CT Scans May Predict Benefit of Preoperative Therapy for Sigmoid Colon Cancer

Results from a prognostic study of patients with sigmoid colon cancer suggest that T3 substaging and identification of tumor deposits and extramural venous invasion via computed tomography (CT) scans may predict whether or not recipients of preoperative therapy will benefit from the treatment (JAMA Netw Open. 2019;2[12]:e1916987).

“Preoperative TNM stratification of colon cancer on…CT…does not identify patients who are at high risk of recurrence that could be selected for preoperative treatment,” explained Nigel D’Souza, MBBS, Department of Colorectal Surgery, Croydon University Hospital, London, United Kingdom, and colleagues.

Seeking to assess the utility of CT findings for the prognosis of sigmoid colon cancer, Dr D’Souza et al conducted a prognostic study of 414 patients (mean age, 66.1 years) who underwent bowel resection for sigmoid colon cancer between January 2006 and January 2015 at a tertiary care center.

The relationship between CT findings and disease recurrence was assessed using Cox proportional hazards regression analysis, and CT staging systems were used to calculate Kaplan-Meier survival plots for disease-free survival (DFS).

A total of 122 (29.5%) patients had disease recurrence over a median follow-up time frame of 61 months. Nodal disease was not found to be tied to disease recurrence on multivariate analysis; however, tumor deposits (hazard ratio [HR], 1.90; 95% CI, 1.21-2.98; P = .006) and extramural venous invasion (HR, 1.97; 95% CI, 1.26-3.06; P = .003) identified via CT were related to disease recurrence.

CT-T3 substage classification revealed significant differences in DFS (HR, 1.88; 95% CI, 1.32-2.68), whereas CT-TNM did not (HR, 1.55; 95% CI, 0.94-2.55). Of note, poor outcomes were most strongly associated with tumor deposits or extramural venous invasion detected via CT (HR, 2.45; 95% CI, 1.68-3.56).

“In this study, T3 substaging and detection of tumor deposits or extramural venous invasion on preoperative CT scans of sigmoid colon cancer were prognostic factors for disease-free survival, whereas TNM and nodal staging on CT had no prognostic value,” Dr D’Souza and colleagues said.

“T3 substaging and detection of tumor deposits or extramural venous invasion of sigmoid colon cancer was superior to TNM on CT and could be used to preoperatively identify patients at high risk of recurrence,” they concluded.—Hina Porcelli