Abstract
A system of classifying colorectal carcinomas into five prognostic groups is described. This classification includes not only tumor spread, regional lymph node involvement, and distant metastases, but also resectability and R-classification (residual tumor or curability). All patients with colorectal tumors can be classified by means of this system. The five prognostic groups differ statistically significantly (p less than 0.01) from one another with respect to age-corrected 5-year survival rates.