centre-level cN/pN completeness ranged from 73.5% to 100%. cT3–4 was associated with occult pN+ after centre adjustment (OR, 3.10; 95% CI, 1.71–5.62). Sensitivity analyses were materially consistent. Conclusions: Routine CT nodal classification showed limited concordance with pathology. The cT3–4 association is exploratory and does not establish a prediction or treatment selection rule; cN alone should not determine treatment.