Prognostic significance of perineural invasion in stage IIA colon cancer.

Background: Perineural invasion (PNI) may influence the prognosis of colon cancer, but little is known about its predictive value. The aim of this study was to reveal the role of PNI in predicting prognosis after curative resection of colon cancer, especially T3N0.

Methods: Two hundred and fifty-five patients who underwent curative resection for colon cancer at Samsung Medical Center and were later diagnosed with stage T3N0 by a pathological report between November 2004 and December 2007 were retrospectively recruited into the study.

Results: Among the 255 patients, 156 were male and 99 were female. The mean age was 61 years (range, 25 to 88 years). The most common tumour location was the sigmoid colon (93 patients, 36.5%). The median follow-up period was 61 months (range, 1 to 98 months). PNI was detected in 18 patients (7.1%). Adjuvant chemotherapy was performed in 205 patients (80.4%). The 5-year disease-free survival rate was greater for patients with PNI negative tumours compared with those with PNI positive tumours (92.0% versus 76.0%, P = 0.025). Adjuvant chemotherapy was not associated with significant differences in survival rate (94.8% versus 96.9%, P = 0.625). On multivariate analysis, PNI was an independent prognostic factor for disease-free and overall survival (P = 0.046, hazard ratio (HR) = 3.113, 95% confidence interval (CI) = 1.020-9.505 and P = 0.019, HR = 9.395, 95% CI = 1.453-60.755 respectively).

Conclusions: PNI is the only significant prognostic factor affecting disease-free and overall survival in patients with T3N0 colon cancer.