Should the presence of EMVI influence therapy in colorectal carcinoma?

Aims: Dukes stage is used to estimate prognosis and to guide therapy in colorectal carcinoma. Adjuvant chemotherapy in node positive Dukes C tumours is advocated but its role in Dukes B tumours is less certain. Additional pathological features may assist in identification of ‘‘high risk’’ Dukes B colorectal carcinomas which may benefit from additional therapy. This study aims to determine the influence of Extra Mural Venous Invasion (EMVI) on outcome in patients with colorectal carcinoma.Methods: All patients with Dukes B and Dukes C colorectal cancer discussed by our regional colorectal multi-disciplinary team (MDT) from June 2006 to August 2011 were included. Patient and tumour characteristics were collated prospectively from MDT records, with supplementary data extracted from pathology reports. All pathology reports were authorised by consultant pathologists. Data were analysed using SPSS 19.Results:Eight hundred and seventy seven patients were included. Three hundred and eighty six (44%) had Dukes B EMVI negative tumours (B−), 57(6·4%) (B+), 266 (30·3%)(C1−), 91 (10·3%)(C1+), 33(3·7%)(C2−) and 44(5%)(C2+). At last follow up 327 (85%) of (B−), 40 (70%) (B+), 196 (74%) (C1−),47 (52%) (C1+), 12 (36%) (C2−) and 11 (25%) (C2+) were alive respectively.Median follow up was 810 days. Median survival (Kaplan-Meier) overall between Dukes B and Dukes C tumours irrespective of EMVI status differed significantly(p<0·001). A significant difference in survival was also apparent according tothe presence or absence of EMVI within each Dukes category (B, C1 & C2),(p<0·001). There was no difference in survival (Kaplan-Meier) between DukesB+(1372 days (1179–1566 95%CI)) and Dukes C1−(1545 days (1447–164395% CI)) tumours (p=0·530) and between Dukes C1+(1128 days (947–130995% CI))and Dukes C2−(995 days (740–1250 95% CI)) (p=0·563).Conclusions: EMVI negatively impacts on survival irrespective of Dukesstage. EMVI positive Dukes B tumours have similar outcome to Dukes C1 EMVInegative tumours. The presence of EMVI should be considered in decisions totreat patients with Dukes B tumours with adjuvant chemotherapy.