Prognostic significance of lymphovascular or perineural invasion in patients with locally advanced colorectal cancer

BackgroundThis study was designed to evaluate the prognostic significance of the positivity of lymphovascular (LVI) and perineural invasion (PNI) in patients with locally advanced colorectal cancer.MethodsFrom January 1999 to December 2009, 1,437 consecutive patients who underwent curative surgery for stage II or III colorectal cancer were analyzed. Patients were then categorized into 4 groups: LVI−/PNI− (n = 850), LVI+ only (n = 178), PNI+ only (n = 271), and LVI+/PNI+ (n = 138).ResultsWith a median follow-up period of 56 months, the 5-year overall survival rates of patients with LVI−/PNI−, LVI+ only, PNI+ only, and LVI+/PNI+ were 82%, 73%, 71%, and 56%, respectively (P < .001), and the 5-year disease-free survival rates of patients with LVI−/PNI−, LVI+ only, PNI+ only, and LVI+/PNI+ were 80%, 70%, 65%, and 46%, respectively (P < .001). In multivariate analysis, LVI+/PNI+ was an independent prognostic factor for both overall survival (P < .001) and disease-free survival (P < .001).ConclusionsPositivity of both LVI and PNI is a strong predictor of overall and disease-free survival in patients with stages II and III colorectal cancer.