The relationship of depth of penetration and tumor size to the number of positive nodes in Dukes C colorectal cancer.

This study examines the interrelationships of depth of penetration, tumor size, and the number of positive nodes in Dukes C colorectal cancer. The results indicated that depth of tumor penetration was related to both tumor size and the number of positive regional lymph nodes. Tumors with positive nodes which failed to penetrate the muscularis propria (C1) were smaller, and were associated with fewer positive nodes than were tumors penetrating all coats of the bowel (C2). Although tumor penetration was related to tumor size and the number of positive nodes, no correlation was evident between tumor size and the number of positive nodes within the C1 and C2 patient subsets. The data underscore the biological significance of depth of tumor penetration and militate against tumor size as a prognostic discriminant in patients with colorectal cancer. The findings represent a contradiction to the prevailing biological concepts relative to the behavior of solid tumors as reflected in the TNM classification scheme.