Preoperative Local Staging of Colon Cancer by CT: Radiological Staging Criteria Based on Membrane Anatomy and Visceral Adipose Tissue

BACKGROUND:Accuracy of preoperative T staging for colon cancer remains disappointing. OBJECTIVE:This study aimed to propose specially designed radiological staging criteria based on membrane anatomy and visceral adipose tissue and compare the staging performance with the routinely used method. DESIGN:This is a prospective observational study. SETTING:This study was conducted at a high-volume colorectal center. PARTICIPANTS:Consecutive patients with colonoscopy-proven colon carcinoma referred for clinical staging and elective resection were enrolled. INTERVENTION:The preoperative CT data were separately reviewed by 2 teams of radiologists for assigning T-stage categories (T1-2, T3, or T4) using the routine staging method or the newly proposed radiological criteria. MEASURES:Diagnostic performance for T staging was compared between the 2 criteria. RESULTS:Between October 2019 and August 2020, 190 patients were included. Compared with pathological results, T stage was correctly determined in 113 of 190 patients (59.5%) with the conventional CT criteria. With the newly developed criteria, 160 patients (84.2%) were found to be correctly staged. Accuracies between the 2 criteria significantly differed (p < 0.001). For T1-2 staging, there were no significant differences between the sensitivities of conventional and new criteria (57.1% vs 61.9%; p = 0.990) or between their specificities (95.3% vs 98.2%; p = 0.131). However, for T3 and T4 staging, the newly developed CT criteria exhibited significantly higher sensitivity (T3: 85.2% vs 57.4%; p < 0.001; T4: 90.7% vs 64.8%; p < 0.001) and specificity (T3: 82.7% vs 64%; p = 0.006; T4: 89.7% vs 69.1%; p < 0.001) than the conventional criteria. Moreover, the new criteria (area under the curve = 0.902) performed significantly better than the conventional criteria (area under the curve = 0.670; p < 0.001), for identifying the T4-stage tumor. LIMITATIONS:The limitations are that it is a single-center study and there was no external validation. CONCLUSIONS:The specially designed radiological criteria can offer more accurate T staging than the routine method in colon cancer. See Video Abstract at http://links.lww.com/DCR/B992.