Extramural venous invasion and depth of extramural invasion on preoperative CT as prognostic imaging biomarkers in patients with locally advanced ascending colon cancer.

PURPOSE

This study evaluates the prognostic significance of EMVI and DEMI on preoperative CT in patients with ascending colon cancer.

METHODS

This retrospective study included consecutive patients with T3 ascending colon cancer from January 2012 to December 2016 in a tertiary center. Two radiologists independently reviewed EMVI, DEMI, and nodal status on preoperative CT. We assessed the association of age, sex, mucinous adenocarcinoma, EMVI, and DEMI with metastasis on preoperative CT using univariable and multivariable analysis. We also compared disease-free survival (DFS) with and without variables (age, sex, mucinous adenocarcinoma, EMVI, DEMI and adjuvant chemotherapy) using Cox's proportional hazards models. We assessed interobserver agreements on imaging features using the Cohen's weighted kappa.

RESULTS

Of 237 patients [107 men; mean (standard deviation) age, 66 (13) years], 24 had metastases on preoperative CT. Positive EMVI was associated with metastasis (odds ratio 16.9; P < 0.001) on multivariable analysis. Of 194 patients [83 men; 65 (13) years] included for DFS analysis, recurrence was observed in 31 (16%) with median follow-up of 53 months. Positive EMVI [hazard ratio (HR) 4.8; P < 0.001] and DEMI > 5 mm (HR 5.5; P < 0.001) were associated with worse DFS. Interobserver agreements were good (kappa = 0.64-0.67).

CONCLUSION

Positive EMVI and DEMI > 5 mm on preoperative CT were associated with a worse T3 ascending colon cancer prognosis. Thus, these CT findings could be used as imaging biomarkers for T3 ascending colon cancer risk stratification.