Y. Z. Qwaider1, N. M. Sell1, C. E. Stafford1, R. Ricciardi1, L. Bordeianou1, H. Kunitake1, D. L. Berger1 1Massachusetts General Hospital,General/GI Surgery,Boston, MA, USA
Introduction:
Extramural vascular invasion (EMVI) is a known poor prognostic factor in colon cancer. However, the benefit of adjuvant chemotherapy in patients with EMVI is still 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 stage II and III colon adenocarcinoma who underwent surgical resection at a tertiary medical center between 2004 and 2015. Patients who received neoadjuvant therapy were excluded. 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, American Society of Anesthesiologists (ASA) score, and anatomic site.
Results:
A total of 781 patients (393 stage II and 388 stage III) were included in this study. The mean age was 68 ± 15 years and the mean follow-up duration was 54 ± 42 months. Females constituted 52% of the cohort. Adjuvant chemotherapy was prescribed to 69 stage II patients (18%) and 278 stage III patients (72%). Overall, 298 patients (38.1%) were EMVI positive. Extramural vascular invasion was present in 92 stage II patients (23%) and 206 stage III patients (53%). The Cox regression model showed that in patients with EMVI, those who did not receive adjuvant chemotherapy had a 1.9 fold (1.3–2.9) increase in the hazard of death compared with those who received chemotherapy. All pairwise comparisons are shown in Table 1.
Conclusion:
Patients who were EMVI negative fared better than those who were EMVI positive. In patients who were EMVI positive, adjuvant chemotherapy improved overall survival, even for stage II patients.
