Measurement of circumferential tumor extent of colorectal cancer on CT colonography: relation to clinicopathological features and patient prognosis after surgery

Purpose: To examine the relationship between circumferential tumor extent of colorectal cancer (CRC) on CT colonography (CTC) and clinicopathological features including patient prognosis after surgery. Materials and methods: This retrospective study performed at our institution from January 2013 to December 2019 enrolled 195 consecutive patients (110 men, 85 women; mean age, 64.7 years) with CRC evaluated by contrast-enhanced CTC before surgery. The circumferential tumor extent rate (CER) was measured by CTC in virtual colon dissection (VCD) mode to examine the relation between the CER and clinicopathological features and patient prognosis. Results: CER had association with tumor invasion depth (T), nodal involvement (N), distant metastasis (M), and stage. The Kruskal–Wallis tests showed significant difference for T, N and the stage (p < 0.0001, p = 0.0021 and p < 0.0001) and Wilcoxon rank sum test showed significant difference for M (p = 0.0015). According to the log-rank test, there were no significant differences in OS or DFS between patients with high and low CER. Conclusion: Circumferential tumor extent was significantly correlated with TNM categories and stage of CRC, but not with patient prognosis after surgery.