Absence of a relationship of size of primary colon carcinoma with metastasis and survival.

This retrospective study analysed the relationship of tumor size to regional and systemic metastasis and to survival according to stage of disease. Colon cancers (391 cases) that were treated surgically at M. D. Anderson Hospital from 1955 to 1975 were reviewed. Staging of disease was based on the Astler-Coller modification of Dukes' staging classification. The mean diameters (cm +/- s.e.m.) of Dukes' B1, B2, C2 and D tumors were 4.47 +/- 0.34 (n = 46), 6.61 +/- 0.29 (n = 147), 5.39 +/- 0.23 (n = 71) and 5.78 +/- 0.24 (n = 120), respectively. The mean diameter of Dukes' B2 tumors was significantly greater than C2 (P less than 0.001) and D (P less than 0.05) tumors. Within stage B and C, size of the primary tumor showed no relationship to five year adjusted survival. Our findings suggest that colon carcinoma metastasis and survival are independent of tumor size. Because tumor burden does not account for distant disease, specific tumor cell phenotypes and biological processes are probably more important in determining metastatic disease.