Preoperative computed tomography assessment of circumferential resection margin in retroperitonealized colon cancer predicts disease-free survival

Abstract

Objectives The aim of this retrospective study was to predict circumferential resection margin (CRM) involvement on preoperative

CT, and prognostic impact of CRM assessment by CT (ctCRM) in patients with retroperitonealized colon cancer.

Methods This study included patients who underwent resection for ascending or descending colon cancer between July 2010 and

February 2013. Positive ctCRM was defined as tumor distance to the retromesenteric plane of ≤ 1 mm. The origin of positive

CRM was divided into primary tumor or other tumor components including lymph nodes, tumor deposits, or extramural venous

invasions. Logistic regression analysis was performed to identify preoperative factors to predict pathologic CRM (pCRM). A

Cox proportional hazards model was used in multivariable analysis to determine the preoperative factors affecting disease-free

survival (DFS).

Results A total of 274 patients (mean age, 64.0 years ± 11.0 [standard deviation]; 157 men) with retroperitonealized colon cancer

were evaluated. Of 274 patients, 67 patients (24.5%) had positive CRM on surgical pathology. The accuracy of preoperative CT

in predicting pCRM was 79.6% (218/274). Among preoperative factors, only CRM assessment on CT was independently

associated with pCRM (p < 0.001). Positive ctCRM by primary tumor was an independent factor for DFS (HR, 3.362 [1.714–

6.593]) and systemic recurrence (HR, 3.715 [1.787–7.724], but not for local recurrence on multivariable analyses.

Conclusions Preoperative CT can accurately predict pCRM, and positive ctCRMby primary tumor is an independent risk factor

for DFS and systemic recurrence, but not for local recurrence in retroperitonealized colon cancer.