Impact of Lymphovascular Invasion in Patients With Stage II Colorectal Cancer: A Propensity Score-matched Study.

Background/aim Whether lymphovascular invasion (LVI) is a high-degree risk factor in stage II colorectal cancer has not been fully clarified, as different results have been reported in the literature. If LVI is a risk factor, postoperative chemotherapy may be recommended. The purpose of this study was to evaluate the impact of lymphovascular invasion on disease recurrence and patient prognosis in conjunction with stage II colorectal cancer (CRC). Patients and methods A total of 636 patients with stage II CRC, each undergoing radical resection between April 2007 and December 2015, were selected for the study. Subjects with or without venous or lymphatic invasion were assigned to positive and negative groups, respectively. We then compared overall survival (OS) and disease-free survival (DFS) using propensity score matching. Results After matching (n=226, each group), OS and DFS were found to be significantly lower (OS: p=0.047; DFS: p=0.004) in patients positive (vs. negative) for venous invasion. However, the same was not true of lymphatic invasion. After matching, positive and negative groups (n=92, each) did not significantly differ in terms of OS (p=0.951) or DFS (p=0.258). Conclusion In patients with stage II CRC, venous invasion proved to be a significant high-degree risk factor that may warrant adjuvant chemotherapy.