Perineural Invasion in Stage I-III Colon Cancer: Prognostic and Predictive Significance

Perineural invasion is an independent poor prognostic factor in stage III colon cancer but does not predict outcomes in node-negative disease. Adjuvant chemotherapy benefits patients with node-positive but not those with node-negative disease when perineural invasion is present. Higher recurrence odds are seen only in poorly differentiated tumors among perineural invasion-positive tumors. Findings discourage adjuvant chemotherapy use in node-negative colon cancer with perineural invasion due to potential adverse effects.