Multivariate analysis (risk state analysis) was performed to evaluate the single and joint effects of pathologic variables on the survivals of 1067 cases of colorectal carcinoma. Nineteen of the twenty-eight variables analyzed were found to have statistically significant prognostic value, with over half having a strong influence on prognosis. The first seven, ranked in order of their effects on survival, are metastasis in lymph nodes, depth of invasion, histologic grading, lymphocyte infiltration of the cancer, GH (immune response in regional lymph nodes), growth pattern and fibrous proliferation around the cancer. The joint effects of combinations of these major variables are even more striking than those of single ones.