Adjuvant Chemotherapy Benefits on Patients with Extramural Vascular Invasion in Stages II and III Colon Cancer.

INTRODUCTION

Extramural vascular invasion (EMVI) is a poor prognostic factor in colon cancer. However, the benefit of adjuvant chemotherapy in patients with EMVI is not well defined. The objective of this study is to determine if there is a survival benefit for using adjuvant chemotherapy in patients with EMVI-positive colon cancers.

METHODS

We performed a retrospective review of all patients with stages II and III colon adenocarcinoma who underwent surgical resection between 2004 and 2015. Cox regression was used to determine the effect of chemotherapy on EMVI-positive patients while adjusting for the extent of invasion, regional lymph node metastasis, histologic grade, age, site of tumor, and ASA score.

RESULTS

A total of 750 patients were included in this study. Extramural vascular invasion was present in 93 out of 387 stage II patients (24%) and 187 out of 363 stage III patients (52%). The Cox regression model showed that in patients with EMVI, those who did not receive adjuvant chemotherapy had a 1.6-fold (1.1-2.3) increase in the hazard of death compared with those who received chemotherapy.

CONCLUSIONS

Patients who were EMVI-negative fared better than those who were EMVI-positive. In patients who were EMVI-positive, adjuvant chemotherapy improved overall survival.