The prognostic significance of extramural venous invasion detected via contrast-enhanced computed tomography colonography in colon cancer.

Abstract

167 Background: The precise effects of extramural venous invasion (EMVI) and Spiculation on colon cancer recurrence remain poorly understood. This study investigated the clinical significance of ctEMVI and ctSpiculation as diagnosed via preoperative contrast-enhanced CT colonography (CTC) using three-dimensional multiplanar reconstruction (3D MPR) images. Methods: Patients with stage I–Ⅲ colon cancer (T2 or deeper) diagnosed via CTC at the National Cancer Center Hospital in Japan between 2013 and 2018 were retrospectively evaluated for ctEMVI and ctSpiculation, diagnosed by two observers using 3D MPR images of slices 0.5 mm thick. The interobserver reliability was assessed with Cohen’s kappa statistic, and recurrence-free survival (RFS) was analyzed using Kaplan–Meier curves. Preoperative clinical factors were subjected to Cox regression analysis in relation to RFS. Results: Of 922 patients, 544 eligible cases were analyzed. There were 50 (9.2%) ctEMVI-positive cases and 494 (90.8%) ctEMVI-negative cases, along with 186 (34.2%) ctSpiculation-positive cases and 358 (65.8%) with negative findings. Kappa coefficients for ctEMVI and ctSpiculation were 0.830 and 0.718, respectively. Kaplan–Meier analysis and log-rank tests demonstrated lower RFS in ctEMVI- and ctSpiculation-positive cases (p<0.001). In multivariable analysis, ctT4 (HR 2.95, 95% CI 1.73–5.02) and ctEMVI (2.97, 1.81–4.87) were independent factors associated with RFS. When stratifying TNM stages based on ctEMVI status, in N(+) (i.e., Stage III), ctEMVI-positive group had worse prognoses than negative group (5-year RFS rates; 52.0% vs. 78.5%, p=0.003). Similarly, in N(–) (i.e., Stage I and II), T3N0EMVI(+) cases had significantly worse prognoses than T3N0EMVI(–) and Stage I cases (50.6% vs. 89.3% and 90.1%) and were comparable to the T4N0 group (50.6% vs. 46.7%, p=0.844). Conclusions: Both ctEMVI and ctSpiculation are associated with RFS. ctEMVI is an independent predictor of recurrence and may be valuable in combination with preoperative TNM staging to identify patients at high risk for recurrence. [Table: see text]