Figure 1

Classification of rectal cancer patients (test cohort) into early and late T stages or into node-negative and node-positive disease based on tumor diameter using classification and regression tree analysis (CART). For the classification of patients by T stage, numbers in parentheses describe (the number of patients with early T, late T stage) followed by (percentage of patients with early T and late T stages). For the classification of patients by N stage, numbers in parentheses describe (the number of patients with node-negative, node-positive disease) followed by (percentage of patients with node-negative, node-positive disease).