[Study of Dukes' staging of colorectal carcinoma by the prognosis. National Cooperative Group on Pathology and Prognosis of Colorectal Cancer].

The authors make a recommendation of modified Dukes' staging basing on the prognosis of 3122 patients with colorectal cancer. The fact that there are no significant differences in the 5 year survival rates is observed in the lesions limited to the mucosa and those invading into the submucosa (P greater than 0.2), the two groups should be classed as stage A1. The fact that differences present in the 5 year survival rates of cancers invading into the superficial and deep layers of muscularis is statistically significant (P less than 0.001), the lesion should be subdivided into stages A2 and A3. The cancer penetrating through the muscular layer is classed as stage B. Because no significant differences in the 5 year survival rates are found between the metastasis in the local and mesenteric nodes (P greater than 0.1), stages C1 and C2 should be merged into stage C. Distant metastasis is classed as stage D. The Dukes' staging of colorectal cancer and other staging systems are briefly discussed in this paper.