Prognostic significance of extramural vascular invasion in T4 rectal cancer

Abstract

Aim: Extramural vascular invasion (EMVI) has been proposed as an adverse prognostic indicator in colorectal cancer, although its use remains both variable and controversial. This study aimed to determine the survival effect of EMVI in T4 rectal cancer.

Method: Patients undergoing surgery with curative intent for primary T4 rectal cancer between 1971 and 2011 were included from two prospectively collected rectal cancer databases. The main end-point was 3-year survival.

Results: From 1142 patients undergoing resection of rectal cancer during the study period, 126 (11.0%) had T4 rectal cancer and were included in the study group. Sphincter preservation was performed in 61 (48%) and a pathologically negative resection margin (R0) was achieved in 104 patients (82.5%). EMVI was present in 51 patients (40.5%) and was an independent predictor of positive lymph node status (adjusted odds ratio 2.66, P = 0.013). Considering all patients, EMVI was associated with reduced overall survival (P = 0.007) and disease-free survival (P = 0.002), but not local recurrence-free survival (P = 0.198). In only those undergoing R0 resection, EMVI predicted reduced disease-free survival with positive nodal status (P = 0.021); it did not predict survival with negative nodal status.

Conclusion: Overall, EMVI was a strong prognostic marker of survival. However, after complete surgical resection in patients with node-negative disease, EMVI did not predict local recurrence.

Keywords: Rectal cancer; extramural vascular invasion; prognosis.